The Little Spacecraft That Could
The world's first mission to attempt to land on an asteroid, collect samples, and return them to Earth has completed what is, arguably, the most difficult challenge on its agenda, and will begin the long journey back to Earth in early December. If all goes as planned, the sample will be returned in a capsule slated to land in the Australian outback in June 2007. Every command necessary for the sampling was carried out, JAXA announced Saturday evening Japan Standard Time (JST) on its website, and agency officials firmly believe that the mission succeeded in the world's first collection of samples of surface materials from an asteroid. It is highly probable, according to the agency, that the asteroid explorer has snatched several grams of surface samples from the near Earth asteroid named after the "father" of Japan's space program, Hideo Itokawa, but the exact volume will not be known until the spacecraft returns safely to Earth.
The spacecraft was on its own once it began to carry out the series of commands for Saturday's touch-down, because signals take around 17 minutes to get from Earth to Hayabusa. The spacecraft's autonomous navigation relies on the Optical Navigation Camera and Light Detection and Ranging (ONC/LD&R) instrument that measures the distance to and the shapes of the asteroid surface. Once the data from those and other instruments are fully analyzed, more specific details will be forthcoming.Hayabusa which means "falcon" in Japanese -- flew up and away from the asteroid after snatching its prey, and was subsequently "restored" by its ground team and instructed to return to its home orbit around 7 kilometers away from the asteroid.
Japan, meanwhile, is soaring into space exploration history with a flight that has provided a stellar boost for the Japanese space program, and cause for major celebration in the homeland. "This is a superb achievement, a great moment is space exploration," said Planetary Society Executive Director Louis D. Friedman. "Automated surface sample return from another world has been done only from the Moon, and only by the Russians. This venture by the Japanese space agency is bold, and Hayabusa has been brilliantly executed mission."
Hayabusa which was developed at the Institute of Space and Astronautical Science (ISAS), a space science research division of JAXA -- launched from Japan's Kagoshima Space Center on May 9, 2003 and arrived in September of this year despite being rocked on the way by several solar flares, and losing one of its three reaction wheels used to control the spacecraft's orientation, point instruments, antennas, or subsystems at chosen targets.Since then it has met with other misfortunes, including the loss of another reaction wheel and the loss of its tiny robot lander, Minerva, which it released at the wrong time. Still, from every mishap, Hayabusa has rebounded.
The handful of dirt and dust that Hayabusa snatched Saturday may seem a small prize for all the effort, but the knowledge these samples hold about our solar system is by all accounts great. Asteroids preserve in their make-up the pristine materials that went into formation of the solar system, unlike the Moon or other larger planetary bodies that have undergone thermal alterations over the eons.