Will Humans Go to Mars before 2033?

[sdsds]

For this topic "going to Mars" can be interpreted fairly liberally: if a living human gets within a few thousand kilometers of the Martian surface it's fair to say they "went to Mars." The choice of "before 2033" is largely due to the orbital mechanics; April of 2033 is the next particularly favorable opportunity while the opportunities in 2028 and 2030 are more challenging.

It's not a poll; just a simple 'yes or no' question and an opportunity to share thoughts on the subject. (Though if someone wants to turn it into a poll that's fine.)

[Oli]

No.

I don't see any indication that SpaceX is developing surface infrastructure. There's no time.

Even 2033 is very unlikely given Trump is in power until 2028.

Edit: Ah you meant flyby or orbit, sorry. I'm not sure Musk is interested in that.

[SweetWater]

I would say no, it's too short a timeframe for development and testing of the needed technology to do it safely.

While not specifically posed as such in the question, effectively the only group of people who might be doing this in 2033 would be SpaceX on a Starship. If, say China decided tomorrow that they really wanted to send a crew on some sort of free-return trajectory around Mars in 2033, could they pull it off? Maybe, I'd say even probably, if probably is a 51% chance, but there's no indication that they have any interest in doing that. NASA doesn't have the inclination or the resources to, and while Bezos certainly has the financial resources and interest in space, he's never show specific interest in Mars.

SpaceX certainly has the will and the resources, but I do not believe they have the time. There are 3 launch windows (2026, 2028/29, and 2031) to use for testing between now and 2033. The Starship testing program clearly has more teething issues than SpaceX expected it to. We can assume they've been working on propellant transfer and long-term storage of LOX/Methane behind the scenes, but we don't really have any idea what those solutions will be, and it is unrealistic to expect them to work perfectly the first time, only because they're new and no one has really tried to do that before. SpaceX needs good relationships with federal agencies like NASA, the FAA, and the EPA to keep up their pace of testing, and I think that just became much less of a sure thing.

One problem with Mars launch windows is that it's hard to be hardware rich and to test, break things, and test again if you can only launch every 26 months. I don't see an uncrewed Starship going to Mars in 2026. 2028/29 is a possibility, but I don't see such a test as likely to be completely successful. Even if a test in 2031 is successful, are people going to go in the very next launch window? Maybe, but Elon has never shown any interest in flybys, and 2033 is WAY too early to have EDL issues resolved, ISRU cracked, etc.

That said, if Elon is still in charge of SpaceX in 2033, maybe his feelings on that count will be different when he is on the other side of 60.

[spacenut]

I think they can.  NASA would have to change to help support this.  Once SpaceX can get Starship operational, then anything is possible. 

Things to consider.
1) Fuel depot and fuel transfer in space
2) Cargo Starship that can deliver cargo to Mars.
3) Sabatier equipment for making fuel
4) Ice mining equipment for water needed to make fuel
5) Or an orbital fuel depot at Mars
6) Communication satellites around Mars
7) Habitats and rovers
Solar panels, a lot of them
9) Maybe a fuel depot at LL1 or LL2 for topping off of Starships headed to Mars
10) NASA involvement to help develop the above equipment. 
11) Tanker Starships to deliver fuel to depots.
12) Starlink Starships to finish Starlink constellation for higher internet speed and more Starlink customers.

All of the above is waiting on operational Starships. 

[sdsds]

[...] effectively the only group of people who might be doing this in 2033 would be SpaceX on a Starship.

Thanks for your thoughtful response! (I did consider limiting the discussion to crewed Starship, and then decided doing so would put unnecessary limits on the discussion.)

[...] it's too short a timeframe for development and testing of the needed technology to do it safely.
[...] That said, if Elon is still in charge of SpaceX in 2033, maybe his feelings on that count will be different when he is on the other side of 60.

Sending humans to Mars in 2031 would almost certainly require a change in the general attitude towards crewed spaceflight safety, and maybe specifically Musk would need to advocate for a "bolder and sooner" approach rather than a "safer but later" approach. At the recent SpaceX all-hands meeting Musk reportedly sounded ambitious:

My notes from the talk
[...]
  - Would send humans 2028 if 2026 is successful, goal of building infrastructure
    - Walks that back a few sentences later, maybe two windows worth of landings with Optimus instead of humans first
    - No humans in any of the rendered imagery for 2026 or 2028.

[Robotbeat]

Probably not but it can be done.

[JulesVerneATV]

Fuel depot and fuel transfer in space

people online believe China is currently testing something on Shijian-25, Shijian-21

[Robotbeat]

I don’t think the refueling itself is necessarily that hard. I think thermal management will take iteration, tho.

[Vultur]

*Before* 2033? Probably not. If Starship basically works*, I think 2033 is a very likely first landing date for humans, but 2031 is very unlikely.

 Nov-Dec 2026 is extremely ambitious to do anything at all, and if it's possible at all would probably be only a flyby. Given that, a 2029 cargo delivery would have to go smoothly first time for 2031 crew to be possible.

OTOH, in the mid term I'm more optimistic. A second OLM is coming along, and assuming they can fix the current problems (perhaps with v3) development may advance very rapidly. There's just not that much time before the 2026 synod, but 2029 is another question entirely.

I really don't expect propellant transfer per se to be in itself a big deal, once they get attitude control and a better RCS and reliability resolved.

Initial Mars tests (or cargo delivery that largely fails and becomes initial tests) 2029, serious cargo delivery 2031, would allow for crew 2033.

I do think the intent is to accept risks that NASA would consider completely unacceptable, like sending humans before the ISRU to return is fully set up.

*IE the program is not canceled or radically descoped to be e.g. just a super heavy Starlink launcher, and there's no really long stand down to redesign fundamentally

[AmigaClone]

NASA/ SpaceX I would say no chance at all.

China has a small chance - but the China's national leadership would need to be more committed to that idea than the US Government was to the idea of 'man on the moon before the end of the decade' in 1965.

[jstrotha0975]

Not at the rate the Starship project is currently going.

[Slarty1080]

It doesn't seem likely to me, although with so many moving parts that it is very hard to say for sure.

Hopefully they can crack the current structural problems this year sufficiently to allow them to make a start on refining the heat shield before the end of the year.

Next year should see Raptor 3 and Starship V3 introduced with different plumbing. If this all goes relatively smoothly(a big if) then Starship might become operational by the end of 2026 launching Starlink. At that point the launch cadence should start to slowly build and each launch should allow both Starlink deployment and Starship refinement.

With luck 2026 will also see the testing of orbital re-tanking. If this goes smoothly (a big if) then Starship might be ready for missions beyond LEO by 2027. That would leave enough time for an uncrewed Starship atmospheric test EDL possibly after deploying Starlink like sats into Mars orbit in the 2028/29.

If the 2028/29 atmospheric test works (another big if) they should be looking at a mock proof landing of Starship in crew configuration as well as testing deployments of ISRU, Solar etc etc.

If that goes as planned (if) then just may be 2033 could see the first crew to Mars.

But that plan would be the shortest possible time frame with a non zero probability of actually occurring. Realistically some of the ifs will give difficulties leading to 1-3 launch windows delay.

Then there are all the other things that have to be thrown into the mix. The machinations of the critters on the hill, changes of administration, Elon Musk's Health, Chinese activity etc etc. Fingers crossed.

 

[VSECOTSPE]

SpaceX is the only substantive and active game in town for H2M.  They’re going to need:

1) Working Starship to/from LEO.
2) Frequent, large-scale cryo propellant xfer.
3) Multi-year, large-scale cryo propellant storage.
4) Comms to/from Mars
5) PNT at Mars
6) EDL proven at Mars
7) Water ice at Mars
ISRU proven at Mars
9) Multi-year life support

Items 1-5 are needed before 6 can be tested.  Items 1-5 will not be ready by the launch window at the end of 2026, so we’re really looking at the window at the end of 2028 before Item 6 can be tested.

Realistically, SpaceX will need more than one bite at the EDL apple before Item 6 is checked off.  Assuming the late 2028 window gets used up on (and learning from) Mars EDL failures, that means the early 2031 window before work could begin at the Martian surface on items 7-8. 

Like with Mars EDL, realistically, finding Martian water ice is usable form and proving out propellant production will take more than one window.  If the 2031 window gets used up on water ice prospecting or  and propellant production failures and it’s only after the 2033 window that there’s tanks of CH4 waiting for the return leg, then the first crews won’t be sent to Mars until the mid-2035 window.

I think 2035 is a somewhat realistic, median estimate.  I think 2033 and earlier requires SpaceX to get Mars EDL or water ice prospecting/propellant production right within their first windows.  That seems unlikely and unrealistically optimistic.

Personally, I’m even a little more skeptical than that because of the lack of details and apparent work at SpaceX on items 4/5 and 7/8 to date (unless Musk has a secret evil villain volcano base where this work has been going on).  Putting StarLink sats in Mars orbit alone doesn’t provide a link to Earth.  And an Optimus robot walking on the Martian surface isn’t equipped to assay water ice or process propellant.  These are things where NASA experience and expertise could come in really handy so SpaceX doesn’t have to reinvent the wheel.  But with the Trump/Musk fallout, that working relationship will probably not be as close as it has been.  Taking that into account, I don’t think SpaceX will be in a position to send the first crews until the mid-2037 or late-2039 windows.

A decade to a decade-and-a-half still to go is my 2 cents.  FWIW...

[Coastal Ron]

Just doing a flyby of Mars in 2033 would require a "success oriented schedule", meaning most everything works from here on out. But as we've seen with the Starship test program, while they may be making progress, nothing has been close enough to perfect to think they have a clear path of progress ahead of them.

And so far SpaceX has only been able to focus on getting Starship to space, next they have to figure out how to survive reentry. And once they do that, then they have to figure out how to keep humans alive in space.

The Trump I Administration was lucky that SpaceX was already working on getting to Mars and was willing to support the return-to-Moon effort. SpaceX was lucky to have an additional source of funding, and maybe even some NASA support. Because without SpaceX it was unlikely that the Artemis program could have realistically landed humans on our Moon this decade - and it is still going to be a hard regardless.

Going to Mars with humans is a HUGE endeavor, and I'm quite happy SpaceX is doing it. But there are so many unknown unknowns, and I'm not sure SpaceX will be able to solve them quickly enough before 2033. Nothing against them, because they are likely the best positioned to attempt this, just that it is so darn hard.

My $0.02

[Robotbeat]

SpaceX is the only substantive and active game in town for H2M.  They’re going to need:

1) Working Starship to/from LEO.
2) Frequent, large-scale cryo propellant xfer.
3) Multi-year, large-scale cryo propellant storage.
4) Comms to/from Mars
5) PNT at Mars
6) EDL proven at Mars
7) Water ice at Mars
ISRU proven at Mars
9) Multi-year life support

Items 1-5 are needed before 6 can be tested.  Items 1-5 will not be ready by the launch window at the end of 2026, so we’re really looking at the window at the end of 2028 before Item 6 can be tested.

Realistically, SpaceX will need more than one bite at the EDL apple before Item 6 is checked off.  Assuming the late 2028 window gets used up on (and learning from) Mars EDL failures, that means the early 2031 window before work could begin at the Martian surface on items 7-8. 

Like with Mars EDL, realistically, finding Martian water ice is usable form and proving out propellant production will take more than one window.  If the 2031 window gets used up on water ice prospecting or  and propellant production failures and it’s only after the 2033 window that there’s tanks of CH4 waiting for the return leg, then the first crews won’t be sent to Mars until the mid-2035 window.

I think 2035 is a somewhat realistic, median estimate.  I think 2033 and earlier requires SpaceX to get Mars EDL or water ice prospecting/propellant production right within their first windows.  That seems unlikely and unrealistically optimistic.

Personally, I’m even a little more skeptical than that because of the lack of details and apparent work at SpaceX on items 4/5 and 7/8 to date (unless Musk has a secret evil villain volcano base where this work has been going on).  Putting StarLink sats in Mars orbit alone doesn’t provide a link to Earth.  And an Optimus robot walking on the Martian surface isn’t equipped to assay water ice or process propellant.  These are things where NASA experience and expertise could come in really handy so SpaceX doesn’t have to reinvent the wheel.  But with the Trump/Musk fallout, that working relationship will probably not be as close as it has been.  Taking that into account, I don’t think SpaceX will be in a position to send the first crews until the mid-2037 or late-2039 windows.

A decade to a decade-and-a-half still to go is my 2 cents.  FWIW...

7 and 8 don’t have to be figured out before they go. There’s also a lot of overlap in these things. If you are storing hundreds of tons of liquid oxygen, that’s decades’ worth of oxygen for the crew. Just need regenerative CO2 scrubbing, which is pretty easy in comparison (and done all the time in submarines). Heck, 400t of oxygen, if you are really optimistic, can keep a crew of 12 alive without CO2 scrubbers for years operating open-loop (where you flush out a low pressure pure O2 environment to keep the CO2 below 1%, or have the crew breathe out through an exhaust)… although that’s probably not healthy or realistic. Better to just ship backup supplies of disposable CO2 scrubbers than rely on that.


Having insane mass margins brings a kind of resiliency that’s not often appreciated. Just 12t of lithium hydroxide scrubbers can scrub the CO2 for a crew of 12 for years, even though ISS or Shuttle or Orion based regenerative CO2 scrubbers are pretty easy. (And you can take advantage of all that active cooling power to do cryogenic CO2 scrubbing as well, if you want.)

[Robotbeat]

SpaceX already has a life support system for HLS which is based on the Dragon capsule’s life support system, I think. This is a very reliable system. No reason this can’t work for several years, as it uses pretty basic one time use scrubbers, etc.

[Robotbeat]

Note that SpacwX intends to use Starlink for Mars communications. Starlink can already do direct-to-cell, has some basic navigation and timing capability already, and SpaceX has also proposed a Starlink-based system to replace GPS. So I’d say PNT and communications are two of the things they’ve most been preparing for. No one has ever launched or operated anywhere close to as many satellites as SpaceX has, so I doubt this is the long pole.

I’m actually more concerned about landing on an unprepared site than I am about most things on that list. This is difficult to test and to make it safe enough for crew is very non-trivial. Surface cryo storage is also tough, but doable.

[VSECOTSPE]

7 and 8 don’t have to be figured out before they go.

Before the first crews go, the program needs tanks of LCH4 on the Martian surface for crew return options.  Even if the plan is to for everyone to have one-way tickets, there’s any number of unknowns and unknown unknowns that require a modicum of contingency planning.  A lot of those issues — human, environmental, certain kinds of system failures — can’t be dealt with via brute force mass and spares.  Being able to bring crews back is a great way to deal with a large range of contingencies.

SpaceX already has a life support system for HLS which is based on the Dragon capsule’s life support system, I think. This is a very reliable system. No reason this can’t work for several years, as it uses pretty basic one time use scrubbers, etc.

There’s differences in designing a system to last a few weeks or months versus a few years.  Even if you think you can use the former for the latter, you have to test for that duration in a relevant environment, which probably means a program culminating in an Apollo 7 type demo in Earth’s vicinity.  That can be done in parallel with the other steps above, so I didn’t put Item 9 on the critical path.

Even if that works and even with lots of mass to play with, dealing with unknown unknowns for that duration and at that distance probably necessitates dissimilarly redundant backup life support.  This paper, among others, gets into some of the important subtleties:

https://ntrs.nasa.gov/api/citations/20170010347/downloads/20170010347.pdf

Note that SpacwX intends to use Starlink for Mars communications.

StarLink has no interplanetary transmit/receive capability.  Lacks the gain, power, pointing, Earth ground stations, etc.  NASA DSN is nearly the only system/institution with that capability and experience. Doesn’t mean SpaceX can’t do it, but they have to work on it and unless that’s been happening off-stage out of the public eye, they’re not.

This is the central problem with the systems SpaceX needs for H2M other than Starship.  There’s a lot of handwaving about using SolarCity solar panels, StarLink satellites, Optimus and Tesla trucks, etc.  But there’s very little actual work going on to bring these or other systems forward, address the holes in their capabilities, adapt them to their Martian environments, integrate them, test them for the necessary durations, etc.  Again, maybe it’s all been happening at Musk’s secret volcano base and no one has told me.  But absent some evidence of this kind of work in parallel with Starship, SpaceX will either need to beg/borrow/steal from NASA (less likely since the Trump/Musk divorce) or add some modicum of years to the sched.

FWIW...

[Robotbeat]

SpaceX would likely use Starlink arrays, not Solar City. They’re making like hundreds of megawatts already. but I suppose you think the Starlink arrays on Starship HLS are also fake?

It’s also weird to just assume no thought has gone into using Starlinks, in spite of the fact they’re flexible systems, could trade distance for bitrate to keep positive link budget… and SpaceX has already used them for talking directly with Dragon and Starship, even in very challenging conditions. But sure, fine, let’s grant that.

It’s not a problem for SpaceX to use the DSN. The DSN is regularly used by other nations, including European spacecraft. This is not a problem. Focus on non-fake problems.

[Robotbeat]

7 and 8 don’t have to be figured out before they go.

Before the first crews go, the program needs tanks of LCH4 on the Martian surface for crew return options.  …

They don’t. Not if Mars surface cargo logistics has been proven so crews can be resupplied indefinitely and years of supplies are sent ahead of time.

[goretexguy]

For reference:
1) Working Starship to/from LEO.
2) Frequent, large-scale cryo propellant xfer.
3) Multi-year, large-scale cryo propellant storage.
4) Comms to/from Mars
5) PNT at Mars
6) EDL proven at Mars
7) Water ice at Mars
ISRU proven at Mars
9) Multi-year life support

This is how I break things down:

Dec 2026 - demonstrate ability to get to Mars, maybe attempt a landing with Optimus. Deploy Marslink satellites for communications and a rudimentary GPS system. (Demonstrates #1 & 4)

Jan 2029 - launch 2 ships a few days apart. Successfully land ship #2 adjacent to ship #1. More Marslinks and Optimus bots. Rollout solar arrays, find ice and begin a fuel generation plant. (Demonstrates #1, 4, 5, 6, 7, & .

2029 (or later) - humans fly extended duration trips on Ships in Cislunar space. Possibly attempt landings on the Moon*. (Assists #5, 6 & 9, possibly 7 if Optimus can wander on the surface and find things.)

2030 (or later) - refuel and launch one of the landed ships on Mars to prove the rocket works after a long idle state and cold soak. Ideally, this vessel would ultimately return to Earth. (At this point, SpaceX should have Marslink receiving stations in Earth orbit, instead of using ground stations which would be subject to all manner of political mischief.) (Demonstrates #1-9)

2031 - launch many (10+) Ships to Mars and land them. These Ships have the basic materials to build a permanent outpost . More Optimus bots to get the work moving along, providing a go/no go for sending people. (Re-demonstration of #1-9)

2033 - launch many Ships to Mars, some with humans, in an audacious, make-Apollo-a-footnote mission.

* Lunar landings don't need humans. Just show that the autopilot can successfully find and land on an unprepared site in non-earthlike conditions.

My 2 cents.

[TheRadicalModerate]

SpaceX is the only substantive and active game in town for H2M.  They’re going to need:

1) Working Starship to/from LEO.
2) Frequent, large-scale cryo propellant xfer.
3) Multi-year, large-scale cryo propellant storage.
4) Comms to/from Mars
5) PNT at Mars
6) EDL proven at Mars
7) Water ice at Mars
8 ) ISRU proven at Mars
9) Multi-year life support

Items 1-5 are needed before 6 can be tested.  Items 1-5 will not be ready by the launch window at the end of 2026, so we’re really looking at the window at the end of 2028 before Item 6 can be tested.

Realistically, SpaceX will need more than one bite at the EDL apple before Item 6 is checked off.  Assuming the late 2028 window gets used up on (and learning from) Mars EDL failures, that means the early 2031 window before work could begin at the Martian surface on items 7-8. 

Like with Mars EDL, realistically, finding Martian water ice is usable form and proving out propellant production will take more than one window.  If the 2031 window gets used up on water ice prospecting or  and propellant production failures and it’s only after the 2033 window that there’s tanks of CH4 waiting for the return leg, then the first crews won’t be sent to Mars until the mid-2035 window.

I think 2035 is a somewhat realistic, median estimate.  I think 2033 and earlier requires SpaceX to get Mars EDL or water ice prospecting/propellant production right within their first windows.  That seems unlikely and unrealistically optimistic.

Personally, I’m even a little more skeptical than that because of the lack of details and apparent work at SpaceX on items 4/5 and 7/8 to date (unless Musk has a secret evil villain volcano base where this work has been going on).  Putting StarLink sats in Mars orbit alone doesn’t provide a link to Earth.  And an Optimus robot walking on the Martian surface isn’t equipped to assay water ice or process propellant.  These are things where NASA experience and expertise could come in really handy so SpaceX doesn’t have to reinvent the wheel.  But with the Trump/Musk fallout, that working relationship will probably not be as close as it has been.  Taking that into account, I don’t think SpaceX will be in a position to send the first crews until the mid-2037 or late-2039 windows.

A decade to a decade-and-a-half still to go is my 2 cents.  FWIW...

The one disagreement I have with your list is that water ice and ISRU prop manufacturing aren't needed.  Assuming the Starship Formerly Known As v3, it's pretty easyą to get that landed and returned to LMO using just a single full tank of prop in VLEO.  From there, aerocapturing enough prop to return to Earth is also pretty easy.ą

Even without the SFKAv3, a single v2 only needs about 75t of LCH4 to get to LMO.  If you can land that and a few tonnes of LH2 to catalyze LOX generation using RWGS, that's a far cry from full-up prop production.

_________
ą"Pretty easy" assumes a very, very good cryocooler.

[Robotbeat]

Note that for a given mass of fuel, it is about 100 times easier to actively cool the methane than the hydrogen. In terms of power requirements.

This is due to less heat leakage from a smaller delta-t, less surface area because the propellant is denser, and the far lower temperature differential to pump heat through, which also makes the heat pump both closer to the ideal Carnot efficiency and of course improves the Carnot efficiency.

So if SpaceX pursues active cooling (which they must in order to do ISRU anyway), it’s actually a much easier problem than it would be for Blue origin.

[VSECOTSPE]

It’s also weird to just assume no thought has gone into using Starlinks, in spite of the fact they’re flexible systems, could trade distance for bitrate to keep positive link budget…

This is the kind of handwaving I’m talking about.  Existing Mars spacecraft use X-band for data return.  For high data rates, StarLink is a Ka-band system.  The pointing requirements necessary to use a Ka-band system at Mars distances challenge/exceed the limits of existing systems:

High rate telemetry from Mars requires an extremely large EIRP at Ka-band.  In order to conserve on-board power, extremely large apertures are considered as part of the overall system trade.  Apertures on the order of 1000 wavelengths, at Ka-band, result in antenna bandwidths that approach the attitude knowledge and control capability of modern spacecraft, thereby increasing pointing losses to unacceptable levels.

https://ntrs.nasa.gov/api/citations/20080012561/downloads/20080012561.pdf

Doesn’t mean this and other challenges can’t be overcome.  But unlike we internet space cadets, SpaceX can’t handwave these problems away; they actually have to develop a solution.  My concern or point in the context of estimating initial H2M landing dates is there’s little/no evidence that SpaceX is working these other systems and issues in parallel with Starship.  If that’s true, then addressing these systems and issues serially will add some years to the schedule.

and SpaceX has already used them for talking directly with Dragon and Starship, even in very challenging conditions.

In Earth orbit.  Mars is more than two orders of magnitude farther away.  Challenges like gain and pointing are very different.  Saying that because Starlink works in Earth orbit that it will work at Mars distances is like saying that because my kid can hear me yelling at him from a block down the street, he should be able to hear me yelling at him from 100+ blocks away.  Obviously not true,

It’s not a problem for SpaceX to use the DSN. The DSN is regularly used by other nations, including European spacecraft. This is not a problem. Focus on non-fake problems.

It takes years to make those arrangements with NASA and the DSN.  Unless SpaceX has been working with the DSN on a Mars mission in parallel with Starship, this will add some years to the schedule.  (Hopefully the Trump/Musk divorce doesn’t prevent work towards such an arrangement in the first place.)

It doesn’t necessarily affect the first H2M landing, but the DSN is not a long-term solution for what SpaceX wants to do at Mars.  The DSN is grossly oversubscribed, and incapable of supporting the data demands of hundreds of Mars crew in any event.  SpaceX will need to build its own antenna farm and network infrastructure.

Not if Mars surface cargo logistics has been proven so crews can be resupplied indefinitely and years of supplies are sent ahead of time.

Many contingencies can’t be solved with supplies.  There are reasons why crews and crewmembers would need to return to Earth that have nothing to do with running short on supplies.

When you have a hammer, like Starship’s large payload mass, everything starts to look like a nail.  But many problems are screws and bolts, and you still need some screwdrivers and wrenches, like a crew return capabilty, to address those other contingencies.

[VSECOTSPE]

The one disagreement I have with your list is that water ice and ISRU prop manufacturing aren't needed.  Assuming the Starship Formerly Known As v3, it's pretty easyą to get that landed and returned to LMO using just a single full tank of prop in VLEO.  From there, aerocapturing enough prop to return to Earth is also pretty easy.ą

If I understand you correctly, we’re trading the complexity of prospecting for water and manufacturing propellant on the Martian surface for an RPO in Mars orbit between returning Starships and some flavor of a depot Starship sent to Mars orbit.  Once you’ve proven RPO in Mars orbit, that simplifies a lot operationally.  But in terms of reducing the time to the first H2M landing, I don’t know that it saves us anything.  Propellant production at Mars and RPO in Mars orbit are both unproven capabilities.  I’d guesstimate that both impose a high likelihood of initial failure/steep learning curve that will eat up a launch window or two solving the same bottleneck before a crew can be sent.

Schedule aside, the handwaving in Musk’s presentations about finding water and ISRU is concerning.  Even after a couple decades of missions and research, planetary scientists still debate whether the geological signatures (like “weepings”) that we associate with water at Mars are actually due to water.  SpaceX needs some backup solutions like forwarding depots to Mars orbit.

Even without the SFKAv3, a single v2 only needs about 75t of LCH4 to get to LMO.  If you can land that and a few tonnes of LH2 to catalyze LOX generation using RWGS, that's a far cry from full-up prop production.

Obviates the water prospecting, which is good.  But no one has done the Sabatier process at Mars and getting all the details of maintaining the correct temperatures and pressures for the reaction and getting the impurities separated, the gases separated, and the reverse water gas shift implemented in a foreign environment may still consume a launch window or two.

Professionally, I lived through a couple decades of STS launch delays due to hydrogen leaks, so long-term LH2 storage makes me nervous, both from an operational and safety standpoint.  But being able to forgo water prospecting is obviously worth the risk.

[TheRadicalModerate]

If I understand you correctly, we’re trading the complexity of prospecting for water and manufacturing propellant on the Martian surface for an RPO in Mars orbit between returning Starships and some flavor of a depot Starship sent to Mars orbit.  Once you’ve proven RPO in Mars orbit, that simplifies a lot operationally.  But in terms of reducing the time to the first H2M landing, I don’t know that it saves us anything.  Propellant production at Mars and RPO in Mars orbit are both unproven capabilities.  I’d guesstimate that both impose a high likelihood of initial failure/steep learning curve that will eat up a launch window or two solving the same bottleneck before a crew can be sent.

RPO would likely require a fairly robust PNT system.  But I think that some Marslink deployment would go a long way to retiring RPO risk.ą

Schedule aside, the handwaving in Musk’s presentations about finding water and ISRU is concerning.  Even after a couple decades of missions and research, planetary scientists still debate whether the geological signatures (like “weepings”) that we associate with water at Mars are actually due to water.  SpaceX needs some backup solutions like forwarding depots to Mars orbit.

I don't think the presence of water is a requirement for a human Mars mission.  It is a requirement for colony-scale (and possibly base-scale) settlement.  But early exploration missions need to be able to keep their crews alive--and return them alive--irrespective of the presence of ISRU water.  IMO, that requires full importation of prop, or at least importation of LCH4 or LH2 (to make LCH4).

Obviates the water prospecting, which is good.  But no one has done the Sabatier process at Mars and getting all the details of maintaining the correct temperatures and pressures for the reaction and getting the impurities separated, the gases separated, and the reverse water gas shift implemented in a foreign environment may still consume a launch window or two.

I'm not proposing Sabatier here.  It's easy to land enough LCH4 to at least get back to LMO.  I believe it's not much more difficult to land enough to get the crew all the way back to Earth.

The question is how to make LOX.  At least two possibilities:

1) MOXIE-style CO2 electrolysis.  Currently very energy intensive, and very low-scale.

2) Reverse water-gas shift (RWGS).  There's a huge amount of industrial experience with WGS, and a fair amount with RWGS:  CO2 + H2 --> CO + H2O.  Vent the CO, electrolyze the water, cryocool the O2,  and recycle the hydrogen.

Professionally, I lived through a couple decades of STS launch delays due to hydrogen leaks, so long-term LH2 storage makes me nervous, both from an operational and safety standpoint.  But being able to forgo water prospecting is obviously worth the risk.

My intuition is that the less LH2 (or maybe just compressed GH2) you need, the better.  A lot depends on how efficient you can make your RWGS rig.  If you can make it really efficient, you might easily be able to make enough LOX for a return mission with only a couple of tonnes of LH2.  That allows you to put it in a proper dewar, with proper insulation and heavy-duty fittings, to eliminate its tendency to jailbreak.

So the real question is how well you can scavenge the water from your RWGS setup.

________
ąYou had objections to Marslink hand-wavery, which are legitimate.  However, I'm considerably less worried about pointing accuracy then you are, because you can have the entire constellation relay interplanetary traffic through a big honkin' bird that has the proper antennae at the proper frequencies.

However, I don't think that RPO requires any interplanetary traffic.  It mostly requires PNT, which remains local to Mars.

Interplanetary bandwidth is an issue.  But it's less of an issue if you have high bandwidth in the local environment, and lots of memory.

[Robotbeat]

CO2 electrolysis isn’t terribly challenging. MOXIE was a small scale demonstration, but solid oxide electrolysis has been done at a pretty large scale and so scaling up MOXIE is very straightforward and easy to test on Earth. The efficiency is just as good as RWGS.

[Vultur]

7 and 8 don’t have to be figured out before they go.

Before the first crews go, the program needs tanks of LCH4 on the Martian surface for crew return options. 

I don't think Elon Musk necessarily agrees with that.

I do *not* think contingency return is expected to be an option immediately. If something goes wrong with ISRU, crew may have to wait for the next synod cargo delivery.

(And I'm OK with that. Given travel times, you can't get back to Earth *quickly* anyway. You need to be able to deal with emergencies with what you bring.)

OTOH, I also think the initial crew will be accepting risks far higher than NASA would be comfortable with.

[TheRadicalModerate]

CO2 electrolysis isn’t terribly challenging. MOXIE was a small scale demonstration, but solid oxide electrolysis has been done at a pretty large scale and so scaling up MOXIE is very straightforward and easy to test on Earth. The efficiency is just as good as RWGS.

Let's figure this out, as much as possible.  Wikipedia says that CO2 electrolysis needs 25-30kW to produce 2kg/hour.  That's about 13kWh/kg, right?

The back-end of the RWGS process requires water electrolysis, which is 55kWh/kg of H2, which would be 6.9kWh/kg of O2.  I don't have a clue how to estimate energy needed to produce H2O through RWGS, but if it's more than about 5.4kWh/kg of H2O, then CO2 electrolysis has it beat.  Since the reverse reaction is endothermic, it's probably not great.

However, both of these are kind of appalling.

I can get a v2-ish Starship back to Earth orbit (propulsive capture, but it'll need refueling), for 900t of LOX.  To produce that in two years (not absolutely necessary; it could be 4.2 years, or 6.4 years), you'd need to produce 1233kg/day.  Scaling, that would require 15.4MW of firm power.

Using that model I built for our APU vs. solar argument (solar won handily for Mars), that's a power system mass of 1940t.  I can land all the prop I need (1150t of methalox) for considerably less.ą

That doesn't mean that it's silly to produce ISRU prop; it just means that it's expensive to start up.  For the earliest missions, it almost certainly makes more sense to land the prop, or land enough prop to get to LMO to meet a depot.

_______
ąThis is all prop landed and propulsive capture, which retires most of the risk that VSECOTSPE was objecting to. 

You can do substantially better than this by landing just enough prop to get back to LMO, and a depot in orbit for the rest.  And if somebody will actually let you aerocapture/EDL (I don't think that's going to happen, but who knows?), you can do even better.

[Robotbeat]

Starship requires an enormous amount of energy to make propellant.

It’s best to just look at the high heating value of the fuel and multiply by 2 (50% efficiency) to get the required input.

[VSECOTSPE]

I don't think Elon Musk necessarily agrees with that.

I do *not* think contingency return is expected to be an option immediately. If something goes wrong with ISRU, crew may have to wait for the next synod cargo delivery.

(And I'm OK with that. Given travel times, you can't get back to Earth *quickly* anyway. You need to be able to deal with emergencies with what you bring.)

OTOH, I also think the initial crew will be accepting risks far higher than NASA would be comfortable with.

A lot of this comes down to how hard is it to establish that Starship return capability.

If it’s as simple as sending some extra Starships one-way with extra LCH4 tankage, then why not establish that Starship return capability before the first crews go?

If it’s as complex as producing LCH4 locally from Martian water ice and atmosphere, then SpaceX may not even be able to do it remotely in the first place and have to send a crew to establish that initial Starship return capability anyway

Reality will probably be somewhere in between.

There’s not enough detail in Musk’s presentations to know exactly what SpaceX has planned.  ISRU/propellant production comes the synod after the first human landings in his timeline.  But whether Starship return is dependent on ISRU/propellant production is unclear.  Starship payload capability may determine whether establishing Starship return from Mars is easy or hard, but Starship capability is a moving target for now, so even SpaceX may not know internally yet.  (Or SpaceX just has not dealt with these details while Starship consumes all the talent and man-hours.)

Like so many things, flight safety is too often argued in terms of poles.  Either no price is too high to ensure astronaut lives or any effort to improve safety is a wasteful distraction from the mission.  In reality, resources are always constrained, and there is no bigger distraction from the mission than dead or dying astronauts.  So it’s a question of best effort.  Is the organization/leadership/program doing everything reasonable to ensure crew health and safety?  Are they wasting large amounts of resources polishing a safety issue for little return?  Or are they ignoring modest investments that could dramatically improve crew survivability?  At OMB, I used to review laundry lists of potential Shuttle upgrades through these exact lenses.

My sense is that a Starship return capability is something that could be reasonably afforded and established within a synod or two that would inoculate the program against a range of scenarios that could consume the program in its early, tender years.  The crew/program/leadership/stakeholders/public doesn’t want to an astronaut with, say, a probable cancer diagnosis sitting on the surface of Mars with no way back to Earth conjunction after conjunction at the same time it’s trying to get a base camp established. 

I’d have a different recommendation if I knew it would take five synods to establish that Starship return capability.  But in general, I favor modest delays to increase sustainability and the probability of long-term success over meeting artificial deadlines.  I’d like to think SpaceX will move away from the Apollo-end-of-the-decade and Artemis-beat-the-Chinese-by-2030 mentalities that don’t lead to anything sustainable.

My 2 cents... YMMV.

[lykos]

You have to change the art of thinking.
Don't expect and don't plan to bring the astronauts back in first place.
When it's clear from the beginning, that they have to stay at least for one synode, many problems are solved.
There are no expectations and no disappointments.
There are big risks and people will die that's a fact. You can try to make it save, and you have to, but people will die.
Do not make to big promises.

[sdsds]

If a crew of ten departed Earth in 2031 and one of them were to die from cancer sometime after arrival we would mourn the loss, and honor the deceased as the first human to die on Mars. If all in the crew were to die because the resupply ship didn't arrive in 2033, that would be shameful. Not for them, but for those of us still on Earth.

[TheRadicalModerate]

You have to change the art of thinking.
Don't expect and don't plan to bring the astronauts back in first place.
When it's clear from the beginning, that they have to stay at least for one synode, many problems are solved.
There are no expectations and no disappointments.
There are big risks and people will die that's a fact. You can try to make it save, and you have to, but people will die.
Do not make to big promises.

The issue isn't if some people die.  But if they all die, that's another story.

I think a single-synod nominal mission is a desirable baseline.  The big question is whether it's worth planning for an opposition-class short-stay abort.  They don't exist for all windows, and sometimes their outcomes may be riskier than hunkering down and waiting for the next conjunction.

My guess is that, by the time they get to Mars, a crewed mission will have uncovered multiple instances of systems that are underperforming or degrading faster than expected.  If mission management has an abort in its toolkit, some of those contingencies might trigger it.  If an abort doesn't exist and the systems are going to fail before the next window opens, that's a problem.

This all seems like Mission Planning 101 to me:  Think about what can go wrong, provide spares and backups when possible, see if there are other ways to mitigate the contingencies, and be as ready as possible for the unexpected. 

Above all, don't be reckless.  Taking informed risks is just part of human spaceflight.  But the emphasis should be on the "informed" part.

[Vultur]

My guess is that, by the time they get to Mars, a crewed mission will have uncovered multiple instances of systems that are underperforming or degrading faster than expected.

Why? I would *not* expect that - before getting to Mars, the systems won't be experiencing conditions all that different from what they'd have experienced on previous crewed test flights. (I don't expect them to make the Artemis II mistake of never testing the life support system with actual humans before a deep space mission.)

[sdsds]

In their Table 4, M. Vasile et al. / Acta Astronautica 56 (2005) 705 – 720 present an interesting free-return trajectory with a launch date in 2032.
https://www.esa.int/gsp/ACT/doc/MAD/pub/ACT-RPR-MAD-2005-%28Acta%29DesignOfEarthMarsTransfersWithEvolutionary.pdf

Δv1 and Δv4 are the Earth departure and return maneuvers. This seems ... not impossible.

[Helodriver]

It still surprises me to see the degree of handwavium being consumed about orbital refueling, loitering depots, interplanetary cruise and surface operations on Mars where storage of cryogenics is concerned.

The longest duration cryogenics have ever been used in American space flight is 17.5 days on a shuttle with an Extended Duration Orbiter tankage kit. Thats it. EDO was just an array of well insulated spherical tanks plumbed into the existing orbiter cryogenic system to power fuel cells and were not refilled, exposed to off nominal solar heating, or EDL stress. Starship needs its thin walled orders of magnitude larger tanks to contain two kinds of cryo for months or years without leaking, excess boiloff or breakdown of cryocoolers, fittings and seals, an unprecedented challenge without analogue. Its loss of mission and/or vehicle and crew if any of that fails and is likely to be far more difficult if not the most difficult technical task, up there with EDL on unprepared surfaces.  It may take multiple synods just to get that right, notwithstanding other issues.

[TheRadicalModerate]

It still surprises me to see the degree of handwavium being consumed about orbital refueling, loitering depots, interplanetary cruise and surface operations on Mars where storage of cryogenics is concerned.

The longest duration cryogenics have ever been used in American space flight is 17.5 days on a shuttle with an Extended Duration Orbiter tankage kit. Thats it. EDO was just an array of well insulated spherical tanks plumbed into the existing orbiter cryogenic system to power fuel cells and were not refilled, exposed to off nominal solar heating, or EDL stress. Starship needs its thin walled orders of magnitude larger tanks to contain two kinds of cryo for months or years without leaking, excess boiloff or breakdown of cryocoolers, fittings and seals, an unprecedented challenge without analogue. Its loss of mission and/or vehicle and crew if any of that fails and is likely to be far more difficult if not the most difficult technical task, up there with EDL on unprepared surfaces.  It may take multiple synods just to get that right, notwithstanding other issues.

ZBO doesn’t take several synods. It may take several multi-week missions, but they can happen in cislunar space or even LEO.   Mars EDL, on the other hand, is quantized in synod increments, because the only place it can be tested is on Mars.

[Robotbeat]

Mars EDL is similar to Earth EDL. In fact, NASA often tests parachutes or new heatshields (HIAD) or whatever at Earth. Sometimes that’s too expensive, like with sky crane, but it is among the options NASA could use. It’s not a perfect copy, but the differences can be accounted for with arcjet and wind tunnel tests.

Of course, SpaceX is going to get PLENTY of practice doing Earthside EDL. And the more tanker trips required, the more EDL practice.

This is one reason I sort of wish SpaceX would do more legged landing tests with Starship instead of just chopsticks. I suppose they may still do some since it’s needed for Earth 2 Earth rocket cargo to austere locations, ie the Air Force contract. Of course, they do have lots of experience doing landing tests to prepared flat landing pads with Falcon (literally hundreds of tests), and starship did do a few suborbital landing tests with legs, but trying to find a landing site on Mars that just happens to be equivalently flat seems unlikely. So I hope they do do some non-flat landing tests before Mars 2026. (Although in the latest presentation, no legs are shown for the 2026 mission but are for the later ones, implying they may attempt to land on the skirt or use the tiny flip out legs… neither option seems reliable for an unprepared site, to say the least.)

This is one thing that lunar missions would actually help with.

[Robotbeat]

Helodriver: it’s totally false that the shuttle extended orbiter kit is the longest duration cryogenics on an American spaceflight mission. Several space telescopes or other missions operated for months or years using either a cryogenic tank or a combination of passive and active cooling (JWST).

[Greg Hullender]

Obviously there's a lot to be done to make 2035 work, but ten years is a lot of time. Ten years ago (22 Dec 2015), SpaceX successfully recovered a Falcon 9 booster for the first time. Ten years before that, SpaceX was making its first attempts to launch a Falcon 1.

I'd say 2035 is the NET date, assuming a good dress rehearsal in 2033. And assuming current politics doesn't introduce delays.

[Robotbeat]

Starhopper first flew in 2019. 10 years after that is 2029.

[sdsds]

[...] Several space telescopes or other missions operated for months or years using either a cryogenic tank or a combination of passive and active cooling (JWST).

And looking just at propellant, there's the Intuitive Machines Nova-C lander that uses methalox. So far that's only been a few days after launch but it's still an impressive accomplishment. On the other hand I don't claim to understand engine 'start box' requirements but restarting RS-25 in space after an extended cold-soak was deemed too challenging, thus requiring J-2X development. So is cryocooling or engine restart the bigger challenge for the 2031 timeframe?

Either way, going outbound on a free return trajectory seems ... prudent. I think that always exists if one chooses an outbound trajectory arc that has a 2 year period.

[TheRadicalModerate]

Either way, going outbound on a free return trajectory seems ... prudent. I think that always exists if one chooses an outbound trajectory arc that has a 2 year period.

A 2:1 transfer orbit is still pretty sporty when it gets to Mars.  In the nominal case, even after applying more than 2.3km/s of braking delta-v, the periapse speed would still be something like 8.4km/s.  That's not your only choice for a free return, but your options are pretty limited if you assume that the reason you aborted is because the Raptors aren't running.  That requires an Earth aerocapture, with enough thruster propulsion to raise your perigee enough so that the orbit's stable enough for somebody to come rescue you.

I just don't see zero boiloff being that big a deal.  It's a zillion fiddly details, but they can all be debugged in cislunar space, so your tests aren't constrained by the departure window.  It may take longer than a synod, but so will everything else.

Same thing for Raptor reliability.  It's probably fair to say that Starship doesn't exist without an insanely reliable engine, so that's unlikely to be a gating item for anything to do with Mars.  (By the time refueling is robust, the Raptor will be, too.)

[Helodriver]

Helodriver: it’s totally false that the shuttle extended orbiter kit is the longest duration cryogenics on an American spaceflight mission. Several space telescopes or other missions operated for months or years using either a cryogenic tank or a combination of passive and active cooling (JWST).

Yes and irrelevant. Those are tiny tanks, a few hundred kg max, filled once on the ground, heavily insulated, not tanks that are the load bearing walls of a launch vehicle containing 100s of tons of propellant, subject to constant inflow, outflow, connections and differing thermal and pressurization cycles while persisting for months in depots and years for interplanetary missions with lives on the line. Its comparing apples and orcas. Likely to be much harder doing long duration high volume cryo than expected and its absolutely mission critical. Many unknown unknowns.

[Robotbeat]

Yes and irrelevant? Tiny tanks?? You’re the one who used the Shuttle’s long duration mission tanks as an example!

Ugh, I’m so sick of all the bad faith discussion on the Internet. Complete inability to actually admit a point.

[sdsds]

[...] its absolutely mission critical.

The only prudent approach "before 2033" would be an operational concept where a cryogen storage anomaly results in a survivable mission abort. That works for an outbound trajectory arc on an ellipse with a period of 2 years since Earth will be there when you get back to perihelion.

[...] if you assume that the reason you aborted is because the Raptors aren't running.  That requires an Earth aerocapture

Your friends back on Earth have will have had two years to improve their technology. It's their job to conduct the rescue. At a minimum they should be able to send out enough supplies to let you loop around one more time. Four years is a long time to spend in space, but the crew of the Hermes were willing to loop around back to Mars to pick up Mark Watney....

[sdsds]

A 2:1 transfer orbit is still pretty sporty when it gets to Mars.  In the nominal case, even after applying more than 2.3km/s of braking delta-v, the periapse speed would still be something like 8.4km/s.  That's not your only choice for a free return,

Indeed you're right, it isn't the only option. In their Figure 12 Wooster et al. (2006) suggest the 3-year free return requires considerably less delta-v to rendezvous with Mars.
https://ssdl1.gatech.edu/sites/default/files/ssdl-files/papers/conferencePapers/AIAA-2006-6308.pdf

(I hope the attached image depicts that correctly.)

[VSECOTSPE]

The longest duration cryogenics have ever been used in American space flight is 17.5 days on a shuttle with an Extended Duration Orbiter tankage kit. Thats it. EDO was just an array of well insulated spherical tanks plumbed into the existing orbiter cryogenic system to power fuel cells and were not refilled, exposed to off nominal solar heating, or EDL stress.

NASA’s Robotic Refueling Mission-3 demonstrated zero boil-off over four months of 42 liters of LCH4 at the ISS using a cryocooler.

https://en.m.wikipedia.org/wiki/Robotic_Refueling_Mission

NASA and SpaceX transferred 10 metric tons of LOX between tanks on Starship’s third launch:

https://ntrs.nasa.gov/api/citations/20250003325/downloads/In-Space%20Cryogenic_Hauser.pdf

These advances obviously exceed the two-week-ish duration and couple-tons-of-cryogenics scale of the EDO pallet.

Scaling these advances up up and doing inter-vehicle transfers involves addressing knowledge gaps regarding non-linear coupling between the thermodynamics, the fluid dynamics, and the structural dynamics involved:

https://www.nature.com/articles/s41526-024-00377-5.pdf

These unknowns may be hard to overcome, or they may be trivial.  We just don’t know.  But the state of the art has moved beyond the Shuttle-era EDO.

FWIW...

[Helodriver]

Yes and irrelevant? Tiny tanks?? You’re the one who used the Shuttle’s long duration mission tanks as an example!

Ugh, I’m so sick of all the bad faith discussion on the Internet. Complete inability to actually admit a point.

EDO used as an example because that's the largest capacity long duration human mission cryo ever flown by anyone, ever, and its only 3,600 pounds of fluids for just 17.5 days.

Its nothing personal at all, but what's bad faith in internet discussion is to just assume storing orders of magnitude more cryo in comparatively Battlestar Galactica sized tanks a few millimeters thick for months and years is some kind of done deal, when its a top technological show stopping risk unavoidably inherent to the basic vehicle and mission architecture. Pure Handwavium.

The thread topic is humans to Mars by 2033, its 2025 and Starship cumulatively has what, less than 2 hours total time in space after 9 flights? The learning and achievement curve required is already steep with the hardest parts not even begun yet. I wish them success and luck, they're going to need it. Peace.

[TheRadicalModerate]

(I hope the attached image depicts that correctly.)

The 3-year in the paper is a 1.5:1, and it is indeed pretty sedate on Mars arrival.  You'd could almost do a propulsive capture with a v2-sized Starship.

[sdsds]

(I hope the attached image depicts that correctly.)

The 3-year in the paper is a 1.5:1, and it is indeed pretty sedate on Mars arrival.  You'd could almost do a propulsive capture with a v2-sized Starship.

This concept deserves more consideration. I think compared with a Hohmann style transfer it takes:
 - a bit more departure delta-V
 - a bit more arrival delta-V
 - a bit longer time in transit to Mars

In exchange it gets enhanced crew safety in the mission abort case. The green ellipse in the drawing is intended to have a semi-major axis of ~1.31 AU, for an orbital period of 1.5 years. It's a bit weird that for an aborted Mars encounter the ship first gets back to Earth's orbit when Earth is on the opposite side of the Sun; it needs to loop around a second time so Earth gets back to that location again.

I think it also provides the option (of perhaps dubious value) to launch much earlier in the window and target the second crossing of the Mars orbit.

[Greg Hullender]

Its nothing personal at all, but what's bad faith in internet discussion is to just assume storing orders of magnitude more cryo in comparatively Battlestar Galactica sized tanks a few millimeters thick for months and years is some kind of done deal, when its a top technological show stopping risk unavoidably inherent to the basic vehicle and mission architecture. Pure Handwavium.

Just in the interest of consistent nomenclature, to argue in bad faith means to make an argument you know is false. It is a particularly vicious form of bald-faced lying, so an accusation of bad faith should never be made lightly. But the key is that the person has to be doing it on purpose. Ignorance and wishful thinking don't count.

As Robotbeat points out, a lot of people resort to bad-faith arguments when they realize they're wrong but are unable to admit to it. I'd suggest that anyone who does that ought to be banned for life, but, sadly, some of the forum's best contributors (i.e. people who cite papers to support their points and who do their own math) have this failing. Sigh.

I don't think that's what happened this time, though. I think you two are just talking past each other. I like VSECOTSPE's post on the topic.

[Robotbeat]

I’m not calling for anyone to be banned. I’m just frustrated when someone moves the goal posts. Someone uses a relatively small scale example as an example of the current state of the art, I mention something of similar scale but with FAR longer cryogenic capabilities, they shift the goalposts of the argument back to “human mission” (which is not actually that relevant when discussing what is technologically possible as otherwise NASA would’ve insisted it be tested uncrewed first) and much larger scale (Battlestar Galactica) than their original example.

I think in orbit refueling is over rated as a difficulty compared to landing a large vehicle on an unprepared landing site. Mars has eaten a LOT of space probes, and they were all hypergolically fueled. The Moon has eaten lots of space probes recently, and not because some of them were cryogenically fueled.

[TheRadicalModerate]

(I hope the attached image depicts that correctly.)

The 3-year in the paper is a 1.5:1, and it is indeed pretty sedate on Mars arrival.  You'd could almost do a propulsive capture with a v2-sized Starship.

This concept deserves more consideration. I think compared with a Hohmann style transfer it takes:
 - a bit more departure delta-V
 - a bit more arrival delta-V
 - a bit longer time in transit to Mars

In exchange it gets enhanced crew safety in the mission abort case. The green ellipse in the drawing is intended to have a semi-major axis of ~1.31 AU, for an orbital period of 1.5 years. It's a bit weird that for an aborted Mars encounter the ship first gets back to Earth's orbit when Earth is on the opposite side of the Sun; it needs to loop around a second time so Earth gets back to that location again.

I think it also provides the option (of perhaps dubious value) to launch much earlier in the window and target the second crossing of the Mars orbit.

Loss-of-propellant accidents are a real risk on Mars flights.  They're mitigated to some extent (possibly to a large extent) by the existence of independent header tanks.  Loss-of-engine accidents I think are much less of a worry, simply because of engine redundancy.

Free-return makes sense when there's a legitimate case to be made that the entire main propulsion system could go down, and even then, the only cases where a free-return helps is if the vehicle can aerocapture at Earth, using only thrusters to manage its post-capture orbit.  (Note that thrusters are also vulnerable to loss-of-prop accidents, especially since Starship intentionally wants to to consolidate the prop supply for both main propulsion and thrusters.)

A two-year free return is a long time, and a three-year is a really long time.  However, the worse problem is if the constraints on the resonance force much longer transit times in the nominal cases.

I don't think that's necessarily a showstopper.  As long as the orbit period is right, there's no requirement that you depart from perihelion; you can create orbits with a perihelion less than 1AU, which will get you to Mars in <4 months, but still have orbital periods = 2.00000 years.


I think there are three key decision points in the mission:

1) Capture/no-capture:  Whether to do the trajectory correction that moves you inside Mars's Hill Sphere for however you're going to capture.  If you choose to abort, you free return.

Major reasons for abort:
a) Major questions about the viability of the main propulsion system.
b) Other structural damage that makes aerocapture/EDL non-viable.

2) Land/no-land:  If you've captured into a stable orbit, you need to decide whether you're in good enough shape to land.  If not, you abort back to Earth ASAP, using the shortest opposition-class orbit you can afford.

Major reasons for abort:
a) Structural damage incurred during aerocapture (e.g. loss of tiles).
b) Unacceptable ECLSS degradation, with no better backup on the surface.
c) Crew health, where a propulsive abort gets you home faster than the free return.

3) Stay/no-stay:  After you've landed, you need to evaluate whether the Ship is in good enough shape to remain on the surface:

Major reasons for abort:
a) Precarious landing attitude or surface conditions.
b) Unacceptable ECLSS conditions (but good enough for short-stay exploration).

[Robotbeat]

Whole ship redundancy (send ships in pairs) mitigates the risk you’re talking about.

[TheRadicalModerate]

I think in orbit refueling is over rated as a difficulty compared to landing a large vehicle on an unprepared landing site. Mars has eaten a LOT of space probes, and they were all hypergolically fueled. The Moon has eaten lots of space probes recently, and not because some of them were cryogenically fueled.

I'm not particularly worried about refueling per se, but loss of propellant accidents (through excessive boiloff, MMOD damage, or plain ol' structural failure) are a major in-transit risk.  There are things that mitigate that risk (e.g. header tanks), but contingency planning will be important.  Not sure I agree with sdsds that free-returns are necessary, but they might be.

That said, the way you mitigate these risks is you do long-term cislunar tests:  put a Starship in DRO or some other orbit that simulates interplanetary lighting conditions, let it sit for several months, then bring it home.  You can gather boiloff and fatigue data in exquisite detail--and you can do it whenever you want, unlike Mars EDL tests.  So this is only the critical path if the number of fly/evaluate/fix/fly cycles is so large that they exceed all the other critical paths that lead up to human missions.

Seems unlikely.

In re. landing on rough surfaces:  I'm assuming that you can double up on the thrusters needed for lunar landings and reduce Mars landing risk substantially.  I flatly don't believe that a Raptor will ever be throttleable to the point where it doesn't dig its own grave on natural surface--especially a dry natural surface.

The big question is what restrictions thrusters put on landable payload mass.

At 100t payload and a 160t dry mass, burnout thrust has to be 970kN.  The corresponding HLS thrust for a 15t payload (adequate for a crew module) and a 120t dry mass is 220kN.  That's a factor of 4.4, which, if you're doing it simply by adding more engines, is an awkward number, and a lot of engines.

On the other hand, if you're willing to live with 40t crew modules and lightly-loaded cargo ships, you're down to 750kN, a factor of 3.4.

Seems to me that 4 thrusters @ 60kN each allows you to do 5 with one-engine-out capability for the Moon, with a nominal throttle of 73%.  The comparable Mars system at 40t payload, also with one-engine-out capability, needs 14 engines, throttled to 89%.

Fourteen engines is a lot, especially with TPS in the way.ą  Maybe the answer is to over-design your HLS thruster to something like 125kN, with quite deep throttling. 


________
ąThere's a good case to be made that your return ride is in LMO for the duration of the surface mission.  That way, it doesn't matter what shape your TPS is in after the landing.

[Coastal Ron]

Whole ship redundancy (send ships in pairs) mitigates the risk you’re talking about.

A simple redundancy of 2X may work for two mature systems that could suffer a failure from outside factors (or just bad luck), but Starship is not yet mature, and having a second ship that could suffer from the same failure mode won't cut it for a multi-year mission.

Dissimilar redundancy is unlikely, since no one else is building an interplanetary spaceship at this time, so I would think that a small fleet of Starships would be the best way to reduce the risk, especially if it allows crews to survive in any mode (i.e. orbit or on the surface) until the next fleet arrives. Say 4-6?

[Robotbeat]

Engine out still works without dissimilar redundancy. Additionally, it’s sort of taken as a given that crew won’t be on the first landing.

[MickQ]

________
ąThere's a good case to be made that your return ride is in LMO for the duration of the surface mission.  That way, it doesn't matter what shape your TPS is in after the landing.

I think this should be standard procedure for at least the first few synods of crew landing.  Until TPS is absolutely reliable or able to be repaired before or during the return flight.

[Greg Hullender]

I'm assuming that you can double up on the thrusters needed for lunar landings and reduce Mars landing risk substantially.  I flatly don't believe that a Raptor will ever be throttleable to the point where it doesn't dig its own grave on natural surface--especially a dry natural surface.

Has anyone heard anything from SpaceX about these thrusters? I like the idea of a "Starling" engine, which is like a tiny Raptor that can handle liquid or gaseous propellants. Something you could use on a depot for long ullage burns without burning huge amounts of fuel and use on landers (maybe waist high) to avoid digging holes in the regolith. But it takes a long time to develop a new engine (or so I'm told), and I haven't heard a thing about this. Maybe I just missed it, or maybe they're playing this one very close to the vest, but it's another thing to worry about.

[Robotbeat]

They have fired them before. Some of the earliest Super Heavy boosters built had them, but I think they might have been removed before flight, not sure.

They’ve been in development for years but I don’t know the current status of them or how much SpaceX is investing in them at the moment.

[SpaceLizard]

I think there may be a common and deleterious conflation of the damage caused by 33 simultaneous 78%+ thrust Raptors firing and a single less than 60% thrust Raptor firing...

[sdsds]

Not sure I agree with sdsds that free-returns are necessary, but they might be.

As a matter of clarification, this was in the context of crewed missions before 2033. Pretty clearly it doesn't apply to missions without crew. It also might not apply once there have been some number of successful missions.

More generally it might make sense to ask why anyone would attempt a crewed mission before 2033 if it were technically feasible. The big one that comes to mind is prestige, particularly if prestige had been lost to an adversary in the new Moon race. Saving face, as some call it. Leap-frogging ahead to Mars might provide that, even with only a token fly-past mission.

[crandles57]

More generally it might make sense to ask why anyone would attempt a crewed mission before 2033 if it were technically feasible. The big one that comes to mind is prestige, particularly if prestige had been lost to an adversary in the new Moon race. Saving face, as some call it. Leap-frogging ahead to Mars might provide that, even with only a token fly-past mission.

By the time it is technically feasible, will Optimus have developed to the point it can be trained to do almost anything a human could, even if a little slower? Would the public then wonder if it is then prestige or just foolishly risky with little point/benefit versus doing stuff with robotics? Or does it remain easy to spin that you need scientists? engineers? others? on Mars?

Developing Starship and demonstrating it and talking up the capabilities in order to reduce launch costs and expand the launch market, I can see the investment case for doing this. The expense of developing, building and sending all that is needed for a colony, well maybe lots of large income streams develop over time but is this likely to be a good investment? Does this lead us more to: Talk up the inspiring possibilities and hope governments will pay good money for prestigious automated science oriented observation stations? Maybe you end up with spare capacity between projects to do stuff like build a base for humans for your extreme camping 3 year trip and things slowly develop from there?

If it develops more like this then it is obviously well beyond 2033.

Is SpaceX developing Starship but not doing much on colony development other than talking up inspiring possibilities? Is this justified by a goal oriented approach that you need Starship working before allotting much effort to colony development work? Is it there a lack of detail on colony development work? Is this justified by a need for secrecy or does it point more to the above develop Starship, talk inspiring stuff, and hope government contracts flow and otherwise wait and see what to do later?

Is this a more realistic view of what SpaceX is doing? Or overly cynical - know cost of everything and value of nothing?

(Perhaps this should move a different thread as it has drifted off topic?)

[Greg Hullender]

By the time it is technically feasible, will Optimus have developed to the point it can be trained to do almost anything a human could, even if a little slower?

Nope. No way in Hell. It might actually be useful for something by then, but that's the most to expect. As someone who spent a lifetime working on AI, I'm constantly amazed at how much people overestimate what it can do. The newest stuff is pretty cool--don't get me wrong--but it's not magic, and it never will be.

The expense of developing, building and sending all that is needed for a colony, well maybe lots of large income streams develop over time but is this likely to be a good investment?

No. There is no commercial reason to go to Mars in the 21st Century. Certainly not before 2033. Maybe not ever. Pretending otherwise is a mistake.

The Economist once published an article that argued there were four reasons to go to space: Money, Power, Knowledge, and Glory. Since there's no money and no military reason to go there, that leaves science (which is mostly satisfied by unmanned missions), and Glory. If you want a colony on Mars, you've got to hype the Glory angle for all its worth, because it's all you've got.

And, just for the record, I think a Mars colony (and a permanent lunar base) would be glorious!

[saturnsky]

No,,even with private investment,,the cost,,and the unknown risks of space, will be a major block....lets utilize the Moon first,,economic development, mineral exploitation, and see if humans can live for extended times on different worlds....

[crandles57]

No. There is no commercial reason to go to Mars in the 21st Century. Certainly not before 2033. Maybe not ever. Pretending otherwise is a mistake.

The Economist once published an article that argued there were four reasons to go to space: Money, Power, Knowledge, and Glory. Since there's no money and no military reason to go there, that leaves science (which is mostly satisfied by unmanned missions), and Glory. If you want a colony on Mars, you've got to hype the Glory angle for all its worth, because it's all you've got.

And, just for the record, I think a Mars colony (and a permanent lunar base) would be glorious!

no commercial reason
SpaceX develops starship to reduce launch costs per Kg and to expand the launch market.

Musk demonstrating Starship can put 100 tonnes cargo on Mars at a cost of say 6 starships to Mars, what effect does that have? Development costs are, of course, extra and much more but going to be spent anyway to develop it. The effect of this being done (or even just in progress) might well have an impact on ambition and on the Earth launch market. This seems like it could be commercially viable.

If it has an effect of causing scientists to want to put 100 tonnes of various telescopes on Moon and/or Mars and governments wanting the prestige of it at an expensive but affordable price, then the cargo demonstration cost may well have been commercially viable.

You probably don't send 100 tonnes of telescopes fully assembled so you have to have some ground preparation and building. Once that ground preparation and building work is done, you can abandon the equipment or use it. So you use it to make the next step look more economically attractive and this develops more in situ resources.

to go to Mars in the 21st Century. Maybe not ever.
We really don't know how things will develop over long periods - imagine discussing aeroplanes for rapid global transport for significant portions of population around 1880, before cars were common. How much government spending is needed to start such a process and make it sufficiently self sustaining is probably impossible to estimate, it might just be an amount they turn out to want to spend. Basically, never say never to commercial viability.

[Vultur]

I think it's correct to say that it's not commercially viable, at least considering the sort of timelines expected for return on investment.

But I also think that doesn't matter. There are ways around the need for commercial viability, e.g. a "Mars Settlement Foundation" set up with a sufficiently large initial capital that it can keep the ships flying just from interest.

(Now, in the longer term, being economically *self-supporting* is something quite different from the *initial settlement* being commercially viable.)

[sdsds]

I think it's correct to say that it's not commercially viable.

But I also think that doesn't matter. There are ways around the need for commercial viability, e.g. a "Mars Settlement Foundation" set up with a sufficiently large initial capital that it can keep the ships flying just from interest.

Indeed, and the U.S. government might not be the only viable sovereign customer/patron. And SpaceX might not be the only viable beneficiary of such patronage.

[Vultur]

I think it's correct to say that it's not commercially viable.

But I also think that doesn't matter. There are ways around the need for commercial viability, e.g. a "Mars Settlement Foundation" set up with a sufficiently large initial capital that it can keep the ships flying just from interest.

Indeed, and the U.S. government might not be the only viable sovereign customer/patron. And SpaceX might not be the only viable beneficiary of such patronage.

I actually wasn't talking about government patronage at all. I was talking about a private non-profit foundation, which would be immune from the difficulties of year by year government budgets - a risk a settlement like this can't really afford.

[Robotbeat]

Fundamentally, developing a colony on Mars is literally no different than on Earth except for a few things:

The pressure vessel, the energy, the heat rejection, and the oxygen as well as various mineral resources. And, of course, the logistics.

And let’s just say, for the point of argument, that the gravity is identical to Earth’s.

If you build an enormous 1km tall, 100km diameter pressurized hab on Mars, decently well-shielded (say in a cave network?) and with some sort of River or something to maintain temperature and a large light source to provide solar equivalent illumination.

You can use just regular earth equipment inside. Nothing different needs to be done. Farming would be done identically. You might want to develop carbonfree or carbon neutral methods of refining metals and stuff, but you don’t need a Mars CNC machine or a Mars hammer or a Mars toilet or a Mars water treatment facility. You can use the same basic stuff you use on Earth, just with more consideration maybe to atmospheric impacts and externalities (altho this is a long term issue… with a large air buffer, this doesn’t become an issue for like decades).

Eventually, you need to maintain your pressure vessel, your light source, your heat rejection. But you can presumably do that with normal earth designs for almost everything.

You may decide to use more efficient food production that makes stuff in vats to conserve pressurized volume and energy, but this is something companies on Earth already are doing. Vertical farms are already a thing.

A lot of the minerals on Mars are very similar to Earth and you’d mine them in similar ways.

You need to maintain your pressure vessel, but you’d use Earth style technology to do it.

Therefore the biggest thing SpaceX needs to do is to solve this logistics problem.

NASA has spent a ton of money miniaturizing stuff like life support and water treatment and to make the equipment work in zero gravity. But this is because they’re dealing with a much smaller scale. For a settlement the size of a city, you’d make oxygen using large scale industrial electrolyzers, capture CO2 with large equipment like used for making cement or maybe large scale amine based CO2 capture cycles. You’d take advantage of a level of gravity very similar (at least on a log scale) to Earth’s (compared to microgravity, a million times less) to not need special centrifugal separation systems.

There is the ability to use largely unmodified versions of Earth equipment if you manage to operate at a large enough scale.

And the main constraint for that is logistics. None of that works without getting mass to Mars as cheaply as possible. If you get launch and landing costs down by a factor of 10,000, you don’t need to reinvent everything as some exquisitely miniaturized process, you can just use Earth equipment. Which is much cheaper and more proven.

So it makes sense that SpaceX would be focusing on logistics, not reinventing all technology to work on Mars. There are a few things that need modification, like you have to use electrified versions of things a lot more, but that’s doable. SpaceX already has hundreds of megawatts worth of space rated solar array manufacturing capacity for Starlink and they are already planning to leverage that for Starship.

[crandles57]

Fundamentally, developing a colony on Mars is literally no different than on Earth except for a few things:
...
So it makes sense that SpaceX would be focusing on logistics, not reinventing all technology to work on Mars. There are a few things that need modification, like you have to use electrified versions of things a lot more, but that’s doable. SpaceX already has hundreds of megawatts worth of space rated solar array manufacturing capacity for Starlink and they are already planning to leverage that for Starship.

Sure logistics needs to come first and you don't need to reinvent all technology but ...

Most new cities we have built have had wood locally available as an easy to shape building material and most have fields suitable for agriculture. Sure we have some bases on Antarctica that don't have either of those. Shipping costs to Antarctica might increase the cost of some things by at least 5 fold. With Mars it will be more like 500 fold. This places extreme emphasis on in situ resource utilisation which forces you to try to do lots while little is available. 1g vs .38g adds to uncertainty of the best approach and how well things will work in an environment we don't have much experience with. So while the technology does not need reinventing, the different prices, unusual resource limitations, and gravity will mean lots does need to be redesigned to fit different needs we haven't really experienced before.

[TheRadicalModerate]

Fundamentally, developing a colony on Mars is literally no different than on Earth except for a few things:
...
So it makes sense that SpaceX would be focusing on logistics, not reinventing all technology to work on Mars. There are a few things that need modification, like you have to use electrified versions of things a lot more, but that’s doable. SpaceX already has hundreds of megawatts worth of space rated solar array manufacturing capacity for Starlink and they are already planning to leverage that for Starship.

Sure logistics needs to come first and you don't need to reinvent all technology but ...

Most new cities we have built have had wood locally available as an easy to shape building material and most have fields suitable for agriculture. Sure we have some bases on Antarctica that don't have either of those. Shipping costs to Antarctica might increase the cost of some things by at least 5 fold. With Mars it will be more like 500 fold. This places extreme emphasis on in situ resource utilisation which forces you to try to do lots while little is available. 1g vs .38g adds to uncertainty of the best approach and how well things will work in an environment we don't have much experience with. So while the technology does not need reinventing, the different prices, unusual resource limitations, and gravity will mean lots does need to be redesigned to fit different needs we haven't really experienced before.

What do either of these comments have to do with whether humans will go to Mars by 2033?  Land a small hab, or live in the lander:  that's all that's required in the timeframe.

[Robotbeat]

Fundamentally, developing a colony on Mars is literally no different than on Earth except for a few things:
...
So it makes sense that SpaceX would be focusing on logistics, not reinventing all technology to work on Mars. There are a few things that need modification, like you have to use electrified versions of things a lot more, but that’s doable. SpaceX already has hundreds of megawatts worth of space rated solar array manufacturing capacity for Starlink and they are already planning to leverage that for Starship.

Sure logistics needs to come first and you don't need to reinvent all technology but ...

Most new cities we have built have had wood locally available as an easy to shape building material and most have fields suitable for agriculture. Sure we have some bases on Antarctica that don't have either of those. Shipping costs to Antarctica might increase the cost of some things by at least 5 fold. With Mars it will be more like 500 fold. This places extreme emphasis on in situ resource utilisation which forces you to try to do lots while little is available. 1g vs .38g adds to uncertainty of the best approach and how well things will work in an environment we don't have much experience with. So while the technology does not need reinventing, the different prices, unusual resource limitations, and gravity will mean lots does need to be redesigned to fit different needs we haven't really experienced before.

I find it obvious that it;'s going to be way harder than past efforts.

But the logistics ARE the problem. All the things you need to convert random rocks and the Martian atmosphere into useful resources are industrial equipment largely already existing on Earth, not some new, hyper-weight-optimized new technology.

Also: the way to resolve uncertainty is to just start doing it. People physically on Mars will have the highest level of motivation and best information to actually solve the problems. Not analyze forever.

[crandles57]

What do either of these comments have to do with whether humans will go to Mars by 2033?  Land a small hab, or live in the lander:  that's all that's required in the timeframe.

While it does look like they are discussing a much slower timetables, in part it is about assessing the current situation: Is SpaceX really doing lots of colony development work or just talking inspiring stuff to try to expand the Earth launch market and only really developing Starship. It may be necessary to understand the current situation correctly in order to assess whether humans to Mars by 2033 is at all realistic.

[crandles57]

On the assess where are we now, how do you read:

“My boss Elon Musk founded this company @SpaceX in 2002 with the purpose of building rockets and spaceships to enable people to live on other planets”

Do you see it as a commitment to the colony development work and expense, or merely to starship development to 'enable' it without necessarily committing to the colony development work?

Is it a) Deliberately ambiguous to give inspiring impression they are planning to do colony development work without actually committing to much other than providing the transport i.e Starship?

b)  Musk/SpaceX are willing to fund some efforts to show it is possible, put some optimus on Mars as inspiring symbols of possibilities for PR and Earth launch market development but they will wait for government programs to either do or fund much of the colony development work?

c) They are intending on doing quite a lot of colony development as mildly limited funding permits but will try to pause in order to take any government assistance programs to help.

d) They are pretty much all in on doing lots of colony development as a large proportion of available funding permits regardless of whether there are government programs or funding to assist.

or some other option?

I am thinking b) maybe some of the way towards c) (change mildly to something nearer strictly? or maybe just for some limited time to see how it goes?)

[laszlo]

... the way to resolve uncertainty is to just start doing it.

As long as you don't mind potentially killing your entire crew. There's no quick return path for any of the currently feasible architectures. Any problem (hardware, physical or psychological) must be dealt with by the crew with the resources at hand. Other than a radio link, there will be no help from Earth for months or years. And if the problem involves the communication system, not even that.

Therefore it's vital that the issues are identified before flight so that the ship is carrying sufficient resources to handle them. A quick, just-do-it approach is not the way to go. Remember all the outrage about endangering astronauts by launching them on Starliner? That's nothing compared to a just-do-it Mars mission.

[Robotbeat]

What do either of these comments have to do with whether humans will go to Mars by 2033?  Land a small hab, or live in the lander:  that's all that's required in the timeframe.

While it does look like they are discussing a much slower timetables, in part it is about assessing the current situation: Is SpaceX really doing lots of colony development work or just talking inspiring stuff to try to expand the Earth launch market and only really developing Starship. It may be necessary to understand the current situation correctly in order to assess whether humans to Mars by 2033 is at all realistic.

They are not doing a bunch of serious colony development work. The hey have done some ISRU R&D, but the focus really is on Starlink, Starship, and maintaining Falcon & Dragon operations. starship Ground support equipment and logistics plays into eventual ISRU development.

Starlink plays into ISRU development in the form of power production. Assume optimistically you need 1000tons of methalox to get back. 200t of Methane made at 50% efficiency using solar arrays 1.5AU further away and only a 25% capacity factor needs 3MW of nominal peak power over 26 months. That’s probably overly optimistic, let’s call it 5MW due to dust, cryo cooling, etc.

5MW of space rated solar cells from a traditional vendor would be about $5B. And would use up all their capacity.

But Starlink v3 at 60kW per satellite, 40000 satellites replaced every 5 years, accounts for about 500MW of solar array production every year. The arrays are much cheaper, too, potentially as cheap as $1/Watt, reducing the cost of a Starship’s surface ISRU arrays to $5M (not counting transport…at 100W/kg, that 5MW has a mass of 50t).

So power production and some of the cryogenic aspects of ISRU which might have commonality with Earthside GSE are two pretty important parts of the puzzle they’re working on anyway. Although the large surface solar arrays would be deployed differently than with Starlink.

[Vultur]

... the way to resolve uncertainty is to just start doing it.

As long as you don't mind potentially killing your entire crew. There's no quick return path for any of the currently feasible architectures. Any problem (hardware, physical or psychological) must be dealt with by the crew with the resources at hand. Other than a radio link, there will be no help from Earth for months or years. And if the problem involves the communication system, not even that.

Therefore it's vital that the issues are identified before flight so that the ship is carrying sufficient resources to handle them. A quick, just-do-it approach is not the way to go. Remember all the outrage about endangering astronauts by launching them on Starliner? That's nothing compared to a just-do-it Mars mission.

I don't think it's going to be totally "cowboy" but I do think the risk assumed will be significantly higher than NASA would be comfortable with.

But the plan involves pre-placed cargo flights, and Starship is large. There's a lot of room for redundant equipment and supplies. Waiting an extra synod if return isn't "go", for the next cargo Starships to arrive, should be survivable - that's a key point.

Also, those pre-placed cargo flights will test out the system before putting humans on it. I am sure there will be life support test flights nearer Earth (may not be Polaris 3 anymore, but it'll probably be done in some form).

I would expect there'd be a previous synod of flights to Mars before the actual pre-placing cargo flights, too - either intentionally or because the first round of cargo flights fails or isn't successful/smooth enough to send humans next go.

(That's why I don't think before 2033 is possible. Launching some Starship to Mars in 2029 synod feels entirely reasonable if they don't have a truly major - years long - stand down: but it's being successful enough to set up for humans in 2031 not so much.)

[Robotbeat]

Yeah, the way to avoid just cowboying it is to preplace hundreds of tons of cargo with extremely high reliability, back ups and spares, like just normal disposable CO2 scrubbers and oxygen candles and freeze-tolerant bags of water and food (kept cold outside—maybe not literally outside, but thermally insulated from the interior—, food will last for decades and still being nutritious… A lot of the difficulty Nasa has had with shelf stable items isnt radiation or whatever, but that they don’t typically store food in a freezer so vitamin C degrades. This is not a problem if you keep things frozen).

[Robotbeat]

Although… including some regenerative CO2 scrubbers (Orion, Shuttle, submarine, or space station heritage) and some Walmart room dehumidifiers (and backpack camping water filters) and some cheap water electrolyzers or MOXIE would help with reducing the need to dip into those supplies.

[Vultur]

I think both is likely. Use regenerative life support and ISRU oxygen (they'll be making vast quantities of oxygen for fuel ISRU anyway) as plan A, bring tons of backup supplies as plan B for survival if there is a problem with plan A.

If initial crews are small, 4 years of backup life support consumables should be totally workable.

[Robotbeat]

Backup supplies are also the perfect thing to send on early test missions. well-packaged granola bars and freeze-tolerant water bags/bottles and soft passive CO2 scrubbing lithium hydroxide curtains and even well-packaged oxygen candles will likely still be somewhat salvageable if the starship falls over in a landing attempt.

There actually are low cost Earth developed versions of this stuff. They’re a regulatory requirement for mine shelters (or airplanes, in the case of oxygen candles), for instance, and backup supplies used by the military for submarines or medical equipment. So you can buy the stuff in bulk from certified providers and adapt it for Mars.

[TheRadicalModerate]

I think any chance at refueling being up and running at a scale adequate to do Mars tests in late 2026 just went out the window.

[Vultur]

I doubt this one explosion changes the timeline *that* much. It's what may say about the overall state of the program that might.

OTOH, if V3 doesn't have these issues...

(I was already very skeptical about Mars stuff in 2026, but I don't think this specific incident moves the needle that much, except in that it makes "nothing much will get done until V3" more likely.)

[Robotbeat]

Upper stage failures during tests happen. Happened to ULA, in fact. It sucks, but it’ll be fine.

[soyuzu]

Upper stage failures during tests happen. Happened to ULA, in fact. It sucks, but it’ll be fine.

Every Starship V2 produced so far failed at some point is not fine, though. Many rockets was cancelled with equal or less continuous failure.

[daedalus1]

The third Mars launch window from now will definitely not carry humans. So the answer to this thread question is - no.

[Apollo22]

Upper stage failures during tests happen. Happened to ULA, in fact. It sucks, but it’ll be fine.

Every Starship V2 produced so far failed at some point is not fine, though. Many rockets was cancelled with equal or less continuous failure.

Like Europa, Ariane ancestor. The Blue Streak worked fine (just like Super Heavy, btw), but everything above it was crap and never worked properly together. The core reason was that every nation involved worked its own separate way : nobody cared about full integration.