Author Topic: Possible cost-reduction possibilities for the NASA portions of MSR  (Read 104776 times)

Offline edzieba

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Looks like the edge of isidis planita looks is about a 100km away, and thats assuming driving in a straight line, and that it is smooth and flat there on the edge too. 
Landing hundreds of km away is not an option.

Thats the issue with all these "Starship will fix everything" ideas. When you look at doing it, gigantic and very expensive questions keep coming up that people like to handwave away
The same 'handwaving' would be required for any lander that cannot land in Jezero. If that arbitrary "you need to land far away" limitation is removed, then like any other lander it can land closer.
A limitation introduced by handwaving can also be removed thus.

Offline deadman1204

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Looks like the edge of isidis planita looks is about a 100km away, and thats assuming driving in a straight line, and that it is smooth and flat there on the edge too. 
Landing hundreds of km away is not an option.

Thats the issue with all these "Starship will fix everything" ideas. When you look at doing it, gigantic and very expensive questions keep coming up that people like to handwave away
The same 'handwaving' would be required for any lander that cannot land in Jezero. If that arbitrary "you need to land far away" limitation is removed, then like any other lander it can land closer.
A limitation introduced by handwaving can also be removed thus.
If you recall, this silly thing about landing over there came up because its a "safe and easy" place to land instead of on hilly boulder fields.
So we are back to pretending that starship can land on steep slopes full of boulders and and not fall over/dig holes/blow up/damage engines/ect

Offline TheRadicalModerate

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How close is 'immediate' and how does it compare to rover distances traversed to date? Any rugged terrain in between?
Jezero is on the border of Isidia Planaria. Unfortunately Isidis Planitia is to the East of Jezero, and Perseverance is currently climbing the Western rim of Jezero; so either Perseverance would need to double-back its existing journey (aided by retracing a known-good path) and then climb the opposite rim, or a fetch rover would need to detour around Jezero to meet Perseverance or drive down into Jezero then trace Perseverance's Western climb, or a 'fetch helicopter' would need the range endurance to feasibly fly across Jezero the Perseverance and back (likely multiple times to fetch all sample canisters).

Landing location is a challenge all proposals will share, so all will need to tackle their case for landing nearby, or their case for traversing from a more distance site. This is also a challenge for the original MSR proposal, which (after elimination of the fetch rovers and fetch helicopters) would be immobile so reliant entirely on Perseverance to traverse to it.

I didn't realize that the west side of Jezero was watershed for the gullies penetrating the crater walls.  That likely makes it Cat IV territory, even if there were a policy in place to relax some areas to Cat II.

I suspect any landing location that's farther than a few km away from either Three Forks or a likely location for Perseverance starts to get scored as high risk.  IMO, that rules out Isidia Planaria (which likely could be relaxed to Cat II).

Offline TheRadicalModerate

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To clarify, you’re saying you think it’s dumb if the landed starship is also the return vehicle, correct?

How do you think this changes if there is no intention for the landed starship to take off again? (i.e. the payload is a MAV?)

Hadn't thought about landing a Starship with a MAV.  That might work, especially since it would allow the MAV to be 6-7.5m long, and up to 2m wide.

The MAV could sit horizontally on the garage deck, and be rotated into launch position (i.e., pointed out the hatch).  The issue would be how you launch the silly thing.  It's possible that you can catapult it out of of the garage's hatch.  It'll be ~37m in the air, so as long as the SRM can fire and gimbal to keep it from hitting the ground, that might work.  This would make the landed Starship's tilt tolerances quite critical, though.  It might require some sort of leveling mechanism to overcome worst-case tilt on landing.  It also might require some kind of opposite-side leg bracing to counteract the recoil from catapulting it out of the hatch.

This isn't that different from how the plan-of-record MAV is intended to be launched.  However, since this MAV could be substantially larger, all of the mass margin problems would go away.

Figure an expendable landed Starship, nearly no prop at landing, and a payload (elevator, fetch rover / helicopter(s), and MAV) of 4t.  Total waist thruster thrust would be ~530kN.  This would take about 350t of prop from LEO, which would be maybe 260t of prop via tankers--two launches.

However, now you really need either the ERO or a second StarKicker in LMO.

Note that none of this obviates the need for Cat II clearance for a landing site close enough to Perseverance and/or Three Forks.

Offline edzieba

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Looks like the edge of isidis planita looks is about a 100km away, and thats assuming driving in a straight line, and that it is smooth and flat there on the edge too. 
Landing hundreds of km away is not an option.

Thats the issue with all these "Starship will fix everything" ideas. When you look at doing it, gigantic and very expensive questions keep coming up that people like to handwave away
The same 'handwaving' would be required for any lander that cannot land in Jezero. If that arbitrary "you need to land far away" limitation is removed, then like any other lander it can land closer.
A limitation introduced by handwaving can also be removed thus.
If you recall, this silly thing about landing over there came up because its a "safe and easy" place to land instead of on hilly boulder fields.
So we are back to pretending that starship can land on steep slopes full of boulders and and not fall over/dig holes/blow up/damage engines/ect
What a shame Jezero is 100% covered with "steep slopes full of boulders" and thus landing Perseverance there was an impossibility and did not occur.
Oh, wait...

Offline thespacecow

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There are very basic problems of landing starship on a sloped boulder field without falling over, or the engines digging a hole and falling over. It won't be able to use the tiny engines that hls is proposing.

What sloped boulder field?

You think NASA is stupid enough to drop the sample tubes in a sloped boulder field, knowing full well they'll need to land a lander nearby to pick them up?

And there's nothing preventing the HLS landing thrusters from being used on Mars. Also there's nothing preventing SpaceX from landing some bulldozers to clear the landing zone and build a proper landing/takeoff site from prefab materials.
That part where everyone is talking about using starship for MSR, not the broad featureless plains where insight landed.

What "broad featureless plains where insight landed"?

You do know the broad featureless plain images I posted come from Perseverance, not Insight, right?



Quote from: deadman1204
I ask these questions, because I'm thinking about the actual issues, not the fanfiction which describes most starship discussion

If you have really been thinking, you'd realize NASA wouldn't just drop the sample tubes in a random place, let alone a place difficult to land, because they know in advance they'll need to land a lander nearby, so one of the most important criteria for selecting the sample depot site is that it has a nice, flat, easy to land area nearby.

And NASA being NASA, they wouldn't just check this out from orbital survey, they'll actually drive Perseverance there to do a scouting on the ground for MSR. This is *exactly* what has happened.

The fact that you don't even know this shows how little you care about Mars 2020 mission and MSR, so what are you even doing here?

Offline TheRadicalModerate

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What a shame Jezero is 100% covered with "steep slopes full of boulders" and thus landing Perseverance there was an impossibility and did not occur.
Oh, wait...

I hate to sound like a broken record, but arguing the different preconditions for this separately is kinda pointless, at least if we're talking about a Starship landing.  A Starship landing site must:

1) Be close enough to Perseverance and/or Three Forks to be de-risked, AND...
2) Have terrain that is smooth enough to de-risk a landing (and ascent), AND...
3) Be re-classifiable to Category II.

You have to satisfy all three of these to have a Starship mission that works.

Now, if you have a clean, Cat IV-compliant lander, we know that there are spots near Three Forks that satisfy conditions #1 and #2, because Perseverance landed near there, while #3 is moot.  Given that a Cat IV-compliant lander is also considerably smaller than a Starship, with a lower CoG, it's also likely that there are acceptable Cat IV landing sites--even fairly rough ones--close to Perseverance.  So site selection, for a traditional Cat IV lander, while not trivial, certainly isn't a showstopper.  The same can't be said for Starship.

Offline Todd Martin

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JAXA has a Phobos sample return mission scheduled for launch in 2026 with a desire to follow up afterward by assisting with MSR.  JAXA has a launch vehicle, scientists and engineers with experience in sample return missions, and rover collaboration with Germany and France.  I suggest that JAXA be invited to provide and deliver fetch rovers as well as the sample return canister.  NASA would still provide and deliver a MAV (Mars ascent vehicle).

Offline mikelepage

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To clarify, you’re saying you think it’s dumb if the landed starship is also the return vehicle, correct?

How do you think this changes if there is no intention for the landed starship to take off again? (i.e. the payload is a MAV?)

Hadn't thought about landing a Starship with a MAV.  That might work, especially since it would allow the MAV to be 6-7.5m long, and up to 2m wide.

The MAV could sit horizontally on the garage deck, and be rotated into launch position (i.e., pointed out the hatch).  The issue would be how you launch the silly thing.  It's possible that you can catapult it out of of the garage's hatch.  It'll be ~37m in the air, so as long as the SRM can fire and gimbal to keep it from hitting the ground, that might work.  This would make the landed Starship's tilt tolerances quite critical, though.  It might require some sort of leveling mechanism to overcome worst-case tilt on landing.  It also might require some kind of opposite-side leg bracing to counteract the recoil from catapulting it out of the hatch.

This isn't that different from how the plan-of-record MAV is intended to be launched.  However, since this MAV could be substantially larger, all of the mass margin problems would go away.

Figure an expendable landed Starship, nearly no prop at landing, and a payload (elevator, fetch rover / helicopter(s), and MAV) of 4t.  Total waist thruster thrust would be ~530kN.  This would take about 350t of prop from LEO, which would be maybe 260t of prop via tankers--two launches.

However, now you really need either the ERO or a second StarKicker in LMO.

Note that none of this obviates the need for Cat II clearance for a landing site close enough to Perseverance and/or Three Forks.

Attaching a quick and dirty animation of what I was thinking. MAV in this animation is nearly 11m long, 1.4m diameter. Assuming some kind of mechanism to redirect MAV thrust out the slot hatch at the bottom. I was hoping this would be enough to do direct return to Earth.

No crane mechanism here: this setup presumes that another part of the starship payload (alongside the MAV) is some kind of platform for fetch copter deployment/landing, and a clean room/airlock system where the fetch copters can drop the samples and have them containerised into what goes into the MAV payload capsule.

How close is 'immediate' and how does it compare to rover distances traversed to date? Any rugged terrain in between?
Jezero is on the border of Isidia Planaria. Unfortunately Isidis Planitia is to the East of Jezero, and Perseverance is currently climbing the Western rim of Jezero; so either Perseverance would need to double-back its existing journey (aided by retracing a known-good path) and then climb the opposite rim, or a fetch rover would need to detour around Jezero to meet Perseverance or drive down into Jezero then trace Perseverance's Western climb, or a 'fetch helicopter' would need the range endurance to feasibly fly across Jezero the Perseverance and back (likely multiple times to fetch all sample canisters).

Landing location is a challenge all proposals will share, so all will need to tackle their case for landing nearby, or their case for traversing from a more distance site. This is also a challenge for the original MSR proposal, which (after elimination of the fetch rovers and fetch helicopters) would be immobile so reliant entirely on Perseverance to traverse to it.

I didn't realize that the west side of Jezero was watershed for the gullies penetrating the crater walls.  That likely makes it Cat IV territory, even if there were a policy in place to relax some areas to Cat II.

I suspect any landing location that's farther than a few km away from either Three Forks or a likely location for Perseverance starts to get scored as high risk.  IMO, that rules out Isidia Planaria (which likely could be relaxed to Cat II).

Perhaps it's just me, but I saw Ingenuity as game-changing for de-risking Martian flight in general and the fetch copter concept in particular. If a safe, Cat II landing site at Isidis Planitia is 100km away, then I'm not sure why this would be especially more risky than if the landing site was <10km away. Run a campaign of landing ~3 such starships, landing 1-2 weeks apart during the same transit window so lessons from EDL can be iterated/tested rapidly. Each has some number of robust fetch copters capable of making the traverse and picking up a tube each, perhaps multiple times, plus the MAV as shown. Derisk the mission through numbers.  Bonus is that we probably get to see external footage of at least one of the starships landing on Mars.

Offline Negan

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Can a Starship flyover a Cat IV area low enough to airdrop a Cat IV payload?

Offline edzieba

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Can a Starship flyover a Cat IV area low enough to airdrop a Cat IV payload?
Complex and unnecessary: if you already have an encapsulated (a fundamental necessity for Cat IV) payload, you may as well drop if off above the atmosphere and have it perform the known-good EDL sequence so many have before it. That eliminates the risk of a non-Cat IV RUD dropping debris in a area it should not.

Offline TheRadicalModerate

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Attaching a quick and dirty animation of what I was thinking. MAV in this animation is nearly 11m long, 1.4m diameter. Assuming some kind of mechanism to redirect MAV thrust out the slot hatch at the bottom. I was hoping this would be enough to do direct return to Earth.

Two things:

1) The original MAV design launched directly from the SRL, but everybody got paranoid about the effects of exhaust impingement on the SRL, and whether it would cause something to hit the MAV and damage it.  That's why they went with tossing it into the air and then starting the engines.

The same argument for the architecture you're envisioning applies.  I guess you could toss it vertically, as you have it, but it seems harder than blowing it out through a horizontal door.

2) A direct return to Earth has restricted Cat V challenges, because it's hard to "break the chain of contact" without transferring something like the OS from one vehicle to another.  It's not an insurmountable problem, but it's not straightforward.


Quote
Perhaps it's just me, but I saw Ingenuity as game-changing for de-risking Martian flight in general and the fetch copter concept in particular. If a safe, Cat II landing site at Isidis Planitia is 100km away, then I'm not sure why this would be especially more risky than if the landing site was <10km away. Run a campaign of landing ~3 such starships, landing 1-2 weeks apart during the same transit window so lessons from EDL can be iterated/tested rapidly. Each has some number of robust fetch copters capable of making the traverse and picking up a tube each, perhaps multiple times, plus the MAV as shown. Derisk the mission through numbers.  Bonus is that we probably get to see external footage of at least one of the starships landing on Mars.

You're assuming that the loss of certain samples is acceptable.  I'm not sure that's a valid assumption.  It seems as if the science team is willing to pick and choose between which samples they want, but that doesn't necessarily mean that point-losses amongst what they choose won't be fairly devastating.

Long-distance flight on Mars is a very low-TRL proposition.  Even with multiple helicopters, there's some time/distance/repetition threshold where the chance of failure grows very rapidly.  Maybe you can get a few tens of km to be fairly reliable.  But 180km (which seems like the round trip that would be required for a landing in the flatter parts of Isidis Planitia) would be well outside the capability of an Ingenuity-like platform, which only went 17km.

Remember, they're trying do de-risk the mission, not push the envelope.

Offline TheRadicalModerate

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Can a Starship flyover a Cat IV area low enough to airdrop a Cat IV payload?
Complex and unnecessary: if you already have an encapsulated (a fundamental necessity for Cat IV) payload, you may as well drop if off above the atmosphere and have it perform the known-good EDL sequence so many have before it. That eliminates the risk of a non-Cat IV RUD dropping debris in a area it should not.

That kinda depends on its size.  The POR version of the MSR went through the tortures of the damned because it's just not possible to use the existing aeroshell architectures beyond about a 4.6m diameter.

I never got a good answer on how much reducing the entry speed from interplanetary to orbital helped with EDL.  It'll certainly reduce the mass of the heat shield, but it's unclear whether it helps with parachute deployment, aeroshell detachment, and landing.  I'm kinda guessing that it doesn't.

Supersonic retropropulsion helps with everything, at the expense of a lot more entry mass. A deployment from an orbital Starship effectively eliminates any limits on entry mass.  But it's still a new architecture.

Offline TheRadicalModerate

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Can a Starship flyover a Cat IV area low enough to airdrop a Cat IV payload?

I'm assuming that the instantaneous impact track for a Cat II mission (assuming such a mission is allowable) can't cross a Cat IV region at all.

Offline thespacecow

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I don't understand this obsession with planetary protection even after NASA literally gave Starship a get out of jail free card by omitting forward protection from the requirement. I mean how explicit do you want NASA to be?

Science wise, there's nothing preventing Starship from landing in Jezero crater, it's not a special region, it's near the equator and the ice layer is thought to be tens of meters deep, RIMFAX hasn't seen any ice either. NASA will want to write some papers to justify the decision, but at this point there're no showstoppers, merely need to do the paperwork.

Offline Negan

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Can a Starship flyover a Cat IV area low enough to airdrop a Cat IV payload?

I'm assuming that the instantaneous impact track for a Cat II mission (assuming such a mission is allowable) can't cross a Cat IV region at all.

My bad. I should have used Jezero Crater instead of Cat IV.

Offline chopsticks

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With the new announcement I right away thought of Impulse. I won't be surprised if they come up with something. They're already working on a mars lander.

Offline TheRadicalModerate

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Can a Starship flyover a Cat IV area low enough to airdrop a Cat IV payload?

I'm assuming that the instantaneous impact track for a Cat II mission (assuming such a mission is allowable) can't cross a Cat IV region at all.

My bad. I should have used Jezero Crater instead of Cat IV.

I'd be amazed if Jezero itself didn't remain Cat IV.

I don't understand this obsession with planetary protection even after NASA literally gave Starship a get out of jail free card by omitting forward protection from the requirement. I mean how explicit do you want NASA to be?

Science wise, there's nothing preventing Starship from landing in Jezero crater, it's not a special region, it's near the equator and the ice layer is thought to be tens of meters deep, RIMFAX hasn't seen any ice either. NASA will want to write some papers to justify the decision, but at this point there're no showstoppers, merely need to do the paperwork.

If there actually is a relaxation of some nearby areas to Cat II, that's great.  However, I'd expect use of a lander that couldn't comply with Cat IV to be a major ding on selection criteria.  Maybe not a fatal ding, but responding to an RFP with, "Oh, by the way, you'll have to go do battle with COSPAR or take a bunch of international flak," is never going to be Plan A.

That said, I'd put the odds of Jezero and the rim walls being relaxed to Cat II at near zero.  There are extremely good reasons to leave the areas traversed by Perseverance as pristine as possible, so that a future mission can re-sample to confirm results, if necessary.

The entire surface of Mars is not going to be reclassified to Cat II, at least not for a few decades.  Similarly, there will be regions that aren't special regions that will remain Cat IV, because they won't be able to meet the criterion that there be no surface access to water downwind.

So there probably needs to be a strategy to provide cheap Cat IV services to places that need it.  That isn't going to be a Starship-based lander.  Maybe that isn't a service to be offered for MSR, or maybe it is.  Gaming this out will be important in designing a successful study bid, and it'll be even more important in developing a final mission bid.

And that's why an obsession with planetary protection is warranted.

Offline TheRadicalModerate

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With the new announcement I right away thought of Impulse. I won't be surprised if they come up with something. They're already working on a mars lander.

Reference for Impulse working on any kind of lander?

I think there are a number of companies that might be interested in going after a Mars lander, and at least SpaceX and Blue Origin might be willing to collaborate to provide launch and Mars transport services.

Offline Don2

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I think that SpaceX's biggest invention is the way they develop projects. They lean a lot more heavily on flight testing than everybody else, and they don't see flight test failures as a problem. What does Mars lander development look like in that context?

Any SpaceX program is going to have multiple failures before they are ready to try returning the Mars samples. The problem with Mars is that they can only launch once every two years, and getting flight test data back to Earth is problematic. SpaceX will probably need a data collection and relay satellite at Mars in order to return flight test data. They can rent spare capacity on that spacecraft to others.

They could send multiple copies of their lander at each opportunity, but they will be limited to software modifications. Modifying the hardware will mean a two to four year wait. Because you can't do rapid iterative hardware development at Mars, it is entirely possible that the SpaceX development method won't work for Mars EDL.

Let's assume SpaceX is going to try this anyway. What could they put together for the 2026 flight opportunity? Could they send a Starship for a demonstration landing attempt on Isidis Planitia? Or would it be better to develop some purpose built hardware for the job? With a Starship launch you could have a 9m diameter aeroshell. This would allow for a much heavier lander. The lander would attempt to demonstrate supersonic retropropulsion and a soft precision landing.

Starship would send two aeroshells (plus cruise stages) towards Mars in 2026. They would capture into a highly elliptical Mars orbit. The first landing attempt would probably fail, but it would collect data. The flight software would then be rewritten to give the second landing attempt a chance to succeed.

If that attempt succeeded then in 2028 they would land, grab a soil sample, and attempt to put that into a stable low Martian orbit. If that succeeded they would then launch in 2030 to attempt to return the Perseverance samples to Earth orbit. Once the Mars samples are in orbit then they could figure how to get them to the surface while meeting backward planetary protection requirements.

Is any of that realistic? What do people think about using a purpose built lander for MSR rather than Starship? Can you develop a Mars lander far more cheaply than it has ever been done before if you are willing to accept some failures while you gather data on system performance?

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