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08 August 2010 @ 07:21 pm
Mars Society conference: Sunday  
I'm on an hour-and-a-half layover at the Salt Lake City airport, where there are little carrels with power outlets and free wi-fi. Why can't all airports be like this? (Though, all in all, I'd rather have returned the way I came, via Seattle, which would have given me at least an hour less time in the air.)

The day started with the usual end-of-convention prepositions: get up, wash up, dress up, pack up, check out, eat up, and check in (for my flight). I bought my ticket from Alaska Air, but the flight is actually a Delta flight, and since Alaska doesn't actually fly to Cincinnati itself I was unable to check in on the Alaska web site (which for some peculiar reason requires you to specify the originating city as well as the confirmation code). Fortunately, they gave me a Delta confirmation code as well and I was able to use it to check in via the Delta web site. But the boarding pass, when printed on the hotel's printer, had its outer half-inch cut off and would probably not be acceptable at the airport. Grr. (As it happens I had to check a bag anyway, so it cost me little time to reprint my boarding pass at the gate. My bag, by the way, weighed the same 50 pounds as my Monster Bag from MDRS on the way out, but I seem to have sold at least 12 pounds of books at the conference.)

Having dealt with all that, I was only a bit late for the morning's plenary session by David Chuss, NASA Goddard Space Flight Center, about The Early Universe. Much of this talk was not new to me, but it's nice to be reminded about what we know and how we know it.

He started with the earliest development of cosmology, going back to Tyco Brahe and Newton and the statement "Mathematics starts with a truth and looks at the consequences; cosmology starts with the consequences and looks for the truth." Einstein's general relativity implied that the universe was either expanding or contracting, not static, and he added a term (the "cosmological constant") to get rid of that. Not too much later, Hubble's observations of the apparent motion away from us of distant objects showed that the universe was indeed expanding, and Einstein took the constant back out, saying it was his "greatest blunder."

So, astronomers reasoned, if the universe is expanding it must be cooling. This prompted them to look for the red-shifted light of the early, hot universe, but they were scooped by a couple of microwave engineers who were trying to track down the source of some interference in their antennas and wound up with a Nobel Prize.

NASA has launched several satellites to map this cosmic background radiation, with increasing detail and sensitivity, and they are telling us a lot about the early universe. This radiation is slightly uneven (anisotropy), which tells us that the early universe was lumpy; these lumps coalesced into galaxies, stars, and us. Doing a Fourier transform on this radiation reveals the power curve of the early universe, which (through math I have never been able to follow) explains where the fundamental particles like baryons came from and whether the universe is positively curved (closed, leading to an eventual collapse) or negatively curved (open, continually expanding). Weirdly, the data tells us the universe is exactly flat, which is unexpected and unstable (the slightest curvature in either direction will tend to increase). No one quite understands yet how this can be.

Recent observations of extremely distant objects reveal that they appear to be accelerating away from us -- that is, the expansion of the universe is accelerating. This implies that the universe is mostly (over 75%) composed of "dark energy," whose properties are completely unknown -- all we can say is that it accelerates expansion. A negative value for Einstein's cosmological constant fits this data, but we still have no idea what this might mean in real-world terms.

Careful examination of lumpiness in the cosmic background radiation hints that the very early universe expanded faster than the speed of light ("inflation"); we don't know how this is possible, though perhaps in the first moments of the Big Bang the laws of physics had not yet coalesced into their current form. NASA is launching the Dark Energy Explorer and Webb Telescope satellites to investigate these questions.

In 1900 they thought 20th century physics would be boring, with only a few questions left to answer (the "ultraviolet catastrophe" and the presence or absence of ether). The search for answers to these questions led us to relativity, quantum dynamics, transistors, and GPS. We don't have such low expectations today, but we know we will be surprised.

Kevin Sloan was up next, talking about the Mars Society's University Rover Challenge, which is held each year at the MDRS in Utah (students participating in the challenge stay at a hotel in Hanksville, not at the hab).

The University Rover Challenge gives engineering students a concrete project that they can use to build skills, work in teams, and maybe win cash prizes. This year's URC had 12 teams from 4 countries; 7 teams made it to Utah for the final trials.

We believe that astronauts will work together with various kinds of machine to amplify their abilities. Rovers can, for example, be used to perform tasks outside a Mars base without having to suit up. The rovers in the challenge are wheeled (or tracked) vehicles with cameras and a manipulator arm; they are remotely operated, not autonomous. This is an engineering design, construction, and operation challenge with no artificial intelligence component. Rovers are limited to 50 kilograms and must perform 4 different tasks (they can be reconfigured with different parts for each task, but no configuration can be over 50kg). Most rovers weigh in at right around 49.9kg, but one team was surprised at the official weigh-in and had to quickly strip the rover of unessential cameras and batteries to get under the line.

The four tasks are: Equipment servicing task: navigate to a panel, read the instructions posted there using the rover's camera, and perform several tasks such as flipping switches and plugging in an electrical cord (this part was really hard, only the Oregon State University team was able to do it). Site survey task: find and survey several markers in a field, recording their coordinates with GPS-like accuracy. Sample return task: search for and return samples of biological interest, perform field analysis, and deliver field briefing to judges. This task requires engineers to work with biologists who are directing the work, rather than just drive and scoop. Emergency navigation task: cross difficult terrain, find a stranded astronaut, and deliver emergency supplies in less than 20 minutes. This one too was won by the Oregon State team. One of the Polish teams would have won the contest if they had gotten the full 100 points for this task, but their rover with its single camera was looking the wrong way and drove right past the astronaut.

We got a talk from the winning Oregon State team about their rover design and the lessons they learned from the previous challenge, which was very cool, but I'm running out of time here.

The final session I saw before departing the conference was Joseph Palaia from the NewSpace Center, talking about a planned "themed attraction" called Interspace. He said that the current wave of commercial space development is a "new barnstorming era" and very exciting, but direct participation is extremely expensive and the facilities are too isolated and not set up for the public. Current science and aerospace museums are focused on the past, not this new technology. Interspace is intended to be an interactive, immersive experience for tourists based on what's happening now and in the near future in space. They have a 75-acre site in Florida, near the Kennedy Space Center, and are currently trying to nail down the $72 million they'll need to build it. It looks like a lot of fun and I hope they succeed.

Then I drove to Cincinnati, dropped off the car, and flew to Salt Lake City without incident. At the moment it looks like my flight to Portland is about 15 minutes behind schedule, but I don't anticipate any problems getting home. See you soon!

 
 
 
clever blog titlejulia_reynolds on August 9th, 2010 02:23 am (UTC)
Hey, I saw a review of Mary Roach's new book about the Mars mission and wondered if you've read it yet. If so, what do you think?

http://www.nytimes.com/2010/08/08/books/review/Lord-t.html?_r=1
David D. Levinedavidlevine on August 9th, 2010 03:48 pm (UTC)
Haven't yet read it, but I'm going to a Science Pub with a talk by her this week and may pick up the book there.