Foot hold for manned missions

SpaceNut · 2007-08-05 19:16:42

Precusor, technical developement or demonstrator mission what beyond the MSL will be needed before man can set foot on mars to stay.

Would such a mission be to explore the ice packs, in proving water is trapped there?

Are there other such mission that would need to be executed?

Martian Republic · 2007-08-05 20:41:13

Precusor, technical developement or demonstrator mission what beyond the MSL will be needed before man can set foot on mars to stay.
Would such a mission be to explore the ice packs, in proving water is trapped there?
Are there other such mission that would need to be executed?

Two question would have to be answered for that to happen.

The Nation State getting control over there money supply and then making an expanded Kennedy type Moon Mission kind of goal for colonizing Mars or building a City or something there.

If you don't have one or more Nation like the United States that controls there own credit system and can use it to build the needed infrastructure then you can't finance putting a permanent colony on Mars.

Without a National Mission to build a major out post on Mars by one or more governments, you won't build the needed infrastructure or develop the needed technology to make it happen.

If both of those things don't happen, then I would expect to see any permanent on Mars, let alone of us just going for a visit.

I wish that were not so, but that the way it will either happen or not happen.

Larry,

noosfractal · 2007-08-05 21:21:49

The NASA DRM identifies the following as R&D targets [my comments in square brackets]:

* Resource Utilization [i.e., ISRU]
o Extraterrestrial mining techniques [best way to move Mars dirt]
o Resource extraction process and chemistry [ISRU demonstrators]
o Material preparation and handling in reduced gravity
o Extraterrestrial manufacturing [what would we like to make, what can we make]

* Transportation and Propulsion
o Advanced chemical systems that provide high performance and are compatible with the resources available on the Moon and Mars
o Nuclear propulsion to enable short trip times to Mars
o Aerocapture/aerobraking at the Earth and at Mars for propulsive efficiency and reusable systems [a successful aerocapture demonstrator would be a huge help with EDL issues]
o Lightweight/advanced structures [carbon composites]
o Reduced-g combustors [changes the plume dynamics]

* Cryogenic Fluid Management
o Long-term (years) storage in space
o Lightweight and high efficiency cryogenic liquefaction
o Zero g and microgravity acquisition, transfer, and gauging

* EVA Systems
o Lightweight, reserviceable, and maintainable suit and PLSS [making sure everyone has a working suit for at least 18 months is not trivial]
o Durable, lightweight, high mobility suits and gloves [let's make the counterpressure suits work]

* Regenerative Life Support Systems
o Contamination and particle control [need a "dustlock" for Mars dust]
o Loop closure [to prevent wastage]
o Introduction of locally produced consumables [no trace toxins]
o Food production [greenhouse demonstrator]
o Trash and waste collection and processing
o High efficiency and lighter weight active thermal control systems [cooling fins are way too heavy at the moment]

* Surface Habitation and Construction
o Lightweight structures
o Seal materials and mechanisms [that will last for 18 months]
o Construction techniques using local materials

* Human Health and Performance
o Zero-g adaptation and countermeasures [and low-g adaptation and countermeasures for that matter - long term: what are the pregnancy complications? what are the infant growth complications?]
o Human factors
o Health care at remote locations [vs mass, crew skill sets]
o Radiation protection in transit and on surface

* Power Generation and Storage
o Long life, lighter weight, and less costly regenerative fuel cells
o Surface nuclear power of the order of 100kw
o High efficiency solar arrays

* Teleoperations/Telerobotics
o Remote operations with long time delays
o Fine control manipulators to support wide range of surface activities
o Telepresence sensors and displays

* Planetary Rovers
o Long range (hundreds of km) rovers
o Motor lubricants (long-term use)
o Dust control
o High efficiency lightweight power generation and storage

* Advanced Operations
o Automated systems control
o Systems management and scheduling
o Simulations and training at remote locations

* Fire Safety [i.e., particularly in high pO2 environments]
o Fire prevention
o Fire detection
o Fire suppression

However, these don't really go into colonization issues.

Grypd · 2007-08-06 07:27:09

We need to be able to prove that not only can we survive that we can prosper.

To do this we need to prove ISRU works, that we can grow plants and food crops and that we can complete shelters for ourselves out of Martian materials. We must be able to provide power independent of a nuclear plant from Earth and finally we have to prove that long term exposure to low g is not harmful to us. This is so we can stay.

SpaceNut · 2007-08-06 21:57:52

With the use of probes that have made it to mars and the data that they have collected one would think that some of these if not most have been explored with answers or direction as to what will solve each area.

# 1
Much of this area has been proven to work in so much that earth is not all that different from mars. Here you have the natural resources of plants, animals, water, fire and air to breath all of which where the means to jump start the resource use for Earth use but the methods to jump start these on mars for the future is the main issue.

Material preparation and handling in reduced gravity you would think would be a top priority for manufacturing items on the ISS but it is not, science is the prevailing activity.

Best way to move dirt is sort of a none issue until we are processing it at a level that reqires greater amounts of it than that to which can be move by hand.

# 2
These for the most part are future expectations.

# 3
These save on launch from Earth mass to orbit and allows for greater mars payloads.

# 4
Cryogenic cooling is only an issue because to get the r factor to insulate the tanks means more mass for launch to orbit meaning less payload to allow for better retention or less boil off. Even with a cooling recirculation system we lose payload to orbit.

# 5
New suits are already in process of design..

# 6
There seems to be nothing to indicate that there is anything of hazardous nature to or in the dust, it is mostly a cleaning issue.

Food production is dependent on the mode of growth (hydroponic or soil)first mission for soil may not be easy if there is nothing to compost (poop) into the soil that would be created.

Trash or waste collection is not that big of an issue the material reuse is what needs equipment to make use of the items.

# 7
Lightweight surface structures can be made but the equipment is still a need for the insitu use to make plastics and sealers. Reusing the payload shell or the landers materials to make small at first units then once smelting is started other materials can be introduced into the construction.

# 8
Water shield techiques and plastics will aid in lowering the exposure. Adressed in no doctor but a nurse practicianer level of care and why in other threads. Effects of 0g on pregnancy is a far of future item to study as you go.

# 9
Solar arrays not much use as a primary power source but as a supplemental to allow for increased stores of it in other media forms (compressed gasses, liquified ones of future use) including batteries....

# 10
Telerobotics only works if there is a means to comunicate with them which means satelites to allow for the near constant path to them.

# 11
Problems are not so much with the storage as in the conversions from one type of media to another for its use. High pressure CO2 to blow out the dust build up in joint areas. Exposed lubricated areas plus dust make for ware n tear.

# 12
Nothing here to wait for....

# 13
Pure O2 or high levels not likely to be used. Smoke detectors are in use on the ISS, while plans for suppression would mean getting into space suits and flooding area with CO2 or vacumm to exstingrish. Use of heat cameras to locate hot spot and to allow for repair before returning air atmosphere.

noosfractal · 2007-08-07 01:26:15

#1 ... #13

NASA rates technologies on a readiness (TRL) scale from 1 (wild fantasy) - 9 (proven system). NASA is probably of the opinion that the TRL in these areas is too low, that is, a theoretical solution might exist, or even a prototype that works under ideal conditions, but the detail work that results in a usable (and ideally proven) system is still to be done.

You can have different opinions from NASA, but if you opt for too many unproven systems, one of them will cause mission failure.

With the use of probes that have made it to mars and the data that they have collected one would think that some of these if not most have been explored with answers or direction as to what will solve each area.

This June 2005 paper by the Mars Human Precursor Science Steering Group ...

An Analysis of the Precursor Measurements of Mars Needed to Reduce the Risk of the First Human Mission to Mars
http://mepag.jpl.nasa.gov/reports/MHP_S … 02-05).pdf

... identifies the following precursor investigations ...

The following four investigations are of indistinguishable high priority.
1A. Characterize the particulates that could be transported to mission surfaces through the air (including both natural aeolian dust and particulates that could be raised from the martian regolith by ground operations), and that could affect hardware’s engineering properties. Analytic fidelity sufficient to establish credible engineering simulation labs
and/or performance prediction/design codes on Earth is required.
1B. Determine the variations of atmospheric dynamical parameters from ground to >90 km that affect EDL and TAO including both ambient conditions and dust storms.
1C. Determine if each martian site to be visited by humans is free, to within acceptable risk standards, of replicating biohazards which may have adverse effects on humans and other terrestrial species. Sampling into the subsurface for this investigation must extend to the maximum depth to which the human mission may come into contact with uncontained martian material.
1D. Characterize potential sources of water to support ISRU for eventual human missions. At this time it is not known where human exploration of Mars may occur. However, if ISRU is determined to be required for reasons of mission affordability and/or safety, then, therefore the following measurements for water with respect to ISRU usage on a future human mission may become necessary (these options cannot be prioritized without applying constraints from mission system engineering, ISRU process engineering, and geological potential):
The following investigations are listed in descending priority order.
2. Determine the possible toxic effects of martian dust on humans.
3. Derive the basic measurements of atmospheric electricity that affects TAO and human occupation.
4. Determine the processes by which terrestrial microbial life, or its remains, is dispersed and/or destroyed on Mars (including within ISRU-related water deposits), the rates and scale of these processes, and the potential impact on future scientific investigations.
5. Characterize in detail the ionizing radiation environment at the martian surface, distinguishing contributions from the energetic charged particles that penetrate the atmosphere, secondary neutrons produced in the atmosphere, and secondary charged particles and neutrons produced in the regolith.
6. Determine traction/cohesion in martian soil/regolith (with emphasis on trafficability hazards, such as dust pockets and dunes) throughout planned landing sites; where possible, feed findings into surface asset design requirements.
7. Determine the meteorological properties of dust storms at ground level that affect human occupation and EVA.

This Feb 2006 report from the Mars Exploration Program Analysis Group ...

Mars Science Goals, Objectives, Investigations, and Priorities
http://mepag.jpl.nasa.gov/reports/MEPAG … 0-2006.pdf

... includes a "Prepare for Human Exploration" section with detailed descriptions of the measurements they would like for the above investigations.

RobertDyck · 2007-08-09 16:12:25

NASA is very careful with any human mission. Every technology for Apollo was tested before they proceeded and committed human lives. Even so, every Apollo mission except the last one, Apollo 17, had something go wrong. This demonstrates the need for incremental testing.

Any economically affordable mission plan to Mars requires In-Situ Propellant Production. NASA DRM uses ISPP for its Mars Ascent Vehicle, yet it includes propellant for the return to Earth being carried all the way from Earth. That's one reason the price estimate for Mars Direct was $30 billion including 7 missions, while NASA DRM cost was estimated at $55 billion for the same number of missions. This demonstrates we have to use ISPP for the entire return to Earth. Even so, NASA DRM uses ISPP for a critical step: ascent to Mars orbit. Therefore ISPP is a mission critical technology. It must be tested on an unmanned mission first. The best way to do that is a Mars Sample Return mission. I know, there are people who will claim sample return is a waste of time and money because human explorers can do it much better. As a science mission that may be true, but the technology must be tested and demonstrated before any human relies on it. Therefore sample return is a necessary technology demonstrator precursor.

The other one is aerocapture. Mars Global Surveyor used propellant to slow into Mars orbit. That is, it used a rocket engine. Once in orbit it used aerobraking to reduce its orbit to the correct altitude for mapping, but initial capture into orbit was via rocket. Mars Climate Orbiter was to be the first unmanned mission to demonstrate aerocapture. Unfortunately someone made a US measure to metric conversion error, it dipped too deeply into the atmosphere and burned up. Mars now has another crater. Once the problem was identified and corrected, they didn't even attempt another aerocapture. Again, aerocapture saves so much fuel that for a vehicle as large as a human supporting spacecraft you have to use aerocapture. This technology has to be demonstrated before we can commit human lives.

A high efficiency recycling life support system is also required. You just can't bring enough air and water with you for a trip to Mars and back. The Russian system on Mir, now used for ISS, uses an electrolysis tank to generate oxygen. That recycles half the oxygen astronauts breathe, then water is shipped up as the source of oxygen for the other half. It works fine for a station in Earth orbit, receiving shipments of water every few months, but won't work for Mars. A Sabatier reactor can combine half the CO2 from cabin scrubbers with all the hydrogen from the electrolysis tank to make water and methane. That will generate enough water to close the loop; methane can be dumped to space instead of CO2 and hydrogen. This system is scheduled to be installed in the "Three crew quarters" module, assembly flight 17A, shuttle flight STS-128. Actually the manifest calls it "Three crew quarters, galley, second treadmill (TVIS2), Crew Health Care System 2 (CHeCS 2)". This module is a precursor for Mars.

The Russians were going to install a vacuum desiccator toilet in the Zvezda Service Module, but NASA convinced them the plumbing was too complicated. Then shuttle flights were cancelled after the Columbia accident, for years there was a shortage of water. The Johnson Space Center tested an Advanced Life Support system that included an incinerator toilet. Rather than burning anything you could use an electro-resistive oven to bake feces dry. The vapour can be condensed and filtered through reverse osmosis before entering the water system. Urine is currently filtered via reverse osmosis, let the water from the toilet enter the same system. So there are two systems to extract water: vacuum desiccator or electric oven; either one would minimize water loss. This should be tested on ISS before going to Mars. In fact I would like to see an oven toilet installed in the "Three crew quarters" module before it is launched, and a vacuum desiccator toilet sent up for installation in Zvezda as well. Test both in space to evaluate which works better.

If the mission architecture is to use rotation for artificial gravity, then that has to be tested in space as well. The tricky part is manoeuvring while rotating; no one has done it yet. That is best tested in Earth orbit. Mars Direct uses a tether to connect the habitat to the spent TMI stage; if that's the mission then test manoeuvring while rotating in tethered flight by connecting a Soyuz spacecraft with a spent Progress that's filled with garbage from ISS. A spent Progress is destined to burn up in the atmosphere anyway so no loss of something goes wrong.

RobertDyck · 2007-08-09 16:26:59

The current favoured spacesuit is the NASA Mark III hard suit. Although far from my favourite, it's enough to get the job done. I've often argued is plenty good enough for the Moon, but not good enough for Mars. If a suit is going to hold us back, then just use this stupid thing and get on with it!
http://www.astronautix.com/craft/nasrkiii.htm

The mechanical counter pressure (MCP) suit has many advantages. I could list them all, it should be researched, it would greatly improve any human mission to Mars, but it isn't getting done. Let's go! NOW!

SpaceNut · 2015-12-28 21:59:27

I can see that we have lost a large portion of the topic as a result of the great crash....

Digging in on Mars! How Astronauts Will Survive and Thrive on the Red Planet

mars-1-h2m-cover.jpg?1451279558

Establishing a permanent colony on Mars means living off the land.

Mars has usable resources such as water ice that could help sustain future expeditionary crews on short missions, or pioneers living permanently on the Red Planet, experts say.

"The use of local resources is pivotal for our future human exploration of Mars,"

ISRU was a topic of much discussion at NASA's First Landing Site/Exploration Zone Workshop for Human Missions to the Surface of Mars, which was held in October at the Lunar and Planetary Institute in Houston.

mars-2-tech-path.jpg?1451279838

A recent NASA workshop identified nearly 50 locations on Mars that might serve as future locales for human landings.

mars-4-mobile-home.jpg?1451279974

Red Planet or Bust: 5 Manned Mars Mission Ideas

1.

Inspiration Mars
The nonprofit Inspiration Mars Foundation plans to launch two people, preferably a married couple, on a flyby of the Red Planet in January 2018. The pair won't touch down on Mars but will zoom within 100 miles (160 kilometers) of its surface in August of that year before heading home to Earth.
Inspiration Mars— which is led by millionaire Dennis Tito

2.

Mars One
The Netherlands-based nonprofit Mars One also has its eyes on the Red Planet, though this group aims to establish a permanent colony there.
Mars One hopes to land four astronauts on the Red Planet in 2023, at an estimated cost of $6 billion. The group plans to foot most of the bill by staging a global media event around the entire enterprise, from the astronaut selection process to the pioneers' time on Mars.

3.

Elon Musk's Mars colony
Billionaire entrepreneur Elon Musk — founder of the private spaceflight firm SpaceX and CEO of electric-car company Tesla — has always dreamed big, so it's no surprise that he has his eyes set on Mars.
In fact, Musk has said repeatedly that he established SpaceX in 2002 primarily to help humans become a multiplanet species. And in November 2012, he announced a broad outline of how to make it happen.

4.

Mars Direct
This plan, first developed in the 1990s by Mars Society head Robert Zubrin, urges a live-off-the-land approach in order to keep the costs of a Red Planet colonization effort reasonable.
Astronauts would fly to Mars using existing launch technology. Once there, they would generate oxygen and rocket fuel by pulling feedstock from the Red Planet's thin atmosphere. They would get water — and mineral resources for construction — out of the soil beneath their feet, powering their activities with a nuclear reactor

5.

NASA, too
Getting astronauts to Mars is the main long-term goal of NASA's human spaceflight program. The agency is currently working to send humans to a near-Earth asteroid by 2025, and then to the vicinity of the Red Planet by the mid-2030s, as instructed by President Barack Obama in 2010.
"The vicinity of Mars" is rather vague and broad, so NASA may aim to meet the deadline with a manned mission to Mars orbit or to one of the Red Planet's two tiny moons, Phobos and Deimos. But the space agency does want to put boots on the planet eventually, for both scientific and exploration purposes.

louis · 2015-12-29 08:18:21

Tito's Inspiration Mars mission seems to have slipped to 2021. I don't really expect it to happen myself.

The reference in the first link to the NASA conference gives the game away. NASA has no focus on settlement. It is still trying to address all its interests with references to "geologically interesting regions". The whole of Mars is "geologically interesting" for heaven's sake! Stop letting scientists with special interests dictate the course of Mars exploration. "Settlement first" should be the watchword. Science and discovery can wait - we will be able to plenty once we have established a viable settlement.

My guess would be that Musk is fully aware of NASA's deficiencies in this regard and has his own settlement plan which we will find out more about in 2016.

SpaceNut · 2015-12-29 20:06:57

If money was all that was needed then anyone could go but its a waiting game for launch providers that is needed to catchup to be able to lift the tonnage that we need just for setting up shop and then its the means to land it on the surface that is the next hurttle......

louis · 2015-12-29 21:00:54

Well I think we can do it on 20 tonnes landed - but 40 tonnes if you want to be absolutely sure about a return.

That can be delivered in separate loads (including the final human load) over several years - e.g. 10x4 tonne loads. The technology is definitely there already. If you put together the technology from: Mars robot landings, Mars Rovers, solar system voyages of discovery (even outside the solar system), the Saturn V technology, the Apollo lunar landings, ISS, communications satellites and the recent Space X/Blue Origin return-to-base rocket landings - then I think only someone lacking in any explorative impetus would conclude we couldn't get to Mars...and back.

SpaceNut wrote:

If money was all that was needed then anyone could go but its a waiting game for launch providers that is needed to catchup to be able to lift the tonnage that we need just for setting up shop and then its the means to land it on the surface that is the next hurttle......

GW Johnson · 2015-12-30 10:52:54

Hi Louis:

Back during the Apollo landings, NASA had on its books a manned mission to Mars, set initially for 1983, and pushed back to 1987 by the time Apollo and all manned flight outside LEO was cancelled in 1972. A nuclear thermal engine (NERVA) was to replace the third stage of Saturn 5 to do this. Knowing what we know now about microgravity diseases and radiation from solar flares, and the psychological effects of long close confinement, I rather doubt that a crew would have survived that attempt back then. If nothing else, the 15 gee free return would have killed them in their weakened state.

But by 1995, we knew enough to have done this right, and gotten a crew back alive. You don't do it Apollo style with everything shot on one or a few rockets, and you don't need gigantic rockets shooting huge payloads to do it. You assemble what you want from small payloads sent to LEO, and you depart from there. Yes, we could have done this 20 years ago. It would have cost trillions, because of launch prices 20 years ago: 27,000-30,000+ per pound on the shuttle.

Today, launch prices are far lower at near $2500/lb with Atlas-5 and Falcon-9, and they are about to get even lower with Falcon-Heavy (nearer $1000/lb). So the $trillions becomes $hundreds of billions, and could be even lower if managed on a shorter development schedule than has become customary in recent decades. That's for a mission where everything is sent from Earth, just like the 1983 plan. There is NO technological reason why we could not mount such a program today, leading to a landing in a decade.

In the last 20 years it seems we have learned enough about ISRU to make return propellants, and perhaps some life support supplies, in situ on Mars. That lowers the price further by reducing the tonnage to b e assembled in LEO. It might be possible to do this for under $100 billion, but that's just a guess on my part. It would take a private management approach to actually achieve it; not the way NASA has done business for the last 3 decades.

I don't think squeezing the budget to the bone just to achieve a low price is the way to go. I like bang-for-the-buck criteria better. Mount a slightly larger mission, and just do a whole lot more than flag-and-footprints. Like making landings at more than one site. Like leaving a working experimental base running on automatic at the best of those sites.

One of the enabling items for more bang for the buck is a reusable lander craft. This is feasible single stage with chemical propellants, even the storables. But it is a big ship with a small payload fraction (around 3%). Send propellants from earth to support a minimum mission with it, and then any propellants that you can make on Mars just increase the number of trips and the number of sites explored. More bang for the buck.

The true enabling item to get that increased bang for the buck is that reusable one-stage lander: a very large item to be assembled in LEO. It can even be used to push things to, even from, Mars.

GW

louis · 2015-12-30 19:36:44

In response to post #14 by GW:

GW, I agree with most of what you say but I think your price tags are grossly inflated. Even with NASA's "wish list" pricing, I don't think we ever got higher than $400 billion back in the 80s or 90s (though I guess, one has to allow for RPI increases).

As regards the costs now, well at $2000 a kg, you could launch 50 MILLION - yes million - tonnes to LEO for $100 billion!!!

Obviously launch costs are only a proportion of overall mission cost, but let's say we wanted to get 50 tonnes to the Mars surface, and we applied a multiplier of 4 to the $2000 a kg cost (the multiplier would reflect transit and return costs), then launch and transit would cost only $400 million - not even half way to one billion.

Remember also we have sunk a lot of the development costs already for a Mars mission - e.g. development of life support technologies on the ISS, Mars Rover exploration, development of communications with Mars, development of the Falcon 9/Heavy, Red Dragon and now Space X returnable rocket.

Putting it all together for a Mission will still cost a huge amount but I very much doubt it will cost more than $20 billion over ten years , and if we seek to commercialise the mission, we could get a lot of that back in sponsorship, TV rights, regolith sales and other revenue raising options. Overall net cost needn't be more than $10 billion.

GW Johnson · 2015-12-31 10:25:44

Hi Louis:

I would point out that NASA has never done anything for the quoted price tag since before shuttle. So that baseline Mars mission quote of $450 billion was probably over-optimistic by at least a factor of 2. When you combine that history with inflation, that same mission price is in the $1 to 2 trillion range today. That's why I said "trillions".

In a very well-run program focused on creating working vehicles out of already-developed components and technologies, launch costs ought to be something like 20% of your program costs, based on some very successful but smaller efforts in the past.

If instead you attempt to develop new technologies or components from scratch, your development costs dominate the picture and your launch costs shrink to an insignificant percentage. That's the mistake made with shuttle and with X-30 and some others.

If we use scale-up variations on existing engines, and flight dynamics variations on existing module designs, we can create a manned orbit to orbit transport that we can shake-down in LEO and cis-lunar space pretty quickly. I would even include the Bigelow inflatables in that technology base, since most of the development is done, and one is about to be added to the ISS.

The harder one to do is the lander for Mars, whether one stage or multiple stage. Apollo technology will not serve by itself, this is a more complex problem involving hypersonic aerodynamic deceleration, and most likely supersonic retropropulsion, as well as the Apollo lander technologies. The sooner the development work on these vehicle concepts (and there are several competing concepts) gets done, the sooner we can lay out a program to put people on the surface of Mars.

So overall, part of the project should operate close to my rule-thumb 20% launch costs, but a major chunk is a development program closer to 2% launch costs.

If your mission sends 1000 (arbitrary) tons to LEO at $2.5 million/ton, launch costs look like $2.5 billion. If those are 5% of your total program (also arbitrary), your program costs approach $50 billion. If you screw around too long schedule-wise, trying to hold down spike costs in any given year, those figures could double, or more. That's a $100 billion as semi-realistic for a mission that masses 1000 tons at departure from LEO.

How many sites, how many men, and what kind of base, can you establish for 1000 tons departing from LEO? How much crew survivability and health can you afford?

Do you really believe today's NASA and its ULA favored contractor base would ever try this management approach? Remember, they have done nothing this way since before shuttle, but it is how they ran the Mercury/Gemini/Apollo series.

GW

louis · 2015-12-31 17:09:46

In response to post #15 by GW:

Hi GW -

I had composed a fairly lengthy response replete with references - but I managed to lose it (duh!) and so this is a less full summary:

1. Refreshing my memory on the tonnages issue it appears we need 7 units of fuel in tonnes for every tonne unit delivered from LEO to LMO. However, with ballistic capture we can reduce that by 25% (so 4.3 units). However, for the human landing we want to stick with the 7 units (as I assume we want the shorter journey time afforded by HTO). Robot loads can be delivered in smaller separate loads like Viking with ablative shields, parachutes and a small amount of propellant.

2. I base the human lander on a dragon which can ferry up to 7 people. I assume 5 crew members for the Mars Mission to allow for extra supplies.

3. Delivering 30 tonnes to the surface (say 24 tonnes in useful supplies) would be more than adequate.

4. I allow 10 tonnes for a transit hab and supply module. So with the 6 tonne Dragon, that is 16 tonnes in all to go on the human mission. All other supplies go as robot landings.

5. Total tonnage to launch:

16 + 16x7 = 224 tonnes

30 + 30 x 4.3 = 258 tonnes

Then add something for the return voyage - let's say 150 tonnes?

And maybe a contingency of 100 tonnes.

Total = 732 tonnes x $2 million per tonne = $1.46 billion for the launch.

6. 30 tonnes of supplies at the surface would be a huge amount for five people.

7. A key requirement would be to use dried food as much as possible. Add water. We take water with us but can recycle that easily - we can have several recycling units - so as to make it failsafe. The average American eats about a tonne of food per annum. Our crew won't need that much I expect, but let's assume that. With food having a water content of something like two thirds or more on average, a dried food supply of say 2.5 tonnes would scale up to 7.5 tonnes of food with added water. Add another 2.5 tonnes of complete food supplies e.g. frozen, vaccuum packed, pickled food, energy bars and so on...That would give you 10 tonnes of food (more than sufficient for two years with 5 people). So in terms of tonnage to Mars that would be 5 tonnes of mass. We could probably get by with one tonne of water being delivered to the surface, giving a wide margin of safety. Perhaps it could be less.

8. So out of the 30 tonnes delivered 6 tonnes would be food and water. The remaining 24 tonnes could include: 5 tonnes of PV panel equipment (including storage batteries); 3 tonnes for a pressurised rover; 1.5 tonnes for a robot digger; 0.5 tonnes of medical supplies; 1 tonne experimental farm hab; 1 tonne of scientific experiments; 3 tonnes for a number of robot rovers; 1 tonne for spare space suits - there is still lots of slack to take up. You might use some of the slack for rocket fuel production or ISRU experiments like 3D printing, brick manufacture; solar powered steam engine etc etc.

9. So far on cost we have $1.5b or thereabouts spent on the launch. I maintain there has already been huge sinking of development costs (rover design, rocketry, Bigelow style habs, retropulsive rockets etc etc). This will not be an Apollo style mission where you are inventing nearly everything from scratch. Of course there has to be Mars-specific development, coms improvement and implementation through tests and trials (e.g. in a lunar setting). I know Curiosity cost $2.5 billion - on that basis you might justify a $100 billion price tag but I would counter (a) launch costs have declined dramatically (b) in terms of what goes on at the Mars surface for the human mission, we can keep things reasonably simple. The complicated machinery can stay "indoors". (c) Space X have a record of being able to deliver at a fraction of the cost of NASA.

10. I think we need to ask what costs would be involved in development? A final price tag of under $20 billion seems reasonable to me. But that cost could be shared between several space agencies e.g. NASA, ESA, Jaxa and the Space Agencies of and India and Canada, say. Furthermore if the mission was commercialised at least half that cost could be covered through sponsorship, television rights, regolith sales, and sale of scientific services.

SpaceNut · 2018-11-25 17:30:51

we need to have a solid insitu system

prototype-development-of-an-integrated-mars-atmosphere-and-soil-processing-system-8-1024.jpg

SpaceNut · 2018-12-22 22:46:58

We all dream of the day when we can have a Human mission to mars but we need to get there before we can.....

The Human Exploration of Mars

louis · 2018-12-23 06:35:06

Within the next 20 years?!! That's not "dreaming" that's "postponing indefinitely". If NASA had spent its money wisely we would have been on Mars 20 years ago - by 1998.

If all goes well with Space X's plans, we could see humans on Mars within 6 years. I don't see anything in principle that will stop that, although of course there's a lot of testing between now and a human landing on Mars. Even if they miss the ambitious 2024 target, a 2026 landing would seem very much on the cards.

SpaceNut wrote:

We all dream of the day when we can have a Human mission to mars but we need to get there before we can.....
The Human Exploration of Mars
https://marsforthemany.com/wp-content/u … 20x420.png

SpaceNut · 2019-10-24 18:49:53

I remember years ago that we had a Toehold topic but all that seems we have now is this one. If we are waiting for going big or bust then lets go with small and dig in hard for the future that will catchup someday to what we desire.

louis · 2019-10-25 12:47:42

Yes, I think that was me back in the days when we were still looking to mount mini-missions of 40 tons or less, not Musk's 500 tons monster mission! My concept was that the toehold would be the first sub 40 tons mission...enabling us to begin ISRU on the surface.

I still think it was marginally feasible - but it would have been much more high risk than Space X's mission will be. My concept involved parachuting down quite a lot of the supplies.

SpaceNut wrote:

I remember years ago that we had a Toehold topic but all that seems we have now is this one. If we are waiting for going big or bust then lets go with small and dig in hard for the future that will catchup someday to what we desire.

SpaceNut · 2019-10-25 17:12:44

We had the initial topic over on the Red Colony website if I remember correctly. When it went down I created the topic here as well to see what we could do within the levels of mass that we could land. Sure we can tweek the current landing techniques for mars and bring that mass up to something more realistic but its not going to be a starship for value. The skycrane method with out the crane is sort of simular to using the red dragons supper draco engines for retropropulsion and when the payload is on top we are pretty close to an open lander design for mars just add legs to make it complete. Dumping the shell of the normal Nasa design removes mass for the engine to burn fuel for with regards to isp for landing.

SpaceNut · 2019-11-27 21:45:13

This is what could be a show stopper if there was a mars dust storm so large; that if we only go with a solar solution we are dead in short term.

Global storms on Mars launch dust towers into the sky

A series of runaway storms breaks out, covering the entire planet in a dusty haze.
Last year, a fleet of NASA spacecraft got a detailed look at the life cycle of the 2018 global dust storm that ended the Opportunity rover's mission. And while scientists are still puzzling over the data, two papers recently shed new light on a phenomenon observed within the storm: dust towers, or concentrated clouds of dust that warm in sunlight and rise high into the air.
Scientists think that dust-trapped water vapor may be riding them like an elevator to space, where solar radiation breaks apart their molecules. This might help explain how Mars' water disappeared over billions of years.
Dust towers are massive, churning clouds that are denser and climb much higher than the normal background dust in the thin Martian atmosphere. While they also occur under normal conditions, the towers appear to form in greater numbers during global storms.
A tower starts at the planet's surface as an area of rapidly lifted dust about as wide as the state of Rhode Island. By the time a tower reaches a height of 50 miles (80 kilometers), as seen during the 2018 global dust storm, it may be as wide as Nevada. As the tower decays, it can form a layer of dust 35 miles (56 kilometers) above the surface that can be wider than the continental United States.
"But during a global storm, dust towers are renewed continuously for weeks." In some cases, multiple towers were seen for as long as 3 1/2 weeks.

http://www.marsdaily.com/reports/Dust_s … s_999.html

louis · 2019-11-28 05:53:20

Lol - nothing new there about the effects of dust storms...just the mechanics of their creation. Not a show-stopper!

I have never found a paper that states categorically that insolation falls below 30% of the norm during a major dust storm. Most papers seem to suggest that insolation stays at above 37%. Confusion arises, I think, because of (a) dust accumulation on PV arrays which obviously will further reduce power output (b) people confuse direct insolation for direct plus diffuse insolation, thinking the low dust storm figure for direct insolation relates to what a PV array receives (it doesn't as all a PV array is interested in is photons, not where they come from) and (c) artistic renderings of dust storm effects (NASA admitted some of the "pictures" they released had been created for effect).

These images have misled a lot of people:

https://www.space.com/40873-mars-dust-s … ilent.html

You'll see the text states clearly they are "simulated" images. These photos from Gale Crater are probably more accurate as to the effects on insolation at the surface during a major dust storm:

https://www.nasa.gov/feature/goddard/20 … rm-growing

SpaceNut wrote:

This is what could be a show stopper if there was a mars dust storm so large; that if we only go with a solar solution we are dead in short term.
Global storms on Mars launch dust towers into the sky
A series of runaway storms breaks out, covering the entire planet in a dusty haze.
Last year, a fleet of NASA spacecraft got a detailed look at the life cycle of the 2018 global dust storm that ended the Opportunity rover's mission. And while scientists are still puzzling over the data, two papers recently shed new light on a phenomenon observed within the storm: dust towers, or concentrated clouds of dust that warm in sunlight and rise high into the air.
Scientists think that dust-trapped water vapor may be riding them like an elevator to space, where solar radiation breaks apart their molecules. This might help explain how Mars' water disappeared over billions of years.
Dust towers are massive, churning clouds that are denser and climb much higher than the normal background dust in the thin Martian atmosphere. While they also occur under normal conditions, the towers appear to form in greater numbers during global storms.
A tower starts at the planet's surface as an area of rapidly lifted dust about as wide as the state of Rhode Island. By the time a tower reaches a height of 50 miles (80 kilometers), as seen during the 2018 global dust storm, it may be as wide as Nevada. As the tower decays, it can form a layer of dust 35 miles (56 kilometers) above the surface that can be wider than the continental United States.
"But during a global storm, dust towers are renewed continuously for weeks." In some cases, multiple towers were seen for as long as 3 1/2 weeks.
http://www.marsdaily.com/reports/Dust_s … s_999.html

Last edited by louis (2019-11-28 05:55:22)

SpaceNut · 2019-11-28 09:52:46

In this era of flight to mars we are stuck with payloads of 20 mt and at best no more than 50mt preloaded for the next decade when man could go.

So lets go with the 40% typical over just how many months, with some getting even deeper for a couple months for the dust storms.
Lets say we have 2 x 100 kw solar array systems and batteries to match as thats all we could preload for a single manned landing.
Now lets say we need 100 kw just to sustain ISPP fuel production and 50 kw to sustain mans life support of that 200kw.
A storm that last months at 40% means we are at 120kw available for the support of man to stay and be able to leave.

So what gets sacrificed will be the ISPP fuel production during that time span.
Also man's life support may be able to trim to 40kw but its probably not going to get all that much lower.

I hope that the compound losses on a fixed level of energy can not cause a lose of mission or that the worse we could expect for out come is missing a return home cycle. With that man could only hope that the next cargo cycle delivers more arrays and supplies and not a new crew to allow for a prolonged stay to survive.

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Re: Foot hold for manned missions

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Re: Foot hold for manned missions

#20 2019-10-24 18:49:53

Re: Foot hold for manned missions

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