According to Colwell

I’m attending the annual Fall Meeting of the American Geophysical Union in San Francisco where more than 10,000 scientists spanning a wide range of fields, from my own planetary science, to hydrology, geology, atmospheric science, heliophysics and more are meeting to present their latest research results. Monday I attended an associated workshop on Human-Tended Suborbital Science. The idea of this program, which has some traction at NASA, is to take advantage of the nascent private-sector suborbital launch industry. That is a boring way of describing the numerous enterprises which hope to sell you a ticket for a ride into space. Soon.

SpaceShipOne won the Ansari X Prize in 2004 by completing two trips into space (for these purposes, technically defined as 100 km in altitude) within two weeks. The $10 million prize was certainly far less than the cost to develop the rocket, but Sir Richard Branson recognized a potential tourist market and now Virgin Galactic is nearing completion of the SpaceShipTwo model which will fly 6 paying passengers at a time to suborbital space for about 5 minutes of weightlessness, a view of the curved horizon, and astronaut wings. The name of the first ship is the VSS Enterprise, warming the hearts of all us Trekkies. Branson reportedly offered Shatner a ticket on the first passenger flight, but the former Star Trek actor apparently would like to see a bit more reliability data before he takes his ride.

Monday’s workshop was a dialog between the many companies developing private suborbital launch capabilities and the scientific community that could take advantage of those flights for scientific experiments. I was there to discuss the science that could be accomplished on such flights with experimental studies of the behavior of small colliding particles in microgravity. I have done these experiments on the space shuttle (expensive, limited access) and parabolic flights (short time in reduced gravity, not a very smooth gravity environment), and 5 minutes on a suborbital rocket would certainly open up a broad new parameter space.

One of the striking things to me about the workshop is how many companies are getting close to having rockets flying. In addition to Virgin Galactic, Jeff Bezos of Amazon.com is leading the Blue Origin company’s development of a passenger-ferrying rocket, SpaceX is selling unmanned payload space, and others presented plans for smaller rockets. Whether I ever personally perform experiments on such a rocket, it will certainly be exciting to watch these projects roll out over the next couple of years, and I felt it was only appropriate for me to wear my Star Trek tie to the meeting.

Sunday December 7 I’ll be flying on the Zero-G Corporation’s “G-Force-1″ airplane (a modified Boeing 727) out of the Space Coast Regional Airport. The pilots of G-Force-1 fly the plane as close as possible to a perfect parabola at a constant horizontal speed and a constant negative acceleration of 9.8 meters per second squared. That is, they make the plane follow the path of a freely falling object. Because all objects, regardless of mass, fall at the same rate (remember Galileo and that famous leaning tower), I and everyone else inside the plane will be in a state of freefall for about 25 seconds per parabola. During that time we will experience the same sensation as astronauts orbiting the Earth.

At the end of each parabola, the plane must accelerate upward giving us a weight of about 1.8 times normal (or 1.8 g’s). During one parabola I’ll be testing a modified experiment on the formation of planets. In particular, I’ll be studying the effects of low-speed collisions between a large object and a collection of small particles to see how well things stick together or blow apart when gravity isn’t present to hold them together. I have done similar experiments on NASA’s version of G-Force-1 before (affectionately known as the “vomit comet”). NASA’s plane typically does 45 parabolas per flight, while Zero-G is kinder to its passengers and limits the parabolas to one simulating martian gravity, two simulating lunar gravity, and 12 zero-g parabolas. With that profile, I am confident I will avoid the upset stomach that plagued me on flights on NASA’s plane.