ESA encounters boil-off, goes Kerbal

[DDE]

via @nyrath

CDF Study Report: Human Missions to Mars - Overall Architecture Assesment

”(It’s not a DRM, we swear)”

Jumping off the 400 pages is the utter Kerbalness of the design. ESA rejected any non-off-the-shelf propulsion systems, and stuck with Vulcains and Russian and Ukranian hypergols.

IN SIX STAGES

Three quad hydrolox stages to escape Earth, two twin stages for Mars insertion, and a small stage for TEI.

[NSEP]

All manned mars mission concepts look kinda ridiculous, not gonna lie. 

They use KSP as simulation software it almost looks like XD.

[Green Baron]

Is this authentic ?

If so, then well, i'd have to admit that Nasa has not the dreamer's monopoly ... :-)

[James Kerman]

The paper was published in 2004.

[NSEP]

27 minutes ago, James Kerman said:

The paper was published in 2004.

 

[James Kerman]

When it comes to Mars, my enthusiasm is curbed.
 

 

[PB666]

5 hours ago, DDE said:

via @nyrath

CDF Study Report: Human Missions to Mars - Overall Architecture Assesment

”(It’s not a DRM, we swear)”

Jumping off the 400 pages is the utter Kerbalness of the design. ESA rejected any non-off-the-shelf propulsion systems, and stuck with Vulcains and Russian and Ukranian hypergols.

IN SIX STAGES

Three quad hydrolox stages to escape Earth, two twin stages for Mars insertion, and a small stage for TEI.

Wow, I find that amazing, ESA was actually trying to do imaginative stuff in 2004.

 

[James Kerman]

I am reading it - the paper was meant to be a feasibility study for a 6 man mission to Mars  (3 landing and 100kg samples returned) for a launch between 2025 -2030.  I was wondering if you had the costing paper (mentioned as being a separate document) @DDE ?  This would also be a good read.

[Matuchkin]

It looks as if Elon Musk's Mars mission concept is the most realistic, because, with billions spent on it, I can actually see it happening. Of course, fat chance anyone would want to spend such money. I have a feeling that this project would provide a fatal economic blow on Musk, that will be worse in magnitude than his troubles with Tesla. I don't want to see that genius getting his parents to pay his rent in the next 10 years, among the ruins of his prior inventions. I just don't.

[Rune]

8 hours ago, DDE said:

via @nyrath

CDF Study Report: Human Missions to Mars - Overall Architecture Assesment

”(It’s not a DRM, we swear)”

Jumping off the 400 pages is the utter Kerbalness of the design. ESA rejected any non-off-the-shelf propulsion systems, and stuck with Vulcains and Russian and Ukranian hypergols.

IN SIX STAGES

Three quad hydrolox stages to escape Earth, two twin stages for Mars insertion, and a small stage for TEI.

 I found this on Atomic Rockets today, and yes, it also caught my eye. It's basically a wonderful yardstick. It's the Mars mission we could do yesterday, with no fancy tech and R&D involved. Frankly, we need something like this if we are to compare apples to apples. When was the last such study done, the sixties? Since then, all of them have assumed some sort of technology that we don't yet have in an attempt to be novel or something.

But only after having something like this is when you can then get smart about things, and compare them to a very reasonable baseline. Want to check the impact of using aerobraking to shave dV of the Martian injection? Now you can see exactly how much that saves. Want to see if we need nuclear rockets? Change the stages to nuclear ones, run the numbers, and compare the advantage in IMLEO to the development cost of your nukes. Figure out the launch rates needed to support things.

Looking at it from that perspective, it kinda reinforces my belief that storables+fancy mission planning tricks would be the cheapest, fastest way to do a mission to Mars. Basically, this plan is a 'battlestar gallactica', with all the things launched in a single ship, and it also uses no aerodynamic breaking to reduce delta-V. In that sense, it is basically a brute-force approach, and thus somewhere around 1,300mT IMLEO, if I can read, and if you'll forgive some rounding so I can do the numbers in my head. Which is actually not even that bad, that means tens of heavy lift vehicles, not hundreds... an SLS would lift it in less than 20 flights. Ok, maybe a bit bad. Or is it just a great place to start the conversation?

Suppose that you broke the mission into several transfer windows, and did a... Mars Orbit Rendezvous model, let's call it, for historicity's sake. Then you can send a surface habitat and the lander ahead of crew, and you halve the size of your manned ship. That is a big thing. You can also check things out remotely before sending crew, and test the Earth departure stages and such. Those 'test' stacks incidentally, can be smaller for the unmanned cargo flights, because those ain't returning (Transfer Hab+Return capsule+Return stage is around 150mT, and the lander is around 50). That small architectural change would, alone, break those 1,300mT IMLEO into 300-1000mT chunks launched every two years (the manned window having a significantly higher launch requirement).

Another minor trick that would slash IMLO would be aerobraking (not aerocapture, that needs beefy heatshields). That could take away one of the martian injection stages altogether, at the cost of a few months orbiting Mars before the main ship reaches the low martian orbit that the lander can reach form the surface. And even then the crew could land earlier if the lander stayed on a high elliptical orbit waiting for them, and did a slightly faster entry. Bit ballsy, landing before your return ship gets into position to pick you up if crap happens. But you could use that time to do orbital science. That slight dV gain (the couple km/s or so that can be aerobraked after inserting into high martian orbit), in such a staged low Isp architecture, would have a snowball effect that would cut IMLEO drastically, since it cuts the payload to TMI to about half. So, you know, now we are looking at ~650mT IMLEO, divided among two or three windows (~6years), most of which will be dumb, cheap fuel and mass-produced simple chemical stages. The yearly payload launched to LEO start to gets within the budgets of real-world space agencies pretty quick!

 

Rune. But hey, no fancy tech to sell to politicians.

Edited November 22, 2017 by Rune

[PB666]

Except they did not have Mars reentry and landing worked out.

 

[tater]

ESA contemplating a crew mission to Mars is pretty comical, they can't even land a robot there reliably... nor have they ever sent crew, well, anywhere.

[Green Baron]

You're mean :-)

[tater]

Nothing would make me happier than ESA becoming a real space agency, the more the merrier, and the faster things would move forward.

 

[Rune]

29 minutes ago, tater said:

ESA contemplating a crew mission to Mars is pretty comical, they can't even land a robot there reliably... nor have they ever sent crew, well, anywhere.

Who else? NASA, which these days does the same kind of manned mission ESA does?

 

Rune. This is a paper study. I can make a paper study, if I feel like it.

[Canopus]

17 minutes ago, tater said:

Nothing would make me happier than ESA becoming a real space agency, the more the merrier, and the faster things would move forward.

 

ESA is more of a Space Agency than Roscosmos which is has become little more than a Launch provider. Atleast ESA is actively sending robotic spacecraft around the Solar system. Also with all the Commercial Spacecraft in Development i don't see the need to develop an indigenious manned spacecraft.

[kerbiloid]

Spoiler

Feeling myself Jon Snow. I did know nothing.

But why several almost similar stages?..
The 1st should be several times heavier than 2nd, shouldn't it?

Edited November 22, 2017 by kerbiloid

[Ultimate Steve]

1 hour ago, Rune said:

 

Rune. This is a paper study. I can make a paper study, if I feel like it.

I've actually done this, to a certain extent. It was a design for a 1 man orbital rocket (not particularly useful). I got it mostly done except for the engines. I did get as far as making a 1:10 scale model, though. Currently sitting in my basement. I was going to hang it from the ceiling of my bedroom but it is about four inches shorter than the length of my room... And falling apart...

[Xeorm]

1 hour ago, kerbiloid said:

  Reveal hidden contents

Feeling myself Jon Snow. I did know nothing.

But why several almost similar stages?..
The 1st should be several times heavier than 2nd, shouldn't it?

It starts from Earth orbit already. That cuts wanting a large first stage due to gravity concerns or other concerns from atmosphere. Larger the initial stage you either have more thrust, which requires more support through the whole craft, or you need to worry about a larger burn window. Three stages for the Earth->Mars flight lets them get the most out of what they have, along with allowing for corrections. The next three stages are pretty different, and each have their places.

 

[DDE]

3 hours ago, tater said:

they can't even land a robot there reliably

The should not have involved Roscosmos, us Russians and Mars just don't seem to mix.

[Rune]

2 hours ago, kerbiloid said:

  Reveal hidden contents

Feeling myself Jon Snow. I did know nothing.

But why several almost similar stages?..
The 1st should be several times heavier than 2nd, shouldn't it?

Launch vehicle limitations. They are lofting 80mT transfer stages, so you cluster them until you have enough, then drop them as they empty. If you could do it symmetrically, you would drop them one by one to save the most weight. Yes, this design has more stages than it needs to, and more engines than it needs to. But it can be launched with an Energia, and a single humongous TMI stage can't.

 

Rune. Using Energia as the assumed HLV shows the age of the paper, BTW.

 

[DerekL1963]

4 hours ago, Rune said:

 I found this on Atomic Rockets today, and yes, it also caught my eye. It's basically a wonderful yardstick. It's the Mars mission we could do yesterday, with no fancy tech and R&D involved.

In theory.  In practice... not so much.  We still don't have a demonstrated long duration life support capability.  (The ISS systems have required far too much repair work.)  Nor have we worked out how to land and return yet.

And that's setting aside the usual problems involved in transforming 'technology' into useable designs, and transforming designs into actual flight hardware.

 

[Rune]

Just now, DerekL1963 said:

In theory.  In practice... not so much.  We still don't have a demonstrated long duration life support capability.  (The ISS systems have required far too much repair work.)  Nor have we worked out how to land and return yet.

And that's setting aside the usual problems involved in transforming 'technology' into useable designs, and transforming designs into actual flight hardware.

 

That's engineering. We haven't built ECLSS that last longer than six months without resupply, because we haven't tried to do it. Grab the component of the ISS, overbuild, test to destruction lots of times, then pack enough spares, and a few extra. And do it by triplicate if it's vital. Landing, well, we have actually landed stuff. Large mass? We hadn't landed large masses on Earth until the Shutle flew. And after a few tests and such, land it did. We have also taken off form other bodies. Turns out gravity and rockets work the same way everywhere.

All of that is part of 'building the thing'. We didn't have ECLSS at all until we started building manned spacecraft. And we didn't have long duration ECLSS until we started building space stations. Of course, I'm not saying it wouldn't take a crapload of money to build it all. Of course it will, and how much is a very open question. But this mission plan in particular is, technologically, well within reach. Just like it was when originally written, 13 years ago.

 

Rune. After a certain point, the only way to eliminate the last uncertainties is to actually start doing the thing.

[mikegarrison]

The profile for this mission was 200 days to get there, 100 days in orbit, 30 days on the surface, 400 more days in orbit, and then another 200 days to get home. That's 3 years in space (half of it just waiting for a transfer window) for 30 days on the surface of Mars.

[DDE]

8 hours ago, mikegarrison said:

The profile for this mission was 200 days to get there, 100 days in orbit, 30 days on the surface, 400 more days in orbit, and then another 200 days to get home. That's 3 years in space (half of it just waiting for a transfer window) for 30 days on the surface of Mars.

I’ve seen even worse deals.

9-month transfer, 1-month burns... 7 days on the surface. Hey, that reminds me...

See that bottom variant? 20 Energiya launches, IMLEO = 1700 t; 2 quintiple modules in first stage, quad strap-ons in third stage, and a lone unit as the third stage.

Did I just find YET ANOTHER part of that project that eventually resufaced in Western proposals? That ship was also to use a Dual Thrust Axis lander that currently exists in ACES-derived lunar lander proposals.

Edited November 23, 2017 by DDE