Chair Force Engineer

Wednesday, September 19, 2007

AIAA Space 2007, Part 2

As impressed as I was with the first day of the AIAA's yearly space conference, the second day made the first pale in comparison.

Working the booth in the exhibits area consisted of much of the same swag-peddling as before. Trying to explain hyperspectral imaging to the third-graders who were on a class trip to the conference proved to be very difficult. We received less dignitaries at the booth as we did on the previous day. I did get to talk to members of the contractor teams I've been working with on my day-to-day job. I also met a lot of great folks who now work as experienced members of industry, but used to be junior officers in positions similar to mine.

The most interesting visitor was an eccentric gentleman who wanted to know about what work my unit was doing in the field of "anti-gravity research." I told him that I wasn't aware of any of that research going on; he probably thinks that I'm part of the "Area 51 conspiracy." I should have told him to bother DARPA, since they're the guys who do real research into "mad scientist" ideas. I wish we really did have a means of cheating gravity and building flying saucers, but we're unfortunately grounded by physics.

The exhibitors have been served boxed lunches (and fairly lavish ones, by my standards) by the convention center in Long Beach. But I received a complimentary ticket to the awards luncheon that would include all of the conference's VIP's. I think the gravity of the event sank in when I saw name placards like "Michael D. Griffin" and "Elon Musk" at the head table. I sat in the back of the room, but even still, I was sharing a table with none other than Vladimir Titov (probably the most accomplished cosmonaut to have flown during my lifetime.) I was far too intimidated to speak with him; I spent my lunch watching my table manners, avoiding embarassing faux pas, and trying to be on my best behavior.

The awards segment of the luncheon was brief. Burt Rutan accepted his "Engineer of the Year" award and made some brief remarks that were humble and somewhat moving. The XSS-11 team received a well-deserved award for accomplishing the most spectacular space mission in the history of Air Force Research Lab; sadly, the names of several engineers who made the mission possible were omitted from the awards program. Their efforts will not be forgotten by those who are knowledgeable on the subject of XSS-11.

Administrator Griffin gave the keynote address, and moved the audience with several anecdotes: how the gift of a book on stars as a child turned him into a lifelong space enthusiast, how the afforementioned book was clandestinely flown on STS-114, and how people came from far and wide to see the space shuttle when it made an unexpected ferry stop at Rick Husband Airport in Amarillo, TX. He contrasted the first 50 years of space with the first 50 years of aviation and noted that, by this point in aviation's history, air travel still wasn't commonplace like many of us expected spaceflight to be. Lastly, he remarked that the problem with the government-industry balance in space has not been too much government, but too little industry. The question and answer session ended without anybody getting tasered, so I was pleased.

The afternoon presentations were quite interesting. A group from Space Works Engineering talked about a concept for manned Mars missions. The result wasn't as rosy as Bob Zubrin would like to hear. SpaceWorks predicted four Ares V and one Ares I launch per Mars mission, a crew of only three, a fairly high loss-of-mission rate, and a cost of $100 billion for development of Mars-related hardware and launch of the first four manned missions. When the report becomes publicly available, I'll have more commentary to offer.

Dr. Chauncey Wu had an exceptional presentation on lunar lander designs that had been generated at NASA-Langley. The two preferred concepts were DASH and "Cargo Star." The former would make a horizontal landing and utilize a "lunar crasher" stage. The latter would land in a horizontal configuration, but would require the Orion capsule to transpose from an axial to a transverse position prior to the lunar orbit insertion burn. I'm not too fond of "lunar crashers" because they require extra development over the Apollo "ascent & descent" stages, they contaminate the lunar terrain, and they do not lend themselves to future reliability. Then again, they lend themelves well to shorter vehicles that are easier for a human pilot to land. They key takeaway from his study was that the lunar lander concept and its payload fairing are still nebulous, and the final result will probably surprise a lot of people.

Dr. Allison Zuniga gave the last presentation on Constellation design cycles. It was heavy in program management jargon, but there were still some interesting takeaways. NASA is trying to find ways to add capabilities back to the system, after stripping certain ones away to save mass. For instance, the loiter time of an EDS in earth orbit has shrunk from 90 days to two weeks; hopefully the Ares I&V can be launched within 90 min of each other, but the reduced loiter time is still a major concern. She still maintained that Orion will land on terra firma, while the young JSC engineer from the previous day claimed that the "land-vs-water landing" trade study was still ongoing. Dr. Zuniga still used the Orion 606 configuration in her charts, even though images and details of Orion 607 have been on the internet for weeks. Most troubling, NASA is currently looking at changing the load paths so that the lunar lander will not be crushed when the J-2X ignites to push Orion and the lander to the moon while stacked with the EDS. This issue is by no means a cause for worry, but I'm surprised it hasn't been addressed sooner.

It's great that the lunar lander issues are bing discussed at this point. If the people working these issues are reading this post, I have a few comments I'd like to offer up:
--The lander will necessarily be taller and heavier than it needs to be, as long as NASA requires the lander to perform the lunar orbit insertion burn. The descent tanks will be larger than needed for the descent phase of the mission, and the extra mass & volume will be lugged down to the lunar surface. If the Orion service module was big enough to perform the LOI burn, the extra tank mass could be left in lunar orbit; but this would require more performance out of the crew launcher, and Ares I just doesn't have what it takes to do it.
--I still haven't seen how NASA plans to pump the liquid oxygen and hydrogen into the lunar lander descent stage. I assume they'd do it after the lander is encapsulated in its fairing, but that will require a means of attaching the propellant fill lines to the Ares V launcher and pumping the propellants into the encapsulated lander.