Dallas Bienhoff of Boeing presented their current concepts at a recent NASA in-space servicing workshop. It’s an impressive story of the performance leverage that a depot gives you, even with Constellation. I wonder if the trade includes dry launch in the depot case?
It’s interesting that he shows how they could use a Falcon 9, and an Atlas, but that Delta is unmentioned. Of course, now that ULA has taken over, perhaps Boeing has no institutional bias any more. I assume that this is the story that he’ll be telling at Space Access in a couple weeks, in the panel that we’ll both be on.
I’d like to see more detail on the ops (one of the slides came through as black for me). How do they propose to reuse the GTO/GEO tug? Aerobraking, or impulsively? You might want to check out some of the other papers at the link to Clark Lindsey’s site as well.
I think your black slide was the video – it worked for me when I viewed it as a presentation (F5), it just took a few moments to download/buffer (I think it may be linking to streaming video).
The video showed propellant storage modules being launched on a Falcon 9, how multiple modules would notionally be assembled on orbit, and the mate with servicing space vehicles.
I’m viewing it with Open Office presentation (in Fedora).
Depots (LEO and EML) and ISRU certainly are the route to follow if we desire a sustained presence on the Moon however neither the Bush/Griffin vision nor the Obama/Bolden/Garver vision embrace that approach.
Bill,
Agreed. It really does require a spaced based infrastructure to make it sustainable.
Wrong applications, wrong propellants, wrong size.
Wrong applications, wrong propellants, wrong size.
Care to elaborate? I thought fuel stations were application apathetic, as long as they have enough fuel for the customer they don’t really care what that customer does with it. The Falcon 9 2nd stage uses LOX (and hydrazine for RCS), Delta IV and Atlas V 2nd stages use LH2/LOX, so what would be the proper propellant? How much would the first gas station in space really need to store? Does the modular architecture not allow sufficient scaling?
Those particular concepts look like LOX/LH2, sized for lunar missions (with EDS/Altair). They’re based on Constellation work. Boeing is probably still working numbers for Flexible Path, and not ready to release them.
Care to elaborate?
No, because unlike these Boeing people I’m not somebody with an obsolete central-planning mindset angling for fat NASA contracts. I’ll just add this: there will be some general benefits to depots — mainly that they often allow greater flexibility in missions/operations planning. There are a vast number of possible of such uses. Each of these will put different demands on propellant and scale choices. Real commerce operates at a much smaller scale, on much lower budgets, and with different propellants than the ones chosen here. So what is presented here is far out on the tail of the distribution curve of possibilities. The odds that this will be the most useful architecture for space development are vanishingly small.
EML depots allow the pre-positioning of fuel (and equipment) delivered by fuel efficient, albeit slow trajectories. Greater delta t traded for less delta v.
Assemble your beyond LEO mission at EML-1 and/or EML-2 by remote operation then send the crew on a fast trajectory to their waiting ship and/or lunar lander.
See this paper by Jeffrey S. Parker
http://ccar.colorado.edu/nag/papers/AAS%2006-132.pdf
Ion propulsion would also work but Parker’s BLT trajectories can use conventional rockets.
I forgot to add, wrong orbits. Wrong applications, wrong budget, wrong size, wrong propellants, wrong orbits.
Googaw,
Well shucks, I guess we’ll just have to scrap all the research we’ve done. Googaw knows best!
~Jon
Depots (LEO and EML) and ISRU certainly are the route to follow if we desire a sustained presence on the Moon however neither the Bush/Griffin vision nor the Obama/Bolden/Garver vision embrace that approach.
Propellent depots and ISRU most definitely *are* part of General Bolden’s vision, Bill. Why don’t you take the time to learn about the plan before bashing it?
And why do you think it’s NASA’s job to create a “sustained presence” on the Moon? Lewis and Clark didn’t create a sustained presence in the Pacific Northwest. Private settlers did. We have a good example of what happens when NASA tries to create a “sustained presence” somewhere (ISS). The results are not pretty and not a model that ought to be repeated.
NASA does a much better job when it “boldy goes where no man has gone before” than when it tries to become a hotel keeper.
Googaw knows best!
It’s sort of like Smuckers — with a name like “Googaw,” you’ve got to be right!
I forgot to add, wrong orbits. Wrong applications, wrong budget, wrong size, wrong propellants, wrong orbits.
Let’s look at these.
1. Wrong orbits – if you have a few propellant depots, odds are good that there’ll be some application which is very suboptimally served by going from one of the depots rather than a depot in the optimal position. The point though is that launching from a depot is likely to remain superior to launching via a “right orbit” from the surface of Earth. It’s still considerably better than simultaneous bringing your vehicle and propellant up to speed.
2. Wrong applications – matter of opinion.
3. Wrong budget – is the budget insufficient to build a depot? Is too much spent on the depot for what you get out of it? We don’t know yet because it hasn’t been done. But I imagine the answer will turn out to be “no” in each case.
4. Wrong size – depends on your application and hence is a matter of opinion.
5. Wrong propellants – name a propellant that could be used yet cannot be tended from a propellant depot.
Orbiting one of these in LEO would seem to be the most prudent place to put your first depot – anyone launching from Earth is going to go to LEO or will go past it.
At any orbit lower than 400km the depot would deorbit quickly once the tanks are drained, with that huge cross-section. Considering how much delta-V they’d gain from the refueling, I doubt starting a GTO from 400km would be a game breaker for potential GEO customers. You could start using small refuelable launchers to take moderately sized payloads to GEO if it made economic sense.
28° is easily accesible for most launch locations, only Russia, Kodiak, and Wallops might find it too expensive to reach, and of those 3 Russia is the only site that does a significant amount of business.
Edward, I believe the best agency to own and operate an EML-1 depot would be a private corporation flagged in Singapore or Isle of Man which traded fuel & supplies with every nation on Earth.
And it is the Obama/Bolden/Garver vision that proposes to retain a NASA monopsony on U.S. human spaceflight.
@ Ryan Olcott
Until there are beyond LEO destinations what customers would a LEO depot service?
1. Wrong orbits – if you have a few propellant depots, odds are good that there’ll be some application which is very suboptimally served
The odds are good that practically all economical applications will be very sub-optimally served (really, not effectively served at all) if grossly uneconomic applications are targeted as in the Boeing architecture.
2. Wrong applications – matter of opinion.
If we were doing this anywhere close to rationally, it would be a matter of economics and real market preferences rather than of wild political opinions.
3. Wrong budget – is the budget insufficient to build a depot? Is too much spent on the depot for what you get out of it?
With very high probability the latter. And the wasted money, as bad as that is in the current precarious financial climate, is not the biggest of the problems, the greater problem is that we end up stuck with an “infrastructure” that real commerce cannot afford. Yet another bridge to nowhere, like the Shuttle and ISS, developed to win NASA contracts in fact and serve real commerce only in rhetoric.
We don’t know yet
My point exactly: there are a vast number of possible combinations of orbits, propellants, scales, target applications, etc. We can only guess at which of these are more likely to be economically viable by looking at real commerce. Real commerce uses different orbits, propellants, scales, and budgets than targeted in this study. This strongly suggests that the Boeing architecture is a fringe outlier in the design space, designed to satisfy old sci-fi daydreams and win NASA contracts rather than for real commerce.
4. Wrong size – depends on your application
It depends on picking applications that are compatible with the scales and budgets of real commerce, which the Boeing studies do not.
5. Wrong propellants – name a propellant that could be used yet cannot be tended from a propellant depot.
The main problem is locking in kinds of propellants that will be of far less use to real commercial customers (for a variety of reasons many quite non-obvious).
BTW, I am all in favor of actual research on this topic, things like trying to figure out how to store LH2 for months or preferably years in space — and also research on LCH4 rockets in case such storage turns out to be too expensive or otherwise infeasible. BTW, the desired duration of storage is another thing one can easily get way wrong if one gets the target applications wrong.
Research on depots and tankers that can handle multiple kinds of propellant, so that it can handle what actually turns out to be in demand at a future moment, would also be quite valuable (the value of which is of course not obvious if you have a central-planning mindset with its false certainty and thus have already made up your mind that these Boeing choices must be everybody’s future). We need a flexible path of research that tries out many possibilities. What I am against is “infrastructure”-mongering as if the Boeing architecture would actually be a good idea for NASA to develop or false confidence that our future must look like that so that we don’t need to explore the many other possible depot system configurations.
Edward, I believe the best agency to own and operate an EML-1 depot would be a private corporation flagged in Singapore or Isle of Man which traded fuel & supplies with every nation on Earth.
Bill, this architecture is designed to be 100% funded by big government agencies and not at all by any such corporation not acting as a proxy for such agency’s money. If it were designed for real commerce it would look nothing like it does.
28° is easily accesible for most launch locations, only Russia, Kodiak, and Wallops might find it too expensive to reach
I am no big expert on orbital mechanics but two 20-28 degree plane changes when launching from French Guinea or Kwajalein to GEO sounds like going way out of the way to me. 28 degrees sounds designed for Canaveral which is much less than half of the traffic to MEO and GEO. And to get to GTO from Canaveral one does a plane change to an equatorial orbit, right? So I’d call equatorial LEO the closest thing to an orbit most people could go to before going higher. 28 degrees sounds to me like what you’d choose if you were just angling for a NASA contract and didn’t care about any other customers.
Well, US based heavy launchers typically come out of the Cape or Vandenberg. Kwaj, Kodiak, and Wallops launch small vehicles. So if you want to make it easiest to use for the largest volume customers, an inclination close to the Cape or Vandenberg is a good choice.
Also, it is easier to launch into higher inclinations from a near zero latitude than vice versa. From zero latitude you can hit any inclination, you only lose the little bit of boost (~0.45ish km/s) from the Earth’s rotation (depending on your inclination angle, cos(inc=90°) would lose it all). If you launch from higher latitudes you have to perform a costly (in delta-V) inclination plane change once you are on orbit to move to a lower inclination. You are right in that those plane changes need to be done to go to GEO synchronous, it would just be easier to do them and have leftovers for whatever else if you had a prop depot to hook up to first.
I did find it interesting though that, at least in this package, Boeing didn’t seem interested in reusable fuel shipping payloads. Instead each payload is what appears to be a single use modular tank that becomes part of the depot, is drained an never refilled(?) Not a very sustainable or reusable depot, unless I’m missing something.
It seemed more like forward basing supplies than a fuel station. Which isn’t to poo-poo the idea, it would still be better than creating an unsustainable ultra-heavy lift vehicle to perform a mission all at once. Perhaps this is more cost effective than making a fuel ferry that can survive re-entry to be used again. It certainly would cut out the complexity of a depot refueling system, and an aluminum/steel tank isn’t likely to be a huge cost driver when you’re making enough to sufficiently amortize the original NRE.
Edward, I believe the best agency to own and operate an EML-1 depot would be a private corporation flagged in Singapore or Isle of Man which traded fuel & supplies with every nation on Earth.
Then why don’t you talk to Singapore or the Isle of Man? You don’t want to do anything yourself, but nothing anyone else does is good enough for you?
And it is the Obama/Bolden/Garver vision that proposes to retain a NASA monopsony on U.S. human spaceflight.
You don’t understand what General Bolden’s vision is, or you don’t know what the word “monopsony” means. Possibly both.
Again, why don’t you take the time to learn what the vision is before bashing it? Were you and Mark Whittington separated at birth?
It seemed more like forward basing supplies than a fuel station.
For the applications they are talking about, simply forward-basing a stage to dock to will work much better.
Boeing is just throwing an idea out there. It’s a start.
The last slide showed the propellant depot next to the EDS and lander. It’s hard to judge but I’d guess that a quarter to a third of the depot’s capacity would top up those stages. That implies a fairly low beyond-LEO flight rate and kind of misses the point of having a depot. However, it is a toehold and possible proof of concept.
The size of the tanks and the orbit and the list of possible stored fluids don’t need to be perfect. The market will sort that out.
The key to making propellant depots work is a standardized interface between the depot and the rockets to and from which fluid is transferred. That interface – its precise shape and couplers and handshaking and so forth – must be available to any suppliers and customers.
If that interface is developed in the United States, it will be hidden behind ITAR – is there any way to make it an Open Source project?
If that interface is developed in the United States, it will be hidden behind ITAR – is there any way to make it an Open Source project?
This is a very good idea.