Author Topic: Exploration Gateway Platform hosting Reusable Lunar Lander proposed  (Read 134631 times)


Offline Khadgars

  • Full Member
  • ****
  • Posts: 911
  • Long Beach, California
  • Liked: 126
  • Likes Given: 446
Great article Chris!  I like what I'm seeing so far and we're still many years out from an official game plan!

Offline Jason1701

  • Senior Member
  • *****
  • Posts: 2238
  • Liked: 70
  • Likes Given: 39
I suspect we'll hear little more of this plan because it makes it clear that a HLV is not essential. The architecture would work essentially the same with 2-3 MLV launches per lunar landing, without an HLV's several billion dollars of fixed costs.

Probably a still-born plan.

Offline Sparky

  • Full Member
  • ***
  • Posts: 378
  • Connecticut
  • Liked: 0
  • Likes Given: 0
Incredible! Way to go, Chris!

L1/L2 Depot & station, reusable lander, existing hardware, a human return to the moon in the forseeable future, etc!

Offline Bubbinski

Very good article Chris.  I like this plan.

Maybe a "mission module" could permanently be based there for the Orion to dock to on asteroid missions?
I'll even excitedly look forward to "flags and footprints" and suborbital missions. Just fly...somewhere.

Offline nash_synthetic

  • Member
  • Posts: 2
  • Liked: 0
  • Likes Given: 0
This is a very good idea.  A core module configuration would provide destinations for other experimental modules.  This should be promoted as an ISS sucessor.  Missions to the moon or near Earth objects would no longer be able to be considered "one off."  A permanently manned presence could be maintained with international cooperation.

Offline Sparky

  • Full Member
  • ***
  • Posts: 378
  • Connecticut
  • Liked: 0
  • Likes Given: 0
Looking at the source material again, it seems to me that the only way that the lander is reusable is by using the SLS 3rd stage as a disposable descent stage. Which I suppose is a fair compromise.

Offline pathfinder_01

  • Full Member
  • ****
  • Posts: 1856
  • Liked: 41
  • Likes Given: 0
I suspect we'll hear little more of this plan because it makes it clear that a HLV is not essential. The architecture would work essentially the same with 2-3 MLV launches per lunar landing, without an HLV's several billion dollars of fixed costs.

Probably a still-born plan.

You are not kidding there.

It is known that you could move Orion to l1 in 2 launches.

A 15MT lander is kind of light for a HLV dependant architecture. With a wet mass of 15MT and a dry mass of 7MT and that much Delta V on board, you probably could launch it directly to l1 partially fueled on a Delta IV heavy. Delta IV heavy can push somewhere about 10-16MT to escape.  A delta IV heavy could also possibly deliver a tanker of propellant.

Plus if you can move a 32MT station via SEP you can move a 15MT lander with ease. Not to mention it only holds 8MT worth of propellant. Move the wet lander and some propellant and you could have about 3 landings.

So here again 1-2 EELV launches for the lander.

Only thing that needs the HLV is the disposable stage and even then I am pretty sure you could move a big enough decent stage via SEP if you have the ability to move 32MT. I wonder why the decent stage mass was not shown…..

Offline Rocket Science

  • Senior Member
  • *****
  • Posts: 7730
  • NASA Educator Astronaut Candidate Applicant 2002
  • Liked: 2047
  • Likes Given: 4767
Wow Chris! I felt like a kid again reading the article, so full of promise…. A Reusable Lander… finally!!
If it would only come to be…. 
"The laws of physics are unforgiving"
~Rob, Physics instructor, aviator, vintage auto racer

Offline clongton

  • Expert
  • Senior Member
  • *****
  • Posts: 10256
  • Connecticut
    • Direct Launcher
  • Liked: 2006
  • Likes Given: 619
Great article Chris. It's sad however to see how the naysayers have immediately pounced on the "we don't need no HLV" theme once again instead of trying to stick to the core of the article, which is how the gateway station opens up the possibility of deep space reusable spacecraft having a home in cis-lunar space. While your article relates how the SLS could be used to create and utilize the station, it was clear, at least to me, that it was not about the HLV, but was rather about the EML-1 station itself and what it would do for opening the lunar surface to us once again. For example, launching a lunar surface mission from the Gateway station allows the lander to literally go *anywhere* on the entire lunar globe, near and far side, with anytime return. We can't do that with missions launched from earth orbit.

Once operational servicing, launching and receiving returning reusable landers, the possiblilties for BEO exploration begin to get one thinking. For example there is no reason the reusable lunar lander could not, over time, grow in size and capability, nor anything preventing the gateway station itself, again over time, evolving in capacity and capability. We may even eventually have several landers stationed there, each one in various stages of refurbishment and outfitting for various surface missions. If the Gateway station is international, like the ISS, the landers could be from the various member nations for their own -or combined- lunar exploration programs. All their crews would have to do is get there in smaller spacecraft designed for ferrying service. It could well become the home for Nautilus style solar system exploration spacecraft, perhaps even 2 or 3 of them, which would allow so much flexibility in BEO mission planning, again, with international crews. Having a station at EML-1 truly is the gateway capability that opens the solar system to mankind, beginning with a small reusable lunar lander stationed and serviced there. Over time it will, like the ISS, grow in size and capability. People forget that the station, exactly like the ISS, really is a spacecraft in its own right. If we do go this route, and I hope we do, I hope the station designers consider physical expansion capability in the core design, so that the station itself can be adapted to growing exploration needs as we move on. It doesn't need to start out being huge, just capable of becoming so, when and as budget allows. I can envision the possibility that the station begins life as a man-tended spacecraft, being visited to prepare a lander for a lunar surface mission before execution, and eventually becoming a permanently manned spacecraft servicing several BEO deep space spacecraft, in much the same way the ISS is permanently manned for research work.

Taking this a bit further, I can also envision an ISS replacement whose function is to assemble, repair and refurbish BEO spacecraft, sending them to the Gateway station and retrieving them for rework or repair after mission complete via SEP tugs. These same tugs would then return them to the Gateway station for multiple missions launched from and returned to EML-1.

I know this line of thought gets way beyond your excellent article, but that's what happens when one reads something as well worded and researched as this. Sorry about that :) Thanks to the sources and to you.

Great article Chris. Hopefully it will stimulate some genuine forward thinking about what a gateway station such as this could mean for all of us.
« Last Edit: 12/03/2011 01:25 PM by clongton »
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline kkattula

  • Member
  • Senior Member
  • *****
  • Posts: 2505
  • Melbourne, Australia
  • Liked: 10
  • Likes Given: 3
I suspect we'll hear little more of this plan because it makes it clear that a HLV is not essential. The architecture would work essentially the same with 2-3 MLV launches per lunar landing, without an HLV's several billion dollars of fixed costs.

Probably a still-born plan.

You are not kidding there.
...

I think you guys are underestimating the requirements and overestimating D-IVH capabilities a bit.

D-IVH is only a bit over 9 MT to escape, and after the initial deployment each sortie requires about 35 MT delivered to L1. So you're looking at about 4 x D-IVH per sortie. 

Moving the Lander's propellant by SEP might be possible, but the descent (crasher) stage would need zero boil-off to do the same. (It might need it anyway unless you can launch 3 x D-IVH in very rapid succession.) At best you might replace one of the D-IVH with a smaller launcher.

With the lower complexity and the added capabilities it brings to other missions, SLS looks pretty competitive at 2 missions per year.

So no HLV is not essential, just very sensible.  Therefore not still-born at all.

Offline Ben the Space Brit

  • Senior Member
  • *****
  • Posts: 6872
  • A spaceflight fan
  • London, UK
  • Liked: 490
  • Likes Given: 560
Y'know, I hate to crow... Ah, who am I kidding, I love it! It's great to see that the L1 station idea is being taken seriously enough to earn some NASA time considering it.  At the risk of sounding petty, it's one in the eye for all those who insisted that there is no possible use or requirement for such a facility and continually chided those of us who supported the idea.

With no budget for a lander but the possibility of using long-duration hab-derived tech (which is under development anyway for the NEO missions) for the gateway station, this idea is the only way to start long-duration BEO missions without a regularly-accessible destination.  It is, IMHO at least, the only way in the mid-term to utilise SLS/MPCV in a way that justifies it rather than simply imposes it on a role where a smaller LV could suffice (such as ISS support).  With the L1 station in place, flights out to the Moon's vicinity will become more routine, reducing the scepticism when the time comes to develop the lander.

Another big advantage to the L1 station, in my view at least, is that it is accessible to uncrewed commercial logistical spacecraft launched with a single launch using Medium-Heavy LVs such as the EELV Phase 1 and the Falcon Heavy.  Thus, commercial activity is also expanded into cis-Lunar space and there is a greater fault-tolerance on the supply chain.  Ultimately, development of propellent storage and transfer technologies would allow such LVs to launch crew vehicles out to L1 but using SLS enables a quicker start than waiting for depot technology and IFR-capable upper stages.

Regarding the lander, I'd like to see a phased approach with semi-reusable versions (one or two reuses) to start.  The lessons learnt would contribute to NASA and its contractors learning what is needed to make and maintain in space long-term reusable vehicles (many years operational lifespan).  The L1 station could also act as a hub to assess multiple competing designs in a 'fly-off'.
"Oops! I left the silly thing in reverse!" - Duck Dodgers

~*~*~*~

The Space Shuttle Program - 1981-2011

The time for words has passed; The time has come to put up or shut up!
DON'T PROPAGANDISE, FLY!!!

Offline mmeijeri

  • Senior Member
  • *****
  • Posts: 7442
  • Martijn Meijering
  • NL
  • Liked: 70
  • Likes Given: 162
So you're looking at about 4 x D-IVH per sortie.

Which is still a low flight rate.

Quote
So no HLV is not essential, just very sensible.  Therefore not still-born at all.

Not terribly sensible at all. The good things about this are some slight advantages in not needing EOR (which is a drawback in the larger scheme of things), using reusable spacecraft and creating a market for propellant at L1/L2 without needing LOX/LH2 depots in LEO just yet. We can do much better than that. Also, too bad that there's no money for this if you base it around an HLV.
« Last Edit: 12/03/2011 01:12 PM by mmeijeri »
We will be vic-toooooo-ri-ous!!!

Offline kkattula

  • Member
  • Senior Member
  • *****
  • Posts: 2505
  • Melbourne, Australia
  • Liked: 10
  • Likes Given: 3
Not terribly sensible at all. The good things about this are some slight advantages in not needing EOR (which is a drawback in the larger scheme of things), using reusable spacecraft and creating a market for propellant at L1/L2 without needing LOX/LH2 depots in LEO just yet. We can do much better than that.

Of course they could do better, but if they think they'll need an HLV eventually (and I agree for both volume & mass reasons) and are determined to develop it now while the existing STS infrastructure can be leveraged, (which they appear to be), then it's a sensible early use of SLS.  And more sensible than doing the exact same mission with 4 x D-IVH.

Quote
Also, too bad that there's no money for this if you base it around an HLV.

Evidence?  Once developed and flying, SLS & Orion should cost less than $2B per year to operate. At the current budget level that alone leaves well over $1B per year to spend developing a lander, if an IP doesn't. Much more once CCDEV has transitioned into operations, replacing Soyuz payments, and KSC infrstructure improvements are finished. The other components are mostly already developed, they just need to be integrated.
« Last Edit: 12/03/2011 01:43 PM by kkattula »

Offline kkattula

  • Member
  • Senior Member
  • *****
  • Posts: 2505
  • Melbourne, Australia
  • Liked: 10
  • Likes Given: 3
So you're looking at about 4 x D-IVH per sortie.

Which is still a low flight rate.


Not when you need to do all 4 in the space of a few weeks.

Offline mmeijeri

  • Senior Member
  • *****
  • Posts: 7442
  • Martijn Meijering
  • NL
  • Liked: 70
  • Likes Given: 162
And more sensible than doing the exact same mission with 4 x D-IVH.

No, much less sensible. We need high flight rates if we want to reduce commercial launch prices. And without a drastic reduction in commercial launch prices we can't have commercial development of space.

Quote
Evidence?

Two years ago, when I was energetically advocating something very much like this plan to the SDLV crowd, including Chuck and Ross, they insisted there wouldn't be money for a gateway station and that that was not all that important anyway, something that should come after a moon base. Similarly, the reusable landers that Chuck is now cheering on were considered far too difficult. Since then the budget situation has deteriorated dramatically and the projected development costs of various components have only grown.
« Last Edit: 12/03/2011 01:53 PM by mmeijeri »
We will be vic-toooooo-ri-ous!!!

Offline mmeijeri

  • Senior Member
  • *****
  • Posts: 7442
  • Martijn Meijering
  • NL
  • Liked: 70
  • Likes Given: 162
Not when you need to do all 4 in the space of a few weeks.

That's still a low flight rate when you judge it by its effect on launch prices, though not a low flight rate for an EELV. But fortunately there is no need to do them all in the space of a few weeks. In fact there need be no time pressure at all.
We will be vic-toooooo-ri-ous!!!

Offline Ben the Space Brit

  • Senior Member
  • *****
  • Posts: 6872
  • A spaceflight fan
  • London, UK
  • Liked: 490
  • Likes Given: 560
And more sensible than doing the exact same mission with 4 x D-IVH.

No, much less sensible. We need high flight rates if we want to reduce commercial launch prices. And without a drastic reduction in commercial launch prices we can't have commercial development of space.

But an attempt to force a high flight rate will just make the politicians shout "Too difficult! Too expensive!" and de-fund the project.  Better to start slow with something that they like (and, right now, they love the SLS) and introduce the radical new things we want later when they are nice and anaesthetised.

Your problem has always been that you think that NASA needs to be forced to try radical things straight off.  That simply won't happen.  Realism is needed if anything is to be achieved and, right now, realism means starting with SLS-launched and -sized elements.
"Oops! I left the silly thing in reverse!" - Duck Dodgers

~*~*~*~

The Space Shuttle Program - 1981-2011

The time for words has passed; The time has come to put up or shut up!
DON'T PROPAGANDISE, FLY!!!

Offline mmeijeri

  • Senior Member
  • *****
  • Posts: 7442
  • Martijn Meijering
  • NL
  • Liked: 70
  • Likes Given: 162
Your problem has always been that you think that NASA needs to be forced to try radical things straight off.

No, not at all, that has been your criticism, but it has been false all along. I object to falsehoods being stated as facts, it doesn't mean I couldn't support a compromise. I just won't pretend it is anything else but a compromise. And if the other side is unwilling to compromise as SDLV proponents clearly were, why should I support them?

I supported an SDLV with a Delta upper stage, or even an EELV-compatible ACES, with Orion and with a fully or partially reusable Altair, provided all its propellant was launched on commercial launchers, which pretty much requires the use of hypergolics if we want to do this soon, as all of us wanted. You wouldn't even need a SEP tug or a gateway station, useful as these would be, so the moon first crowd wouldn't have to wait any longer.

Now, two and a half years later, everybody is suddenly on board with something even more ambitious and now I'm the one who isn't willing to compromise or to be incremental on the politics too. I've been totally incremental and I have been bending over backwards to accommodate all concerns (pretexts really, judging by the response) put forward by skeptics.
« Last Edit: 12/03/2011 02:47 PM by mmeijeri »
We will be vic-toooooo-ri-ous!!!

Offline Andy USA

  • Lead Moderator
  • Administrator
  • Full Member
  • *****
  • Posts: 963
  • Los Angeles, California
  • Liked: 117
  • Likes Given: 76
Remember to discuss the article and not to make up your own plans out of it. Don't want this to turn into the new home for the anti-SLS fans, so maybe link the article and create a new thread on US Launchers, Commercial or In Space Hardware forum?

Tags: