I completed my seventh lifetime parabolic flight on Sunday, but first flight with the Zero-G corporation. While my earlier flights on NASA’s KC-135 (now retired and replaced by a C-9) involved anywhere from 36 to 51 parabolas, Zero-G does only 15 parabolas on non-research flights. They also currently have a contract to sell flights to NASA, and I think those do the full set of 40-50 parabolas, but the flight I was on Sunday was sponsored by Space Florida for educators, and operated in pretty much the same mode as their passenger flights. The limited number of parabolas is to limit motion sickness. As someone who has gotten violently ill on the longer flights, I think this is a good idea. Paying five grand (their current ticket price) to get violently ill, even with the unique experience of weightlessness, would probably leave a lot of customers grumpy.
Their flight plan begins with one parabola
simulating martian gravity followed by two “lunars”. Parabolas are flown in groups of three followed by a couple of minutes of straight and level flight to get set up for the next set.
I took on board one of the impact experiment chambers from my earlier “Physics of Regolith Impacts in Microgravity Experiment” (PRIME) to do a test run. The experiment basically consists of shooting a marble into a tray of sand at very low speeds in microgravity and measuring the speed and quantity of material ejected. However, because this was being flown as a commercial flight rather than a government flight, it was not possible to evacuate the test chamber. The test material floated out of the target chamber, limiting the amount of ejecta. However, this provided a fairly dramatic demonstration of the effects of air as a lubricant for granular materials and underscores the need for evacuated test chambers on future flights.
I also tried to do a simpler experiment for classroom demonstration of equipartition of energy in a granular gas. That’s a fancy way of saying “watching different-sized marbles bounce around at different speeds”. This was compromised by the lack of foot restraints on the plane and the general chaos of floating bodies throughout the plane volume. Nevertheless, I think I got some good video.