Using Orion as a temporary LLO space station

cIclops · 2006-09-23 06:09:52

Orion has been designed to stay in LLO while the crew sortie to the lunar surface in the LSAM. Now this paper (abstract only) extends this concept.

“Why must the humans return to Earth between sorties?” Although this is tacitly assumed in the reference ESAS human sortie mission, and indeed in nearly all lunar mission studies, it need not be the case. For example, if the astronauts stay near the Moon (e.g. in lunar orbit in the Crew Exploration Vehicle (CEV) between sorties) and perform multiple descents to the surface during a single mission the value of the mission is increased. First, several sites can be visited at different longitudes around the Moon all selected so that the astronauts visit during daylight hours. Second, the astronauts can easily return to the CEV between sorties not only to rest but possibly to rotate crewmembers or replace hardware and science instruments for subsequent surface sorties. Third, a number of sites can be explored with only one Earth launch and re-entry, reducing the number of critical events needed per site visited (since all sites share the single Earth launch and re-entry). Fourth, the cost per site visited goes down because the mission operations costs are essentially unchanged and only one CEV is required, instead of one CEV per site. Fifth, the efficiency of utilization of the humans goes up, because the humans spend more time doing science on the surface and less time in transit. Sixth, because the astronauts return to the CEV between sorties, they can choose to abort the remaining sorties and return to the Earth at any point during the mission, providing an additional measure of safety. Seventh, since multiple Lunar Surface Access Modules (LSAMs) are available the crew could be rescued by an ‘extra’ LSAM in the event of an emergency with the LSAM on the surface. Eighth, the options for anytime abort to the CEV are increased, and in most cases result in a reduction of propellant needed on the CEV for plane changes.

idiom · 2006-09-23 06:22:33

Thats an interesting idea. The same idea could be used on Mars, not to go four years but to explore multiple sites with the single two-year crew. This might be especially imporntant or useful on the first or second mission while looking for sites most worthy of a two year investigation. At six months or so per site the mission would generate a lot more data very quickly as the 'easy' data would be available four times.

It would mean an extremely reusable and reliable MAV and four HAB launches but I think it might be worth looking into. Plus it would mean there were four nukes scattered about Mars after the first mission.

GCNRevenger · 2006-09-23 10:02:56

Not really... as far as mars is concerned there will be a big difference in that travel much further from the base camp for extended periods will be safe on Mars as opposed to the Moon, since you don't have to worry about solar flares as much. So, you could bring a heavy rover with you able to make qualitatively longer excursions from the landing site. Also the fuel required to deorbit and launch back to orbit four times is so much greater than what you need for one trip with a bigger vehicle that it drives the complexity and cost of a Mars mission way up. That many mission-critical maneuvers makes me nervous too.

The "easy" data is not what we want anyway, robots can do that, we send humans for the "hard" stuff and that takes time.

Lugging a brand new reactor for every landing site doesn't make much sense, the thing takes up about 10% of the mass of every landing, and recovering the highly radioactive/still producing heat for subsequent landings isn't happening.

For the Moon (and Mars too) there is another problem with orbital basing, which is that you are confined to either equitorial sites only, or else you can't have anytime-launch emergency return with a more inclined orbit.

Again, the fuel required for multiple deorbits/reorbits will be pretty signifigant, and since the CEV is a small fraction of the total launch mass (~20% maybe less) then not having to carry it for every landing is not that big of a savings. Also, the size of the orbital living quarters will be substantially bigger, offsetting the bennefit of only needing ~1/4th a CEV per Lunar sortie.

Solar flares are a big problem, that a ten-day mission we can pretty well guess there won't be a problem, but a forecast out to 30-40 days or more? Thats pushing it.

A much better idea is to find sites using robots, build a Lunar base with a LOX supply, and deploy suborbital "hop" missions from that base. You could still cover much of the Moon, but do it with only small amounts of imported fuel, and return quickly to the Lunar base in the event of a solar flare.

This mission plan also calls for multiple LSAM modules, so how much are you really saving? Four LSAMs will still need four heavy lift rockets, though not as large as Ares-V perhaps, plus a "jumbo CEV" at least double the size. And you have the dry weight of several LSAMs instead of just reusing one for suborbital flights. Plus you won't be able to take advantage of equipment reuse, like only carrying one rover between every landing.

cIclops · 2006-09-23 10:55:04

For the Moon (and Mars too) there is another problem with orbital basing, which is that you are confined to either equitorial sites only, or else you can't have anytime-launch emergency return with a more inclined orbit.

Then how will Orion support lunar polar missions? With Orion in a polar orbit this approach would allow sequential sorties to both poles. The anytime return requirement seems to disappeared from the latest docs.

<waves hands about>
An Ares I/Orion launch may well cost about the same as a Ares V/EDS/LSAM, so cost wise it's two missions for the price of 1.5, a good deal.
<waves goodbye>

RedStreak · 2006-09-23 13:48:26

This sounds like a potential application for the moon with a lander modified into a suborbital 'hopper' but I don't think the same could be done at Mars, not when you have an atmosphere to plow through. On Mars a dedicated rover or blimp is required for large areas or multiple site surveys.

For the initial Lunar missions though I wouldn't recommend this approach. I would wait until we have two small bases each with LOX production - one could be polar while the second could be located at a distinct near-equatorial site such as Copernicus crater or Aristarchus. Between the two a hopper could investigate a sizeable section of the surface as this paper suggests, however instead of the CEV it would more be the bases providing support.

All the CEV itself does would be taxi capability. If there is a base established near the equator then all orbit-to-surface transport could be concentrated there to minimize propellant expenditures for orbital maneuvering (to any lattitude or inclination). In the long run the CEV should be treated as the Soyuz and Shuttle for the ISS now, so regardless of how we maneuver on the surface we would only need to launch as many CEVs as needed for crew rotations and the occassional emergency.

GCNRevenger · 2006-09-23 13:52:40

Hmmm I suppose you wouldn't have anytime return

How will Ares-I/Orion possibly cost as much as the big Ares-V with LSAM?

RedStreak · 2006-09-23 16:03:42

Hmmm I suppose you wouldn't have anytime return

What people seem to leave out is: return to where?

Zubrin himself in Mars Direct advokes instead of squealing like mice and rushing back to Earth with a potentially-crippled spacecraft ala Apollo 13's condition or worse to stay on the planet.

The Moon, when compared to Mars certainly, isn't a merciful world for life-support but with Earth only 3 days away as an astronaut I'd be more at ease if my lander were on the surface especially with a working lunar base to turn to rather than floating adrift with a CEV riding my back like a dead elephant to quote Apollo 13.

At the very least, a planetary body even as desolate and empty as the Moon cuts the worries of keeping your spacecraft stable - burning up fuel that could be used for a return trip your ship obviously isn't doing at the time. Also whereas you're exposed in all directions in empty space the Moon cuts radiation in half instantly; sit inside a habitat with a layer of regiolith atop and the worry is gone entirely. Any crew vessel would carry at least a week's worth of supplies - time enough for a would-be-back-up CEV, which if the current shuttle program is considered with a back-up flight, would likely be on stand-by for rescue - flown automated (which is a VSE requirement) so the crew have room.

Obviously this is applicable if there's working equiptment on the Moon and with a working LSAM. If a mission is designed for long duration (i.e. 30 days) it is possible for immediate use as well. This is why putting machines first on Luna is a priority so the crew have a haven away from Earth to return to...especially if Earth is beyond their reach.

GCNRevenger · 2006-09-23 17:06:27

Not really practical, the first series of missions will definatly happen without the bennefit of a surface base, and it is not practical to preposition a safe-haven within a space-suited walk reliably, much less the cost.

In any event, emergency return is mainly in the event of a wounded astronaut or a serious failure on the LSAM, such as the solar arrays giving out or life support fails, in which case the vehicle will not be liveable within hours. In such a case, the only practical chance for survival is immediate return to the CEV. Apollo-XIII's case does not have much applicability in the case of emergency surface return.

A rescue mission is probably not a practical option, it takes some weeks to prepare Shuttle even in "emergency" preparation mode, and preparing/assembling/launching another LSAM module to the Lunar surface or a CEV to Lunar orbit is not practical in such a short time frame. NASA is only planning on two Lunar missions a year even. This is one of those risks that will probably just have to be lived with.

I find it amusing and somewhat sad that you have the "himself" suffix when you invoke Zubrin's name, like e is some supreme authority or something, and not the wild-eyed wannabe rocket messiah who thinks entirely too highly of himself.

RedStreak · 2006-09-23 17:38:57

I find it amusing and somewhat sad that you have the "himself" suffix when you invoke Zubrin's name, like e is some supreme authority or something, and not the wild-eyed wannabe rocket messiah who thinks entirely too highly of himself.

Note how I'm not capitablizing the h GCN. However Zubrin's engineering and simplicity has gained support enough to finally influence NASA, regardless of how extreme (which I will admit at times) his personal philosophy can be.

Getting back to being stranded in Cislunar space if the CEV is damaged then the crew would turn to utilizing the LSAM, if the LSAM is damaged then the CEV.

I will say the good that came out of Apollo 13 is the fact that even if a vehicle wasn't designed to do something doesn't mean it's incapable and I'm sure every engineer knows. The LSAM would definetely be a great back-up if the CEV totally melts-down. It would probably have enough fuel to initiate a burn to return even w/o circling the Moon in a free-return; likely it'd enter LEO and either rendevous w/ ISS or another CEV, assuming the mission CEV was incapable of reentry. If the senerio is reversed then the CEV may, in order to perform the nessicary maneuvers with a sufficently reduced mass, would probably jettison the LSAM (assuming the helpful LSAM was completely destroyed or empty of fuel) and cruise in free-return trajectory.

I made my statement before under the assumption of a spacecraft nearing or already in Lunar Orbit with sufficent damage to render a return to Earth impossible. Being stranded in orbit over a barren planetoid is pretty bad...being on the surface is no worse off though.

RedStreak · 2006-09-23 17:45:13

Not really practical, the first series of missions will definatly happen without the bennefit of a surface base, and it is not practical to preposition a safe-haven within a space-suited walk reliably, much less the cost.

Depends on whether you're talking dollars or lives...

Numerous space enthusiasts do argue exploring and colonizing planets simply "just in case" Earth goes bad, either by pollution or natural disaster. Unless you want to repeat the old hollow success of Apollo constructing a base is a noted priority once we are capable of Lunar visits.

I am simply suggesting an option astronauts will consider if they have the choice. Whether or not they have any option depends on their wits, engineers' skill, and the choices of politicians directing the space program.

SpaceNut · 2006-09-23 20:24:25

Orion has been designed to stay in LLO while the crew sortie to the lunar surface in the LSAM. Now this paper (abstract only) extends this concept.

Lets not tell gaetanomarano for he will think that this sounds like his lunar space station... especially if you have 2 connected together to a common node docking module port.

Knowing that we have the 1.5 launch vehicles system design, how could we modify them to get this all in one launch to the moon. Would this be low enough in mass to launch it on the CaLV in a single launch?

Commodore · 2006-09-23 21:28:08

Knowing that we have the 1.5 launch vehicles system design, how could we modify them to get this all in one launch to the moon. Would this be low enough in mass to launch it on the CaLV in a single launch?

I've long thought that the LSAM hab/accent module and and the Orion command module were too similar in function to develope a completely new craft. By eliminating the accent module and Orion SM, and replacing them with a just an Orion CM and slightly bulkier TLI stage capable of sustaining low lunar orbit for the required two weeks and propelling the Orion back to Earth before falling back to the Moon, I think we could reduce the 1.5 launch system down to just 1. Granted this puts a bigger load on the LSAM to slow both it, the Orion, and the TLI(largely empty).

GCNRevenger · 2006-09-23 21:33:37

I think that you overstate the risk of the CEV being unable to reenter the atmosphere, that thanks to the stacked design and no fuel cells as in Apollo, the risk the heat shield will be damaged before reentry is pretty much nil. That as long as the capsule is properly oriented, which can be by the CEV capsule, the service module, or the LSAM and the parachute pyros fire then the crew should survive. Even with a depressurized capsule, they could live in the LSAM until reentry time and then ride the capsule in suits.

GCNRevenger · 2006-09-23 21:35:59

Knowing that we have the 1.5 launch vehicles system design, how could we modify them to get this all in one launch to the moon. Would this be low enough in mass to launch it on the CaLV in a single launch?
I've long thought that the LSAM hab/accent module and and the Orion command module were too similar in function to develope a completely new craft. By eliminating the accent module and Orion SM, and replacing them with a just an Orion CM and slightly bulkier TLI stage capable of sustaining low lunar orbit for the required two weeks and propelling the Orion back to Earth before falling back to the Moon, I think we could reduce the 1.5 launch system down to just 1. Granted this puts a bigger load on the LSAM to slow both it, the Orion, and the TLI(largely empty).

You are talking a 20% decrease or so in dry mass, which is pretty signifigant. I don't think you can do it without a bigger launch vehicle.

The CEV capsule can't really re-dock backwards (shield first) with the orbiting TLI/TEI stage for the return to Earth either. The capsule is also all the wrong shape for astronauts to get in/out of suits in gravity (you can't stand up) and you have to lug the CEV's heat shield/parachutes and heavier structure to the surface and back.

RedStreak · 2006-09-23 21:42:28

I think that you overstate the risk of the CEV being unable to reenter the atmosphere, that thanks to the stacked design

Its unlikely but I'm sure there are NASA specialists who are thinking "what if?" much as I am. As with Apollo once on the return path to Earth the SM would be jettisoned and he CEV would return the crew safely.

cIclops · 2006-09-24 05:42:12

How will Ares-I/Orion possibly cost as much as the big Ares-V with LSAM?

Because Orion has a crew. The hidden cost of a man rated vehicle is not just the cost of additional redundancy and development testing, but also the higher quality vehicle preparation and operations, crew training and mission support.

There are no real numbers yet however this formula may have some meaning:

absolute cost comparision:

Ares I first stage << Ares V
Ares I US ~ EDS
Orion > LSAM

Manrating and mission costs may well cover the difference and so roughly equalize the cost between the two elements.

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#1 2006-09-23 06:09:52

Re: Using Orion as a temporary LLO space station

#2 2006-09-23 06:22:33

Re: Using Orion as a temporary LLO space station

#3 2006-09-23 10:02:56

Re: Using Orion as a temporary LLO space station

#4 2006-09-23 10:55:04

Re: Using Orion as a temporary LLO space station

#5 2006-09-23 13:48:26

Re: Using Orion as a temporary LLO space station

#6 2006-09-23 13:52:40

Re: Using Orion as a temporary LLO space station

#7 2006-09-23 16:03:42

Re: Using Orion as a temporary LLO space station

#8 2006-09-23 17:06:27

Re: Using Orion as a temporary LLO space station

#9 2006-09-23 17:38:57

Re: Using Orion as a temporary LLO space station

#10 2006-09-23 17:45:13

Re: Using Orion as a temporary LLO space station

#11 2006-09-23 20:24:25

Re: Using Orion as a temporary LLO space station

#12 2006-09-23 21:28:08

Re: Using Orion as a temporary LLO space station

#13 2006-09-23 21:33:37

Re: Using Orion as a temporary LLO space station

#14 2006-09-23 21:35:59

Re: Using Orion as a temporary LLO space station

#15 2006-09-23 21:42:28

Re: Using Orion as a temporary LLO space station

#16 2006-09-24 05:42:12

Re: Using Orion as a temporary LLO space station

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