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37,050m of 30mm OD / 2mm wall thickness 304L tubing per Starship primary structure. 10 Starships provide 370,500m of tubing to work with.

Based on structural requirements to support 2 meters of Martian regolith, 304L stainless steel would require significant thickness or structural reinforcement (such as corrugation or supporting arches) rather than a simple flat sheet. 

Here is the breakdown based on structural analysis for Martian conditions: 1. Load Calculation (The Challenge) Regolith Depth: 2 meters (sufficient for radiation shielding).

Regolith Density: Approximately \(1000\text{--}1500\text{\ kg/m}^{3}\) (loose to packed).

Martian Gravity: \(0.38\text{\ g}\).Load per \(m^{2}\): 2 meters of regolith creates a vertical load of roughly \(7.6\text{--}11.4\text{\ kN/m}^{2}\) (approx. \(1500\text{\ kg}\times 2\text{\ m}\times 0.38\text{\ g}\approx 11.4\text{\ kPa}\)).

Internal Pressure: The habitat must also maintain internal air pressure (approx. \(10\text{--}100\text{\ kPa}\)), which often acts in favor of the structure by lifting the load, but requires the steel to act as a pressure vessel. 

2. Thickness and Span for 304L Stainless Steel For a flat roof, 304L stainless steel would be prohibitive in thickness. Therefore, structural forms are required. 

Thin Sheet (0.5 mm - 1 mm): Cannot span any meaningful distance; it would buckle under 2 meters of regolith.

Corrugated 304L Sheets (1.5 mm - 3 mm): If using a 2-3 inch deep corrugated profile, a thickness of \(1.5\text{\ mm}\) (\(16\text{\ gauge}\)) to \(3\text{\ mm}\) (\(1/8\text{\ inch}\)) might support the load over short spans of \(1\text{--}2\text{\ meters}\) between supports.

Structural Plate (\(6\text{\ mm}\) - \(12\text{\ mm}\)+): To span larger distances (e.g., \(3\text{--}5\text{\ meters}\)) without intermediate supports, \(304\text{L}\) plates of at least \(6\text{\ mm}\) to \(12\text{\ mm}\) (\(1/4\text{\ inch}\) to \(1/2\text{\ inch}\)) would likely be required to prevent sagging and failure under 2 meters of regolith. 

Summary Recommendation To support 2 meters of regolith over a modest span of 3-4 meters, a \(6\text{\ mm}\) (\(1/4\text{\ inch}\)) thick 304L steel plate, properly stiffened or arched, is a reasonable starting engineering estimate. If using corrugated sheets, thicknesses as low as \(2\text{--}3\text{\ mm}\) could be used if closely supported

SpaceX’s lunar Starship was never designed to blaze back through Earth’s atmosphere in a shower of plasma. Instead, the company has quietly positioned its Human Landing System as a one‑way ferry that lives and dies in cislunar space, while NASA’s Orion capsule handles the brutal trip home. That architectural choice, long embedded in Artemis planning documents, is only now breaking through to a wider public that assumed every Starship would eventually come back to Earth.

Framed correctly, this is less a retreat from reusability than a bet on specialization. By stripping out the heavy heat shield and recovery hardware, SpaceX can turn its lunar variant into a tall, fuel‑hungry elevator between orbit and the Moon, while the rest of the Artemis stack focuses on launch and reentry. The tradeoffs behind that decision reveal how NASA and SpaceX are trying to thread the needle between ambition, schedule pressure, and basic physics.

Artemis needs a lunar shuttle, not a return capsule
NASA’s Artemis architecture was built around the idea that no single vehicle would do everything, and that includes the trip home. The agency’s own outline for Artemis III makes clear that astronauts will launch on the Space Launch System, ride in Orion to lunar orbit, then transfer into a separate lander for the descent and ascent. The Artemis program description spells out that SLS and Orion are the pieces designed for deep‑space transit and Earth reentry, while the lander is a dedicated vehicle for the last leg between orbit and the Moon’s surface.

That division of labor is why NASA refers to SpaceX’s vehicle as the Starship Human Landing System, or HLS, rather than simply Starship. Agency material on the Initial Human Landing concepts shows a tall, stripped‑down lander on the Moon, with Orion waiting in lunar orbit as the ride home. In other words, the mission design assumes from the start that the lunar Starship is a shuttle between the Moon and orbit, not a capsule that ever sees Earth’s atmosphere.

Inside the one‑way Starship design
SpaceX’s own technical descriptions underline that the lunar lander is a specialized branch of the broader Starship family. A detailed overview of Starship‑HLS notes that the Human Landing System is derived from Starship but modified for operation as a lunar lander, and explicitly states that this configuration is not designed to return to Earth. That is not a late‑breaking compromise, it is a core assumption baked into the hardware, from the missing heat shield to the absence of aerodynamic control surfaces needed for atmospheric entry.

The logic behind that choice has even filtered into public discussion among enthusiasts and engineers. In one widely shared explanation, Forrest and Townsend tell fellow fans that engineers “dont’ plan on ont he lunar starship to return to earth, no heatshield, save on the cerami,” while David Cluett promises to explain the trade in layman’s terms. The point is simple: every kilogram not spent on ceramic tiles and reentry systems can be spent on propellant, cargo, or life support for the lunar mission itself.

Why Orion still matters in a Starship era
The decision to keep the lunar Starship in space also explains why Orion remains central to NASA’s plans, despite Starship’s headline‑grabbing capabilities. A technical discussion of whether the lander could replace Orion, framed as Can Starship Lunar return to Earth orbit so Orion is not needed anymore, points back to the reality that Orion on SLS is planned to handle the high‑energy return and splashdown. The Orion capsule is built around a robust heat shield and abort systems that the lunar Starship variant simply does not carry.

Programmatically, that means Artemis is locked into a choreography where SLS, Orion, and the lander are all indispensable. The SLS missions listed for Artemis I, Artemis II, and beyond show a steady cadence of Orion flights, while separate documentation describes how the Starship Human Landing will be instrumental in ferrying crews from lunar orbit to the surface and back. That is why, even in a Starship era, Orion’s role as the Earth‑return vehicle is not a redundancy but a structural pillar of the mission design.

A “simplified” mission profile, still complex in practice
As schedule pressure mounts, SpaceX has been working with NASA on what it calls a simplified mission architecture for the lunar lander, but that streamlining does not include bringing the vehicle home. Company representatives have described to NASA a Starship for NASA approach that reduces the number of on‑orbit refueling events and mission steps while still delivering astronauts to the lunar surface. A separate account of that simplified approach notes that the company is defending the viability of its lander even as it trims complexity to hit key milestones.

Critics inside the space community have questioned whether those changes are enough. At a high‑profile event, former NASA leaders Charlie Bolden and Jim Bridenstine expressed skepticism that the current Starship schedule could deliver on time, even with a leaner mission design. Yet SpaceX has publicly stood behind its timeline, with one detailed feature on its lunar plans, titled around Fly Me to the Moon, stressing that, unlike Apollo, Unlike Apollo, Artemis III will rely on a multi‑vehicle choreography that includes several crucial milestones in 2025.

Refueling, timelines, and the politics of delay
Behind the scenes, the biggest technical swing remains in‑space refueling, which is essential if a non‑returning lander is going to haul enough propellant to and from the Moon. SpaceX’s official updates describe how the next major flight milestones tied specifically to HLS will be a long‑duration flight test and an in‑space propellant transfer in Earth orbit. Without those capabilities, the one‑way lunar Starship would struggle to carry the fuel it needs for multiple sorties between lunar orbit and the surface.

That technical risk feeds directly into political anxiety. In one public exchange, Rob Jacobs But the points out that the many Falcon 9 flights are irrelevant to NASA’s immediate problem, because what the agency needs is HLS, which is a special version of Starship. That concern has grown loud enough that NASA has signaled it may consider new proposals from other top space companies to get America back to the Moon if delays mount, a reminder that the lunar Starship’s one‑way design does not insulate it from competition.

Mars settlement projects typically progress through phases from initial robotic exploration and small outposts (Pre-settlement) to permanent, growing settlements with developing infrastructure (In-settlement), culminating in self-sufficient, potentially terraformed societies (Post-settlement), focusing first on establishing basic life support, resource utilization (ISRU), energy, and habitats before expanding to a city-like presence with economic independence. Key stages involve robotic reconnaissance, crewed landings, building propellant plants, establishing habitats, developing local agriculture, mining, and transitioning to self-sufficiency, requiring advances in transportation, closed-loop life support, and energy systems.
Key Phases & Stages
1.    Pre-Settlement (Robotic & Early Outpost):
•    Robotic Reconnaissance: Detailed surveys, sample collection (e.g., Perseverance), testing technologies for fuel/oxygen production from the atmosphere.
•    Cargo Pre-Deployment: Sending autonomous cargo, including fuel production equipment, before human arrival.
•    First Crewed Missions: Establishing a rudimentary base, completing the propellant plant for return fuel, and testing life support.
2.    In-Settlement (Permanent & Growing Colony):
•    Infrastructure Development: Building habitats, mining water, growing crops, creating power systems (solar/nuclear).
•    Resource Utilization (ISRU): Extracting and processing Martian resources (water, metals, minerals) for construction and fuel.
•    Population Growth: Increasing crew sizes, developing a local economy, and establishing governance.
3.    Post-Settlement (Self-Sufficiency & Beyond):
•    Industrial Independence: Scaling up mining, manufacturing (3D printing, metals, plastics) to reduce Earth reliance.
•    Societal Development: Growing into towns/cities, developing unique Martian culture, governance, and potentially independent political structures.
•    Terraforming (Long-Term): Modifying the environment to create breathable air and habitable zones, a highly speculative long-term goal.
Key Technologies & Goals
•    Transportation: Reliable, efficient Earth-Mars transport (e.g., SpaceX Starship).
•    Life Support: Perfecting closed-loop systems for air, water, and food.
•    Energy: Sustainable power generation (solar, nuclear).
•    ISRU: Water extraction, atmospheric processing for fuel/oxygen, material processing.
•    Habitats: Durable, radiation-shielded shelters (surface and underground)

Mars settlement projects, like SpaceX's vision, progress through phases: pre-settlement (outposts), in-settlement (permanent bases), and post-settlement (self-sufficient society), aiming for crewed landings in the late 2020s/early 2030s and self-sufficiency by mid-century, requiring massive initial cargo (Starships carrying 100+ tons) for habitats, life support, and resource utilization (ISRU) like water and fuel production from Martian air and ice, with the ultimate goal of a large, self-sustaining population.
Phases of Development (Conceptual)
1.    Pre-Settlement (Exploration & Outpost)
•    Focus: Robotic missions, establishing basic infrastructure, resource identification (water ice, minerals).
•    Key Tech: Advanced rovers, ISRU (In-Situ Resource Utilization) for oxygen/methane (fuel/air).
•    Timeline: Current robotic exploration, early cargo missions (late 2020s).
2.    In-Settlement (Permanent Base)
•    Focus: First human landings, establishing initial habitats, expanding resource production (ISRU, agriculture), reducing Earth dependency.
•    Key Tech: Habitable modules, power systems, water processing, basic manufacturing.
•    Timeline: First crewed landings (early 2030s), developing permanent presence.
3.    Post-Settlement (Self-Sufficient Society)
•    Focus: Large-scale population, full industrialization, economic self-sufficiency, cultural development.
•    Key Tech: Advanced manufacturing, large-scale life support, robust local economy, potential for terraforming elements.
•    Timeline: Decades-long process, aiming for self-sufficiency by 2050+.
Timeline & Mass Estimates (SpaceX Example)
•    Early Missions (2020s-2030s): Cargo & Crew via Starship (100+ tons capacity).
•    Cargo: Essential for habitats, initial supplies, ISRU equipment.
•    Crew: Small groups (4-10+), increasing over time.
•    Self-Sufficiency: Goal by 2050, requiring a million people using numerous Starships over many launch windows (every ~26 months).
Mass Requirements & Challenges
•    High Mass: Water, air (oxygen/nitrogen), fuel, food, equipment, habitats.
•    ISRU Critical: Extracting water ice and using atmospheric CO2 for oxygen and methane fuel (CH4) is essential to reduce launch mass from Earth.
•    Example: Water is heavy; a Starship (100 tons payload) could carry enough water for 20 people for years, but continuous resupply is needed.
In essence, Mars settlement requires a phased approach, leveraging current tech like Starship for massive cargo delivery, transitioning from outposts to permanent bases, and finally, fostering self-sufficiency through local resource utilization to support a growing population

Establishing a Mars propellant plant to refuel a Starship for a return trip likely requires several cargo missions, with estimates suggesting 2 to 6+ ships to deliver necessary infrastructure (solar panels, mining equipment) and initial fuel stocks. While some scenarios suggest 3-4 ships can enable a return via in-situ resource utilization (ISRU), initial, safer approaches might use 6+ tankers to establish necessary infrastructure. 

Seems that we are not going to our landing site of Korolev Crater

SpaceX is planning to land multiple uncrewed Cargo Starships on Mars as early as 2030, with a focus on locations in the northern lowlands, such as Arcadia Planitia, which are rich in subsurface water ice. While the Korolev Crater is a notable, 82-kilometer-wide, ice-filled feature, it is located at 73° North latitude, which is generally outside the prime, lower-latitude, or mid-latitude zones (closer to the equator for solar power) favored for initial,, easier landings.

Key Aspects of Multiple Cargo Starship Landings on Mars:
Landing Locations: SpaceX has downselected candidate sites, primarily focusing on Arcadia Planitia, Deuteronilus Mensae, and Phlegra Montes. These areas offer flat, low-elevation, and less rocky terrain, reducing the need for extensive obstacle avoidance.

Challenges and Strategy: Landing requires high precision due to the thin atmosphere, necessitating a "belly-flop" maneuver followed by a vertical landing using legs. The ships are designed to land at least 6–9 engines to generate sufficient braking force.

Landing Procedures: Multiple Starships are expected to land in close proximity (within a few kilometers of each other) to build up an initial outpost.

Infrastructure Setup: The initial cargo missions will land equipment, including tools to extract water from ice for propellant production (using the Sabatier process) and for creating breathable oxygen.

Why Not Directly in the Center of Korolev Crater?
Latitude and Solar Power: Korolev Crater is at a high northern latitude (73°N), whereas early missions require closer to the equator (under 40° latitude) for consistent solar power and better thermal management.

Terrain: The center of the crater is a 1.8-kilometer-deep, 60-kilometer-wide mound of solid water ice. While this is ideal for resources, it is a massive glacier, not a "level surface" in the sense of a stable, rocky landing pad, making it unsuitable for heavy, vertical-landing rockets.
Therefore, multiple Starships would likely land on the level plains of Arcadia Planitia or adjacent to large, accessible ice deposits rather than inside the Korolev Crater itself, even though that crater is a significant source of ice

Infrastructure Requirements: A fully operational plant capable of producing 1,000+ tons of propellant (methane and oxygen) for a return journey requires substantial power, estimated at 5 GWh, needing ~250 metric tons of equipment, equivalent to 2+ fully loaded cargo Starships.

Fuel Mining & Production: The process involves extracting water ice and capturing \(CO_{2}\) from the atmosphere.

Alternative/Interim Methods: Rather than immediate, full ISRU, early missions might rely on landing 3-4 Starships, where 3 are drained to fuel 1 for the return trip, or using 4-6 ships to establish a rudimentary plant.

Scale: SpaceX aims to send at least 2 uncrewed cargo ships before the first crewed mission to set up power, mining, and life support. Ultimately, the number of ships depends on the efficiency of the ISRU plant, the power capacity installed, and the willingness to risk the first crew's return capability

Water source from Korolev Crater

Based on current SpaceX Mars mission architecture, establishing a propellant plant on Mars to refuel a Starship for a return journey, utilizing water ice, requires a multi-stage, cargo-heavy operation. Initial Setup Phase: To establish the necessary propellant plant (Sabatier reactors, mining equipment, solar arrays) at a location like Korolev Crater, early, uncrewed missions would need to land several cargo Starships (potentially 2–5) containing roughly 100+ tons of equipment each.Propellant Production Requirement: To refuel a single Starship for a return journey, the plant must produce approximately 1,200 metric tons of propellant (methane and oxygen).Operational

Requirement: While early estimates suggested 1–2 cargo ships worth of equipment could start production, a more robust and faster turnaround (within one synod, or 26 months) likely requires at least 3-4 cargo ships to be active to ensure enough power and water processing capability to produce the ~1,200+ tons of fuel. In summary, to start a plant, 2-5 dedicated cargo Starships are required to land the equipment, with at least 3-4 of them acting as operational plant components/fuel depots to reliably produce enough fuel for one return trip. 

Key considerations: Water Source: Korolev Crater is an ideal, high-latitude location (\(73^{\circ }\text{N}\)) with large, accessible, near-surface water ice deposits, reducing the need for deep drilling.

Power: The limiting factor will be the mass of solar panels or nuclear reactors required to power the electrolysis process to turn that water into hydrogen, requiring significant cargo mass for power generation.

Launch Windows: These cargo ships must arrive at least one, if not two, synodic periods (26–52 months) before the crew arrives, to ensure the tanks are full

A number of press releases on the Internet claim that SpaceX will send a human mission to Mars as early as 2028, but only very limited information is available [2020Making Life Multiplanetary. Available from: https://www.spacex.com/media/making_lif … pdf.SpaceX. Updates. Available from: https://www.spacex.com/updates/.]. Such a claim is difficult to appraise without further detail, and as far as we can tell the challenges appear to be overwhelming. Maiwald, et al. [2121Maiwald V, Bauerfeind M, Fälker S, Westphal B, Bach C. About feasibility of SpaceX's human exploration Mars mission scenario with Starship. Sci Rep. 2024 May 23;14(1):11804. doi: 10.1038/s41598-024-54012-0. Erratum in: Sci Rep. 2024 Sep 5;14(1):20718. doi: 10.1038/s41598-024-71955-6. PMID: 38782962; PMCID: PMC11116405.] reviewed the SpaceX plan for a large-scale human mission to Mars, making educated guesses about missing data, and they found significant problems with the mass balance for the mission.

The SpaceX plan is extremely ambitious (and is likely to be very costly as well) with at least 72 heavy lift launches to land a crew of twelve and several hundred tons of infrastructure on a long-stay mission.

Several unique architectural innovations were introduced, such as using a single vehicle for departure from LEO, landing on Mars, and returning directly from Mars without rendezvous. The propellants used throughout (transfer to Mars, ascent from Mars, and transfer to Earth (CH4 + O2) remain the same, thus simplifying the mission. The three major challenges are (1) landing a 200 MT vehicle on Mars (2) producing 1,200 MT of CH4 and O2 on Mars via ISRU, and (3) implementing many repeated heavy lift launches. Nevertheless, the SpaceX mission concept provides an interesting departure from previous mission scenarios that might provide a good basis for long-term planning of a human mission to Mars decades in the future.

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