Maybe

A space capsule has landed in rural Australia, and its contents will help answer a lot of questions about asteroids and the formation of the solar system… Maybe.

The capsule in question hails from the Hayabusa spacecraft. Designed by the Japan Aerospace Exploration Agency (JAXA), Hayabusa wasn’t just built for exploratory purposes. JAXA wanted to use Hayabusa to test new technologies for sending unmanned spacecraft to planetary bodies, explore them from orbit, land on them, collect samples, and return those samples to Earth. The spacecraft’s target was 25143 Itokawa, an asteroid (hereafter referred to as ‘Itokawa’). Discovered in only 1998, Itokawa orbits the sun in a meandering path that crosses Mars’ orbit. In case you were wondering, the asteroid was named for Japanese rocket scientist Hideo Itokawa (1912-1999), the father of the Japanese space program. For such an honor, some critics are regretting that the asteroid named for Dr. Itokawa was Hayabusa’s target, considering the number of technical glitches and failures that plagued the spacecraft’s mission

Launched from Japan in 2003, Hayabusa was supposed to reach the Itokawa asteroid by July 2005. However, problems with the spacecraft began soon after its launch. A powerful solar flare damaged some of Hayabusa’s solar cells, reducing the available power for the spacecraft’s engines and delaying its rendezvous with Itokawa by two months. Upon arrival, Hayabusa took detailed photographs of the asteroid’s surface, allowing scientists to map it. However, a number technical difficulties severely limited the spacecraft’s ability to explore Itokawa in detail. For example, Hayabusa was supposed to release a small lander, MINERVA (MIcro/Nano Experimental Robot Vehicle for Asteroid). Tiny MINERVA was designed to “hop” across the asteroid’s sruface, taking and transmitting detailed photographs of the surface conditions back to Hayabusa. However, when Hayabusa descended toward the asteroid’s surface to release the lander, the spacecraft didn’t receive the Earth-based command to release MINERVA before Hayabusa’s own computer ordered the spacecraft to ascend to avoid crashing into the asteroid. When Hayabusa finally did release the lander, the spacecraft was already climbing back into a higher orbit, and MINERVA skipped off into space, lost forever.

Other numerous technical failures and glitches plagued Hayabusa, affecting its control, propulsion, and communications systems. However, scientists remained determined to carry out the spacecraft’s primary mission: to land on Itokawa, collect surface samples, and return them to Earth. Thanks to the solar flare damage, Hayabusa’s scheduled three landing attempts were reduced to two. On the first landing, Hayabusa successfully reached the surface and became the second spacecraft to land on an asteroid. But, its landing position prevented Hayabusa’s computers from fully deploying the sample collection apparatus. Despite this failure, JAXA scientists claimed that a significant amount of asteroid surface “dust” and particulate matter was stirred up by Hayabusa’s landing, and that some of this dust likely landed in the sample collection container. JAXA attempted a second landing later, but a leaky thruster activated computer safety mechanisms which prevented Hayabusa from again deploying its sample collector. Hopeful that Hayabusa contained at least some amount of asteroid dust and debris, JAXA scientists announced the spacecraft would return home as planned. However, other malfunctions hampered JAXA’s ability to send commands to Hayabusa, delaying the start of the spacecraft’s return journey until 2007.

After a three year journey back to Earth, Hayabusa entered Earth orbit earlier this month. Earlier today, the craft released its sample container (hopefully holding some asteroid “dust”) to land on Earth. JAXA scientists piloted Hayabusa and timed the sample container’s release to force it to land in the Woomera Prohibited Area, an isolated weapons-testing range in South Australia. Despite the other technical malfunctions that have plagued Hayabusa’s mission, preliminary reports indicate that the sample collector successfully survived Earth atmospheric reentry, and that the collector’s parachute facilitated its relatively gentle landing somewhere in the Woomera Prohibited Area. Recovery helicopters are on their way to recover the sample collector and return it to JAXA.

It will be some months before JAXA scientists can analyze the contents of the sample collector and determine whether or not Hayabusa successfully obtained and returned material from the Itokawa asteroid. If the spacecraft did succeed, scientists will be able to study the asteroid’s composition directly, learning secrets about the formation of the solar system billions of years ago. The partial failure of Hayabusa’s collection apparatus, combined with other numerous failures and technical glitches, have left some questioning the spacecraft’s success. After all, this craft and its mission were designed to test new technologies for retrieving samples from planetary bodies and returning them to Earth. At best, Hayabusa barely succeeded in achieving that goal, and at the cost of many more mission failures, such as the loss of the MINERVA lander. If the sample collector is indeed empty, then many will argue that Hayabusa made this round trip for nothing.

But, such a conclusion would overlook another significant milestone of the Hayabusa mission: this unmanned spacecraft left Earth, landed somewhere else, and came back. That’s a new achievement for humankind, and a feat every other unmanned probe will have to copy in order to collect and return samples to Earth. Also, Hayabusa’s many failures have been valuable (if not embarrassing) learning experiences for JAXA and other space agencies. Many of Hayabusa’s technological components were prototypes, and it is now evident that these prototypes have numerous bugs that must be fixed before the next mission. Some may argue that this mission was too expensive to “waste” on the goal of finding out whether or not these prototypes would work. But sometimes in space exploration, we can only learn by trying, correcting, and (sometimes) failing.

And if Hayabusa’s sample collector did indeed pick up some fragments of the Itokawa asteroid, then maybe the mission was a success after all… Maybe.

The image above shows Hayabusa entering Earth’s atmosphere, with the Milky Way in the background. Image provided courtesy of JAXA.

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