Author Topic: SpaceX / NASA Collaboration - Red Dragon - Goddard Teleconference.  (Read 29409 times)

Online Robotbeat

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Producing water from the air is similar to later methods (getting it from regolith or dirty ice) & is simple enough to put on an early mission.

Heck, a small scoop that gets some regolith and extracts some water from it also would be even more similar. Not too different than some of the instruments on Viking or MSL, but simpler.
Which again isn't at all useful for anything more than a stunt, since you'll obtain minute quantities of water from whatever a small scoop can gather (assuming SpaceX would even try to engineer such a thing for a Red Dragon demo mission). From that minute few droplets of water, you'll get ... how much methane exactly? Silly waste of resources to devote that much power, mass, and software development for such a useless activity.
Huh? So by the same measure, you think MOXIE is just a stunt?

Exactly the same argument could be made. But it's a stupid argument, because demonstrating something at the small scale is what you do to mature a technology, increase its TRL, and develop it to the point that you CAN develop a large capability.

Let's put our thinking caps on.

Not a stunt, a demonstration, a proof of concept. Make it work, measure results, feed back into planning for the next time. 

What would you prefer in its place?  It's not useful to just say no to something, say what you would prefer to be done.

Is there a real need for a payload on the 1st flight anyway?  Mars EDL is the primary objective, a huge accomplishment if successful.  It may be worth it to forgo the payload to save mass for EDL.
Red Dragon is very big, so it certainly has mass for a small payload. The real question is if they can get it all done in time, and that could very easily be "no, we have to wait for the next window."

Please look at this:
https://en.wikipedia.org/wiki/Mars_Oxygen_ISRU_Experiment
« Last Edit: 09/25/2016 07:33 PM by Chris Bergin »
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Offline mfck

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TL/DR: the payload for this flight should, imo, be a payload management and deployment system


It has been said* that RD will not have a docking adapter in the top hatch and that the conical fairing is jettisoned before TMI. While the former makes perfect sense mass- and cost-wise, I wonder if the latter will be done for mass efficiency or because there are some flight instruments planned under that fairing.

Thinking about it further, in the light of the current payload discussion and assuming that RD is not a one-off stunt, but rather a step in developing a  planetary lander platform, a service, I'd hazard a guess that the payload on this flight will be a payload rack system, that can stow, manage and deploy various payload modules; something akin to what NanoRacks are doing, but Dragon specific. Such system would have internal and external parts and must be developed and tested early. It has plenty of aspects to test in-flight, and through EDL:

- in-flight payload management, such as  power, termal, data services
- in-flight payload deployment, such as cubesats, impacters (though it'd make sense to put those in the trunk, i guess)
- during EDL this could deploy an EDL specific sensor suite, augmenting the RD flight systems and, possibly the comms.
- assuming successful landing planetary payload management and deployment could be tested.

 They could put other payloads as guinea pigs for this ride or could just put dummy devices to allow the full systems test.

If they proved such system working in the 2018 synod, there might be more than 2 SX RDs in the next one.

I don't think there will be any SX developed ISRU plant prototype on the 2018 flight. You'd want higher chances of planetside delivery for such a payload, methinks

------

* I have no idea if this is actually so


Edited for clarity
« Last Edit: 09/25/2016 10:00 PM by mfck »

Offline CuddlyRocket

Even extracting the water from the atmosphere is not helpful in that respect as it cannot yield the amounts of water for fuel ISRU and supplying a base later. ... Only producing the water in the same way that will be needed for ISRU later is going to give really useful data. Everything else is more PR.

Water has other uses than ISRU. Granted, any process to produce water in the quantities needed for ISRU will likely also produce the water for other purposes. But, I'd want a back-up water supply using an entirely separate process, and there may be a need to produce water in small quantities using compact equipment; perhaps in satellite habitats or on long-range rovers?

In general, I'm suspicious of the idea that there is one 'best' way to do anything. Especially in a new environment, diversity is a strength and safeguard.

Offline guckyfan

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Water has other uses than ISRU.

Not sure what you mean. Everything using local water from any source is ISRU. You are not thinking of bringing water from earth, correct?

But, I'd want a back-up water supply using an entirely separate process, and there may be a need to produce water in small quantities using compact equipment; perhaps in satellite habitats or on long-range rovers?

In general, I'm suspicious of the idea that there is one 'best' way to do anything. Especially in a new environment, diversity is a strength and safeguard.

I understand there is a need for redundancy. Still there is only one reasonable source for tens of thousands of tons of water for the main settlement. That's glacial water. For redundancy different systems for extracting it can be used.

You have a point for satellite habitats. Quite possible that those might use alternative sources for water.

Offline john smith 19

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TL/DR: the payload for this flight should, imo, be a payload management and deployment system
I like this idea. As a system it's likely to be quite mechanically complex and because of what it does need a lot of exposure to the (hostile) Martian environment.

This suggest it won't be right first time and need a few iterations, so best to get the first version on Mars ASAP, yet not a disaster if the landing fails. IOW an excellent candidate for a first mission.

Which again isn't at all useful for anything more than a stunt, since you'll obtain minute quantities of water from whatever a small scoop can gather (assuming SpaceX would even try to engineer such a thing for a Red Dragon demo mission). From that minute few droplets of water, you'll get ... how much methane exactly? Silly waste of resources to devote that much power, mass, and software development for such a useless activity.
Logically the amounts would be tiny but it would validate the design and raise the TRL level of various critical components. It would also anchor the (no doubt numerous) simulations of efficiency with actual results. Lastly it might suggest areas where more sensors are needed track specific problems with the plant.

You might be surprised how much knowledge can be extracted from a small sample. The British worked out their Plutonium extraction process from less than 40 micrograms of the actual element.

You can argue that an ISRU test is a poor use of whatever resources the RD will have, in which case you have 2 problems.

SX have stated that Martian settlement using ISRU is a major long term goal of theirs. What would you suggest that would make as big a contribution to their long term goal as early field trials of their ISRU system?

This is an SX mission. NASA  are helping, but SX ultimately decides what they take along as payload. I would expect them to prioritize SX payloads, subject to them being ready. What does NASA have that can be got flight ready for 2018?

I agree ISRU is likely to be power hungry and it's unlikely RD will deploy any kind of PV array. I'd love to see some radiation sensors inside the cabin to see what levels look like inside the "protection" of the pressure vessel. I'd really like to find some way to send some experiments along to test muscle and bone deterioration without  sending actual live specimens during the flight and landing, but I think that will be very difficult and unless someone's already working on such a plan it won't be ready in time.
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Online Robotbeat

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Even extracting the water from the atmosphere is not helpful in that respect as it cannot yield the amounts of water for fuel ISRU and supplying a base later. ... Only producing the water in the same way that will be needed for ISRU later is going to give really useful data. Everything else is more PR.

Water has other uses than ISRU. Granted, any process to produce water in the quantities needed for ISRU will likely also produce the water for other purposes. But, I'd want a back-up water supply using an entirely separate process, and there may be a need to produce water in small quantities using compact equipment; perhaps in satellite habitats or on long-range rovers?

In general, I'm suspicious of the idea that there is one 'best' way to do anything. Especially in a new environment, diversity is a strength and safeguard.
First of all, I'd challenge the claim that air reclamation of water can't yield enough water. It certainly can! But the same technique could be used for extracting water from ice or regolith, it's just that you would heat the regolith/ice first in a sealed enclosure and your yield would be MUCH higher. But the techniques are basically the same. Or could be, depending on exactly what approach you take.
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Offline Herb Schaltegger

Even extracting the water from the atmosphere is not helpful in that respect as it cannot yield the amounts of water for fuel ISRU and supplying a base later. ... Only producing the water in the same way that will be needed for ISRU later is going to give really useful data. Everything else is more PR.

Water has other uses than ISRU. Granted, any process to produce water in the quantities needed for ISRU will likely also produce the water for other purposes. But, I'd want a back-up water supply using an entirely separate process, and there may be a need to produce water in small quantities using compact equipment; perhaps in satellite habitats or on long-range rovers?

In general, I'm suspicious of the idea that there is one 'best' way to do anything. Especially in a new environment, diversity is a strength and safeguard.
First of all, I'd challenge the claim that air reclamation of water can't yield enough water. It certainly can! But the same technique could be used for extracting water from ice or regolith, it's just that you would heat the regolith/ice first in a sealed enclosure and your yield would be MUCH higher. But the techniques are basically the same. Or could be, depending on exactly what approach you take.

And again ... how do you integrate this stuff into a Red Dragon mission and how do you justify the proportionally gigantic share of the power, mass and data budget to justify it? That's the question no one has an answer for. Continuing to avoid it doesn't make it go away.

But I admit I am getting quite bored; it's like everyone loses their minds when Mars is mentioned. "Maaaaaarrss! Yaaaaaay!"
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Offline Space Ghost 1962

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Not a stunt, a demonstration, a proof of concept. Make it work, measure results, feed back into planning for the next time. 

We can do that on Earth in a lab or an environment chamber filled with CO2 and a floor covered in iron-rich soil, perchlorate salts and a tiny bit of water. In fact, it HAS been done that way.

Has to be done that way. Part of building a package is to do your best at simulating the operating environment.

And I'll be the first to say that much/many science payloads aren't as well thought out as they should have been prior to launch. Certain current missions I could call out in detail.

Quote
Quote
What would you prefer in its place?

The mass/power/data required for an ISRU stunt to be devoted to longer surface life, more/higher fidelity data recording from the powered EDL phases of flight, longer surface life, or basically anything else.


That's going too far. And I'm certain that high fidelity vehicle performance data is already a given - SX's recent anomaly/LOM have underscored that need.

But I do agree that having a robot play with a chemistry set inside a capsule on Mars is more than a bit of a joke.

Quote
Quote
It's not useful to just say no to something ...

When one has engineering experience and knowledge relevant to the discussion and knows the relatively tiny payoff for a stunt compared to how much effort and spacecraft resources necessary to carry it out, it certainly *IS* useful.

Is it a stunt to acquire samples in a mining flow (arm, bucket loader/trencher, coring drill with slurry pump, ...), and assay yields and impurities? Even if the scale of the operation is centimeters not meters?

Is it a stunt to precipitate atmospheric components to get mass yields for lightbulb wattage "production plant", where you can possibly validate reaction/force product with an actual static test thruster? And quite possibly redo the experiment a few hundred times, being able to visually inspect the throat for combustion products/erosion?

At which point do we move from "stunt" to "engineering test article"?

Online Robotbeat

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Even extracting the water from the atmosphere is not helpful in that respect as it cannot yield the amounts of water for fuel ISRU and supplying a base later. ... Only producing the water in the same way that will be needed for ISRU later is going to give really useful data. Everything else is more PR.

Water has other uses than ISRU. Granted, any process to produce water in the quantities needed for ISRU will likely also produce the water for other purposes. But, I'd want a back-up water supply using an entirely separate process, and there may be a need to produce water in small quantities using compact equipment; perhaps in satellite habitats or on long-range rovers?

In general, I'm suspicious of the idea that there is one 'best' way to do anything. Especially in a new environment, diversity is a strength and safeguard.
First of all, I'd challenge the claim that air reclamation of water can't yield enough water. It certainly can! But the same technique could be used for extracting water from ice or regolith, it's just that you would heat the regolith/ice first in a sealed enclosure and your yield would be MUCH higher. But the techniques are basically the same. Or could be, depending on exactly what approach you take.

And again ... how do you integrate this stuff into a Red Dragon mission and how do you justify the proportionally gigantic share of the power, mass and data budget to justify it? That's the question no one has an answer for. Continuing to avoid it doesn't make it go away.....
How does MOXIE answer those SAME EXACT QUESTIONS?

THAT is the thing that /you/ keep avoiding. NASA is basically doing the same thing on the 2020 rover, except CO2-based instead of water-based.

So if doing a subscale ISRU demo is so dumb for SpaceX (whose architecture depends so deeply on ISRU), why is NASA doing MOXIE??

Until you answer that question, I see no reason to try to answer your kind of silly questions (silly because the answers are obvious...).
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Herb Schaltegger

Even extracting the water from the atmosphere is not helpful in that respect as it cannot yield the amounts of water for fuel ISRU and supplying a base later. ... Only producing the water in the same way that will be needed for ISRU later is going to give really useful data. Everything else is more PR.

Water has other uses than ISRU. Granted, any process to produce water in the quantities needed for ISRU will likely also produce the water for other purposes. But, I'd want a back-up water supply using an entirely separate process, and there may be a need to produce water in small quantities using compact equipment; perhaps in satellite habitats or on long-range rovers?

In general, I'm suspicious of the idea that there is one 'best' way to do anything. Especially in a new environment, diversity is a strength and safeguard.
First of all, I'd challenge the claim that air reclamation of water can't yield enough water. It certainly can! But the same technique could be used for extracting water from ice or regolith, it's just that you would heat the regolith/ice first in a sealed enclosure and your yield would be MUCH higher. But the techniques are basically the same. Or could be, depending on exactly what approach you take.

And again ... how do you integrate this stuff into a Red Dragon mission and how do you justify the proportionally gigantic share of the power, mass and data budget to justify it? That's the question no one has an answer for. Continuing to avoid it doesn't make it go away.....
How does MOXIE answer those SAME EXACT QUESTIONS?

THAT is the thing that /you/ keep avoiding. NASA is basically doing the same thing on the 2020 rover, except CO2-based instead of water-based.

So if doing a subscale ISRU demo is so dumb for SpaceX (whose architecture depends so deeply on ISRU), why is NASA doing MOXIE??

Until you answer that question, I see no reason to try to answer your kind of silly questions (silly because the answers are obvious...).

We're not talking about MOXIE. This is what is known as a "strawman argument." You can do better than this, Chris. The topic at hand is Red Dragon. Until you grasp that, I'm out.
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Offline Lar

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Maybe taking a bit of time away is a good idea, you guys. BETEO, please.
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
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Online Robotbeat

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Even extracting the water from the atmosphere is not helpful in that respect as it cannot yield the amounts of water for fuel ISRU and supplying a base later. ... Only producing the water in the same way that will be needed for ISRU later is going to give really useful data. Everything else is more PR.

Water has other uses than ISRU. Granted, any process to produce water in the quantities needed for ISRU will likely also produce the water for other purposes. But, I'd want a back-up water supply using an entirely separate process, and there may be a need to produce water in small quantities using compact equipment; perhaps in satellite habitats or on long-range rovers?

In general, I'm suspicious of the idea that there is one 'best' way to do anything. Especially in a new environment, diversity is a strength and safeguard.
First of all, I'd challenge the claim that air reclamation of water can't yield enough water. It certainly can! But the same technique could be used for extracting water from ice or regolith, it's just that you would heat the regolith/ice first in a sealed enclosure and your yield would be MUCH higher. But the techniques are basically the same. Or could be, depending on exactly what approach you take.

And again ... how do you integrate this stuff into a Red Dragon mission and how do you justify the proportionally gigantic share of the power, mass and data budget to justify it? That's the question no one has an answer for. Continuing to avoid it doesn't make it go away.....
How does MOXIE answer those SAME EXACT QUESTIONS?

THAT is the thing that /you/ keep avoiding. NASA is basically doing the same thing on the 2020 rover, except CO2-based instead of water-based.

So if doing a subscale ISRU demo is so dumb for SpaceX (whose architecture depends so deeply on ISRU), why is NASA doing MOXIE??

Until you answer that question, I see no reason to try to answer your kind of silly questions (silly because the answers are obvious...).

We're not talking about MOXIE. This is what is known as a "strawman argument." You can do better than this, Chris. The topic at hand is Red Dragon. Until you grasp that, I'm out.
We're talking about MOXIE because the same reasons apply.

Why bother with the power, mass, etc, of MOXIE when it's just a 1% subscale demo?

Because the technology is critical to surface crewed missions on Mars, and the technology must first be matured and shown that it works in the real environment. Just like MOXIE, they can't just say it'll work in the lab, because it's too critical of a technology to just hope it works for the first time at full scale. And a subscale demo is the fastest way to mature the technology.

The same exact logic applies to SpaceX doing an ISRU demo. But whereas NASA has only baselined oxygen ISRU for initial missions, SpaceX has baselined both methane and oxygen ISRU, which means they need to extract water (and Musk has explicitly said they need to mine water robotically on the surface before any crewed missions). SpaceX's timeline is even more compressed than NASA's, so it's critical they demonstrate it in some form as soon as possible. Maybe they'll make it in 2018 (I wouldn't count on it, but hey), maybe they'll do it in 2020.

Does that answer your questions in a satisfactory manner?
« Last Edit: 09/26/2016 01:22 AM by Robotbeat »
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Offline CuddlyRocket


Water has other uses than ISRU.

Not sure what you mean. Everything using local water from any source is ISRU. You are not thinking of bringing water from earth, correct?

Sorry, I'm so used to thinking of ISRU in terms of propellant manufacture, I forgot it's not restricted to that! And no, I'm not thinking of water from Earth.

Quote
But, I'd want a back-up water supply using an entirely separate process...

I understand there is a need for redundancy. Still there is only one reasonable source for tens of thousands of tons of water for the main settlement. That's glacial water. For redundancy different systems for extracting it can be used.

More than redundancy; which can just mean two or more of the same system. I mean an entirely separate system. Two different systems for extracting glacial water (though useful in themselves) don't help if something unexpected makes it unusable. But it doesn't have to have the same capacity.; just keep people alive and healthy until things can be sorted out.

Offline john smith 19

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Is it a stunt to acquire samples in a mining flow (arm, bucket loader/trencher, coring drill with slurry pump, ...), and assay yields and impurities? Even if the scale of the operation is centimeters not meters?

Is it a stunt to precipitate atmospheric components to get mass yields for lightbulb wattage "production plant", where you can possibly validate reaction/force product with an actual static test thruster? And quite possibly redo the experiment a few hundred times, being able to visually inspect the throat for combustion products/erosion?

At which point do we move from "stunt" to "engineering test article"?
Indeed.

In theory we know how to make an ISRU unit work but test on Earth already showed problems with the prototype hardware. The nearest analogy in terms of mechanical complexity to this is (I think) the ECLSS stuff on the ISS. The gross chemistry and physics is well understood. But then you throwin all those  "trace" air pollutants (some of which humans seem very sensitive to). Then you throw in the dust clogging caused by some of the filter pellets being pulverized over time and so on.

Validating what SX thinks will happen against what does happen is pretty important.

I think this will be complementary  to MOXIE

BTW this telecon may have been the first open announcement of this project but it's been running for about a year with NASA on board (and probably somewhat longer inside SX) so I would not rule out ISRU hardware already under construction.
« Last Edit: 09/26/2016 04:16 PM by john smith 19 »
BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C Apply So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

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