Battered, drained of fuel, and travel-weary, Japan’s asteroid-sampler is almost home. The Hayabusa, which the Japanese Aerospace Exploration Agency (JAXA) launched in 2003, is scheduled to drop its sample canister in the Australian outback in June. But, the project leaders warn, there’s still a chance than the beleaguered sojourner won’t make it. And even if it does successfully return to Earth, it’s possible that the sample capsule may not contain extraterrestrial rock.

Hayabusa spent three months exploring the Itokawa asteroid in late 2005, even making an unplanned landing on the asteroid’s surface. The probe spent up to a half-hour on Itokawa, making it the first spacecraft to lift off from an asteroid [Space.com]. The craft also took 1,600 pictures and more than 100,000 infrared images.

But things soon turned sour. Hayabusa’s instruments for collecting asteroid samples didn’t deploy as expected, leaving the Japanese research team uncertain how much, if any, material the probe will have on board when it comes back home. While telemetry showed that Hayabusa likely did not fire its projectile as planned while on Itokawa’s surface, scientists are hoping that bits of dust or pebbles traveled through the probe’s funnel and into its sample return capsule [Space.com].

There have been plenty of other difficulties, too. Since its launch in 2003, Hayabusa has lost three of its four ion engines, leaked out all of its chemical propellant and is down to a single reaction wheel. The trouble delayed Hayabusa’s departure from Itokawa, which forced JAXA to postpone the craft’s return to Earth from 2007 until 2010 [Spaceflight Now]. In November JAXA nearly conceded that Hayabusa would never come home. Then, in a stroke of innovation combined with good fortune, the engineers managed to combine the parts that still worked from two of the thrusters to propel the craft. Now it just might make it back.

The saga of the Hayabusa outlines the ambitious nature of President Obama’s newly revised space plan for the United States; on Thursday DISCOVER covered the difficulty of a daring manned mission to an asteroid that he proposed. But for a journey of far more than a thousand miles, the successful return of the Hayabusa would be a terrific first step.

Related Content:
DISCOVER: Japan Stakes Its Claim in Space, on Hayabusa mission
DISCOVER: One Giant Step for a Small, Crowded Country, on Japan’s moon aspirations
80beats: Danger, President Obama! Visiting an Asteroid Is Exciting, But Difficult
80beats: Will NASA’s Next Step Be an Astronaut Rendezvous with an Asteroid?

Image: JAXA