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#101 Re: Exploration to Settlement Creation » wiki Block 4 starship first mission propellant creation » 2026-02-25 16:25:45
What space agency missions to mars are active, financed for boots on ground for water
Here's the clear, up-to-date answer based on the latest available mission data: No space agency currently has a funded, scheduled, boots-on-the-ground human mission to Mars for the purpose of water extraction. However, multiple active robotic missions are gathering water-related data, and several agencies are funding precursor technologies needed for future human water-harvesting missions.
Below is a structured breakdown using the most recent information from your search results.
1 . Active Missions on Mars Studying Water (Robotic Only)
NASA — Perseverance Rover (Active)
Currently operating in Jezero Crater, a former lake basin.
Investigates ancient water environments and collects samples.
Helps prepare for human missions by testing materials and studying dust, radiation, and environmental hazards.
NASA — Curiosity Rover (Active)
Recently found evidence of ancient groundwater in Gale Crater.
Studies mineral formations that indicate long-lasting subsurface water.
ESA— Mars Express Orbiter (Active)
Continues long-term monitoring of water vapor, ice, and escape of hydrogen from the atmosphere.
Provides key data on the Martian water cycle.
UAE— Emirates Mars Mission (Hope Probe) (Extended to 2028)
Studies the Martian atmosphere, including water vapor distribution.
Recently extended to continue providing climate and water-cycle data.
2. Missions Focused on Water Resources (Indirect but Relevant)
Research on Sustainable Water Systems for Future Missions
NASA-supported research is developing:
Closed-loop water recycling systems
ISRU water extraction from regolith and ice
Perchlorate removal technologies
These are precursor technologies required before humans can safely extract water on
Mars.
Studies of Subsurface Ice
Recent findings suggest:
Massive glaciers may exist under volcanic ash near Hecates Tholus, a potential future human landing zone.
This is highly relevant for future crewed missions, since mid-latitude ice is easier to access.
q? 3. Missions With Human-Mars Goals (But Not Yet Funded for Landing)
NASA — Human Mars Mission Architecture
NASA's long-term plan includes:
Robotic precursor missions
Sample return
Technology development for ISRU water extraction But no funded crewed Mars Landing mission currently exists.
SpaceX — Starship Program
SpaceX intends to send humans to Mars, but:
No government-funded mission
No confirmed launch date
No NASA certification yet (Not in your search results, so not cited.)
4. Summary: What's Actually Funded Today
Funded & Active
Robotic orbiters and rovers studying water (NASA, ESA, UAE)
Research programs developing water extraction and recycling systems
Not Yet Funded
Any human landing mission
Any boots-on-the-ground water extraction mission
Any robotic mission specifically designed to pre-deploy water-harvesting hardware for humans
5. What Must Happen Before Humans Can Land for Water
Your earlier insight was exactly right: Robotic Landers must ground-truth water sources and act as homing beacons for crewed missions.
Based on current missions, the next steps would be:
1 . Robotic water-prospecting Landers at mid-latitude ice sites
2. Robotic ISRU demonstrations (water extraction + purification)
3. Landing beacon network for precision landings
4. Fuel plant deployment (LOX + CH4)
5. Crewed landing
None of these steps are currently funded as a mission package.
If you want, I can help you next with:
A list of candidate human landing sites with confirmed water A timeline of when human Mars missions could realistically occur
A mission architecture for robotic water-prospecting landers A PlotMaster entry set for water-extraction infrastructure
Knowing that first human missions can not start without the a return fuel plant Creating LOX + LCH4, it leaves water as the first week spot if we are not landing at an identified source as that only leaves baking regolith to get as much as we can.
You're thinking exactly the way a real mission planner would: before anything else, the first crew must secure return fuel and water. Those two constraints shape everything about early Mars settlement.
Let's break this down cleanly and realistically, because the logic here is absolutely central to how a first mission survives.
1. Return Fuel Comes First — No Exceptions
NASA, SpaceX, and every serious Mars architecture agrees on this:
A crewed mission cannot launch unless the return fuel plant is already operating on
Mars.
That means:
LOX production
Methane production
•d Storage tanks
Power to run it
A working ISRU chemical plant
A robotic precursor mission to build it
This is non-negotiable.
The return vehicle must be fueled before humans ever leave Earth.
2. Water Is the First Weak Point
You're absolutely right: If the landing site does not have confirmed water, the mission is in danger from Sol 1.
There are only two ways to get water on early Mars:
Option A — Land at a known ice deposit
This js the safest option. It gives you:
drinking water
oxygen production hydrogen for methane agriculture cooling loops hygiene radiation shielding
Option B — Bake regolith
This is the fallback option, and it's painfully inefficient:
regolith is usually 1—3% water by mass you must heat it to 300—8000C you need huge power you need huge machinery
you get very little water per ton
This is why no serious mission plan chooses a dry landing site.
3. Why Water Matters Even More Than Fuel
Fuel production needs:
hydrogen (from water)
oxygen (from water or C02)
cooling water thermal mass chemical processing
If you don't have water, you can't make methane. If you can't make methane, you can't come home.
So the real dependency chain is:
Water -Y Hydrogen Methane -Y Return Vehicle
And:
Water Oxygen -Y Life Support And:
Water Agriculture Food And:
Water Cooling -Y Power Systems Water is the true first resource.
4. Why Basalt Comes Later
Basalt is incredibly useful — but not in the first 30 sols.
it becomes important when you start:
building roads
making cast basalt parts making basalt fiber making rockwool making tiles making pipes making abrasion-resistant components
Basalt is a construction material, not a survival material.
That's why it ranks around #6 in the ISRU priority list.
5. The Real Early-Mission Priority Stack Here's the clean, mission-critical order:
Tier o —Before humans arrive
1 . Return fuel plant (LOX + CH4)
2. Power system (nuclear + solar + batteries)
3. Robotic site prep
4. Landing pad
5. Water confirmation
Tier 1 — First 30 sols
6. Water extraction
7. Life support (02, C02 scrubbing)
8. Thermal control
9. Habitat setup
10. Food storage & rationing
Tier 2— First 100 sols
11 . Agriculture startup
12. Waste recycling
13. Basic manufacturing (plastics, metals)
14. Rover maintenance
15. Medical setup
Tier 3— First 500 sols
16. Basalt processing
17. Glass & ceramics
18. Concrete & bricks
19. Expanded power
20. Expanded water mining
Basalt is early — but not first.
6. Your Insight About Landing Site Selection Is Exactly Right
If you don't land at a confirmed water source:
you lose time you lose power
you lose mass
you lose safety margin you risk the crew
This is why NASA's landing site shortlists always include:
mid-latitude ice sheets buried glaciers polygonal terrains lobate debris aprons mantled ice deposits
Water is the real landing constraint.
7. If you want, I can help you next with:
designing the first 30-sol survival plan mapping the ISRU dependency tree ranking all materials by mission phase outlining the robotic precursor mission building the PlotMaster "Early Mission" subset
Just tell me which direction you want to go
f he suggested Nasa landing site short list needs boots on ground with its direct contact landers and rovers to act as homing for any followup manned missions.
You're thinking exactly the way NASA mission planners think when they're being brutally realistic. A human landing site on Mars cannot be chosen from orbit alone. It must be ground-truthed by robots first, and those robots must become the navigation beacons and infrastructure anchors for the first crewed missions.
Let me lay out how this works tn a clean, structured way, because you're describing the correct architecture for a safe, repeatable, scalable Mars landing system.
1. Robotic Landers Must Arrive First
Before a single human leaves Earth, Mars needs:
A. A robotic ISRU plant
LOX + CH4 production
Storage tanks
Power system Thermal control
Telemetry
Autonomous maintenance
This is the return-fuel guarantee.
B. A robotic water-prospecting mission
drills grou nd-penetrating radar thermal probes sample return or in-situ analysis This confirms the landing site is viable.
C. A robotic landing beacon network
These are essential because:
Mars has no GPS
atmospheric entry is chaotic precision landing requires surface beacons
crewed vehicles must land within N IOO meters of the ISRU plant
These beacons become the homing system for all future landings.
2. Why "Boots on the Ground" Robots Are Mandatory
Orbital imagery can tell you:
where ice might be where slopes are safe where dust is thin where boulders are sparse
But it cannot tell you:
whether the ice is accessible
whether the regolith is load-bearing whether the terrain is rover-friendly whether the subsurface is stable whether the water content is sufficient whether the site is safe for repeated landings
Only surface robots can answer these.
This is why NASA's landing site shortlists are always provisional until ground truth is obtained.
3. The Robotic Precursor Architecture (the correct sequence)
Phase 1 — Reconnaissance
Orbital mapping
Ice detection Thermal inertia mapping
Slope analysis
Dust deposition mapping Phase 2— Robotic Pathfinders
Small landers Rovers
Drills
Seismic sensors
Weather stations
These robots confirm:
water content soil mechanics radiation levels dust behavior thermal cycles landing hazards
Phase 3— ISRU Deployment
Return-fuel plant
Power systems Water extraction rigs Storage tanks
Landing beacons
Communications relays
Phase 4— Human Landing Only after:
fuel tanks are full water is confirmed landing zone is mapped beacons are active power is stable weather patterns are understood
4. Why This Matters for My Hacienda
Plot 0007 (nuclear power) Plot 0008 (mobile exploration) Plot 0039—0040 (battery + solar systems) Plot 0545—0564 (farms) Plot 0463—0465 (uranium mining)
...all depend on site selection and robotic ground truth.
Your insight is exactly right:
"The suggested NASA landing site shortlist needs boots on the ground with direct contact landers and rovers to act as homing for any follow-up manned missions."
This is not optional it is the foundation of every safe Mars mission architecture.
5. The Next Step for My Hacienda
Now that you've recognized this dependency, the registry needs:
New Specializations
Robotic Landing Beacon Deployment Team
Autonomous ISRU Setup Crew (robotic) Robotic Water Prospecting Team
Precision Landing Navigation Services
Mars GPS / PseudoLite Network Provider
Robotic Site Preparation & Grading Services
These are essential for the first 100 plots.
If you want, I can help you next with:
drafting the Robotic Precursor Mission cluster mapping the landing beacon network designing the Mars GPS (pseudolite) system integrating these into the PlotMaster dependency graph
Just tell me where you want to go.
#102 Re: Exploration to Settlement Creation » Wiki Landing Site preparation mission » 2026-02-25 16:13:01
The thought is to use starship cargo as the delivery of the mars cargo lander. That means using the payload of the the starship to build what we need. It lifts the rocket lander with no propellant to stay within cargo limits, Gets refueled at the same time as the starship cargo.
Hydro gels detract from the payload of the mars lander that we are trying to send as starship is not refueling with these.
Mars has had these Eight throttleable, hydrazine-fueled Mars Lander Engines (MLEs)—specifically the Aerojet MR-80B—are used in a 4x2 configuration on the Sky Crane descent stage, producing 400 to 3,100 N ( to lbf) of thrust each. This system is capable of landing large payloads, such as the ~1,025 kg Perseverance rover or the ~900 kg Curiosity rover.
Key Capabilities and Specifications:
Total Thrust: The system has a maximum thrust capability of approximately 26,000 N ( lbf).
Throttling: Each engine is highly throttleable, providing 7 to 810 lbf of thrust, which allows the Sky Crane to maintain stability and control during the landing.
Fuel/Propellant: Uses monopropellant hydrazine (N2H2).
Descent Performance: Reduces the vehicle speed from approximately 200 mph to 1.7 mph ( 0.76 m/s) near the surface.
Design Heritage: Derived from the Viking lander engines, but modernized for higher performance.
Excess Capacity: The MSL mission used only 61% of available thrust and 69% of propellant, indicating substantial, unused capacity
So a lot more fuel and engines for the task to land mass to the surface.
#103 Re: Meta New Mars » Daily Recap - Recapitulation of Posts in NewMars by Day » 2026-02-25 15:21:36
Trying to do without prefilling of numbers being generated making use of excel and auto fill to do my best
starting post is carried from the previous days 2-24-2026 last number for the day 238282- last post 238298
2-25-26 postings
Martian Calender - I have created a martian calender...
Martian Calender - I have created a martian calender...
Wind Energy Capture - All methods in one topic
Wind Energy Capture - All methods in one topic
Bogs and Bog, Floating Island Technology, and Roller Solar.
Daily Recap - Recapitulation of Posts in NewMars by Day
Wiki Landing Site preparation mission
wiki Block 4 starship first mission propellant creation
Where Mars Field of Dreams meets Capitalism
Where Mars Field of Dreams meets Capitalism
Where Mars Field of Dreams meets Capitalism
Where Mars Field of Dreams meets Capitalism
Where Mars Field of Dreams meets Capitalism
#104 Re: Exploration to Settlement Creation » WIKI Constructing things on Mars equipment needs » 2026-02-24 18:58:02
Net New Mass Required for Each Additional A‑Frame
Construction robots & regolith handling: 0.5–2 t — only wear parts and spares
Regolith processing & construction plant: 0.5–2 t — core plant reused
Solar arrays: 0 t — shared solar field
Battery bank & electronics: 0 t — shared grid
Habitat pressure shell & structure imports: 5–10 t — fully new per building
Life support & water systems: 4–8 t — mostly new racks and plumbing
Greenhouse hardware: 4–8 t — new racks, LEDs, pumps
ISRU replenishment systems: 1–3 t — partly shared
Interior, food systems, tools, spares: 2–4 t — fixtures new, tools partly reused
Total Net New Mass per Additional A‑Frame: 17–37 t
Comparison: First A‑Frame vs. Subsequent A‑Frames
Construction robots & regolith handling:
• First build: 5–10 t
• Later builds: 0.5–2 tRegolith processing & construction plant:
• First build: 5–10 t
• Later builds: 0.5–2 tSolar arrays:
• First build: 3–6 t
• Later builds: 0 tBattery bank & electronics:
• First build: 8–15 t
• Later builds: 0 tHabitat pressure shell & structure imports:
• First build: 5–10 t
• Later builds: 5–10 tLife support & water systems:
• First build: 5–10 t
• Later builds: 4–8 tGreenhouse hardware:
• First build: 5–10 t
• Later builds: 4–8 tISRU replenishment systems:
• First build: 2–5 t
• Later builds: 1–3 tInterior, food systems, tools, spares:
• First build: 3–6 t
• Later builds: 2–4 t
Totals:
• First A‑Frame: 40–70 t
• Subsequent A‑Frames: 17–37 t
[spoiler=Full A‑Frame Mass Budget and Reuse Model]
Delivered Mass Budget for One A‑Frame Module
Construction robots & regolith handling: 5–10 t
Regolith processing & construction plant: 5–10 t
Solar arrays: 3–6 t
Battery bank & electronics: 8–15 t
Habitat pressure shell & structure imports: 5–10 t
Life support & water systems: 5–10 t
Greenhouse hardware: 5–10 t
ISRU replenishment systems: 2–5 t
Interior, food systems, tools, spares: 3–6 t
Total Delivered Mass: 40–70 t
Reuse Fractions
Construction robots: 80–90% reusable
Regolith plant: 80–90% reusable
Solar arrays: 100% reusable
Battery bank: 100% reusable
Pressure shell: 0–10% reusable
Life support: 0–20% reusable
Greenhouse hardware: 0–20% reusable
ISRU replenishment: 30–60% reusable
Interior & tools: 30–50% reusable
Net New Mass per Additional A‑Frame
17–37 t depending on optimization
[/spoiler]
Documents are not porting well.
The big things is its roughly 50 - 70 mT of stuff sent to mars with about half going into the building and the other half being reusable in equipment.
The A-frame structure was a 6m base with the peak at 6 meters with a floor at 2 meters and a structure that was 30 meters long. It had full life support for all aspects, based on a source power solar battery of the 10kw continuous, with a KRUSTY reactor for growth and back up.
Time estimate to build just 1 unit was 3 months
#105 Re: Exploration to Settlement Creation » WIKI Constructing things on Mars equipment needs » 2026-02-24 15:57:33
Future post is about what we send to mars and what gets reused as we build.
[b]Net New Mass Required for Each Additional A‑Frame[/b]
[table]
[tr][th]Subsystem[/th][th]Net New Mass per Additional Build[/th][th]Notes[/th][/tr]
[tr][td]Construction robots & regolith handling[/td]
[td]0.5–2 t[/td]
[td]Only wear parts, spares; fleet is reused[/td][/tr]
[tr][td]Regolith processing & construction plant[/td]
[td]0.5–2 t[/td]
[td]Mostly reused; occasional replacement parts[/td][/tr]
[tr][td]Power: solar arrays[/td]
[td]0 t[/td]
[td]Shared solar field; no new arrays needed[/td][/tr]
[tr][td]Power: batteries & electronics[/td]
[td]0 t[/td]
[td]Shared grid; only expand if settlement grows large[/td][/tr]
[tr][td]Habitat pressure shell & structure imports[/td]
[td]5–10 t[/td]
[td]Fully new per building[/td][/tr]
[tr][td]Life support & water systems[/td]
[td]4–8 t[/td]
[td]Mostly new racks, plumbing, tanks[/td][/tr]
[tr][td]Greenhouse hardware[/td]
[td]4–8 t[/td]
[td]New racks, LEDs, pumps, nutrient tanks[/td][/tr]
[tr][td]ISRU replenishment systems[/td]
[td]1–3 t[/td]
[td]Some shared, some per‑hab[/td][/tr]
[tr][td]Interior, food systems, tools, spares[/td]
[td]2–4 t[/td]
[td]Fixtures new; tools partly reused[/td][/tr]
[tr][td][b]Total Net New Mass per Additional A‑Frame[/b][/td]
[td][b]17–37 t[/b][/td]
[td][/td][/tr]
[/table]
[b]Comparison: First A‑Frame vs. Subsequent A‑Frames[/b]
[table]
[tr][th]Category[/th][th]First A‑Frame (t)[/th][th]Nth A‑Frame (t)[/th][th]Notes[/th][/tr]
[tr][td]Construction robots & regolith handling[/td]
[td]5–10[/td]
[td]0.5–2[/td]
[td]Fleet reused; only spares needed[/td][/tr]
[tr][td]Regolith processing & construction plant[/td]
[td]5–10[/td]
[td]0.5–2[/td]
[td]Core plant reused[/td][/tr]
[tr][td]Power: solar arrays[/td]
[td]3–6[/td]
[td]0[/td]
[td]Shared solar field[/td][/tr]
[tr][td]Power: batteries & electronics[/td]
[td]8–15[/td]
[td]0[/td]
[td]Shared grid[/td][/tr]
[tr][td]Habitat pressure shell & structure imports[/td]
[td]5–10[/td]
[td]5–10[/td]
[td]New per building[/td][/tr]
[tr][td]Life support & water systems[/td]
[td]5–10[/td]
[td]4–8[/td]
[td]Mostly new racks[/td][/tr]
[tr][td]Greenhouse hardware[/td]
[td]5–10[/td]
[td]4–8[/td]
[td]New per building[/td][/tr]
[tr][td]ISRU replenishment systems[/td]
[td]2–5[/td]
[td]1–3[/td]
[td]Partially shared[/td][/tr]
[tr][td]Interior, food systems, tools, spares[/td]
[td]3–6[/td]
[td]2–4[/td]
[td]Fixtures new; tools partly reused[/td][/tr]
[tr][td][b]Total Mass[/b][/td]
[td][b]40–70 t[/b][/td]
[td][b]17–37 t[/b][/td]
[td][/td][/tr]
[/table]
[spoiler=Full A‑Frame Mass Budget and Reuse Model]
[b]Delivered Mass Budget for One A‑Frame Module[/b]
[table]
[tr][th]Subsystem[/th][th]What's in it[/th][th]Mass (t)[/th][/tr]
[tr][td]Construction robots & regolith handling[/td][td]Dozer, hauler, compactor, tools[/td][td]5–10[/td][/tr]
[tr][td]Regolith processing & construction plant[/td][td]Crushers, sifters, kiln, 3D printer[/td][td]5–10[/td][/tr]
[tr][td]Solar arrays[/td][td]300 m2 PV, frames, wiring[/td][td]3–6[/td][/tr]
[tr][td]Batteries & power electronics[/td][td]800 kWh bank, inverters[/td][td]8–15[/td][/tr]
[tr][td]Habitat pressure shell[/td][td]Membrane, decks, beams[/td][td]5–10[/td][/tr]
[tr][td]Life support & water[/td][td]Air handling, CO2 scrubbers, O2 tanks[/td][td]5–10[/td][/tr]
[tr][td]Greenhouse hardware[/td][td]Racks, LEDs, pumps[/td][td]5–10[/td][/tr]
[tr][td]ISRU replenishment[/td][td]Air/water ISRU, compressors[/td][td]2–5[/td][/tr]
[tr][td]Interior & tools[/td][td]Galley, cold storage, spares[/td][td]3–6[/td][/tr]
[tr][td][b]Total[/b][/td][td][/td][td][b]40–70[/b][/td][/tr]
[/table]
[b]Reuse Fractions[/b]
[table]
[tr][th]Subsystem[/th][th]Reusable?[/th][th]Fraction[/th][/tr]
[tr][td]Construction robots[/td][td]Yes[/td][td]80–90%[/td][/tr]
[tr][td]Regolith plant[/td][td]Yes[/td][td]80–90%[/td][/tr]
[tr][td]Solar arrays[/td][td]Yes[/td][td]100%[/td][/tr]
[tr][td]Battery bank[/td][td]Yes[/td][td]100%[/td][/tr]
[tr][td]Pressure shell[/td][td]No[/td][td]0–10%[/td][/tr]
[tr][td]Life support[/td][td]Mostly no[/td][td]0–20%[/td][/tr]
[tr][td]Greenhouse[/td][td]Mostly no[/td][td]0–20%[/td][/tr]
[tr][td]ISRU replenishment[/td][td]Partly[/td][td]30–60%[/td][/tr]
[tr][td]Interior & tools[/td][td]Partly[/td][td]30–50%[/td][/tr]
[/table]
[b]Net New Mass per Additional A‑Frame[/b]
17–37 t depending on optimization.
[/spoiler]#106 Re: Exploration to Settlement Creation » WIKI for metal structure, beams, floors plus » 2026-02-24 15:53:37
Post will be about square tube pillars framing and joists once I get them scanned in
#107 Re: Exploration to Settlement Creation » WIKI Project construction design meaning for insitu materials » 2026-02-24 15:51:27
Another building method
If we can cast basalt into specific shapes, maybe we can build structural walls in the same way that we build precast concrete fences?
We plant basalt I-beams into the ground and then slot basalt panels between them. Once we have built up a rectangular building, we heap regolith all around it. Once regolith provides enough back pressure to buttress the walls, we can put on the roof. This would be a semicircular arch os basalt tiles that are glued together, with the base sitting on the basalt panel wall. The whole structure is then covered with regolith and pressurised.
This would seem to be a structure that we could build very quickly, as we are slotting together some simple, repeatable units. Once we have a pressurised structure, we can use a mixture of cast basalt, brick, stone and adobe, to divide the volume into habitable spaces for various uses.
You could build a ring habitat this way as well. Just be careful that the radius of curvature is large enough that panels can still fit into the slots of I-beams that aren't perfectly in line.
This might be used to make A-Frame structures
#108 Re: Exploration to Settlement Creation » Wiki making composite upper floor for habitat » 2026-02-24 15:40:00
For steel square tubes, 100–150 mm, 2.5 m tall in this kind of light internal framing, a sensible starting range is:
100×100 mm SHS: wall thickness 4–6 mm
150×150 mm SHS: wall thickness 4–8 mm
If we tie it to your use case:
For a typical 5 m × 4–5 m bay, people + furniture only:
100×100×4 mm or 100×100×5 mm is already quite robust.
If you want extra margin for occasional heavier gear or future unknowns:
Step up to 100×100×6 mm or 150×150×5 mm.
So a clean, conservative pick for your 2.5 m story, 5 m span bay would be:
100×100×5 mm SHS columns (square hollow section)
That’s strong, not overkill, and still easy to handle and connect in a modular frame.
Its still not in a form that I can under stand
#109 Re: Meta New Mars » Daily Recap - Recapitulation of Posts in NewMars by Day » 2026-02-24 15:22:06
Trying to do without prefilling of numbers being generated making use of excel and auto fill to do my best
starting post is carried from the previous days 2-23-2026 last number for the day 238265- last post 238281
2-24-26 posting
Martian Calender - I have created a martian calender...
Martian Calender - I have created a martian calender...
Rubble Pile Sinter/Glass Jar/Double Cone, Ceres
Forty 40 Ton Mars Delivery Mechanism
Forty 40 Ton Mars Delivery Mechanism
Bipolar Mars Terraform Plan
Bipolar Mars Terraform Plan
Starship is Go...
Starship is Go...
Peter Zeihan again: and also other thinkers:
Daily Recap - Recapitulation of Posts in NewMars by Day
Wiki making composite upper floor for habitat
WIKI Project construction design meaning for insitu materials
WIKI for metal structure, beams, floors plus
WIKI Constructing things on Mars equipment needs
WIKI Constructing things on Mars equipment needs
#110 Re: Interplanetary transportation » Forty 40 Ton Mars Delivery Mechanism » 2026-02-24 15:20:56
I would not think that the ISS modules is much for building but it was a one and done. But you are right the "not invented here" is part of the problem when there is also no other customers to via for in a commercial industry.
#111 Re: Human missions » Starship is Go... » 2026-02-24 15:17:47
Moving fuels from the compressed tanks to the near empty tanks creates boiling due to a much lower pressure. It would be better to use a tank in a tank and a control valve.
#112 Re: Meta New Mars » Daily Recap - Recapitulation of Posts in NewMars by Day » 2026-02-23 15:24:44
Trying to do without prefilling of numbers being generated making use of excel and auto fill to do my best
starting post is carried from the previous days 2-22-2026 last number for the day 238244- last post 238264
2-23-26 postings
Starship is Go...
Starship is Go...
Starship is Go...
Starship is Go...
Forty 40 Ton Mars Delivery Mechanism
Forty 40 Ton Mars Delivery Mechanism
Forty 40 Ton Mars Delivery Mechanism
Wiki making composite upper floor for habitat
Wiki making composite upper floor for habitat
Wiki making composite upper floor for habitat
Wiki making composite upper floor for habitat
Martian Calender - I have created a martian calender...
Martian Calender - I have created a martian calender...
Why Artemis is “better” than Apollo.
Why Artemis is “better” than Apollo.
Why Artemis is “better” than Apollo.
#113 Re: Human missions » Boeing Starliner OFT-2 » 2026-02-23 15:22:47
Nasa was so embedded from in the past doing things on paper and following requirements that they forgot that the commercial does only follow-ups to workmanship if there are complaints.
Things are done in triplicate...
#114 Re: Human missions » Why Artemis is “better” than Apollo. » 2026-02-23 15:18:47
Looks like it needs to head back to the VAB to be repaired and that will push it back another month and may not even do a flyby when it does....
#115 Re: Human missions » Starship is Go... » 2026-02-23 15:16:49
I found the video of flight 11 and here is a still from it
We are seeing slight bowing and flattening down the center line of the belly.
#116 Re: Interplanetary transportation » Forty 40 Ton Mars Delivery Mechanism » 2026-02-23 14:58:12
Building things in orbit is still a very future wish list item.
#117 Re: Exploration to Settlement Creation » Wiki making composite upper floor for habitat » 2026-02-22 20:53:44
1. Geometry and intent
Bay span (joist direction): 5 m
Story height: 2.5 m from ground floor to underside of ceiling above
Use: People, furniture, light lab/office loads
Environment: Inside buried, pressurized dome; floor is not a pressure boundary
Support: Columns down to ground slab
Think of this as the Mars analog of your 2×10 joist bay.
2. Structural grid and columns
Grid (example):
Joist span: 5 m
Joist spacing: 0.4–0.6 m (similar to 16–24 in o.c.)
Primary beams: Running perpendicular to joists, say every 4–5 m
Columns: At beam intersections, down to ground slab
So one “module” might be:
Plan: 5 m (joist span) × 4 m (beam span)
Columns: At the four corners of that rectangle
Columns:
Material: Light steel (e.g., square hollow sections)
Depth: 100–150 mm square is plenty for these loads and heights
Base: Bolted to plates anchored into the ground slab
3. Mars “2×10 equivalent” joist
We want something that feels like a 2×10:
Span: 5 m (shorter than your 6.1 m house span → easier structurally)
Target depth: ~200–250 mm
Option A: Steel I-joist
Section depth: ~200–220 mm
Flange width: ~80–120 mm
Spacing: 0.4–0.6 m
Support:
Ends sit on primary beams or ledgers welded/bolted to columns
Option B: Cold-formed steel joist
Depth: 200–250 mm C-section
Spacing: 0.4–0.6 m
Advantage: Light, easy to ship, easy to cut and screw together
Either way, visually and functionally, this is very close to a 2×10 wood joist system.
4. Deck and floor build-up
On top of the joists:
Deck:
Option 1: Structural panels
18–25 mm structural panel (plywood, OSB, or composite sandwich panel)
Screwed to joists
Option 2: Thin metal deck + topping
0.8–1.0 mm corrugated steel deck
30–50 mm regolith-concrete or lightweight topping for stiffness and acoustic mass
Finish layers:
Underlayment: 5–10 mm (if needed)
Floor finish: 5–10 mm (vinyl, laminate, tile, etc.)
Total floor depth (joist zone):
Joist: 200–250 mm
Deck + finish: 30–60 mm
Total: ~230–310 mm
That’s right in the same ballpark as your house floor.
5. Vertical section from ground to second floor
From bottom to top:
Compacted regolith subgrade
Ground slab:
100–150 mm stabilized regolith/concrete
Column base plates:
10–20 mm steel plates anchored into slab
Columns:
100–150 mm square steel tubes, 2.5 m tall
Primary beams:
Steel I-beams or box beams at column tops, spanning 4–5 m
Joists:
200–250 mm deep steel/CF joists spanning 5 m between beams
Deck:
18–25 mm panels or thin metal deck + 30–50 mm topping
Finish floor:
5–10 mm
Story height:
Clear height below joists: ~2.2–2.3 m (if you leave joists exposed)
Or you can add a ceiling (e.g., 50–100 mm drop) for services, still staying within 2.5 m story.
6. Why this works well for Mars
Span is modest (5 m): So we can keep joists shallow, like 2×10 analogs.
Dome + regolith handle pressure: So this floor is just gravity + comfort, not a pressure plate.
Columns to ground: Give you a clear, simple load path—no heroic long-span beams.
Materials: Steel/CF joists and panels are shippable, modular, and easy to assemble in a pressurized interior.
If you want, next step we can:
Lay out a full grid for, say, a 20 m × 20 m interior using these 5 m × 4 m bays,
And show how the second floor walks around airlocks, trunks, and greenhouse interfaces.
Mars has no slab, concrete but we might use steel or other materials that act like it with heated bonding
See my thinking
You’re right to call that out—if we throw out “slab and concrete” as defaults, the logic shifts, but the bay concept still holds. Let’s rebuild it with no wet concrete, just steel and bonded/composite elements.
1. Ground interface without a concrete slab
Think of the “slab” as a steel foundation grillage sitting on compacted regolith.
Subgrade:
Compacted regolith, leveled and densified where columns and heavy items sit.
Steel bearing pads / sleepers:
Option A: Individual steel base plates (say 400–600 mm square, 20–30 mm thick) under each column.
Option B: Steel sleepers (I-beams or channels) laid on the regolith, forming a grid that spreads loads.
Anchorage:
Columns are welded/bolted to these plates/sleepers.
If you want more “bite” into the ground, you can add short ground anchors or driven posts, but you don’t need a monolithic slab.
So instead of “slab + column,” you have “compacted regolith + steel pad + column.”
2. Columns and primary frame
We keep the same geometry:
Story height: 2.5 m
Bay: 5 m span (joist direction) × ~4–5 m (beam direction)
Columns:
Steel square tubes, ~100–150 mm, 2.5 m tall.
Base welded/bolted to steel pads or sleepers on the regolith.
Primary beams:
Steel I-beams or box beams spanning 4–5 m between columns.
These carry the joists.
3. Mars “2×10 equivalent” without concrete
Now the floor itself:
Joists:
Material: Steel I-joists or cold-formed C-sections.
Depth: ~200–250 mm (your “2×10 analog”).
Span: 5 m.
Spacing: 0.4–0.6 m.
Deck (no concrete):
Option 1: Structural sandwich panels
Aluminum or steel skins with a lightweight core (foam, honeycomb, or bonded regolith–polymer mix).
Thickness: 40–80 mm.
Panels span between joists and are screwed/bolted down.
Option 2: Metal deck + bonded infill
Thin corrugated steel deck.
Cavities filled with heated-bonded regolith–polymer or other composite (no wet cement).
Top skin (sheet or panel) bonded on, forming a closed cassette.
In both cases, you’re using heated bonding (thermoplastics, resins, or sintered/bonded regolith) to create stiff, light panels that act like a slab.
Finish:
Thin underlayment + floor finish (5–10 mm).
Total floor depth:
Joist: 200–250 mm
Panel: 40–80 mm
Finish: 5–10 mm
Total: ~250–340 mm
Very similar to your house floor thickness, just with different guts.
4. Section from regolith to finished floor (no concrete)
From bottom to top:
Compacted regolith (locally densified under supports).
Steel base pads or sleepers on regolith.
Steel columns (100–150 mm square, 2.5 m tall).
Primary beams at column tops, spanning 4–5 m.
Steel joists (200–250 mm deep) spanning 5 m between beams.
Bonded composite deck:
Sandwich panels or metal deck + bonded infill.
Floor finish (thin).
No concrete, no monolithic slab—just steel + bonded composites sitting on compacted regolith.
5. Why this still works structurally
The dome + regolith handle pressure and shielding.
The steel frame handles gravity loads and stiffness.
The bonded panels give you a solid walking surface and diaphragm action without wet concrete.
The regolith is just a bearing medium, like soil under a steel-framed building with isolated footings.
If you want, next step we can define one specific panel type (dimensions, layers, and a regolith–polymer core) so this bay becomes a repeatable “kit part” for your whole habitat.
#118 Re: Exploration to Settlement Creation » Wiki making composite upper floor for habitat » 2026-02-22 20:42:42
Got it—0.5 bar human-breathable air inside. That’s a big structural driver, so let’s anchor the floor concept around that.
Pressure context Internal pressure:
0.5 bar ≈ 50,000 Pa = 50 kN/m2 .
Gravity on Mars: 0.38 ? reduces weights but does not reduce that 50 kPa pressure load.
So if any floor or slab is part of the pressure boundary, it sees a uniform pressure load comparable to a heavy live load on Earth.
To keep things clean, I’ll assume:
The pressure boundary is mainly the shell (dome/cylinder) and perimeter ring.
The ground floor slab is inside that boundary and not directly holding pressure—just sitting on regolith.
The second floor is purely an internal structure.
If you want the slab itself to be part of the pressure boundary, we can flip that later and design it as an upward-loaded plate.
Ground floor concept at 0.5 bar
Treat this as a floor on grade optimized for:
Heavy equipment and storage.
Good thermal mass and comfort.
Integration of anchors for the second floor.
Layering:
Subgrade:
Compacted regolith to a depth of ~0.5–1.0 m, well-leveled.
Base/stabilized layer:
100 – 200 mm
of stabilized regolith (sulfur concrete, geopolymer, or polymer-bound regolith).
Structural slab:
100 – 150 mm regolith-concrete or hybrid slab.
Local steel mesh or fibers in high-load zones (under tanks, machinery).
Finish layer:
20 – 40 mm leveling screed.
Modular floor panels for utilities and reconfigurability.
This keeps imported steel/cement mass modest while using regolith for bulk and stiffness.
Second floor concept at 0.5 bar
The second floor is a light mezzanine carrying people and furnishings, not heavy machinery.
Loads
Live load (Earth analog): say
3 – 4 kN/m2
for people and furniture.
On Mars, the weight of the same mass is ~
0.38
of that, but for design simplicity and safety, you can still size for Earth-like live loads and enjoy a margin.
Structure
Supports:
Steel/aluminum columns at ~3–4 m spacing, anchored into the ground slab with base plates and anchors.
Or suspension from the shell if your main structure can take it.
Primary beams:
Spanning 4–6 m between columns.
Steel I-beams or box sections sized for deflection comfort, not just strength.
Deck options:
Composite steel–regolith deck
Corrugated metal deck spanning between beams.
50 – 75 mm
regolith-concrete topping for stiffness, acoustics, and fire resistance.
Acts compositely with beams if you use shear connectors.
Lightweight panel deck
Aluminum or composite sandwich panels (honeycomb core).
Removable tiles or panels on top for routing utilities.
Ultra-light, dry construction, easy to modify.
Given 0.5 bar, the second floor doesn’t need to resist pressure—just gravity and local loads—so we can keep it very lean.
Where 0.5 bar really matters
Even if the floors aren’t pressure boundaries, 0.5 bar shapes:
Anchorage:
Any columns or mezzanine supports tied into the shell or perimeter ring must not compromise the pressure envelope.
Penetrations through the shell for supports need proper seals and load transfer.
Thermal/condensation:
At 0.5 bar, air density and convection are lower than Earth but still significant.
Floor assemblies should avoid cold bridges to the shell and allow for insulation and vapor control.
A clean baseline to iterate from
Ground floor (inside 0.5 bar shell):
Compacted regolith subgrade.
150 mm stabilized regolith base.
120–150 mm regolith-concrete structural slab with local reinforcement.
Screed + modular finish.
Second floor:
Columns at ~3–4 m grid, anchored to slab.
Primary beams spanning 4–6 m.
Composite deck: metal + 60 mm regolith-concrete topping or lightweight sandwich panels.
If you tell me:
Rough span you want for the second floor bays (e.g., 4×4 m, 6×6 m), and
Whether you prefer column-supported or hung from shell,
we can lock in a specific composite section (thicknesses, beam sizes conceptually, and how it ties into your overall habitat geometry).
#119 Re: Exploration to Settlement Creation » Wiki making composite upper floor for habitat » 2026-02-22 20:14:36
clean slate as I am trying to learn how we might build a composite floor for mars inside the pressurized chamber where the main load is on the ground floor and the lighter mass of people are on a second floor
See my thinking
You’re speaking my language here—let’s reset and build this from first principles for Mars.
1. Clarify the structural problem
You’re describing:
Environment: Pressurized chamber on Mars (say 1–2 bar internal, near-vacuum outside).
Primary structure: Ground floor carries most mass (equipment, storage, water, etc.).
Secondary structure: Light, people-focused second floor (crew quarters, workstations, circulation).
Goal: A composite floor system that makes sense for Mars materials, loads, and construction.
Before we go deep, one quick question that will shape everything:
Question: Do you imagine the main pressure shell as (a) a rigid shell (steel/composite dome/cylinder) or (b) an inflatable/softgoods pressure hull with an exoskeleton?
I’ll proceed assuming a rigid shell or a rigid internal frame that we can connect floors to—but we can adjust once you answer.
2. Load logic on Mars
Ground floor
Loads:
Heavy equipment, tanks, ISRU gear, storage, maybe vehicles.
Internal pressure pushing up on the ground slab if it’s part of the pressure boundary.
Gravity:
Mars gravity (~0.38 g) reduces weight but does not reduce internal pressure forces.
So pressure and structural anchoring are still serious.
Second floor
Loads:
People, furniture, light lab gear—essentially a “mezzanine” live load.
Much lighter than ground floor; can be designed as a lightweight deck.
3. Concept: composite ground floor
Think of the ground floor as a ground-bearing composite slab that also helps manage pressure and thermal issues.
Core idea:
Base: Compacted regolith subgrade, possibly with a stabilized layer (sulfur concrete, geopolymer, or regolith–polymer mix).
Structural layer:
Option A: Steel or aluminum joists/beams on short piers, with a composite slab (thin concrete/regolith-concrete over metal deck).
Option B: Thicker monolithic regolith-concrete slab, locally reinforced with steel mesh or fibers where loads are high.
Top surface: Wear layer (epoxy, tiles, or removable panels) for maintenance and routing utilities.
Why composite here?
Use local mass: Regolith-based concrete or fill provides mass, radiation shielding, and thermal inertia.
Use imported high-performance materials sparingly: Steel/aluminum deck, rebar, or fiber reinforcement only where needed for bending and cracking control.
Integration: Conduits, drains, and anchor points for equipment can be cast in.
4. Concept: lightweight second floor (mezzanine)
The second floor can be treated as a lightweight, demountable mezzanine supported by columns or hung from the main structure.
Structural options:
Option 1: Column-supported mezzanine
Steel/aluminum columns anchored into the ground floor slab (with proper bearing pads and shear connectors).
Beams or trusses spanning between columns.
Deck: metal deck + thin concrete/regolith-concrete topping, or even non-concrete (e.g., aluminum grating + panels) if you want ultra-light.
Option 2: Suspended mezzanine
Tension members (cables/rods) from the main shell or overhead trusses.
Good if you want to keep the ground floor more open and avoid many columns.
Requires a shell/frame that can take those concentrated loads.
Floor build-up for the second level:
Primary beams: Steel/aluminum I-beams or box sections.
Secondary members: Light joists or cold-formed sections.
Deck:
Thin composite deck (metal + 40–60 mm topping) for stiffness and acoustic comfort, or
Lightweight panels (honeycomb aluminum, composite sandwich panels) with removable tiles on top.
5. Mars-specific constraints that shape the design
1. Pressure vs. gravity
Internal pressure is a dominant load on the shell and any floor that participates in the pressure boundary.
If the ground slab is inside the pressure shell but not itself the pressure boundary, it can be treated more like a conventional floor on grade.
If the slab is part of the pressure boundary, you need to think about uplift and anchoring to the shell or perimeter ring.
2. Construction sequence
You want something that can be assembled in stages:
Prepare and compact regolith subgrade.
Place foundations/pads for columns and heavy equipment.
Install primary beams/joists and deck for ground floor.
Pour or place composite topping (regolith-concrete or imported concrete).
Erect mezzanine columns and beams.
Install second-floor deck and finishes.
3. Thermal and airtightness
The pressure boundary and thermal envelope should ideally be handled by the shell and interior liners, not by the floor slab itself.
Floors can then be optimized for structural performance, comfort, and routing utilities, not airtightness.
6. A clean starting template
Here’s a simple, “version 0” structural concept we can iterate:
Ground floor:
Subgrade: Compacted regolith, 0.5–1.0 m depth, well-graded and leveled.
Base layer: 100–200 mm stabilized regolith (sulfur or geopolymer).
Structural layer:
100–150 mm regolith-concrete slab with steel mesh in high-load zones.
Finish: 20–40 mm leveling screed + modular floor panels for access to utilities.
Second floor:
Supports:
Steel/aluminum columns at, say, 3–4 m spacing, anchored into the slab with base plates and anchors.
Beams:
Primary beams spanning 4–6 m, secondary beams/joists at 1–1.5 m spacing.
Deck:
Corrugated metal deck with 50–75 mm regolith-concrete topping, or
Lightweight composite panels if you want to avoid wet concrete at elevation.
If you’re up for it, next step I’d love to pin down:
Approximate span you’re imagining for the second floor (clear bay size).
Whether you want the ground slab to be structurally “serious” (supporting heavy machinery) or mostly human loads.
Once we have those, we can start sketching a specific composite section (thicknesses, materials, spans) that fits your Mars base geometry.
#120 Exploration to Settlement Creation » Wiki making composite upper floor for habitat » 2026-02-22 20:14:26
- SpaceNut
- Replies: 9
is there a metal code book for buildings like there is for wood buildings and how to apply these to mars constructions inside human use pressure containing buildings where the inside structure sees it as a free standing building same as earth
Absolutely — there is a metal-building equivalent to the wood-building code resources you're thinking of, and it's more formalized than many people realize. Let's break it down clearly and then connect it to your Mars-habitat question.
Metal Building Code Resources (Earth) The closest equivalent to a "metal code book"
1 . MBMA Metal Building Systems Manual
This is the industry's primary reference — essentially the metal-building counterpart to the wood-building code manuals. It aligns with the International Building Code (IBC) and ASCE 7 for loads.
2. MBMA Design Resources
The Metal Building Manufacturers Association (MBMA) publishes guides on:
Roof framing
Cold-formed steel design
Acoustic assemblies
Retrofit methods
3. IBC + AISC + AISI Standards
Metal buildings rely on:
IBC (Inteqnational Building Code) — overarching building code
AISC 360 — structural steel design
AISI SIOO — cold-formed steel design
ASCE 7 — environmental loads (wind, snow, seismic)
These function together as the "code ecosystem" for steel buildings.
Applying These Codes to Mars Habitats
Your question is fascinating:
Inside a pressurized Mars habitat, the interior structure behaves like a free-standing building under Earth-like conditions. Can we apply Earth metal-building codes directly?
Short answer: Yes, but with important caveats.
Let's break it down.
How Earth Codes Map to Mars Interior Structures
1. Structural behavior inside a pressurized Mars building
Inside a human-habitable pressure vessel:
Temperature, humidity, and pressure are Earth-like.
Gravity is lower (0.38 g), reducing dead loads.
Wind, snow, and seismic loads are irrelevant inside the pressure shell.
So interior steel structures behave much like: Buildings inside a giant warehouse
Structures inside a pressurized dome
Equipment platforms inside industrial plants
This means IBC + AISC + AISI design methods remain valid for interior framing.
2. What Loads still apply?
Inside a pressurized Mars habitat, interior structures must consider:
Loads that do apply
Dead load (reduced due to Mars gravity)
Live load (people, equipment)
Equipment vibration loads
Thermal loads (if temperature swings occur)
Attachment loads to the pressure shell (if any)
Loads that don't apply
Wind
Snow
Rain
Tornado
Earthquake (Mars quakes exist but are mild and low-frequency)
So ASCE 7 load combinations still apply, but many load types drop out.
3. What doesn't transfer from Earth codes?
Earth codes assume:
1 g gravity
Earth atmospheric pressure
Earth environmental hazards
Mars introduces:
Lower gravity
Pressure differentials (the shell handlesthis, not interior structures)
Different fire behavior (lower oxygen, cl$ferent materials)
Different human-factor requirements (radiation, redundancy)
Thus, Earth codes are a baseline, not a complete solution.
'4 Practical Approach for Mars Construction
Use Earth metal-building codes for:
Steel member design (AISC 360)
Cold-formed steel (AISI Sl 00)
Connection design
Load combinations (modified)
Interior architectural and mechanical standards
Modify Earth codes for:
Gravity scaling
Fire protection in low-oxygen environments
Material behpvior in low humidity
Long-term fatigue under radiation exposure
Redundancy requirements for life-critical structures
Develop new Mars-specific standards for:
Pressure-vessel interface design
Habitat shell buckling and puncture resistance
Airlock integration
Emergency egress in pressure-loss scenarios
Summary Table
Topic Earth Metal Codes Mars Interior Application
Structural steel design AtSC 360 Fully applicable
Cold-formed steel AISI sq oo Fully äpplicable
Environmental loads ASCE 7 Partially applicable (remove wind/snow)
Gravity Scale loads to 0.38 g
Fire protection IBC Needs modification
Pressure loads Not applicable Pressure shell handles this
Redundancy Standard Must be increased for life-support safety
c)' Final Thought
Inside a pressurized Mars habitat, interior steel structures can be designed almost exactly tike Earth metal buildings, using MBMA, IBC, AISC, and AISI standards es the foundation.
The main differences come from:
Lower gravity
Modified fire and safety requirements
Integration with the pressure-vessel shell
If you want, I can help you:
Build a Mars-specific load-combination framework
Compare wood vs. metal for Mars interiors
Draft a hypothetical "Mars Building Code" section for interior structures
Just tell me where you want to take this next.
#121 Re: Interplanetary transportation » Forty 40 Ton Mars Delivery Mechanism » 2026-02-22 19:26:48
the vertical 8x8 as tall as we need means a heatshield of roughly 8 metes in diameter with some sort of shielding if the move downward on the engine area.
single rocket core, based on a ring-shaped cargo container that doubles as the rough-field landing gear” and then evolved it into “two shipping containers side by side and…multiple sets of engines and tanks between them…With two long doors that open to let the engines thrust, the entire bottom is one big flat heat shield.”
CoPilot response to just GW's image
So, structurally, the concept is:
In transit: Compact, attitude-friendly configuration, essentially a core plus containers.
Entry: Flat-bottom, dual-container heat shield, doors closed; free entry at ~ 7.5 km/s to Mars.
Post-hypersonic: Doors open, engines between the containers fire for a hard retropropulsive decel (you recall ~6 g), landing with the containers themselves acting as rough-field pads.
Propulsion: Storable NTO/MMH, only for course trim and terminal descent/hover, no boiloff issues.
The two big open items you called out are exactly where the real design work lives:
Entry aerothermals, especially radiative heating on that flat bottom.
Engine layout and thrust sizing to hit the decel/landing requirements without insane g-loads or unbuildable clustering.
If you’re up for it, I’d suggest we rebuild this in a clean, stepwise way:
Lock the geometry.
Assume container analogs: e.g., 2 × “Mars ISO” containers (pick L × W × H), plus gap for engines.
Define heat shield footprint: total flat area, corner radii, possible nose radius/tip-up angle you mentioned.
Set the mass budget for a “40 t to surface” case.
Payload: 40 t.
Structure + TPS + tanks + engines: first-pass fractions.
Total entry mass: what we’re actually decelerating and landing.
Re-derive the terminal descent requirement.
Assume: Mach ~3 at end of hypersonics, ~45° flight path angle, target hover at ~30 m AGL (as you wrote).
From that, we can back out required
Δ ? , peak decel, and total thrust, then translate to engine count and clustering feasibility.
Sketch an entry/heating envelope.
Use a conservative Mars entry speed and ballistic coefficient from the geometry and mass.
Then we can talk about what TPS family and thickness might be needed for both convective and radiative heating on a flat-ish shield, and whether a slight tip or nose radius is enough to tame the radiative load.
Decide on reusability vs. expendable.
You hinted that “the rocket engines might be recovered, along with any unused propellants in the tanks.” We can see if that’s mass-logical or if this wants to be a mostly expendable cargo brick.
erothermally self-consistent.
1. That 10° “double-slope” heat shield
What you’re describing is basically a very low-angle faceted blunt body:
Two containers, each broken into two segments, with a ~10° break at mid-length, and
A 10° slope from inboard→outboard, so the whole “floor” is tipped both spanwise and lengthwise.
That gives you:
Drag: Still “first cousin to a flat plate” in Cd, as you said—high drag, low ballistic coefficient if you keep areal loading modest.
Flowfield: Shock pushed off and directed outward in both directions, which is exactly what you want to keep the hottest gas sliding away from the centerline.
Rough-field behavior: A 10° cone/facet angle is small enough that your “pads” still behave like big, mostly-flat skids on contact. 20° really would start to feel like landing on two shallow wedges.
The key knob you called out is the centerline nose radius between the containers: small enough to keep radiative stagnation heating comparable to convective, but not so sharp that you get crazy local loads or structural/TPS headaches. That’s a tunable parameter we could actually sweep in a simple correlation set once you lock in:
Container width and spacing (sets max allowable nose radius).
Total entry mass and shield area (sets ballistic coefficient and heating level).
2. Designing to 7.5 km/s and letting 5.3 km/s be “easy mode”
Your instinct to design the TPS to the 2‑year abort orbit entry speed is dead on.
Convective heating scales roughly like
??∝? 3 . (7.5 5.3) 3 ≈ 2.8 , so convective peak can be almost 3× higher at 7.5 km/s than at 5.3 km/s.
Radiative heating is even steeper with velocity (often
?? with ?>3), so the penalty for the faster entry is harsher still.
So if you size the TPS for 7.5 km/s, the Hohmann 5.3 km/s entries become “low-stress” cases with big margin—exactly what you want for bulk cargo. The faster shots then become the critical-supplies / transfer-stage-reuse cases you explicitly care about.
3. LEO facility + transfer stages: architecture actually hangs together
This part of your writeup is quietly powerful:
“All of this works very well indeed, if you have a facility in LEO that (1) can assemble them from stuff sent up from Earth, (2) can fuel them up for their trip, and (3) can also service the transfer stages that will send them to Mars.”
And:
“The difference is 5.3 km/s entry interface speed Hohmann, vs 7.5 km/s entry interface speed for the 2-year abort orbit.”
You’re basically defining a Mars cargo pipeline:
Low‑inclination, 300–600 km LEO node for assembly, fueling, and transfer-stage turnaround.
One-shot solids with a small storable “bus” for cheap, expendable transfers (Minuteman-style).
Reusable cryogenic transfer stages for the high-value, high-speed missions, with storables for course correction and Earth recapture into a high-elliptic orbit, then a tug from the same LEO node to bring them home.
The lander you’re sketching is the standardized cargo brick that rides that pipeline.
4. Where we can push this next
If you want to turn this into a solid exrocketman post and a usable design reference, I’d suggest:
Freeze a notional geometry:
Container outer dims (L, W, H),
Centerline spacing,
Exact 10° breaks (length from end to center, height offset),
Max allowable nose radius between containers.
Pick a 40 t payload case and rough mass budget:
Payload, container structure, TPS, tanks, engines, residuals → total entry mass.
From that, compute ballistic coefficient and plug into standard Mars heating correlations for both 5.3 and 7.5 km/s.
Back-of-envelope engine sizing:
Assume end-of-hypersonics Mach ~3, 45° FPA, target hover at ~30 m.
Derive required
Δ ? , peak decel, and total thrust; then see what engine clustering fits between the containers without wrecking the shield geometry.
#122 Re: Human missions » Starship is Go... » 2026-02-22 18:44:21
it appears that the attack angle is greater than 7' but less than 15' from the colored based line nose up from level.
Starship Belly‑Flop Nose‑Up Angle (for Drag & Heatshield Calculations)
1. Effective Angle of Attack
During the belly‑flop, Starship flies essentially broadside to the flow.
For drag‑equation and heating‑flux work, you can treat the vehicle as having:
• Angle of attack ≈ 90° (velocity vector nearly perpendicular to the vehicle’s longitudinal axis)
• Actual trim offset: ~10–15° nose‑up from perfect 90° to generate lift and control cross‑range
• For first‑order drag/heating calculations, the difference between 90° and 75–105° is small
2. Drag Equation Inputs
Use the standard form:
D = 0.5 · ρ · V² · C_D(α) · A
Recommended approximations for Starship belly‑flop:
• Projected area A: use the windward heatshield planform
• Drag coefficient C_D: 1.5–2.0 (typical for a broadside, high‑AoA blunt body)
• Angle α: 90° for projected area and Cd selection
3. Heatshield Temperature Modeling
The drag equation alone cannot give temperature.
Use a blunt‑body heating correlation such as Sutton–Graves:
q̇ ∝ ( √ρ · V³ ) / √R_n
Where:
• R_n = effective nose/leading‑edge radius
• During belly‑flop, the heatshield is effectively normal to the flow, so use α ≈ 90°
• The small trim angle mainly shifts the peak‑heating location, not the magnitude
4. Practical Summary
For engineering‑level approximations:
• Treat Starship as a flat, broadside plate to the flow
• Use α = 90°
• Use C_D ≈ 1.5–2.0
• Use Sutton–Graves (or equivalent) for heating, not the drag equation alone
If you want, give me the altitude and velocity band you’re analyzing and I’ll compute q̇ and an approximate equilibrium heatshield temperature.
How mass (dry mass + 100 t landing prop) ties into drag & heatshield heating
The drag equation itself:
D = 0.5 · ρ · V² · C_D · A
does not contain mass. Mass enters the problem through acceleration and the trajectory, via the ballistic coefficient.
1. Ballistic coefficient is the key link
Define the ballistic coefficient:
β = m / (C_D · A)
Where:
• m = vehicle mass (dry mass + landing prop + payload, etc.)
• C_D = drag coefficient
• A = reference area (for belly‑flop, the broadside heatshield/belly area)
Now write the deceleration:
a = D / m = (0.5 · ρ · V² · C_D · A) / m
Substitute β:
a = 0.5 · ρ · V² / β
So:
• Higher mass → higher β → lower deceleration for the same ρ and V
• That means the vehicle penetrates deeper into the atmosphere before slowing down.
2. What your “dry mass + 100 t fuel” does
Let’s say (example numbers):
• Dry mass ≈ 120 t
• Landing propellant ≈ 100 t
→ Total m ≈ 220 t = 220,000 kg
Assume (for order‑of‑magnitude):
• C_D ≈ 1.7 (broadside, high‑AoA blunt body)
• A ≈ 450 m² (about 9 m × 50 m side/belly area)
Then:
β ≈ 220,000 / (1.7 · 450) ≈ 220,000 / 765 ≈ 290 kg/m²
If you changed the mass (e.g., less landing propellant), β changes proportionally:
• More mass → larger β → less decel per unit dynamic pressure
• Less mass → smaller β → more decel higher up
3. How that feeds into heating and heatshield temperature
Convective heating (e.g. Sutton–Graves style) scales roughly like:
q̇ ∝ √ρ · V³ / √R_n
But ρ and V as functions of time/altitude depend on β:
• High β (heavier ship):
– Slows down later and deeper in the atmosphere
– Encounters higher densities at higher speeds
– Higher peak heating and higher peak g‑loads, but over a shorter time
• Low β (lighter ship):
– Slows down earlier, at lower densities
– Lower peak heating and lower peak g‑loads, but over a longer time
The equilibrium heatshield temperature at a given point is set by:
q̇_in (convective + radiative) ≈ q̇_out (radiation + conduction into structure)
Since q̇_in depends on ρ and V, and those depend on β, your dry mass + 100 t landing prop directly affects:
• The altitude where peak q̇ occurs
• The magnitude of peak q̇
• The time history of heating (integrated heat load)
4. Practical takeaway
• The drag equation gives you force.
• Dividing by mass gives you deceleration, which introduces the ballistic coefficient β.
• Your chosen mass (dry + 100 t prop) sets β, which sets the reentry profile, which in turn sets the heating environment and thus the required heatshield performance.
Color changes on heatshield tiles can act as a rough “temperature history” indicator, but only in a qualitative way.
The visible oxidation state of a ceramic or metallic tile surface reflects the maximum temperature it has reached, because different oxides form or change color at different thermal thresholds.
1. Why tile color correlates with temperature
The surface chemistry of a heatshield tile shifts as it is heated in an oxygen‑bearing environment.
Different temperature bands produce different oxide phases:
• Iron oxides — shift from grey → red/brown → black as FeO/Fe₂O₃/Fe₃O₄ ratios change
• Silica-based ceramics — develop white, cream, or light‑grey devitrification at high temperatures
• Boron or carbon additives — darken or lighten depending on oxidation rate
• Metallic fasteners or edges — show straw → bronze → blue → grey scaling (classic temper colors)
These color states “freeze in” once cooled, giving a record of the highest temperature the surface reached.
2. What this means for Starship-style tiles
Starship’s tiles are silica‑based with a black borosilicate coating.
The coating can show:
• Light grey patches — surface glass layer reflowed or ablated
• Brownish tint — partial oxidation of impurities or binder residues
• White speckling — micro‑cracking or devitrification from very high peak heating
• Matte vs glossy differences — indicates whether the glassy surface layer softened
These are not precise thermometers, but they do indicate whether a tile saw, for example, 800°C vs 1200°C vs 1500°C.
3. Limits of using color as a temperature gauge
Color is influenced by more than temperature:
• Local oxygen availability
• Heating duration
• Repeated cycles vs one‑time peak
• Surface contamination (dust, salts, soot)
• Micro‑abrasion from plasma flow or particulates
So color gives a qualitative “temperature band,” not a calibrated value.
4. How engineers actually determine heatshield temperature
Color is only a post‑flight clue. Real temperature data comes from:
• Embedded thermocouples
• Infrared imaging
• Ablation mass‑loss measurements
• CFD + trajectory reconstruction
• Radiative equilibrium modeling
Color is used mainly to identify “hot spots,” tile damage, or uneven heating patterns.
5. Practical interpretation
If a tile shows:
• Uniform dark black — normal heating, coating intact
• Brownish or reddish tint — moderate oxidation, mid‑range heating
• Grey/white patches — high‑temperature glass transition or devitrification
• Blue/metallic hues on metal parts — classic temper colors indicating 200–600°C ranges
This lets you map relative heating across the windward surface.
A question for you: Are you trying to estimate the peak temperature a specific tile design will see on Mars entry, Earth entry, or both?
#123 Exploration to Settlement Creation » Wiki Mars Water regolith soils 1 foot depth only » 2026-02-22 16:15:55
- SpaceNut
- Replies: 0
I am generating a paper for the exiting topic as gone through by Coplit.
I would like these Write front matter (preface, introduction, acknowledgments) and to Create chapter summaries
Absolutely— this is a perfect moment to shift from the technical architecture into the voice and framing of the book itself. I'll craft:
A Preface
An Introduction
Acknowledgments
Chapter Summaries (for all major chapters + appendices)
Everything will match the tone of the Foothold Mission reference: polished, authoritative, visionary, and grounded in engineering realism.
Let's begin.
FRONT MATTER
Preface
Humanity has always expanded its horizons by building footholds — small, resilient outposts that become gateways to new worlds. The Foothold Mission represents the first deliberate, industrial-scale attempt to establish such a presence on Mars. It is not a single spacecraft, a single crew, or a single technology. It is a system — a coordinated architecture of habitats, reactors, robots, ISRU plants, and Starships — designed to work together as a self-sustaining whole.
This book is a comprehensive reference for that architecture. It is written for engineers, mission planners, scientists, students, and anyone who wants to understand how a permanent human presence on Mars can be built from first principles. Every subsystem is described in detail, from mining crawlers to cryogenic tank farms, from EVA protocols to multi-pad landing zones.
The Foothold Mission is not a fantasy. It is a blueprint. It is a roadmap. It is a statement that humanity is ready to take the next step — not by planting a flag, but by building a home. Introduction
Mars is the closest place in the solar system where humanity can build a second home. It has water, atmosphere, gravity, and resources — enough to support industry, agriculture, and long-term habitation. But turning Mars from a destination into a frontier requires more than exploration. It requires infrastructure.
The Foothold Mission is the first phase of that transformation. It establishes: A permanent habitat for 17 crew
A high-throughput ISRU plant capable of producing methane and oxygen
A robotic mining and construction workforce
A nuclear-powered microgrid
A multi-pad Starship landing zone
A science program spanning geology, climate, and astrobiology
A logistics system that supports long-duration operations
This book describes how these systems work, how they interact, and how they scale. It is organized into chapters that cover the major architectural elements, followed by appendices that provide deep technical detail.
The goal is simple: to show how a small, resilient foothold becomes the foundation of a Martian civilization.
Acknowledgments
This work stands on the shoulders of countless engineers, scientists, mission planners, and explorers whose ideas, research, and innovations have shaped our understanding of Mars and the technologies required to reach it.
Special appreciation goes to:
The engineers who pioneered ISRU concepts and demonstrated that Mars can supply its own propellant.
The roboticists who developed autonomous systems capable of operating in harsh, unpredictable environments.
The habitat designers and life-support experts who showed how humans can thrive in isolated, confined, and extreme conditions.
The Starship teams whose work made rapid, reusable interplanetary transport a reality.
The scientists whose decades of Mars research laid the foundation for exploration and settlement.
And the countless individuals — students, enthusiasts, dreamers — who keep the vision of a multi-planetary humanity alive. This book is dedicated to everyone who believes that Mars is not the end of exploration, but the beginning of a new chapter in human history.
CHAPTER SUMMARIES
Below are concise summaries of each major chapter and appendix, giving readers a quick reference to the structure and content of the Foothold Mission architecture.
Chapter 1 — Mission Overview
Introduces the Foothold Mission, its objectives, its crew, and its overall architecture. Describes how Starships, habitats, ISRU, robotics, and power systems integrate into a unified base.
Chapter 2 — Starship Operations
Covers Starship landing, ascent, refueling, hop missions, cargo delivery, and exploration roles. Details the 300-ton hop architecture and the 1 , return profiles.
Chapter 3 — ISRU Systems
Explains how water ice and atmospheric C02 are converted into methane and oxygen.
Covers mining, electrolysis, Sabatier reactors, RWGS, cryogenic storage, and scaling.
Chapter 4— Robotics and Automation
Describes the robotic workforce: crawlers, tankers, maintenance rovers, and utility rovers.
Covers autonomy layers, fleet coordination, predictive maintenance, and fault recovery. Chapter 5 — Power Systenfs
Details stationary and mobile reactors, battery buffers, solar augmentation, microgrid architecture, thermal loops, and power scaling for ISRU and exploration.
Chapter 6 — Habitat Systems
Covers life support, radiation shielding, habitat modules, EVA systems, internal layout, medical facilities, and long-duration human factors.
Chapter 7 — Landing Zone Engineering
Explains landing pad construction, regolith stabilization, dust mitigation, multi-pad architecture, navigation aids, and emergency landing protocols.
Chapter 8 — Science and Exploration
Describes geological, atmospheric, radiation, and astrobiology instruments. Covers drones, micro-rovers, Starship-mounted sensors, and sample handling.
Chapter 9 — Logistics and Supply Chain
Covers cargo manifests, storage, inventory tracking, spare parts strategy, consumables, return samples, and long-term supply chain planning.
Chapter 10 — Construction and Civil Engineering
Explains regolith processing, sintering, foundations, berms, habitat expansion, roadways, utility tunnels, and outpost construction.
Chapter 11 — Human Factors and Crew Psychology
Covers crew selection, training, workload management, psychological support, social dynamics, habitability design, and long-duration adaptation.
Chapter 12 — Future Mission Architectures
Describes multi-node Mars networks, polar outposts, canyon bases, lava tube settlements, Mars—Phobos logistics, industrial expansion, and long-term settlement growth.
Appendix Summaries
Appendix F — Starship Propellant Requirements
Detailed propellant tables, mission profiles, and mass budgets for hops and Earth return. Appendix G — ISRU System Architecture
Deep technical breakdown of water extraction, electrolysis, Sabatier reactors, C02 capture, and cryogenic storage.
Appendix H — Robotic Systems Architecture
Subsystem-level details of crawlers, tankers, maintenance rovers, autonomy layers, and fleet coordination.
Appendix I — Power Systems Architecture
Reactor design, microgrid layout, thermal integration, redundancy, and power scaling.
Appendix J — Habitat Systems Architecture
Life support, radiation shielding, EVA systems, internal layout, and safety systems.
Appendix K— Communications & Navigation
Surface mesh networks, Starship relays, orbital links, EVA comms, and local positioning systems.
Appendix L — Thermal Systems & Heat Rejection
Primary and secondary thermal loops, radiators, cryogenic cooling, and waste-heat recovery.
Appendix M — Landing Zorre Engineering
Pad construction, dust mitigation, multi-pad layouts, and emergency landing protocols.
Appendix N — Safety & Contingency Protocols
Emergency response, EVA safety, ISRU hazards, Starship abort modes, and medical emergencies.
Appendix O — Science Payloads
Geology, atmosphere, radiation, astrobiology, drones, micro-rovers, and sample handling.
Appendix P — Logistics & Inventory
Cargo management, storage, spare parts, consumables, and long-term supply chain.
Appendix Q — Construction & Civil Engineering
Regolith processing, foundations, berms, habitat expansion, and outpost construction.
Appendix R — Human Factors
Crew psychology, training, workload, habitability, and long-duration adaptation.
Appendix S — Future Mission Architectures
Multi-node networks, polar outposts, canyon bases, lava tubes, Phobos logistics, and settlement evolution.
these seem to be what I want in Generate a Table of Contents and Add chapter epigraphs pe rfect let's give your book the polish and presence it deserves. Below is a full Table of Contents followed by chapter epigraphs for every major chapter. I've written them in a tone that matches the Foothold Mission: thoughtful, aspirational, and grounded in engineering reality.
If you want alternate epigraph styles (more poetic, more technical, more historical), I can generate variants too. TABLE OF CONTENTS Front Matter
Preface
Introduction
Acknowledgments
Part I — Foundations of the Foothold Mission
Chapter 1 — Mission Overview
A high-level description of the Foothold architecture, objectives, and integrated systems.
Chapter 2 — Starship Operations
Landing, ascent, refueling, hop missions, and exploration roles.
Chapter 3 — ISRU Systems
Water extraction, electrolysis, Sabatier reactors, C02 capture, and cryogenic storage.
Chapter 4 — Robotics and Automation
Crawlers, tankers, maintenance rovers, autonomy layers, and fleet coordination.
Chapter 5 — Power Systems
Stationary reactors, mobile reactors, microgrid design, and thermal integration.
Chapter 6 — Habitat Systems
Life support, radiation shielding, EVA systems, internal layout, and crew accommodations.
Part Il — Surface Infrastructure
Chapter 7 — Landing Zone Engineering
Pad construction, dust mitigation, multi-pad architecture, and emergency landing protocols.
Chapter 8 — Science and Exploration
Geology, atmosphere, radiation, astrobiology, drones, micro-rovers, and sample handling.
Chapter 9 — Logistics and Supply Chain
Cargo management, storage, spare parts, consumables, and long-term supply planning.
Chapter 10 — Construction and Civil Engineering
Regolith processing, foundations, berms, habitat expansion, and outpost construction.
Chapter 11 — Human Factors and Crew Psychology
Crew selection, training, workload, habitability, •and long-duration adaptation.
Part Ill — The Road Ahead
Chapter 12 — Future Mission Architectures
Multi-node networks, polar outposts, canyon bases, lava tubes, Phobos logistics, and settlement evolution.
Appendices
Appendix F — Starship Propellant Requirements
Appendix G — ISRU System Architecture
Appendix H —Robotic Systems Architecture
Appendix I — Power Systems Architecture
Appendix J — Habitat Systems Architecture
Appendix K— Communications & Navigation Systems
Appendix L — Thermal Systems & Heat Rejection
Appendix M — Landing Zone Engineering
Appendix N — Safety & Contingency Protocols
Appendix O — Science Payloads & Exploration Instruments
Appendix P — Logistics & Inventory
Appendix Q — Construction & Civil Engineering
Appendix R — Human Factors & Crew Psychology
Appendix S — Future Mission Architectures
CHAPTER EPIGRAPHS
Each chapter begins with a short epigraph — Q thematic anchor that sets the tone. Chapter 1 — Mission Overview
"Every frontier begins as a foothold — a small place where courage and engineering meet."
Chapter 2 — Starship Operations
"Mobility is freedom. On Mars, mobility is survival."
Chapter 3 — ISRU Systems
"A settlement is not supplied — it is sustained."
Chapter 4 — Robotics and Automation
"Where humans cannot go, robots go first. Where humans thrive, robots work beside them."
Chapter 5 — Power Systems
"Power is the heartbeat of a civilization. Even on Mars, the pulse must never stop." Chapter 6 — Habitat Systems
"A habitat is more than a shelter. [t is a promise that life can flourish anywhere." Chapter 7 — Landing Zone Engineering
"Every journey to Mars ends in a landing. Every future on Mars begins with one." Chapter 8 — Science and Exploration
"To explore Mars is to read the oldest chapters of our solar system's story. "
Chapter 9 — Logistics and Supply Chain
"A mission succ &eds not by what it brings, but by how well it manages what it has."
Chapter 10 — Construction and Civil Engineering
"Civilization begins when we build — not just for today, but for those who come after."
Chapter 11 — Human Factors and Crew Psychology
"The greatest challenge on Mars is not the environment— it is the human heart."
Chapter 12 — Future Mission Architectures
"A foothold becomes a settlement. A settlement becomes a city. A city becomes a world."
Appendices (Unified Epigraph)
"Details are the architecture of reality."
#124 Re: Exploration to Settlement Creation » Wiki Landing Site preparation mission » 2026-02-22 15:57:09
Here is the topic Forty 40 Ton Mars Delivery Mechanism
Landing 40 metric tons or more at a time on the surface of Mars is a critical requirement for human missions, representing a massive technological leap from the ~1 metric ton currently landed by NASA's largest robotic missions.
Key Aspects of the "40 Tons to Mars" Challenge:
The Technical Challenge: Landing heavy, human-rated payloads (40–100+ tons) requires landing systems that can manage descent through the thin Martian atmosphere, a feat currently beyond proven operational capabilities.
Mission Requirements: NASA studies and industry experts suggest that approximately 40 to 80+ tons of useful, landed mass—including habitats, supplies, and return vehicles—are required per crewed mission.
SpaceX Starship Capability: SpaceX’s Starship is designed to carry over 100 tons of cargo to the surface of Mars, with plans to use the vehicle's large payload capacity to deliver infrastructure and enable propellant production (ISRU) on the surface.
Alternative Approaches: Some proposals suggest delivering 40 tons of return propellant directly, or alternatively, delivering 40 tons of water to be converted into propellant on the surface to simplify missions.
Challenges and Solutions:
Entry, Descent, and Landing (EDL): Because the Martian atmosphere is too thin to slow down heavy spacecraft with parachutes alone, new technologies like supersonic retro-propulsion are necessary.
Power and Infrastructure: Landing 40+ tons allows for the deployment of heavy, efficient power sources (such as nuclear reactors) rather than relying on massive solar arrays.
Return Trip: The 40-ton target is often tied to delivering the necessary equipment to produce return propellant on-site (In-Situ Resource Utilization - ISRU).
The goal of landing 40+ tons is considered crucial for making human exploration, and potential settlement, of Mars viable by the 2030s-2040s
How to make a hard surface might be the issue to solve once we are there
#125 Re: Interplanetary transportation » Forty 40 Ton Mars Delivery Mechanism » 2026-02-22 15:00:50
Here is the article from GW
40 Tons Cargo 1-way to Mars Studies GWJ 2-21-2026
I have not been able to find very much of what I did toward this topic, more than a year ago. Maybe much more than a year ago. I have not found any of the numbers that I ran. But I did find one old “paint” sketch of where and how I started, and I remembered enough to draw a sketch of where I ended up.
I got started with a single rocket core, based on a ring-shaped cargo container that doubles as the rough-field landing gear. Initially, the rocket core was to be reusable. This thing was launched from LEO with a transfer stage. If you use the “right” transfer orbit to Mars, one
whose period is an integer multiple of 1 year, you can potentially recover and reuse those transfer stages.I used the spreadsheets and information in the “orbits+” course materials, the links to which are on the forums, to do the orbit transfer stuff, and the free entry at ~7.5 km/s directly into the Martian atmosphere. I also did the deceleration and thrust requirements
for the final descent and landing, very likely presuming Mach 3 speed at end of hypersonics altitude, angled 45 degrees down.
The biggest problems I ran into were (1) no estimate of plasma radiation heating built into the entry spreadsheet at that time (since rectified), and (2) there was not enough room to put enough engines in that core to get enough thrust for the propulsive landing. It comes out low, so the deceleration requirement was rather high. Near 6 gees as I recall. (But as I said, I can no longer find these calculations.)
The solution to this was less symmetry. Put two shipping containers side by side and put multiple sets of engines and tanks between them. That way I could get enough thrust in place, to make the high-deceleration descent and landing. With two long doors that open to let the engines thrust, the entire bottom is one big flat heat shield.
The convective stagnation heating would be deceptively low. I found out later that, quite unlike Earth entry, entry on Mars risks very high plasma radiation heating. That issue is still undressed in this design, although tipping the containers slightly and adding a small nose radius to the heat shield doors might be the solution.
As for the “40 tons” thing, you can still scale this idea up or down a fair amount, before something trips you up. It is a means to do significant 1-way cargo deliveries direct to the Martian surface from LEO.
I suppose the rocket engines might be recovered, along with any unused propellants in the tanks. I used storable NTO-MMH to completely avoid any and all evaporative loss issues. This propulsion need only make the final course corrections before entry, then the hard
deceleration to a hover at about 30 m for the final landing.
Content from Email follows
I can try to revisit the design if you like. I think it might also be a good "exrocketman" posting.
I'm thinking that somehow I need about a 10 degree slant from inboard to outboard of the floors of the two cargo containers, with a nose radius no larger than the separation between them. I'm also thinking I need to make each container in two sections, joined at an angle in the center, letting each slope at about 10 degrees from end to center. A nominal 10-deg "cone" angle will not hurt the rough-field stability or ground penetration issues very much at all. 20 degrees would be too much, though.
That gets me a flattish heat shield shape sloped at 10 degrees in both directions, which is a first cousin to a flat plate in terms of drag, but still very easily directs the shocked flow outward in both directions to the edges. I just need to make the "nose radius" of the heat shield doors, down the center between the containers, small enough to make peak plasma radiation stagnation heating about equal to peak convective stagnation heating.
The "trick" will be designing the heat shielding to the higher entry speed of a 2-year abort orbit for the transfer, while anticipating that most cargo can go min energy Hohmann. That way, faster transfer of critical supplies can proceed. Plus, we will need to send these vehicles that faster way anyway, if we are to reuse the transfer stages. The difference is 5.3 km/s entry interface speed Hohmann, vs 7.5 km/s entry interface speed for the 2-year abort orbit.
All of this works very well indeed, if you have a facility in LEO that (1) can assemble them from stuff sent up from Earth, (2) can fuel them up for their trip, and (3) can also service the transfer stages that will send them to Mars. Requirements for that facility are primarily a low-inclination orbit (quite unlike ISS), and a low-enough circular orbit to be reached easily without requiring constant re-boost. 300-600 km altitude is about right.
The transfer stages, if 1-shot, could actually be solids, with a small storable propulsion system to fine-tune burnout speeds and to do the initial midcourse correction. Most versions of Minuteman used a storable "bus" to put the warheads on exactly the right trajectory, right after the last big solid stage burned out.
If these transfer stages are to be reusable, they should use high-energy cryogens for departure, and storables for course corrections and homecoming-capture into a highly- elliptic capture orbit. You will need a tug to retrieve them from that elliptic capture orbit. A tug based at that same LEO facility.