Possible cost-reduction possibilities for the NASA portions of MSR

[Eric Hedman]

A modern BEV with a 70 kWh battery and a mass of 2 tonnes can easily run a couple hundred km without a recharge, carrying a ~200

Handwaving nonsense.  try 1 tonne

No, Exastro has it about right.  A Long-range Tesla Model 3 has a 75kWh battery and a gross mass of about 1.8t.

But the weight makes the rolling resistance worse, and it also puts a limit on cornering capability, because inertia is not your friend.  And the cornering capability is ultimately what's going to limit your speed to something very slow, even if your vision system has superhuman performance.

I am talking about rover on Mars.  we haven't landed more than a ton.

And that is the problem with this mission.  It doesn't fit easily into the one ton limit of existing technology used on Mars.  The mission architecture ignored this and that's why this pickle exists.  It will be interesting to see if a practical solution is put forth that is affordable.  I have serious doubts.

[edzieba]

A modern BEV with a 70 kWh battery and a mass of 2 tonnes can easily run a couple hundred km without a recharge, carrying a ~200

Handwaving nonsense.  try 1 tonne

No, Exastro has it about right.  A Long-range Tesla Model 3 has a 75kWh battery and a gross mass of about 1.8t.

But the weight makes the rolling resistance worse, and it also puts a limit on cornering capability, because inertia is not your friend.  And the cornering capability is ultimately what's going to limit your speed to something very slow, even if your vision system has superhuman performance.

I am talking about rover on Mars.  we haven't landed more than a ton.

Sorry, I didn't include the context to make the point clear.  The hope is that a specialized surface transport capable of covering long distances quickly would help enable the use of a Starship-like lander which could be cheap and could deliver tens of tonnes to the surface, but which is excluded from landing close to the MSR samples by planetary-protection considerations.

This fast, AI-guided rover is suggested as a potential alternative to the ballistic hopper suggested above.

'Fast' is a non-requirement - the sample tubes do not have a use-by date. It add a lot of complexity, cost, and several new failure modes, for no practical benefit.

[dglow]

A modern BEV with a 70 kWh battery and a mass of 2 tonnes can easily run a couple hundred km without a recharge, carrying a ~200

Handwaving nonsense.  try 1 tonne

No, Exastro has it about right.  A Long-range Tesla Model 3 has a 75kWh battery and a gross mass of about 1.8t.

But the weight makes the rolling resistance worse, and it also puts a limit on cornering capability, because inertia is not your friend.  And the cornering capability is ultimately what's going to limit your speed to something very slow, even if your vision system has superhuman performance.

I am talking about rover on Mars.  we haven't landed more than a ton.

Sorry, I didn't include the context to make the point clear.  The hope is that a specialized surface transport capable of covering long distances quickly would help enable the use of a Starship-like lander which could be cheap and could deliver tens of tonnes to the surface, but which is excluded from landing close to the MSR samples by planetary-protection considerations.

This fast, AI-guided rover is suggested as a potential alternative to the ballistic hopper suggested above.

'Fast' is a non-requirement - the sample tubes do not have a use-by date. It add a lot of complexity, cost, and several new failure modes, for no practical benefit.

Agree. Autonomous roving on Mars has the luxury of time, with the ability to slow or stop for further analysis whenever needed. Being the only mass of consequence in motion sets this task apart from Terran taxis.

[TheRadicalModerate]

'Fast' is a non-requirement - the sample tubes do not have a use-by date. It add a lot of complexity, cost, and several new failure modes, for no practical benefit.

Agree. Autonomous roving on Mars has the luxury of time, with the ability to slow or stop for further analysis whenever needed. Being the only mass of consequence in motion sets this task apart from Terran taxis.

In the context we were discussing, namely a hypothetical Cat II region, far away from Jezero, where a Starship or other dirty, heavy lander could land, "fast" is a requirement, if the goal is to return stuff by 2040.  Hundreds of km of traverse and return in less than a decade requires a substantial speed-up of the system.  Also, time and distance increase the risk of a rover failure.

Note that this is why I'm skeptical that a long-distance fetch rover is a viable solution.  It's possible than an aircraft will work, but it seems to me that a Cat IVb-compliant hopper is a better solution.

All of this of course assumes that the Cat II region is created, and Starship is selected for the mission.  Neither of these seems particularly likely, unless efforts to find the needed performance in the MAV (in its current mass and volume constraints) fails.

[Exastro]

This fast, AI-guided rover is suggested as a potential alternative to the ballistic hopper suggested above.

'Fast' is a non-requirement - the sample tubes do not have a use-by date. It add a lot of complexity, cost, and several new failure modes, for no practical benefit.

Agreed that getting the sample tubes back quickly is not necessary. 

But I'd suggest that a rover that moves much faster than MER (but much slower than typical automobile traffic) would have significant advantages.  For example, it doesn't need to be as tolerant of radiation or of temperature extremes, both of which are likely to matter if it's carrying anything like a commercial AI system and battery pack.  A rover that can accomplish its retrieval mission in a day or a few days makes it a lot easier to design an ascent or return vehicle that uses cryogenic prop, perhaps drawn from the big lander it arrived on, potentially enabling that part of the architecture to be lighter, smaller, simpler, and/or higher performing.  A fast rover is less likely to be exposed to dust storms.  And if it fails its mission by breaking down, it does so quickly enough to allow another fast rover to potentially drive to it, collect the samples it's carrying, and finish the mission.

Not sure what these new failure modes are.  The most obvious one might be a kinetic crash into an obstacle (which pretty much has to be a rock IIUC).  But it seems straightforward to design a rover that can survive that at the speeds much faster than MER.  The second failure mode would be getting flipped, which could be hard to mitigate by sheer toughness but could be handled by good suspension design and simply slowing down in terrain where the risk of getting flipped is high and driving around the obstacle isn't practical.

[dglow]

'Fast' is a non-requirement - the sample tubes do not have a use-by date. It add a lot of complexity, cost, and several new failure modes, for no practical benefit.

Agree. Autonomous roving on Mars has the luxury of time, with the ability to slow or stop for further analysis whenever needed. Being the only mass of consequence in motion sets this task apart from Terran taxis.

In the context we were discussing, namely a hypothetical Cat II region, far away from Jezero, where a Starship or other dirty, heavy lander could land, "fast" is a requirement, if the goal is to return stuff by 2040.  Hundreds of km of traverse and return in less than a decade requires a substantial speed-up of the system.

Okay, but the 'luxury of time' point was with respect to Terran taxis. Enormous speedups are available if the baseline/floor is our current fleet of rovers, while still operating well below the needs (top speed, reaction times) of robotaxis.

Note that this is why I'm skeptical that a long-distance fetch rover is a viable solution.  It's possible than an aircraft will work, but it seems to me that a Cat IVb-compliant hopper is a better solution.

All of this of course assumes that the Cat II region is created, and Starship is selected for the mission.  Neither of these seems particularly likely, unless efforts to find the needed performance in the MAV (in its current mass and volume constraints) fails.

I'm in favor of the Starship-as-orbiting-lander-dispenser approach, using multiple landers of existing, proven design where none of them push up against current mass limits.

[TheRadicalModerate]

I'm in favor of the Starship-as-orbiting-lander-dispenser approach, using multiple landers of existing, proven design where none of them push up against current mass limits.

That's where I started out, but the problem is that you can only leverage the Starship performance if you completely redesign the landers, and that's too much risk for MSR.  (Starship itself as a vehicle capable of carrying a lander into LMO is also a fair amount of risk, but I think that's manageable--if you can come up with a really compelling reason why leveraging the mass and volume reduces lander risk, which is harder.)

Maybe Starship is a complete no-brainer from a cost standpoint, and can be used to send a couple of 5.4m landers to MTO.  But so can an FH, or a Vulcan, or a New Glenn.  That's really a NASA LSP decision, not an architectural one.

[TheRadicalModerate]

Companies describe studies to revise Mars sample return.

NorGrumm describes MAV mass-reduction (but doesn't appear to be considering going to liquid fuel).  LockMart waves its arms about systemic mass reduction.  Quantum pitches an ERO that hands off the OS to their reentry vehicle, effectively eliminating the EEV mass, which in turn I guess reduces CCRS mass.  Boeing, despite explicitly not being invited to the party, pounds the table on their Block 2-launched monstrosity.

Not a peep from SpaceX.  But the report is from a panel at AIAA ASCEND.  They might not have been on the panel.

[StraumliBlight]

Companies describe studies to revise Mars sample return.

While searching for the ASCEND "Mars Sample Return (MSR) Reimagined" presentation slides, I found these abstracts uploaded to the AIAA last week:

 • Mars Sample Return Earth Entry System Helicopter Drop Test Reconstruction

 • Aerothermal Analysis and Environment Predictions for the Mars Sample Retrieval Lander (SRL)

In particular, SRL is being designed to enter Mars atmosphere at velocities as high as 8 km/s, which would be the highest for a Mars entry, and is expected to encounter additional shock layer radiation physics compared to previous missions.

 • Preliminary Design of the Supersonic Disk-Gap-Band Parachute for Sample Retrieval Lander

Sample Retrieval Lander requires landing a heavier payload than has ever been attempted on Mars. In support of this endeavor, a 24-meter diameter Disk-Gap-Band parachute is under development.

 • Sample Retrieval Lander Parachute System Deployment Test Campaigns: Modeling, Testbed Development, and Intermediate Results

To reduce risk of canopy damage and better understand mortar velocity upper bound, the Dynamic Extraction Testbed originally used for ExoMars testing was revamped to simulate parachute deployment at high velocity. A test campaign was planned, using a 300-foot zipline and force device to accelerate a trolley above the maximum predicted velocity of 61 m/s and drop the parachute pack.

[thespacecow]

An alternative Mars Sample Return program

As currently envisioned, MSR does little to advance Mars exploration in the long run, and by sucking up a lot of budget and energy may arguably wreak havoc on the rest of the NASA robotic exploration program. An obvious alternative is to re-invent MSR as the first step toward landing humans on Mars rather than as a one-shot effort consisting of technology that is unlikely to benefit a human mission to the surface of Mars.

...

Given that NASA is already committed to making Starship/Super Heavy work as a lunar landing system, the logical next step would be to build on that experience and re-use the basic structure to land on Mars. What better way to test out that architecture than by using it for Mars Sample Return?

Basically the exact same thing I said a few months ago in this thread.

[Jim]

An alternative Mars Sample Return program

As currently envisioned, MSR does little to advance Mars exploration in the long run, and by sucking up a lot of budget and energy may arguably wreak havoc on the rest of the NASA robotic exploration program. An obvious alternative is to re-invent MSR as the first step toward landing humans on Mars rather than as a one-shot effort consisting of technology that is unlikely to benefit a human mission to the surface of Mars.

...

Given that NASA is already committed to making Starship/Super Heavy work as a lunar landing system, the logical next step would be to build on that experience and re-use the basic structure to land on Mars. What better way to test out that architecture than by using it for Mars Sample Return?

Basically the exact same thing I said a few months ago in this thread.

two wrongs don't make a right.

[thespacecow]

An alternative Mars Sample Return program

As currently envisioned, MSR does little to advance Mars exploration in the long run, and by sucking up a lot of budget and energy may arguably wreak havoc on the rest of the NASA robotic exploration program. An obvious alternative is to re-invent MSR as the first step toward landing humans on Mars rather than as a one-shot effort consisting of technology that is unlikely to benefit a human mission to the surface of Mars.

...

Given that NASA is already committed to making Starship/Super Heavy work as a lunar landing system, the logical next step would be to build on that experience and re-use the basic structure to land on Mars. What better way to test out that architecture than by using it for Mars Sample Return?

Basically the exact same thing I said a few months ago in this thread.

two wrongs don't make a right.

It's not wrong at all, given NASA chose SpaceX to do a study of Starship MSR. What's wrong is people still claiming Starship is unsuitable for MSR even after NASA's move.

[redliox]

How far has ISRU factored in?

[dglow]

How far has ISRU factored in?

To date not at all, and I'd wager that none of the studies/proposals involve ISRU.

[Eric Hedman]

How far has ISRU factored in?

This shouldn't figure in at all.  NASA should want a Mars Ascent Vehicle that is as simple as possible and basically ready to launch into Mars orbit just as it lands on Mars.  You want samples loaded and ready to launch with no more complications than necessary such as fueling with local resources.

[VSECOTSPE]

It's not wrong at all, given NASA chose SpaceX to do a study of Starship MSR. What's wrong is people still claiming Starship is unsuitable for MSR even after NASA's move.

NASA let a $1.5M contract for SX to study using Starship in all phases on MSR.  SX got kudos for working with JPL and including a 2029 demo mission in he proposal.  But that’s all.  There’s no further phase, downselect, or funding.  SX got one of seven funded industry studies.  The seven industry studies will be reviewed by a NASA panel, along with studies from APL and an unreleased number of NASA field centers, and if there’s any “there, there” in one or more studies, those studies will be forwarded to the MSR program office, which is working on its own plan.  That’s it.  There’s no further commitment.

Based on the language in Figueroa’s independent review and from science AA Fox, it’s pretty clear that the program office is pursing a disaggregated architecture of a couple relatively proven Perserverance-sized landers and a smaller MAV.  Unless that architecture doesn’t close with adequate margin or unless there’s no funding by a long shot to afford it, there’s no reason for NASA to take on the uncertainties and risks of a plan like SX’s and probably most of the other MSR industry studies.  Those studies were undertaken to leave no stone unturned, not to downselect or define the architecture.  Stranger things have happened, but aside from the two (I think) industry MAV studies, the industry studies are unlikely to have an impact on the MSR architecture going forward.

[Exastro]

It's not wrong at all, given NASA chose SpaceX to do a study of Starship MSR. What's wrong is people still claiming Starship is unsuitable for MSR even after NASA's move.

Blah blah

None of these invalidate anything I said.
.
.

With due respect, let's be more respectful to each other than that.

[VSECOTSPE]

None of these invalidate anything I said.

You wrote:

given NASA chose SpaceX to do a study of Starship MSR.

There is no given beyond the study.  In fact, there’s nothing beyond the study — no follow-on, no downselect, no funding.  There’s just the potential for a referral to the MSR program office if an unrelated NASA review thinks there’s any merit — a program office that, rightly or wrongly, is developing its own solution to MSR.   Anything is possible, but the chance the SX study goes anywhere approaches nil.  The study doesn’t mean what you think it means.

The study is akin to writing a resume for a job that a company is already filling internally.  Yeah, if the company guy getting the job gets run over by a bus, then maybe an outside applicant has a shot.  But otherwise, the position is being filled by someone inside the company, not any outside applicants.

[thespacecow]

None of these invalidate anything I said.

You wrote:

given NASA chose SpaceX to do a study of Starship MSR.

There is no given beyond the study.  In fact, there’s nothing beyond the study — no follow-on, no downselect, no funding.

Did I say there's anything beyond the study? No, I didn't.

So again: "None of these invalidate anything I said."

[VSECOTSPE]

Did I say there's anything beyond the study? No, I didn't.

Again, you wrote:

given NASA chose SpaceX to do a study of Starship MSR.

As if that’s a big step forward and somehow validates a Starship architecture for MSR.  I’m telling you, as a ~30-year veteran of this sector, that it doesn’t validate anything and is not a big step forward.  Entire bookshelves in this industry are filled with final reports from studies that went nowhere.  In this particular case, the customer — the MSR program office — is pursuing its own MSR architecture.  Even if the NASA committee reviewing the industry studies forwards the Starship study to the MSR program office, the only reason the MSR program office would seriously entertain the Starship study is if they could not get their MSR architecture to close technically and/or budgetarily.  That’s unlikely and even if that did happen, the MSR program office would then have to go out with some kind of solicitation for an “external” (for lack of a better term) MSR architecture that SpaceX would still have to propose against and win (or not).

If NASA had put a multi-billion dollar solicitation on the street for an MSR architecture — like they did a few years back for the HLS crew landers under Artemis — then we’d have something to talk about and could spitball the odds on who’s going to win.  But that’s not where MSR is at and probably never will be.  It’s just a study and almost certainly a dead-end one, to boot.

"None of these invalidate anything I said."

It’s not about you.  It’s about portraying the situation factually and accurately.

If you really seek validation from an online discussion group about civil space missions, then you probably need to step away from the keyboard for awhile and interact with people without a screen in between you.