Author Topic: Speculation and Discussion: Crew for first SpaceX Mars mission  (Read 41219 times)

Offline rakaydos

  • Full Member
  • ****
  • Posts: 888
  • Liked: 361
  • Likes Given: 9

The way I see it there will be intense competition for cargo space from different design teams and interest groups (see below) so there will be some horse trading –(...)
why? Other than the life support actually needed to make the trip and the basic ability to get out the hatch, everything else can be brought on a dedicated cargo Starship. If the mission requirements balloon too much, send more cargo Starships. This isn't a "bare minimum to get things done" it's "enough to be sure it can be done, no matter what."

Offline Slarty1080

  • Full Member
  • ****
  • Posts: 962
  • UK
  • Liked: 433
  • Likes Given: 229
It seems like something is missing from this discussion. Where's the water? The character of the first missions will be to prove a reliable source of water for fuel production. You must have provable quantities of water before dropping in 100's of tonnes of infrastructure. I agree that later missions will need most everything you can imagine but the thread is titled "Crew for first Mars Mission". I assume this means a permanent settlement site has not been established.

The thing I've had trouble figuring out is whether a water source can be proven without a crew. And without a proven water source how does the ship get refueled. I think first cargo ships must be able to process soil for water. This guarantees fuel reserves for later crewed ship. This also requires certain cargo for soil processing. Then the crewed ship, on next synod, has primary responsibility of finding a water source sufficient for a permanent settlement. These responsibilities should drive the required crew selection. It sounds like drillers and miners are the required types.

A good point. There has been much discussion and speculation about this. I imagine that an uncrewed Starship will need to be landed first and either prove that water is available and accessible or even fill itself with propellants before any crewed missions land.

I fear this might take some time, we don't know for sure. I suspect the most likely method would be a Rodriguez well as described by others here. Basically melting a hole into a glacier, like they do when supplying the South Pole base with water. I can't see them sending a crew until either there is a fully tanked robot sitting on the surface or they are well sure the crew can get it without too much problem.

Extracting water from soil is also a possibility but brings with it a huge array of other issues such as variability of substrate, excavation, transportation, processing, removal of spoil and mechanical wear on equipment (then ISRU water processing after that).

So this thread assumes that the water issue has been settled in the sense that the water is available and accessible and "just" needs to be extracted and processed. So yes ISRU engineer and drilling expert and duplicates are required, but who else?
The first words spoken on Mars: "Humans have been wondering if there was any life on the planet Mars for many decades … well ... there is now!"

Offline DistantTemple

  • Full Member
  • ****
  • Posts: 456
  • England
  • Liked: 354
  • Likes Given: 562
From following this site, ISTM that water is not a solved problem, but far from an overlooked one. A year or so ago there was a NASA paper - presentation from a working party on human landing sites on Mars. One of the main questions addressed in that water availability. Obviously ice deposits are ideal, but less prevalent towards the equator, and landing at lowish latitudes was one initial criteria I think. Otherwise was the more expensive but more widely available water in hydrated mineral form. Gypsum was included.... but I have forgotten my chemistry... I have found one file and attached it... This has been discussed on this site... probably many times.

ISTM there are some pretty reliable guesses for landing to find ice. However if once there it was much harder to extract than expected, perhaps by being under several more metres of loose surface material, or mixed more thoroughly with heavy boulders... etc it might be a problem. Or Other sites may be desirable for other reasons, and nearby ice unknown.

Personally I would like to see SX send its own probe(s) to mars as early as the 2020 synod! And possibly some kind of lander!!! Mad as it sounds for them to quickly prepare a mission that would take NASA at least 4 years! Obviously there was the Red Dragon business.

Maybe that's one thing SX is hoping for with the BFH mad rush.... NASA support for a renewed Red Dragon, or other prospecting mission.

If SX gets good signatures of water from space, and high resolution graphics, where IT hopes to land SS then it will retire some risk, and build confidence. The mix of equipment sent will depend on types of rock, steepness of terrain, the possibility of caves, etc. So every bit of advance info will be helpful.
Edit: found second doc...
« Last Edit: 01/06/2019 09:38 pm by DistantTemple »
We can always grow new new dendrites. Reach out and make connections and your world will burst with new insights. Then repose in consciousness.

Offline Slarty1080

  • Full Member
  • ****
  • Posts: 962
  • UK
  • Liked: 433
  • Likes Given: 229

The way I see it there will be intense competition for cargo space from different design teams and interest groups (see below) so there will be some horse trading –(...)
why? Other than the life support actually needed to make the trip and the basic ability to get out the hatch, everything else can be brought on a dedicated cargo Starship. If the mission requirements balloon too much, send more cargo Starships. This isn't a "bare minimum to get things done" it's "enough to be sure it can be done, no matter what."
The reason why is cost. It may be that Starship and Super heavy will be able to be used 1000 times eventually but that is hardly likely initially, especially when they are introducing improvements and iterating. Things will break and that will be expensive, I’m sure ships will have to be retired early as happened with F9 boosters. So the flights will not be cheap initially due to fewer flights each. And there’s no paying customer.

So I’m hopeful that SpaceX and Elon Musk will get there in the end, but it will be risky and it won’t be cheap. I hope they find the money for dozens of crew members and multiple cargo ships on the early missions, but I don’t think people should get the idea that the quantity of ships and resources will be unlimited, because they won’t. Neither cargo nor cash will be plentiful and it would be best to plan accordingly and get the absolute maximum out of every mission.
The first words spoken on Mars: "Humans have been wondering if there was any life on the planet Mars for many decades … well ... there is now!"

Online AC in NC

  • Full Member
  • ****
  • Posts: 954
  • Raleigh NC
  • Liked: 1034
  • Likes Given: 611
It feels like it's important to state something I don't recall being stated explicitly.  There's a lot of talk about competition for cargo space and competing interests with respect to crew skill.

ISTM, the entire cargo and crew will be totally biased toward keeping the crew alive and ISRU.  Any marginal capacity will provide additional resources for those two ends.
« Last Edit: 01/06/2019 11:25 pm by AC in NC »

Offline mwood

  • Member
  • Posts: 32
  • Plano, TX
  • Liked: 30
  • Likes Given: 0
It seems like something is missing from this discussion. Where's the water? The character of the first missions will be to prove a reliable source of water for fuel production. You must have provable quantities of water before dropping in 100's of tonnes of infrastructure. I agree that later missions will need most everything you can imagine but the thread is titled "Crew for first Mars Mission". I assume this means a permanent settlement site has not been established.

The thing I've had trouble figuring out is whether a water source can be proven without a crew. And without a proven water source how does the ship get refueled. I think first cargo ships must be able to process soil for water. This guarantees fuel reserves for later crewed ship. This also requires certain cargo for soil processing. Then the crewed ship, on next synod, has primary responsibility of finding a water source sufficient for a permanent settlement. These responsibilities should drive the required crew selection. It sounds like drillers and miners are the required types.

A good point. There has been much discussion and speculation about this. I imagine that an uncrewed Starship will need to be landed first and either prove that water is available and accessible or even fill itself with propellants before any crewed missions land.

I fear this might take some time, we don't know for sure. I suspect the most likely method would be a Rodriguez well as described by others here. Basically melting a hole into a glacier, like they do when supplying the South Pole base with water. I can't see them sending a crew until either there is a fully tanked robot sitting on the surface or they are well sure the crew can get it without too much problem.

Extracting water from soil is also a possibility but brings with it a huge array of other issues such as variability of substrate, excavation, transportation, processing, removal of spoil and mechanical wear on equipment (then ISRU water processing after that).

So this thread assumes that the water issue has been settled in the sense that the water is available and accessible and "just" needs to be extracted and processed. So yes ISRU engineer and drilling expert and duplicates are required, but who else?


I get that the focus of thread is more oriented towards what happens after the water issue is solved. But I'll try once more to impress that the first crewed missions will be primarily focused on water and will need the appropriate personnel. After that it will basically be a free for all and the settlement could make good use of just about any hard working dedicated individual willing to learn.

Yes, a crewed launch will require that previous launch has actually produced fuel at the intended target location. Otherwise the site must be abandoned and an uncrewed prospector mission sent to new location. The crewed mission will get delayed to next synod. This repeats until fuel is produced else the crew is on a one way trip. There are definitely water ice sources at poles and recently discovered Korolev crater, https://www.space.com/42828-icy-mars-crater-winter-wonderland-photos.html. It's probably easier to robotically produce fuel in these locations but the location may not be where you want an actual permanent settlement, which is the goal. Do you really want to live long term at Mars north pole? That may be an outpost option, but SXs goal is to colonize.

Mid latitude subsurface liquid water seems very promising for settlement. Which is getting to my point. Mid latitude will have higher temperatures, can be low altitude for higher air pressure, and better solar power efficiency. Data says it's there but you don't know for sure until you actually pump it up and determine quality and quantity. The data may indicate water in the area but you might need to drill multiple wells, and moving multiple of km, before proving the resource. The resource must be proven before dropping 100s of tonnes of supplies for settlement that could be huge loss of time and material. This may take multiple manned missions before a permanent site is selected.

So first crewed missions should be primarily focused on finding a water resource with sufficient quantities to support a refueling depot and settlement. Continued testing for life and other scientific endeavors should proceed in parallel. So initial crewed missions should cover these broad categories. Everyone should be proficient in multiple categories and roles.

1. Command. Ship should have strict chain of command for all the same reasons a chain of command is maintained on ocean vessels.
2. Science & Medical. Medical, life science studies, environmental & radiation monitoring, geology, physics.
3. Engineering: Ship maintenance, life support, drilling experts, climbers for cave and cliff exploration, transportation, power generation, electronics, software, communications.

Offline Slarty1080

  • Full Member
  • ****
  • Posts: 962
  • UK
  • Liked: 433
  • Likes Given: 229
Some more good points made concerning the need to focus on survival skills (ECLSS and ISRU) rather than science (geology and biology) in the first mission(s) and the primacy of establishing an accessible and reliable long term source of water at a Martian base.

Part of the issue is related to the difficulty in arranging for a fully robotic Starship to produce sufficient propellants. There are many issues, unwinding / dispensing and setting up the solar array will be one of them and the long term storage and viability of propellants and the Starship itself would be another.

If it is too difficult to establish a robotically tanked ship and too dangerous to send a crew without having the fuel to return them ready and waiting then there is a third possibility that could be used for the first mission (I mentioned this on another thread).

With three Starships, one for crew, one as an orbital tanker and one as a tanker /cargo lander it is possible to put humans on the surface and return them without any ISRU. This would allow a human crew to set up a robot facility for future missions. It might not be the best option depending on many factors but it is quite possible – I checked the basic numbers if anyone is interested.
The first words spoken on Mars: "Humans have been wondering if there was any life on the planet Mars for many decades … well ... there is now!"

Offline mwood

  • Member
  • Posts: 32
  • Plano, TX
  • Liked: 30
  • Likes Given: 0

With three Starships, one for crew, one as an orbital tanker and one as a tanker /cargo lander it is possible to put humans on the surface and return them without any ISRU. This would allow a human crew to set up a robot facility for future missions. It might not be the best option depending on many factors but it is quite possible – I checked the basic numbers if anyone is interested.

I'm intrigued. I would think that combined payload capacity of 3 ships wouldn't be enough fuel for return. Please explain. Without fully robotic fuel production this may be the only way to guarantee a return trip for the first crew.

Offline Slarty1080

  • Full Member
  • ****
  • Posts: 962
  • UK
  • Liked: 433
  • Likes Given: 229

With three Starships, one for crew, one as an orbital tanker and one as a tanker /cargo lander it is possible to put humans on the surface and return them without any ISRU. This would allow a human crew to set up a robot facility for future missions. It might not be the best option depending on many factors but it is quite possible – I checked the basic numbers if anyone is interested.

I'm intrigued. I would think that combined payload capacity of 3 ships wouldn't be enough fuel for return. Please explain. Without fully robotic fuel production this may be the only way to guarantee a return trip for the first crew.

The trick is to refuel in orbit. Due to the nature of the rocket equation there are big savings to be had by doing this rather than trying to lift everything from the surface of Mars and return it to Earth in one stage.

The general concept was to send 3 Starships. The first is a standard crewed Starship the second is a tanker/cargo Starship. The tanker/cargo starship retanks the crewed Starship in Mars orbit and both land. The crewed Starship now has enough propellant to return to LMO where a waiting orbital tanker has sufficient propellant to retank the crewed Starship for the return to Earth and return itself. The tanker/cargo Starship if left on the surface.

I have assumed that vacuum raptors are available and used on the orbital tanker (but not the other 2) and that the orbital tanker and cargo/tanker take a long low energy trajectory to Mars whereas the crewed Starship makes a rapid transit. No ISRU and no refuelling on the surface of Mars. But at the cost of sending 3 ships to Mars and leaving one there. And also retanking all to capacity in LEO before they depart. Sending the crew on a slower trajectory would save propellant but at the cost of a longer trip.

The previous thread is here:
https://forum.nasaspaceflight.com/index.php?topic=46996.msg1890238#msg1890238
and this is a summary of the relevant bit from page 2:

I think the surface to LMO value was too low thanks for that. I have increased that in line with the value from here: http://www.angelfire.com/md/dmdventures/orbitalmech/DeltaV.htm
Although it doesn't change the picture that much except the tanker/cargo SS can now only bring 90 tons of equipment instead of 100 tons.

Dv   exhV   MassFract   DryMass   PropCargo   GrossMass  PropReq
LEO to LMO  SL raptors (tanker/cargo)                     
3800   3482   2.98       175           320           1474           1299
LEO to LMO  SL raptors (crewed)                 
7250   3482   8.02       185           0               1484           1299
LEO to LMO vac raptors (orbital tanker)                 
3800   3716   2.78        85           413            1385           1300
                 
Surface to LMO (crewed)                 
4400   3482   3.54        125           0               442             317
LMO > Earth (crewed)                 
3400   3482   2.65        125           0               332             207
LMO to Earth (orbital tanker)                 
3400   3716   2.50         85           0                212             127

(tanker/cargo SS left on the surface)   

So I believe this is profile is possible, 3 Starships, one left on the surface no surface tanking no ISRU. As to whether it’s desirable or not that's another question.
The first words spoken on Mars: "Humans have been wondering if there was any life on the planet Mars for many decades … well ... there is now!"

Offline alexterrell

  • Full Member
  • ****
  • Posts: 1658
  • Germany
  • Liked: 102
  • Likes Given: 71


I agree on all except the medical crew. I volunteer (every weekend through the winter) for a First Responder organization. While we do have medical professionals who tend to fill in teaching/certification roles, there are members from all walks of life. All the crew should get First Responder training at the bare minimum.

You might take professional surgeon, and train him up for 3 years to do one of the engineerings roles - perhaps one of the chemical based ones (ISRU equipment...). The "surgeon" role is then his second role.

A professional surgeon hopefully won't be needed. But if it is, best to have back up for the 11 first responders.

Offline niwax

  • Full Member
  • ****
  • Posts: 406
  • Germany
    • SpaceX Booster List
  • Liked: 273
  • Likes Given: 58


I agree on all except the medical crew. I volunteer (every weekend through the winter) for a First Responder organization. While we do have medical professionals who tend to fill in teaching/certification roles, there are members from all walks of life. All the crew should get First Responder training at the bare minimum.

You might take professional surgeon, and train him up for 3 years to do one of the engineerings roles - perhaps one of the chemical based ones (ISRU equipment...). The "surgeon" role is then his second role.

A professional surgeon hopefully won't be needed. But if it is, best to have back up for the 11 first responders.

The question I have is what medical procedures are actually possible on these missions. If all you have is a selection of pills and a first aid kit, it's enough to get basic training for the crew. The same way you could train a surgeon on the limited number of engineering task, you can train an engineer in the limited number of possible medical tasks. I'm sure they will have someone with a lot of medical training but neither the day-to-day workloads nor the equipment allows for it to be their main job on board.
Which booster has the most soot? SpaceX booster launch history! (discussion)

Offline Slarty1080

  • Full Member
  • ****
  • Posts: 962
  • UK
  • Liked: 433
  • Likes Given: 229
For those wanting a trauma surgeon and a paramedic, I suggest pick one and train them as the other. There should be a good degree of crossover. I suspect that there will also be a need to rethink the traditional approach to accident care on Mars. The most likely place for an injury is on the surface and in all likelihood when the paramedic/doctor/surgeon is not present so there will need to be a set of procedures that everyone is familiar with covering a range of EVA casualty situations, for example:

Are they conscious? Can they walk? Has their suit been punctured and if so is it a major or minor rupture? And various combinations of these possibilities and others. In many cases returning the injured crew member to the Starship or pressurised rover as quickly as possible will be the only real option. Triage on the surface is probably limited to emergency patches to prevent excessive decompression and loss of oxygen before they can get inside. Once inside the Starship the medical person can take over or if the casualty is in a rover can at least give advice.

Hobbling back to a Starship crane/lift is one thing but there will need to be an emergency provision on the pressurised rovers as well to make it easy to get an injured crew person back on board. 
The first words spoken on Mars: "Humans have been wondering if there was any life on the planet Mars for many decades … well ... there is now!"

Offline geza

  • Full Member
  • ***
  • Posts: 302
  • Budapest
    • Géza Meszéna's web page
  • Liked: 130
  • Likes Given: 38
Several of you argued convincingly that there is no need for a medical doctor.

What do yo think about a medical scientist, instead? A human factors expert, if you wish.

Human performance is probably the biggest unknown here. Martian gravity? Mental health? Diet? Group dynamics? Ergonomy? Wouldn't be a good idea to have a person, who has a serious backround in space medicine and psychiatry, for studying the human situation? He/she can have practical tasks, as analysing blood samples, or treating ill crew members, but this is not the point. Anybody can be trained for these things. The point is that he/she may be able to recognize emerging issues, medical or psychological, early on. SpaceX needs human factors experts for crew selection and training, anyway. Why don't send one of them to Mars to study the outcome and report back his/her learned lessons for the benefit of the next crew selection/training?

Offline envy887

  • Senior Member
  • *****
  • Posts: 5548
  • Liked: 3354
  • Likes Given: 1647
Several of you argued convincingly that there is no need for a medical doctor.

What do yo think about a medical scientist, instead? A human factors expert, if you wish.

Human performance is probably the biggest unknown here. Martian gravity? Mental health? Diet? Group dynamics? Ergonomy? Wouldn't be a good idea to have a person, who has a serious backround in space medicine and psychiatry, for studying the human situation? He/she can have practical tasks, as analysing blood samples, or treating ill crew members, but this is not the point. Anybody can be trained for these things. The point is that he/she may be able to recognize emerging issues, medical or psychological, early on. SpaceX needs human factors experts for crew selection and training, anyway. Why don't send one of them to Mars to study the outcome and report back his/her learned lessons for the benefit of the next crew selection/training?

I disagree. If there is an actual medical emergency there is no replacement for an experienced medical doctor's abilities. Not just a hospital surgeon, but someone like a military surgeon who has experience treating complex injuries under combat situations with limited front-line equipment and facilities. Active military service is almost certainly the best place to get the experience necessary for the physical and psychological environments on an early Mars expedition.

It's a lot easier to train a medical doctor in biology and psychology than the other way around.

Offline Slarty1080

  • Full Member
  • ****
  • Posts: 962
  • UK
  • Liked: 433
  • Likes Given: 229
Several of you argued convincingly that there is no need for a medical doctor.

What do yo think about a medical scientist, instead? A human factors expert, if you wish.

Human performance is probably the biggest unknown here. Martian gravity? Mental health? Diet? Group dynamics? Ergonomy? Wouldn't be a good idea to have a person, who has a serious backround in space medicine and psychiatry, for studying the human situation? He/she can have practical tasks, as analysing blood samples, or treating ill crew members, but this is not the point. Anybody can be trained for these things. The point is that he/she may be able to recognize emerging issues, medical or psychological, early on. SpaceX needs human factors experts for crew selection and training, anyway. Why don't send one of them to Mars to study the outcome and report back his/her learned lessons for the benefit of the next crew selection/training?

Yes another interesting angle. I think there needs to be a medic of some sort and a backup medic (competent but not an expert). As to the nature of the medic, people have argued for paramedics and trauma surgeons and now we have human factors as well.

If it was me I would take a paramedic and put them through specific training in likely needed surgical procedures as well as psychological factors and run with that. The backup would be an engineer with medical knowledge and specialist training. The whole crew would need training in first aid, dealing with decompression and emergency procedures for getting injured crew members back inside.
The first words spoken on Mars: "Humans have been wondering if there was any life on the planet Mars for many decades … well ... there is now!"

Offline Slarty1080

  • Full Member
  • ****
  • Posts: 962
  • UK
  • Liked: 433
  • Likes Given: 229
Several of you argued convincingly that there is no need for a medical doctor.

What do yo think about a medical scientist, instead? A human factors expert, if you wish.

Human performance is probably the biggest unknown here. Martian gravity? Mental health? Diet? Group dynamics? Ergonomy? Wouldn't be a good idea to have a person, who has a serious backround in space medicine and psychiatry, for studying the human situation? He/she can have practical tasks, as analysing blood samples, or treating ill crew members, but this is not the point. Anybody can be trained for these things. The point is that he/she may be able to recognize emerging issues, medical or psychological, early on. SpaceX needs human factors experts for crew selection and training, anyway. Why don't send one of them to Mars to study the outcome and report back his/her learned lessons for the benefit of the next crew selection/training?

I disagree. If there is an actual medical emergency there is no replacement for an experienced medical doctor's abilities. Not just a hospital surgeon, but someone like a military surgeon who has experience treating complex injuries under combat situations with limited front-line equipment and facilities. Active military service is almost certainly the best place to get the experience necessary for the physical and psychological environments on an early Mars expedition.

It's a lot easier to train a medical doctor in biology and psychology than the other way around.

Or a paramedic could be trained in trauma surgery and psychology. Ultimately it probably doesn't matter exactly. The long and short of it is the medic needs to be able to deal effectively with acute medical emergencies on the spot in the same way that a paramedic or military surgeon. Other medical expert’s detailed knowledge of chronic issues can come from Earth minutes or even hours later.
The first words spoken on Mars: "Humans have been wondering if there was any life on the planet Mars for many decades … well ... there is now!"

Offline Slarty1080

  • Full Member
  • ****
  • Posts: 962
  • UK
  • Liked: 433
  • Likes Given: 229
All this talk of medics got me thinking that the medic might well not be available where the casualty is. So here’s a situation to test out the crew and equipment set up:

Crew of 2 go out 20 miles in the pressurised rover and go EVA. One of them has an accident, gets their leg trapped and falls awkwardly onto some sharp rock and badly punctures their suit and also breaks a leg. Not likely, but not beyond the realms of possibility either.

Assuming the second crew member is on hand to give assistance and emergency patches had been applied to the tear as soon as possible, the first problem is getting the casualty back to the rover. How does this happen if the injured person is unconscious?

Thoughts - that it would not be possible for one to carry the other. So is there any point or necessity to have something like a basic skeleton porters trolley with a pair of wheels that could be used to enable the casualty to be pulled back to the rover? Would this be impractical or is the eventuality unlikely enough as to be dismissed?

Assume they get back to the rover how do they get back inside?

Thoughts – perhaps an emergency entrance would be needed. The rover would be rapidly depressurised the door opened both crew climb, crawl or are dragged in, the door is shut and the rover re-pressurized? Or is it likely that only an airlock or suitlocks are available?

Assuming they get back inside and the rover is pressurised. The casualty can presumably get some first aid from the other crew member and advice from the medic via radio. What kit do they have in the rover? Assuming the second crew member can drive it back to the Starship how would that casualty then be returned into the ship. Assuming that the casualty is stable but unconscious and their suit is damaged beyond use?

Thoughts – would it be useful to carry a large bag with oxygen and a CO2 removal canister good for half an hour so that the casualty suit and all could be bagged and then transferred via the emergency hatch back into the ship – presumably 2-3 others would be able to manhandle/carry or otherwise support the casualty in such a way as to get them back inside.

Further questions how much room in the airlocks and how much room on the lift? Enough for 1 person or 2 or more?
The first words spoken on Mars: "Humans have been wondering if there was any life on the planet Mars for many decades … well ... there is now!"

Tags: