SpaceX Principle Mars Development Engineer gave some more details about Mars colonization

SpaceX plans to live out of the BFS ships initially on Mars and then build out the facilities (habitation, power systems, mining and landing pads).

The SpaceX BFS (Big Falcon Spaceship) would land on Mars with 100 tons including the ship.

Paul Wooster, SpaceX Principal Mars Development Engineer, presented to the Mars Society.

133 thoughts on “SpaceX Principle Mars Development Engineer gave some more details about Mars colonization”

  1. I would think that it will be easier in the beginning to bring the second stage to earth GEO first instead of LEO after launch and fuel it there. It will take more launched to fuel the ship but it will have more fuel to reach Mars and enough to re-lauanch from Mars back to earth as the more fuel to reach GEO instead of LEO is supplemented during the fueling.

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  2. Yeah, 15 tons payload makes not much sense given there are rockets they already have (Falcon Heavy) that could do that, without the reusability part (and requiring the cost of a lander). The stated payload is 100-150 tons, depending on the slideshow you see. Probably this last one has become more conservative.

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  3. A) Profits from Falcon 9. B) You. (When you buy access through Musk’s proposed Starlink satellite internet services company…at least that’s the plan)

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  4. Well, the ship does include living space, so it’s not as bad as all that, but, yes, clearly you need maximum utilization of native resources to make this practical, because getting to other planets is really marginal using chemical propulsion. Having a specialized vehicle for each stage of the trip, the BFR to orbit, something low thrust high ISP for transfer to Mars, then a specialized landing vehicle at Mars, would allow a considerably higher payload fraction. But engineering is a limited resource, too. SpaceX decided to use just one vehicle, with one propellant mix, to conserve THAT resource.

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  5. With almost no atmosphere there, micro meteorites (and largers ones) might punch holes in large structures such as a BFR, the chance of hitting a mars rover is small, huge ships is a different story. It would also be interesting to see, 4 years of radiation in the early ships, will they be able to handle that ?.

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  6. Apparently BFS can land 100t – but that includes the ship itself (85t dry mass), per an answer given at “https://twitter.com/MaxLenormand/status/1033398329097383936” Not much actual payload?!?

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  7. It’s 100-150 tons *to LEO* (usually stated as 150 the slide here says 100 with full reuse). They’re planning to refuel in orbit but the total delta-v from LEO to Mars surface is 10.7 km/s according to wikipedia /wiki/Delta-v_budget#Interplanetary vs 9-10 km/s from Earth surface to LEO. The Mars trip is single-stage too so they don’t get staging benefits like they do during launch from Earth. So even if they fully refuel the BFS the payload to Mars will likely be smaller.You also need to consider whether it’s cargo BFS or crew BFS. The crew version has more facilities on-board but less cargo capacity. But you can count the on-board facilities and crew against the 100+ total tons of payload.

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  8. I would think that it will be easier in the beginning to bring the second stage to earth GEO first instead of LEO after launch and fuel it there. It will take more launched to fuel the ship but it will have more fuel to reach Mars and enough to re-lauanch from Mars back to earth as the more fuel to reach GEO instead of LEO is supplemented during the fueling.

    Reply
  9. Yeah 15 tons payload makes not much sense given there are rockets they already have (Falcon Heavy) that could do that without the reusability part (and requiring the cost of a lander).The stated payload is 100-150 tons depending on the slideshow you see. Probably this last one has become more conservative.

    Reply
  10. A) Profits from Falcon 9.B) You. (When you buy access through Musk’s proposed Starlink satellite internet services company…at least that’s the plan)

    Reply
  11. Well the ship does include living space so it’s not as bad as all that but yes clearly you need maximum utilization of native resources to make this practical because getting to other planets is really marginal using chemical propulsion.Having a specialized vehicle for each stage of the trip the BFR to orbit something low thrust high ISP for transfer to Mars then a specialized landing vehicle at Mars would allow a considerably higher payload fraction. But engineering is a limited resource too. SpaceX decided to use just one vehicle with one propellant mix to conserve THAT resource.

    Reply
  12. With almost no atmosphere there micro meteorites (and largers ones) might punch holes in large structures such as a BFR the chance of hitting a mars rover is small huge ships is a different story.It would also be interesting to see 4 years of radiation in the early ships will they be able to handle that ?.

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  13. Apparently BFS can land 100t – but that includes the ship itself (85t dry mass) per an answer given athttps://twitter.com/MaxLenormand/status/1033398329097383936″”Not much actual payload?!?”””

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  14. Indeed. The manned landers will have significant less payload (things that aren’t attached to the ship + people) because they will include the living quarters, life systems and people. The cargo ones can have more given they can be empty of any such things and just carry the cargo (pressurized or not). All this makes me think that BFR’s payload profile would be ideal for construction and resupply of of orbital facilities. I think we have to significantly expand our presence in orbit and over cislunar space before we try our hand on Mars and other faraway places.

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  15. Any discussion of orbital refueling should include mention of this idea toughsf blogspot com/2017/09/low-earth-orbit-atmospheric-scoops.html (lets see if replacing dots with spaces gets around Vukkles deficiencies)

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  16. All these Mars plans are contingent on successful development of the Raptor engine. I’d like to see an update on Raptor.

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  17. SpaceX should take tankers to a low orbit, transfer to a purpose built unmanned orbital tug, that would indeed be nothing but controls, fittings to attach to tankage, or othe freight, and te highest ISP engine they can manage. That engine might be ion, if the timeline allows for it. The Mars ship would fill it’s tanks at the highest possible orbit. It may make sense to fill it’s tanks in LEO, and top them off just before leaving the earth, moon system.

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  18. It’s 100-150 tons *to LEO* (usually stated as 150, the slide here says 100 with full reuse). They’re planning to refuel in orbit, but the total delta-v from LEO to Mars surface is 10.7 km/s according to wikipedia /wiki/Delta-v_budget#Interplanetary , vs 9-10 km/s from Earth surface to LEO. The Mars trip is single-stage too, so they don’t get staging benefits, like they do during launch from Earth. So even if they fully refuel the BFS, the payload to Mars will likely be smaller. You also need to consider whether it’s cargo BFS or crew BFS. The crew version has more facilities on-board, but less cargo capacity. But you can count the on-board facilities and crew against the 100+ total tons of payload.

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  19. Indeed. The manned landers will have significant less payload (things that aren’t attached to the ship + people) because they will include the living quarters life systems and people.The cargo ones can have more given they can be empty of any such things and just carry the cargo (pressurized or not).All this makes me think that BFR’s payload profile would be ideal for construction and resupply of of orbital facilities. I think we have to significantly expand our presence in orbit and over cislunar space before we try our hand on Mars and other faraway places.

    Reply
  20. Any discussion of orbital refueling should include mention of this ideatoughsf blogspot com/2017/09/low-earth-orbit-atmospheric-scoops.html(lets see if replacing dots with spaces gets around Vukkles deficiencies)

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  21. All these Mars plans are contingent on successful development of the Raptor engine. I’d like to see an update on Raptor.

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  22. SpaceX should take tankers to a low orbit transfer to a purpose built unmanned orbital tug that would indeed be nothing but controls fittings to attach to tankage or othe freight and te highest ISP engine they can manage. That engine might be ion if the timeline allows for it.The Mars ship would fill it’s tanks at the highest possible orbit. It may make sense to fill it’s tanks in LEO and top them off just before leaving the earth moon system.

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  23. They’ll put a solar power satellite up in orbit, and just use rectennas at the colony. With enough local nukes to cover absolute minimum emergency power levels.

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  24. They’ll put a solar power satellite up in orbit and just use rectennas at the colony. With enough local nukes to cover absolute minimum emergency power levels.

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  25. Over at Instapundit one of the judges for that recent Mars habitat competition left a couple of comments. He confirmed that it was basically just a CGI contest, and almost all the entries were total fantasy. Wish I’d known about it in time, I might have tried to create a realistic entry. But I’d have been guaranteed to lose: Apparently their criteria ruled out underground habitats.

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  26. Over at Instapundit one of the judges for that recent Mars habitat competition left a couple of comments. He confirmed that it was basically just a CGI contest and almost all the entries were total fantasy.Wish I’d known about it in time I might have tried to create a realistic entry.But I’d have been guaranteed to lose: Apparently their criteria ruled out underground habitats.

    Reply
  27. Over at Instapundit one of the judges for that recent Mars habitat competition left a couple of comments. He confirmed that it was basically just a CGI contest, and almost all the entries were total fantasy.

    Wish I’d known about it in time, I might have tried to create a realistic entry.

    But I’d have been guaranteed to lose: Apparently their criteria ruled out underground habitats.

    Reply
  28. I still don’t get why you think both moon and Mars (and more) can’t reasonably be done. There won’t just be one or two BFS. So there shouldn’t be a shortage, and the more SpaceX builds, the cheaper and better they’ll likely get. So what if a handful of them get tied up on 1 or 2 year Mars missions? Do you foresee demand to build a huge lunar base or lots of bases? How would that be financed? Lunar water mining? Why would the profits from mining flow to those building and staffing the lunar science bases or colonies? I suspect Musk/SpaceX could be the first to undertake the investment in mining, as a way to move past launching 3 or 4 fuel tankers from Earth for every Mars mission – especially since he’ll need the fuel factory to produce methane, not just hydrogen.

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  29. I still don’t get why you think both moon and Mars (and more) can’t reasonably be done. There won’t just be one or two BFS. So there shouldn’t be a shortage and the more SpaceX builds the cheaper and better they’ll likely get. So what if a handful of them get tied up on 1 or 2 year Mars missions? Do you foresee demand to build a huge lunar base or lots of bases? How would that be financed? Lunar water mining? Why would the profits from mining flow to those building and staffing the lunar science bases or colonies? I suspect Musk/SpaceX could be the first to undertake the investment in mining as a way to move past launching 3 or 4 fuel tankers from Earth for every Mars mission – especially since he’ll need the fuel factory to produce methane not just hydrogen.

    Reply
  30. I still don’t get why you think both moon and Mars (and more) can’t reasonably be done.

    There won’t just be one or two BFS. So there shouldn’t be a shortage, and the more SpaceX builds, the cheaper and better they’ll likely get. So what if a handful of them get tied up on 1 or 2 year Mars missions? Do you foresee demand to build a huge lunar base or lots of bases?

    How would that be financed? Lunar water mining? Why would the profits from mining flow to those building and staffing the lunar science bases or colonies? I suspect Musk/SpaceX could be the first to undertake the investment in mining, as a way to move past launching 3 or 4 fuel tankers from Earth for every Mars mission – especially since he’ll need the fuel factory to produce methane, not just hydrogen.

    Reply
  31. ” Solar will kill you on Mars. ” <-- No, it will not. It's availability on Mars is a known well characterized quantity. " The Opportunity rover was just k-o'd by a long dust storm. " <-- After lasting on solar about 60 times longer than it was planned to... Of course there will also be nuclear on Mars, but that is no excuse to tell hysterical lies about solar.

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  32. > ” That means that the dollar cost to put something on the Moon is 10 to 30 times less than the cost to put it on Mars because the payload needs to pay off the BFS.” Generally true, but if they’re operating multiple rockets at a non-negligible profit margin, they can run some missions at a loss. Furthermore, if it takes 50 missions to pay off the fixed costs (hardware etc), and the lifetime is 100 missions, then the last 50 just need to cover the variable costs (operations, fuel, etc). > “use Lunar Oxygen and just bring enough Methane …” There are 3 options to use Lunar oxygen: 1. Split lunar water. Fairly easy, leaves hydrogen. 2. Direct electro-reduction of Lunar oxides. Probably harder, leaves metals and partially reduced oxides. 3. Split water, use the hydrogen to reduce oxides. Intermediate, recovers the water. Either way, you’ll need equipment to cryogenically cool and liquefy the oxygen, which can also be used to liquefy hydrogen or methane. So unless you choose to go with option 2, you’d already have all the equipment to make hydrolox, and almost all the equipment to make methalox. The only thing you’d be missing is a methane generator. In that case, you may as well bring only the carbon, and make the methane in-situ. That would give you even more cargo capacity, at least until you hit volume limits.

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  33. > That means that the dollar cost to put something on the Moon is 10 to 30 times less than the cost to put it on Mars because the payload needs to pay off the BFS.””Generally true”” but if they’re operating multiple rockets at a non-negligible profit margin they can run some missions at a loss. Furthermore if it takes 50 missions to pay off the fixed costs (hardware etc) and the lifetime is 100 missions then the last 50 just need to cover the variable costs (operations fuel”” etc).> “”””use Lunar Oxygen and just bring enough Methane …””””There are 3 options to use Lunar oxygen:1. Split lunar water. Fairly easy”” leaves hydrogen.2. Direct electro-reduction of Lunar oxides. Probably harder leaves metals and partially reduced oxides.3. Split water use the hydrogen to reduce oxides. Intermediate recovers the water.Either way you’ll need equipment to cryogenically cool and liquefy the oxygen which can also be used to liquefy hydrogen or methane. So unless you choose to go with option 2 you’d already have all the equipment to make hydrolox and almost all the equipment to make methalox. The only thing you’d be missing is a methane generator.In that case you may as well bring only the carbon and make the methane in-situ. That would give you even more cargo capacity”” at least until you hit volume limits.”””

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  34. They’ll be using a bunch of their power to make methalox to refuel the BFS. If solar is unavailable and the batteries are getting empty, they could run that methalox through a generator for a while. Not sure how long it’ll last but maybe long enough to survive the dust storm with minimal life support and other critical systems. Nuclear is better, but a practical Mars-ready reactor may not be available for a while. Opportunity survived for 14 years on solar and batteries.

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  35. They’ll be using a bunch of their power to make methalox to refuel the BFS. If solar is unavailable and the batteries are getting empty they could run that methalox through a generator for a while. Not sure how long it’ll last but maybe long enough to survive the dust storm with minimal life support and other critical systems.Nuclear is better but a practical Mars-ready reactor may not be available for a while. Opportunity survived for 14 years on solar and batteries.

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  36. In terms of kg landed on a celestial body the Moon is superior to Mars. The transit time is 3 days vs 30-90 days for Mars. That means a single BFS can (amortized over its lifetime) land 10x-30x more stuff. That means that the dollar cost to put something on the Moon is 10 to 30 times less than the cost to put it on Mars because the payload needs to pay off the BFS. That’s a HUGE difference. For the Moon you can do ISRU to use Lunar Oxygen and just bring enough Methane to get you from the surface of the Moon and back to Earth.

    Reply
  37. In terms of kg landed on a celestial body the Moon is superior to Mars. The transit time is 3 days vs 30-90 days for Mars. That means a single BFS can (amortized over its lifetime) land 10x-30x more stuff. That means that the dollar cost to put something on the Moon is 10 to 30 times less than the cost to put it on Mars because the payload needs to pay off the BFS.That’s a HUGE difference. For the Moon you can do ISRU to use Lunar Oxygen and just bring enough Methane to get you from the surface of the Moon and back to Earth.

    Reply
  38. For the umpteenth billion time, don’t waste mass on shipping glass for domes to Mars. It just gets a coating of dust. It doesn’t shield against radiation. You don’t need to grow food using dim sunlight. Dig tunnels underground, live underground or in capped and covered (in dirt) craters, and grow food with LEDs. Mass sent to Mars is expensive, don’t waste it on bulk glass.

    Reply
  39. For the umpteenth billion time don’t waste mass on shipping glass for domes to Mars. It just gets a coating of dust. It doesn’t shield against radiation. You don’t need to grow food using dim sunlight.Dig tunnels underground live underground or in capped and covered (in dirt) craters and grow food with LEDs.Mass sent to Mars is expensive don’t waste it on bulk glass.

    Reply
  40. Nah SpaceX charges 80% of ULA prices even though their rockets cost 30% of ULA rockets. So SpaceX is quite profitable because it is competing against Larry, Moe, and Curly.

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  41. Nah SpaceX charges 80{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} of ULA prices even though their rockets cost 30{22800fc54956079738b58e74e4dcd846757aa319aad70fcf90c97a58f3119a12} of ULA rockets.So SpaceX is quite profitable because it is competing against Larry Moe and Curly.

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  42. Solar will kill you on Mars. As in literally dead. The problem is sunlight that is diffuse which is compounded by month long dust storms. What happens on Mars when you turn the power off for a month? That’s right you die. The Opportunity rover was just k-o’d by a long dust storm. Go nuclear and stay warm and alive.

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  43. Solar will kill you on Mars. As in literally dead.The problem is sunlight that is diffuse which is compounded by month long dust storms. What happens on Mars when you turn the power off for a month? That’s right you die. The Opportunity rover was just k-o’d by a long dust storm.Go nuclear and stay warm and alive.

    Reply
  44. SpaceX decided to use just one vehicle, with one propellant mix, to conserve THAT resource. ” For the time being. It is not likely that the effort will in 10 years time be ongoing with the same vehicles with which it is begun.

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  45. SpaceX decided to use just one vehicle with one propellant mix” to conserve THAT resource. “”For the time being. It is not likely that the effort will in 10 years time be ongoing with the same vehicles with which it is begun.”””

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  46. Why are pretending the incident radiation to, at and from Mars is an unknown? It is well characterized and quite manageable. So is micro gravity during travel. What is not known is how much better than micro-gravity is Mars gravity–but that it is better is a certainty. BFR is current state of the art, it involves no new physics or unpracticed engineering. Albeit, F9’s were the flight article which only recently reduced re-usability in boosters to practice.

    Reply
  47. Why are pretending the incident radiation to at and from Mars is an unknown? It is well characterized and quite manageable. So is micro gravity during travel. What is not known is how much better than micro-gravity is Mars gravity–but that it is better is a certainty.BFR is current state of the art it involves no new physics or unpracticed engineering. Albeit F9’s were the flight article which only recently reduced re-usability in boosters to practice.

    Reply
  48. Once they have the Sabatier reactor in place and operational, going back should be possible in principle. You’d still probably need to get the timing right, so emergency return could still be impossible. But as Brett said, the general plan is for a one-way trip, and early colonists will both understand and accept that (that may indeed be a selection criterion for the program). On mobility, there are two opposing effects. On the one hand, there will likely be some muscle degeneration during the trip, but there are ways to reduce that, as employed on the ISS. Depending on the length of the trip, it may not be too bad, and we have some data for that from ISS and earlier astronauts. SpaceX want to keep the trip as short as possible, which helps both with muscle degeneration and radiation exposure. On the other hand, Mars’ gravity is lower. Generally, that would make walking etc difficult, but it’s more than twice the gravity on the Moon, and we know that astronauts can walk around on the Moon (awkwardly). But the lower gravity may just cancel out with the muscle degeneration, so walking may well be about as easy as on Earth. The bigger trouble is brain motor adjustment (the brain gets used to weightlessness), but that should recover partially within hours and fully within probably a few days of arrival.

    Reply
  49. Once they have the Sabatier reactor in place and operational going back should be possible in principle. You’d still probably need to get the timing right so emergency return could still be impossible. But as Brett said the general plan is for a one-way trip and early colonists will both understand and accept that (that may indeed be a selection criterion for the program).On mobility there are two opposing effects. On the one hand there will likely be some muscle degeneration during the trip but there are ways to reduce that as employed on the ISS. Depending on the length of the trip it may not be too bad and we have some data for that from ISS and earlier astronauts. SpaceX want to keep the trip as short as possible which helps both with muscle degeneration and radiation exposure.On the other hand Mars’ gravity is lower. Generally that would make walking etc difficult but it’s more than twice the gravity on the Moon and we know that astronauts can walk around on the Moon (awkwardly). But the lower gravity may just cancel out with the muscle degeneration so walking may well be about as easy as on Earth. The bigger trouble is brain motor adjustment (the brain gets used to weightlessness) but that should recover partially within hours and fully within probably a few days of arrival.

    Reply
  50. > ” That means that the dollar cost to put something on the Moon is 10 to 30 times less than the cost to put it on Mars because the payload needs to pay off the BFS.”

    Generally true, but if they’re operating multiple rockets at a non-negligible profit margin, they can run some missions at a loss. Furthermore, if it takes 50 missions to pay off the fixed costs (hardware etc), and the lifetime is 100 missions, then the last 50 just need to cover the variable costs (operations, fuel, etc).
    > “use Lunar Oxygen and just bring enough Methane …”

    There are 3 options to use Lunar oxygen:
    1. Split lunar water. Fairly easy, leaves hydrogen.
    2. Direct electro-reduction of Lunar oxides. Probably harder, leaves metals and partially reduced oxides.
    3. Split water, use the hydrogen to reduce oxides. Intermediate, recovers the water.

    Either way, you’ll need equipment to cryogenically cool and liquefy the oxygen, which can also be used to liquefy hydrogen or methane. So unless you choose to go with option 2, you’d already have all the equipment to make hydrolox, and almost all the equipment to make methalox. The only thing you’d be missing is a methane generator.

    In that case, you may as well bring only the carbon, and make the methane in-situ. That would give you even more cargo capacity, at least until you hit volume limits.

    Reply
  51. Lots of good long term ideas – but SpaceX has figured out something important that NASA never has – do more with less, even if that isn’t nearly as ‘efficient’, and you’ll actually get things done.

    Reply
  52. Lots of good long term ideas – but SpaceX has figured out something important that NASA never has – do more with less even if that isn’t nearly as ‘efficient’ and you’ll actually get things done.

    Reply
  53. …we have to significantly expand our presence in orbit and over cislunar space before we try our hand on Mars…” Why? I’m not saying there isn’t value in those things, but why wait on Mars? If you want to go to Mars, the best way to learn the most about it is to send uncrewed ships to Mars first. Of course, there are lots who don’t want to go to Mars, which is fine, since both can be done.

    Reply
  54. …we have to significantly expand our presence in orbit and over cislunar space before we try our hand on Mars…””Why? I’m not saying there isn’t value in those things”” but why wait on Mars? If you want to go to Mars the best way to learn the most about it is to send uncrewed ships to Mars first.Of course there are lots who don’t want to go to Mars which is fine”” since both can be done.”””

    Reply
  55. They’ll be using a bunch of their power to make methalox to refuel the BFS. If solar is unavailable and the batteries are getting empty, they could run that methalox through a generator for a while. Not sure how long it’ll last but maybe long enough to survive the dust storm with minimal life support and other critical systems.

    Nuclear is better, but a practical Mars-ready reactor may not be available for a while. Opportunity survived for 14 years on solar and batteries.

    Reply
  56. In terms of kg landed on a celestial body the Moon is superior to Mars. The transit time is 3 days vs 30-90 days for Mars. That means a single BFS can (amortized over its lifetime) land 10x-30x more stuff. That means that the dollar cost to put something on the Moon is 10 to 30 times less than the cost to put it on Mars because the payload needs to pay off the BFS.

    That’s a HUGE difference. For the Moon you can do ISRU to use Lunar Oxygen and just bring enough Methane to get you from the surface of the Moon and back to Earth.

    Reply
  57. For the umpteenth billion time, don’t waste mass on shipping glass for domes to Mars. It just gets a coating of dust. It doesn’t shield against radiation. You don’t need to grow food using dim sunlight.

    Dig tunnels underground, live underground or in capped and covered (in dirt) craters, and grow food with LEDs.

    Mass sent to Mars is expensive, don’t waste it on bulk glass.

    Reply
  58. Solar will kill you on Mars. As in literally dead.

    The problem is sunlight that is diffuse which is compounded by month long dust storms. What happens on Mars when you turn the power off for a month? That’s right you die. The Opportunity rover was just k-o’d by a long dust storm.

    Go nuclear and stay warm and alive.

    Reply
  59. ” SpaceX decided to use just one vehicle, with one propellant mix, to conserve THAT resource. ”

    For the time being. It is not likely that the effort will in 10 years time be ongoing with the same vehicles with which it is begun.

    Reply
  60. Why are pretending the incident radiation to, at and from Mars is an unknown? It is well characterized and quite manageable. So is micro gravity during travel. What is not known is how much better than micro-gravity is Mars gravity–but that it is better is a certainty.

    BFR is current state of the art, it involves no new physics or unpracticed engineering. Albeit, F9’s were the flight article which only recently reduced re-usability in boosters to practice.

    Reply
  61. Ion engines are very weak at present. I don’t think it can contribute anything useful. A solar sail would do more, but that again would be too weak to really be useful.

    Reply
  62. Ion engines are very weak at present. I don’t think it can contribute anything useful. A solar sail would do more but that again would be too weak to really be useful.

    Reply
  63. Once they have the Sabatier reactor in place and operational, going back should be possible in principle. You’d still probably need to get the timing right, so emergency return could still be impossible. But as Brett said, the general plan is for a one-way trip, and early colonists will both understand and accept that (that may indeed be a selection criterion for the program).

    On mobility, there are two opposing effects. On the one hand, there will likely be some muscle degeneration during the trip, but there are ways to reduce that, as employed on the ISS. Depending on the length of the trip, it may not be too bad, and we have some data for that from ISS and earlier astronauts. SpaceX want to keep the trip as short as possible, which helps both with muscle degeneration and radiation exposure.

    On the other hand, Mars’ gravity is lower. Generally, that would make walking etc difficult, but it’s more than twice the gravity on the Moon, and we know that astronauts can walk around on the Moon (awkwardly). But the lower gravity may just cancel out with the muscle degeneration, so walking may well be about as easy as on Earth. The bigger trouble is brain motor adjustment (the brain gets used to weightlessness), but that should recover partially within hours and fully within probably a few days of arrival.

    Reply
  64. On this topic, while a good bolo system requires a heavy mass at its center, and for the Earth system that would have to be launched mass or a captured NEO asteroid, for the Mars end of the trip it might be feasible to anchor a bolo to one of the Martian moons. The’ve got plenty of momentum. I’m not sure they’re in a suitable orbit, though.

    Reply
  65. On this topic while a good bolo system requires a heavy mass at its center and for the Earth system that would have to be launched mass or a captured NEO asteroid for the Mars end of the trip it might be feasible to anchor a bolo to one of the Martian moons. The’ve got plenty of momentum. I’m not sure they’re in a suitable orbit though.

    Reply
  66. I’d suggest a bolo system as part of the mission architecture. That would allow high ISP low thrust momentum to be banked, and then transferred rapidly to the ship, so that the low thrust wouldn’t stretch the trip time. It would be useful for boosting from LEO to geosynch, and for providing at least part of the delta v to head off to Mars.

    Reply
  67. I’d suggest a bolo system as part of the mission architecture. That would allow high ISP low thrust momentum to be banked and then transferred rapidly to the ship so that the low thrust wouldn’t stretch the trip time. It would be useful for boosting from LEO to geosynch and for providing at least part of the delta v to head off to Mars.

    Reply
  68. Oh, I expect the timeline to slip. But you don’t get there on time by planning to get there late. I was really expecting that coming back, outside of a serious emergency early in the program, was not in the cards. SpaceX would not lack for colonists willing to take one way trips, given a promise of adequate support.

    Reply
  69. Oh I expect the timeline to slip. But you don’t get there on time by planning to get there late.I was really expecting that coming back outside of a serious emergency early in the program was not in the cards. SpaceX would not lack for colonists willing to take one way trips given a promise of adequate support.

    Reply
  70. Don’t get your hopes up since harsh reality will change the timelines. To me there are a few unknowns: Radiation exposure on the Earth to Mars leg. The effect of weightlessness on mobility on Mars. The fact that coming back might not be an option. Anything more that the BFR would be too much to develop in a short time frame a decade or two. I expect them to use current state of the art technology.

    Reply
  71. Don’t get your hopes up since harsh reality will change the timelines. To me there are a few unknowns: Radiation exposure on the Earth to Mars leg. The effect of weightlessness on mobility on Mars. The fact that coming back might not be an option. Anything more that the BFR would be too much to develop in a short time frame a decade or two. I expect them to use current state of the art technology.

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  72. Exactly! There is a clear red thread in the Musk endeavours. The tech they are developing can be reused for the Mars project. Solar power, batteries, electric vehicles etc. I don’t know about the flame thrower… They used flame throwers in Alien didn’t they?

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  73. Exactly!There is a clear red thread in the Musk endeavours. The tech they are developing can be reused for the Mars project. Solar power batteries electric vehicles etc.I don’t know about the flame thrower…They used flame throwers in Alien didn’t they?

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  74. Lots of good long term ideas – but SpaceX has figured out something important that NASA never has – do more with less, even if that isn’t nearly as ‘efficient’, and you’ll actually get things done.

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  75. “…we have to significantly expand our presence in orbit and over cislunar space before we try our hand on Mars…”
    Why? I’m not saying there isn’t value in those things, but why wait on Mars?
    If you want to go to Mars, the best way to learn the most about it is to send uncrewed ships to Mars first.
    Of course, there are lots who don’t want to go to Mars, which is fine, since both can be done.

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  76. On this topic, while a good bolo system requires a heavy mass at its center, and for the Earth system that would have to be launched mass or a captured NEO asteroid, for the Mars end of the trip it might be feasible to anchor a bolo to one of the Martian moons. The’ve got plenty of momentum. I’m not sure they’re in a suitable orbit, though.

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  77. I’d suggest a bolo system as part of the mission architecture. That would allow high ISP low thrust momentum to be banked, and then transferred rapidly to the ship, so that the low thrust wouldn’t stretch the trip time. It would be useful for boosting from LEO to geosynch, and for providing at least part of the delta v to head off to Mars.

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  78. Oh, I expect the timeline to slip. But you don’t get there on time by planning to get there late.

    I was really expecting that coming back, outside of a serious emergency early in the program, was not in the cards. SpaceX would not lack for colonists willing to take one way trips, given a promise of adequate support.

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  79. Don’t get your hopes up since harsh reality will change the timelines. To me there are a few unknowns:
    Radiation exposure on the Earth to Mars leg. The effect of weightlessness on mobility on Mars. The fact that coming back might not be an option.

    Anything more that the BFR would be too much to develop in a short time frame a decade or two. I expect them to use current state of the art technology.

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  80. Exactly!
    There is a clear red thread in the Musk endeavours. The tech they are developing can be reused for the Mars project. Solar power, batteries, electric vehicles etc.

    I don’t know about the flame thrower…
    They used flame throwers in Alien didn’t they?

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  81. Indeed. The manned landers will have significant less payload (things that aren’t attached to the ship + people) because they will include the living quarters, life systems and people.

    The cargo ones can have more given they can be empty of any such things and just carry the cargo (pressurized or not).

    All this makes me think that BFR’s payload profile would be ideal for construction and resupply of of orbital facilities. I think we have to significantly expand our presence in orbit and over cislunar space before we try our hand on Mars and other faraway places.

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  82. Any discussion of orbital refueling should include mention of this idea
    toughsf blogspot com/2017/09/low-earth-orbit-atmospheric-scoops.html
    (lets see if replacing dots with spaces gets around Vukkles deficiencies)

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  83. SpaceX should take tankers to a low orbit, transfer to a purpose built unmanned orbital tug, that would indeed be nothing but controls, fittings to attach to tankage, or othe freight, and te highest ISP engine they can manage. That engine might be ion, if the timeline allows for it.
    The Mars ship would fill it’s tanks at the highest possible orbit. It may make sense to fill it’s tanks in LEO, and top them off just before leaving the earth, moon system.

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  84. It’s 100-150 tons *to LEO* (usually stated as 150, the slide here says 100 with full reuse). They’re planning to refuel in orbit, but the total delta-v from LEO to Mars surface is 10.7 km/s according to wikipedia /wiki/Delta-v_budget#Interplanetary , vs 9-10 km/s from Earth surface to LEO. The Mars trip is single-stage too, so they don’t get staging benefits, like they do during launch from Earth. So even if they fully refuel the BFS, the payload to Mars will likely be smaller.

    You also need to consider whether it’s cargo BFS or crew BFS. The crew version has more facilities on-board, but less cargo capacity. But you can count the on-board facilities and crew against the 100+ total tons of payload.

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  85. I would think that it will be easier in the beginning to bring the second stage to earth GEO first instead of LEO after launch and fuel it there. It will take more launched to fuel the ship but it will have more fuel to reach Mars and enough to re-lauanch from Mars back to earth as the more fuel to reach GEO instead of LEO is supplemented during the fueling.

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  86. Yeah, 15 tons payload makes not much sense given there are rockets they already have (Falcon Heavy) that could do that, without the reusability part (and requiring the cost of a lander).

    The stated payload is 100-150 tons, depending on the slideshow you see. Probably this last one has become more conservative.

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  87. Well, the ship does include living space, so it’s not as bad as all that, but, yes, clearly you need maximum utilization of native resources to make this practical, because getting to other planets is really marginal using chemical propulsion.

    Having a specialized vehicle for each stage of the trip, the BFR to orbit, something low thrust high ISP for transfer to Mars, then a specialized landing vehicle at Mars, would allow a considerably higher payload fraction. But engineering is a limited resource, too. SpaceX decided to use just one vehicle, with one propellant mix, to conserve THAT resource.

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  88. With almost no atmosphere there, micro meteorites (and largers ones) might punch holes in large structures such as a BFR, the chance of hitting a mars rover is small, huge ships is a different story.
    It would also be interesting to see, 4 years of radiation in the early ships, will they be able to handle that ?.

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  89. Apparently BFS can land 100t – but that includes the ship itself (85t dry mass), per an answer given at
    “https://twitter.com/MaxLenormand/status/1033398329097383936”

    Not much actual payload?!?

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