I only have a few minutes tonight, but part of what’s been keeping me busy lately has been two Space 2009 papers I’ve been involved with (one as the primary author, and another as a very minor coauthor).
First, the propellant depot paper I keep talking about: AIAA 2009-6756 Near-Term Propellant Depots: Implementation of a Critical Spacefaring Technology (also available on the ULA publications page), and the presentation that went along with it: SPACE 2009 Prop Depot Paper Presentation.
For those who’ve read most of the rest of my posts on propellant depots, there’s only a few key new concepts:
- The Single-Launch Dual-Fluid Depot concept that Frank Zegler and myself both independently came up with this year (which I’ll go into more in a later blog post). This idea holds a lot of promise because it shows how a single EELV launch with existing fairing sizes can put up a depot capable of storing 75-114mT of LOX/LH2.
- The realization that unless you have some sort of high-Isp or propellantless propulsion system (like an ED tether) for stationkeeping purposes, that Zero-Boiloff storage might not be very useful for an LEO depot. The amount of propellant you lose to boiloff is less than the amount you would’ve spent for stationkeeping anyway, so it’s effectively free.
- The realization that LEO depots really ought to be treated as “use-it-or-lose-it”, high-throughput depots, and that its L1/L2 depots that should be used for longer-term storage.
I had been avoiding discussion of the dual-fluid depot concept for a while, mostly so I wouldn’t be stealing my own thunder. Now that the paper is presented and out in the public, I hope to have the time soon to discuss the concept a bit. I also have some space transportation architecture ideas using that depot concept that I may flesh out a bit either here on the blog or in some white papers (which I’ll post on the blog).
The second paper, which was mostly written by Robert Frampton of Boeing talks about a project to use our XA-0.2 vehicle as a testbed for demonstrating autonomous landing systems for planetary landers: AIAA-2009-6571 Planetary Lander Dynamic Model for GN&C
I’m not really sure what I’m allowed to say about the project that isn’t spelled-out in the paper, but I figured I’d bring it to people’s attention, and hopefully at some point in the future I can discuss things more on the MSS blog.