Top Ten Technologies For Reusable CisLunar Transportation Architecture

Dallas Bienhoff:

Architecture has propellant depots, “depot tugs” between LEO and EML1, and landers from EML1 and the moon. Breaking up propulsion steps makes system more efficient. Can be launched and supported in 25-ton chunks (no HLV needed). Can also get tonnage back to LEO via aerocapture, to allow delivery of lunar water there.

Consists of personnel modules (zero-gee and g-oriented), propellant carrier, two modular depots, reusable transfer vehicles, aerobraked reusable vehicle, lander, all Lox/hydrogen.

Top ten techs:

10. Variable mixture ratio lox/hydrogen engine.

9. Low-g and zero-g oxygen/hydrogen liquefaction

8. Low-g water electrolysis

7. Deep-space autonomous rendezvous and docking (AR&D)

6. Aerocapture (need to fly aerocapture experiment from eighties that never flew)

5. Long-life reusable lox/hydrogen engine

4. Aero-assisted entry, descent and landing

3. Long-term zero-g cryo storage

2. Zero-g cryo transfer

1. Zero-g cryo fluid management (storage). Can be done with cryo coolers.

NASA flight technology demos (FTDs) support some but not all, but schedule far too long. Really important stuff out in 2025 time frame.

10, 9, 8, 7 and 5 (half of them) not covered by FTDs.

Needed now, cryo management, storage, transfer.

Next, AEDL, then aerocapture.

First three technologies enable depots, AEDL enhances ETO propellant tankers, long-life engines help cost, deep-space enables depot assembly and lander/stage mating.

Overall, enable reusability, enhance efficiency, promote reduced propellant delivery cost to LEO.

[Update a while later]

Dallas went too fast for me to capture everything, but in answer to a comment here, the reason for variable mixture ratio is that due to other uses (e.g. oxygen for life support), differential boil-off rates in storage, etc., you can’t count on any particular mixture ratio. Electrolysis gives you stoichiometric output, but while that’s the most efficient ratio in terms of energy production, it doesn’t maximize specific impulse (6:1 is the best for that). But the point is that you don’t want to waste any propellant when it cost so much, so you don’t care about Isp per se, as long as the engine can turn whatever ratio into useful thrust. The trades for this problem are very different than the ones for launch systems, when propellant, in whatever ratio desired, is a trivial part of the launch cost.

Transportation Session

Gary Hudson, chairing session, thanking Robin Snelson and Lee Valentine for reviving the conference series. Sobered by the fact that the last time he chaired a session at a Space Manufacturing Conference was almost three decades ago. He leads off with a discussion of advances in space transportation over the past three decades.

Nothing else matters as much as low-cost, routine and reliable LEO access — once in orbit, halfway to anywhere else.

Biggest challenge not technology. It’s market demand, financing and naive regulation. Don’t need “destinations,” or “heavy lift.” This building was built in pieces weighing less than ten tons at a time. Historically, NASA opposition was a concern, but that is the case no longer. Now it’s Congress.

Space launch expensive because we throw the vehicles away, and we fly them only once (reduces reliability). Don’t fly often enough, don’t climb learning curve, to amortize development costs. Everything has been tried, and nothing has worked. Nowhere close to a breakthrough (in terms of propellant costs becoming significant), because of the standing army. ULA, Orbital and SpaceX have developed “commercial” vehicles, but still haven’t fundamentally reduced cost of access to space.

Problem is the gap in market elasticity. Reducing price doesn’t increase revenue in current region of price. Reducing cost to a thousand or five hundred dollars a pound reduces revenue, because demand doesn’t increase fast enough until price far below that. Incentives are to maintain status quo. Need new markets, near-term “affirmative action” missions from NASA to get us over the hump (ISS resupply, prop depots, debris cleanup, exploration support). Not necessarily inappropriate, since past government policies have put us in this box. Medium term, tourism will provide useful markets, but long term goal must be settlement.

Technical roadblocks: no breakthroughs needed, but risk and cost reduction via NASA tech development can be useful.

Political: end to cafeteria filling, and recognizing role of private sector.

Legal: should be based on sensible engineering and science rather than emotional regulation (example of having to watch for desert tortoises on the runway for Burt’s spaceplanes, but not airplanes).

Financial: question not whether or not we can finance, the issue now is global economic collapse and whether the dollar will be worth anything in three months.

No social breakthroughs needed — we’re ready.

Needed breakthroughs:

Patient risk capital (this is where NASA can help).

Paradigm/Perceptual change — need to fix broken regulatory regime (e.g. ITAR), NASA brother-in-law problem.

Technical — highly reusable engines, innovations such as tethers, which is a “good cheat.”

What we don’t need: scramjets and airbreathers.

RLV technologies neede: active sluid cooling for entry, highly operable engines.

Achievable price goals: $500/lb within five years, $100/lb within ten to fifteen. Assuming RDT&E amortized through public/private partnerships, and that standing army is sized for business, not government pork.

Introducing Dallas Bienhoff of Boeing

Live Blogging Jeff Greason

From his opening remarks for the Space Manfacturing Conference.

Didn’t want to be in the rocket business, just wanted a ride. Believed all the claims about the Space Shuttle, and they didn’t happen and got tired of waiting, so now in the rocket places. No point in going just to go — have to have some reason, something to do when you get there. If you haven’t figure out how to use this new land, what’s the point? People have seen that there was no point, but there still can be, but not a focus of what we’ve been doing in space. The point is to live there.

In the 21st century, with amazing technological powers, living twice as long as previously imagined. But we’re not proud of what we’ve done, but seemingly ashamed of it. Almost cowering and unwilling to take on the responsibility of wielding the power we’ve created. It’s a symptom, the disease is the closing of the frontier. New things bring new problem, with new opportunities, but in a society when you think we’ve got all we can, change is a threat. From feeling of running out of resources to thinking that it’s time to shift from creating to redistributing. While we sit on the edge of an ocean full of limitless resources. Worrying about our impact on earth’s climate and environment when Mars sits there begging for an impact on its climate and environment, just to warm it up a little. Time to reach out and grab what the universe is offering us. Picked up a book by Heppenheimer called “Colonies In Space.” Can look back with thirty years of experience and see that some of the technical concepts weren’t quite right, and some of the economics weren’t quite right, but one could say the same about Newton. Someone had to be the first to stand up and say, don’t these people need jobs, something to do to pay their way there? Don’t they need a cash crop, just as every migration has had. Gerry O’Neill was that man, we’re all Gerry’s kids, and it’s time to pick up where he left off, and start thinking afresh about how we get out there, make it pay, leave this earth with people who will not come back, and make it the next part of this great human adventure.

Biting Commentary about Infinity…and Beyond!