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View Full Version : United Launch Alliance: The Moon a Go by 2018!



Warren Platts
2009-Sep-20, 12:12 PM
A few days ago, I read Chris Bergin's excellent article on the new ULA proposal; today, I read the actual AIAA white paper, A Commercially Based Lunar Architecture (http://www.ulalaunch.com/docs/publications/AffordableExplorationArchitecture2009.pdf) that summarizes the overall plan. (Here's a link to ULA's index of publications (http://www.ulalaunch.com/index_published.html) as well--a treasure trove of cool info.)

What a breath of fresh air! I am now convinced: Constellation/Ares must go (away) now! Over the course of two or three months, I've gone from ardent supporter to luke-warm apologist to reluctant naysayer, but now I'm a confirmed, hard-core opponent. We now have the new plan in hand. It is detailed, and it can work. What we need to do is stop farting around: Cxn, Direct, Augustine must all be consigned to the ashcan of history. ATK can go back to building ICBM motors.

Here are some highlights that caught my admittedly idiosyncratic attention:

The plan can get us back to the Moon by 2018 within the current budget
Therefore, the extra $3 X 109 USD is not needed (though we'll take it for extra science missions if they want to give it away :))
International partners would be welcome but they would not be critical path components (i.e., the project can't be derailed by the vagaries of international politics or economics)
ISS gets to stay afloat until 2020
But Shuttle only has to be extended until 2014, if we're worried about "the gap"
The new lunar lander (which they call "Altair" for some reason, though it's really a different species than the Cxn Altair) lands horizontally and can be moved once it lands
A SSTO version of the lander can deliver 7 tons of ISRU propellant per launch to the L2 fuel depot
I suspect that the L2 depot will allow reusable SSTO sorties to any given point on the Moon
Leftover ACES 41 propulsion stages on the Moon can be reused as living quarters, fuel depots, and water and sewage storage
Human civilization on another world begins on the first day that astronauts land--the Moon would never again experience a single day when it wasn't inhabited by humans

Thus the next question is: where to emplace the first lunar base? I would suggest the good old Sea of Tranquility. It's easy to get to, the terrain isn't the most challenging place on the Moon, and there are fairly high quality metal ores there. Granted, there isn't any water there, but mining water out of a -240o C crater isn't going to be a trivial task in any case. Thus, the Sea of Tranquility would serve as the Moon's McMurdo. But eventually, a second, South Pole base would be set up at Shackleton.

Jon Clarke, the ULA proposal will be the test of your ability to be open-minded and imbibe fresh information! :razz:

sanman
2009-Sep-20, 01:36 PM
Why not use the existing LRO/LCROSS missions to scout for lava tubes?
Underground is the best place to build actual places to live, and lava tubes are the best natural formations for this.

Technologies could be tested here on Earth for converting lava tubes or caves into living spaces. I'm imagining that you'd use lasers to map out the interior of some cave. Then on Earth you'd manufacture a large inflatable envelope to fit the dimensions of that cave. The envelope would be made of many layers and would include wiring for fiber optics and power. It would be bonded to an airlock hatch assembly large enough to fit the mouth of the cave and become a door.

You would then clear the cave of any debris, and spray the cave walls with some X-ray-curable foam. Finally, insert the envelope into the cave and inflate it, then after entering via the airlock, use X-ray lamps to harden the foam.

You could probably use the same foam-curing method to make furniture for the interior. Fill up pre-made envelopes with foam, cure it, and you have your interior structures.

ugordan
2009-Sep-20, 03:15 PM
Of all the possible exploration architectures, ones using depots probably come closest to being a win-win for all parties involved. To those dismissing this as ULA's sales pitch, some quotes from the presentation:


The architecture is illustrated using ULA vehicle concepts for convenience. In reality, no single industrial entity can entirely support this architecture. The production and launch rates are simply not sustainable by a single team. It must be a concerted effort of several launch providers, perhaps a consortium linking industry and NASA.

Regarding launching propellant:

This is the dominant commercial task and is expected to be done by the widest possible range of launchers and providers (Figure 8). Whichever launcher delivers propellants for the lowest cost becomes the dominant player, though it is prudent to retain a number of launch providers to ensure propellant delivery in the event of delays. The cost of this activity is a significant proportion of the lunar exploration yearly bill constituting ~75% of the Earth to orbit launch mass. NASA can use competitive pressures to control and even reduce the bulk of its Exploration expenditures. With competitive propellant launch one can expect launch prices to drop over time.

This is an area ripe for startup space launch companies since the value of the cargo is effectively nil. A failure of a low maturity booster does not result in loss of high value, irreplaceable payload and with multiple launch providers such a delay has no impact on the pace of the overall Exploration mission.
Can you imagine a better way for a startup company (SpaceX immediately comes to mind) to generate revenue and incrementally develop reliable vehicles by being paid for launching payload of effectively no value?

Also, economies of scale to all inolved - more launches means more efficient utilization of workforce, infrastructure, production capability ultimately driving down cost of a single launch and increasing reliability. Probabilistic risk assessments be damned, we're talking real flight history and demonstrated reliability numbers here! This is where any competing HLV architecture would be lacking. The lower cost per launch would then benefit other commercial uses of those vehicles - launching comsats, government missions and even NASA's own unmanned missions.

This could even close the business case for developing true RLVs:

It also suggests a debut function for single-stage to orbit, reusable vehicles which initially will likely have low lift capability. The ability to deliver even 1000 lbs of LO2 to a depot once a day with reusable equipment would likely be superior to a single expendable launch every month.

And the depot idea in question isn't really a challenging one compared to some other, more ambitious depot ideas:

The ACES depot has no need for anything close to zero boiloff- especially in LEO. The thermal systems use vaporized hydrogen to completely suppress LO2 boiloff – the enormous heat capacity of hydrogen is fully taken advantage of, yet still on the order of 60 lbm of hydrogen will be vaporized per day. Over the course of a year nearly 10 tons of hydrogen will be consumed- a daunting number. However over 300 tons of propellant will have been transferred through the LEO depot in a year- the heating loss is less than 4% of the throughput. Furthermore the gasified hydrogen, warmed by solar radiation constitutes a simple solarthermal propulsion system with a high Isp of 390 seconds. It is used as a monopropellant to provide the bulk of reboost, stationkeeping and maneuver control. With the assumed boiloff losses this amounts to 2-3 m/sec of delta V per day. Given the demands on the depot this is probably low and would have to be supplemented. So in reality there is no loss- just the cost of doing business in LEO. Striving to suppress heating to the lowest possible level with exotic technology is pointless. Amplifying throughput is the best way to make the depot more efficient.

By using boiloff for station keeping (and Isp of 390 beats even hypergol RCS), there really is no effective loss of propellant as station keeping is required either way.

All in all, it's hard not to like this proposal if you're really open-minded.

Antice
2009-Sep-20, 03:33 PM
considering that i am not even trying to dislike it i cant say i have anything against it.
I still think traditional EELV's are a bit on the small side to do this the cheapest way. but letting everyone in on the deal instead of trying to monopolize will probably fix that after a while. either that or SSTO's will take over. It doesn't really matter to me as long as open competition is maintained at all links in the chain.
I stil have some reading to do before i am sold however. And i do lament the loss of Nova class launchers for launching really big probes or scopes in one go.

The depot method proposed is one of the more flexible ones. since it's not basing itself in LEO. permanent LEO depots = fail. L2 depots are ok. staging a depot run in LEO maybe not needed. it depends on the launcher used.
The place to assemble a Mars vehicle would then be L2 as well. nothing wrong with that since going from L2 to Mars is no worse than going from LEO. altho you do have a propellant penalty prior to assembly.

Warren Platts
2009-Sep-20, 04:53 PM
The depot method proposed is one of the more flexible ones. since it's not basing itself in LEO. permanent LEO depots = fail. L2 depots are ok. staging a depot run in LEO maybe not needed. it depends on the launcher used.
It sounds like the LEO depot is going to be there permanently. But that's OK. As ugordan pointed out above, you can use the boiloff for station keeping, and since station keeping will require more propellant than naturally boils off, LH2 boil-off is a non-issue.

The place to assemble a Mars vehicle would then be L2 as well. nothing wrong with that since going from L2 to Mars is no worse than going from LEO. altho you do have a propellant penalty prior to assembly.There is no penalty; there is a propellant bonus:


Objects that are located at L2 have already had a substantial amount of energy pumped into them. They have effectively reached earth escape velocity while still being bound to the earth. This energy constitutes a substantial portion of the total delta V required to venture to Mars, for example. Many publications have advocated the use of the LaGrange points for departure to the planets but a dedicated depot just for the occasional Jupiter or Mars mission is clearly ineffective. With the road to L2 supported and maintained by Lunar Exploration these departure strategies become very attractive.

Departure from L2 is further aided by incorporating a powered Earth gravitational assist into the mission design. Objects being sent from L2 to Jupiter for example require only a small nudge to place them in a trajectory towards earth with a very low perigee. As the departing spacecraft nears perigee it conducts a burn when it is at an already high velocity. This activity effectively maximizes the delta V that can be achieved from a fixed propellant mass. Rather than assembling stupendous propellant masses in LEO, as is often proposed for a crewed mission to Mars, we can use this L2 departure strategy to gradually pump energy into the objects we wish to send to Mars by caching them at L2 and also get a large delta V leverage at the final departure. Much larger spacecraft can be sent to high C3 destinations using this approach.

(Zegler et al., 2009, 24) (http://www.ulalaunch.com/docs/publications/AffordableExplorationArchitecture2009.pdf)

Glom
2009-Sep-20, 05:50 PM
Is L2 just for interplanetary staging? I got the impression this was a fuel depot for trans-Lunar staging, which would seem a little chicken vs egg.

Warren Platts
2009-Sep-20, 05:54 PM
The L2 depot would support lunar exploration at first, but once it was set up, it would make a practical staging zone for interplanetary missions as well.

Antice
2009-Sep-20, 06:14 PM
you do not need a permanent one in LEO to have one in L2. thing is. the first launch launches a new depot. the second and third top it up then the Leo depot moves to L2 with the fuel and tops the permanent depot up. the fuel keeps better at L2 since it's a much colder environment to operate in.
if one of the tree launches fails the mission is still not a scrub. a fourth contingency load could be standing ready to launch, or you could just shrug and send the surviving suplies out to L2 annyway.
With a true HLV you could send the fuel direct to L2...
but NASA can-not afford one at present. I do have doubts about how useful a depot would be for a moon shot tho.
L2 is kinda a detour, and some risks would be magnified trough the use of having all of these extra steps.
For a mars or NEO shot then L2 is a great staging post.

samkent
2009-Sep-20, 07:24 PM
It sounds like the ole “Yea I can build it for that amount”.
But once they get into it “But you didn’t take into account…”

Warren Platts
2009-Sep-20, 07:53 PM
It sounds like the ole “Yea I can build it for that amount”.
But once they get into it “But you didn’t take into account…”Gimmee a break! Just by skipping solid rocket fueled Ares V, we'll save $30 billion right there. How many years of exploration budget is that worth?


you do not need a permanent one in LEO to have one in L2. thing is. the first launch launches a new depot. the second and third top it up then the Leo depot moves to L2 with the fuel and tops the permanent depot up. the fuel keeps better at L2 since it's a much colder environment to operate in.
if one of the tree launches fails the mission is still not a scrub. a fourth contingency load could be standing ready to launch, or you could just shrug and send the surviving suplies out to L2 annyway.
With a true HLV you could send the fuel direct to L2...
but NASA can-not afford one at present. I do have doubts about how useful a depot would be for a moon shot tho.
L2 is kinda a detour, and some risks would be magnified trough the use of having all of these extra steps.
I don't think you understand the revolutionary guiding philosophy behind the ULA proposal. The main idea is to separate the logistic stream from the crew stream as much as possible; this allows each vehicle to it's maximum potential.

Let's say you have a light payload: currently, the rocket you use will have excess capacity that now goes to waste; with the LEO depot, the booster can dock with the fuel depot and deposit extra fuel that it doesn't need and then get reimbursed for the cost of boosting that fuel, thus lowering the total cost of the mission.

Similarly, let's say you've got a heavy interplanetary probe that would ordinarily take an Ares V to get going. With a fuel depot, you just launch the payload without the fuel required to go to Neptune. Your probe docks with the LEO depot, loads up on fuel, then goes to the L2 depot, and tops off it's tanks once again, heads back to Earth for a gravity assist boost, and then it's off to the races. In this case, you've got to pay for the extra fuel that's been prestaged, but it is a heck of a lot cheaper than buying an Ares V flight that costs $30 billion + USD just to develop, plus billions more just for the ground operations.

Consider an analogy. One problem with wind energy farms is that the best spots tend to be far away from the big cities that would like to use the power. This necessitates the building of expensive high-capacity transmission lines out to the remote wind farm. But the wind does not always blow steadily; yet the transmission line has to be built to be able to transmit the maximum amount of power that the wind farm can generate. Thus, during times of low wind, your expensive transmission line is not working at its designed capacity--it is being used inefficiently. So a possible solution is build a natural gas turbine within your wind farm that produces power levels inversely proportional to the wind farms production, so that the expensive transmission line is being used at its maximum capacity at all times; thus, the return-on-investment of the expensive power line is maximised. Fuel depots in space have the same effect; each expensive rocket is now used at its maximum capacity, thus maximising the ROI.


It is easy to be dazzled by the drama of astronauts lifting off on a pillar of flame but most of the work of going to the moon is just about moving propellants. At least 70% of the job of launching mass to LEO, the first step on the way to the moon, is moving the liquid hydrogen and oxygen we will need for the subsequent steps. Because of its magnitude, moving propellant is far and away the most important element of any lunar architecture but it is often wholly ignored. It is crucial that the handling and moving of propellants be very efficient. The more efficiently propellants are delivered for all the various purposes the greater the overall system affordability and performance.
(Zegler et al. 2009, 4) (http://www.ulalaunch.com/docs/publications/AffordableExplorationArchitecture2009.pdf)

ugordan
2009-Sep-20, 08:15 PM
It sounds like the ole “Yea I can build it for that amount”.
But once they get into it “But you didn’t take into account…”

I, for one, am much more willing to believe the numbers from a company whose designers have developed and successfully flown several vehicles in the recent years.

As opposed to NASA's constantly increasing schedule and cost numbers. By Griffin's own account he wanted the guys at MSFC to "relearn" designing rockets. Yeah, that's a good idea - it's not like the future of U.S. manned spaceflight hinges on that after the shuttle retires or anything. Let's give the center that hasn't designed a flying vehicle in the last 30 years something to do. And lots of monies!

Of course, if you're a die-hard HLV fan, your mileage may vary.

Antice
2009-Sep-21, 05:11 AM
for LEO depot's you have to take into accont that the depot's orbit becomes a primary driver of when you can launch. you either have to launch each and every interplanetary mission from L2 with a daily window for going to L2 or you need a depot in a separate location for each interplanetary launch. if the primary depot is in L2 then only the most heavy probes will need any LEO fuel at all. and for those you treat them as a manned launch and have it as part of a LEO -> L2 cargo run.
Considder this. the Depot in LEO can carry a lot of other stuff than just fuel.

The base message from ULA is that space systems needs to become standardized so that all actors in the field can compete in all aspects of a trip.
that means that there is a disconnect between what you launch the fuel on, and who and what ends up using it. so in the end this system does allow commercial entities to go for a HLV since the economics will be the deciding factor and not philosophy.

Once the Nasa budget is freed from developing launchers then there do become a lot of money freed up for other stuff. in a way industry ends up paying for the development up front instead of Nasa doing it. the end result might be the same cost wise. but for nasa there no longer is any amortization issues to contend with.
besides. make the system able to service anyone willing to pay for it's use and you can share the amortization among multiple customers as well.
This however means that the depot's standards has to be shared internationally.
Call it commerce enhancing tech transfer.

Warren Platts
2009-Sep-21, 11:00 AM
for LEO depot's you have to take into accont that the depot's orbit becomes a primary driver of when you can launch. Same with the weather.
you either have to launch each and every interplanetary mission from L2 with a daily window for going to L2 or you need a depot in a separate location for each interplanetary launch.There is only one EML2; you could launch from the Earth-Sun L2 point, but the number of interplanetary launches do not justify a separate depot at this point; a manned lunar station, on the other hand, will require a constant stream of supplies; because of the Earth-Moon L2 depot, manned spaceflight will subsidize unmanned spaceflight.
if the primary depot is in L2 then only the most heavy probes will need any LEO fuel at all.You will always want to top off with LEO propellant, because L2 propellant will always be more expensive, because L2 propellant has had more energy pumped into it.
Consider this. the Depot in LEO can carry a lot of other stuff than just fuel.Yeah, they could put a deli up there and sell potato chips, soda, and cold beer and beef jerky--that's where the real money is! ;)
The base message from ULA is that space systems needs to become standardized so that all actors in the field can compete in all aspects of a trip.Yes.
that means that there is a disconnect between what you launch the fuel on, and who and what ends up using it."Disconnect" isn't quite the English word you're looking for because "disconnect" carries a connotation of schizophrenia these days--but I see your point: the LV's launching fuel to the depot can have varied designs; nevertheless, they will indeed be connecting with the end user
so in the end this system does allow commercial entities to go for a HLV since the economics will be the deciding factor and not philosophy. Exactly: let Walt Disney design and build it.
Once the Nasa budget is freed from developing launchers then there do become a lot of money freed up for other stuff.By Jove, I think you've got it!
in a way industry ends up paying for the development up front instead of Nasa doing it. the end result might be the same cost wise. but for nasa there no longer is any amortization issues to contend with.
besides. make the system able to service anyone willing to pay for it's use and you can share the amortization among multiple customers as well.Indeed!
This however means that the depot's standards has to be shared internationally.Of course. Like the proposal says, the lunar base will require boatloads of fuel. If Arianespace wants to get in on the act, they could make themselves some money. That will require international standardization, but that's already occurring with the use of standardized airlocks and such.

Vultur
2009-Sep-21, 11:19 AM
Sounds mostly good. A bit underambitious though: they ought to set their sights higher to allow for cuts.

(Also, we won't *really* get anywhere till we have *heavy* launch capability - hundreds of tons plus per launch. Nuclear propulsion is the way to go for any real progress: sadly we'll have to wait for the political climate to moderate on that one... So this sounds like a great near-term plan ... with the caveat that it's only near-term/stopgap.)

Ara Pacis
2009-Sep-21, 06:16 PM
While I would like to have Heavy Lift because of my own grandiose ideas, when arguing with a very good collegiate debater on returning to the moon, the system I came up with was very similar to what's being discussed here. After all, a lot of stuff can be assembled in orbit, and perhaps more cheaply in the shortrun if access costs are lower.

The first roads carried horse-drawn buggies. Over time, with improvements, they are now carrying 18-wheelers. We need the road first.

And I like the idea of a deli in space. If we reduce spaceflight costs with standardization, automation and high utilization, smaller businesses like retail, will end up going along for the ride.