A group of Texas high school students emphasized science in posing their questions via ham radio to International Space Station Expedition 10 Commander Leroy Chiao, KE5BRW. The March 8 contact between Rains High School in Emory and NA1SS was arranged by the Amateur Radio on the International Space Station (ARISS) program. One student quizzed Chiao on how he adjusted to Newton’s Third Law of Motion aboard the space station.
“Well, yes, Newton’s Third Law definitely comes into play in space, and it becomes very obvious that if you push on something, you’re going to react in the opposite direction,” Chiao observed. “That’s something you get used to very quickly, and you quickly learn that all you need is a fingertip to push yourself to the other side of the module.”
Students also raised the subject of exposure to radiation in space. Chiao noted that the crew has both active and passive devices available to determine their radiation exposure.
“Radiation is very important to monitor in space, because we’re getting exposed to it obviously,” Chiao explained. “We have instruments on board that record the radiation history that we’re receiving on the station. We also wear personal dosimeters that are analyzed after we get back down to the ground–they also measure the exposure we’ve received.” The crew also relies on satellite data, he added. Responding to another question, Chiao conceded that radiation exposure could be a limiting factor for long-duration human space ventures.
In reply to another physics-related query, Chiao told one student that a Hot Wheels car could run indefinitely on a track aboard the space station were it not for friction, which eventually would slow it down and stop it. A fish could not swim for long in a blob of water floating in microgravity, Chiao explained fielding another question, because its motion likely would soon break up the globule, leaving the fish literally high and dry.
Handling Earth-station duties for the contact was Nancy Rocheleau, WH6PN, at Sacred Hearts Academy in Honolulu. MCI donated a teleconference circuit to provide two-way audio between Texas and Hawaii. Mentoring the contact was Howard Ziserman, WA3GOV.
Marring portions of the Rains contact were deep signal fades and apparent Doppler shift. ISS Ham Radio Project Engineer Kenneth Ransom, N5VHO, at Johnson Space Center reports that subsequent discussions with an attitude control specialist revealed that the ISS was in a free-drift mode that resulted in some signal blockage for the single ARISS Phase 2 station antenna.
“As fate would have it, the Amateur Radio antenna was not in the optimum position as the ISS passed over Hawaii but instead was pointing spaceward,” Ransom explained.
Fifteen Rains High School students, under the direction of science teacher Deena Harper, participated in the ARISS event, which attracted some media coverage. ARISS http://www.rac.ca/ariss is an international educational outreach program with US participation by ARRL, AMSAT and NASA.