The Japanese chalk up two successes in space
Jun 17th 2010
THE week before last, a falcon was launched into space: Elon Musk’s privately financed Falcon 9 heavy-lifting rocket. This week a different falcon returned from the void. On June 13th Hayabusa, as the bird is known in Japanese, streaked through the night sky of southern Australia to deliver to Earth what researchers hope will be the first sample of rock collected from the surface of an asteroid.
As the picture suggests, most of the craft burned up on re-entry. But a small part, protected by a heat shield made of carbon-phenolic resin, survived and landed in the desert near Woomera. This capsule, it is hoped, will contain material from Itokawa, a half-kilometre-long asteroid whose orbit crosses the Earth’s.
One up, then, to JAXA, Japan’s space agency. Indeed, two up, because on June 10th it successfully deployed Ikaros, a solar sail attached to a small satellite in orbit round the Earth.
In the short term, the mission to Itokawa was the more spectacular of the two. It was dogged by bad luck, ranging from solar flares to boulder-strewn landing fields, and returned to Earth three years late. But return it did, having been nursed through its traumas by a patient ground team at JAXA’s mission-control centre in Tsukuba.
In the long term, though, Ikaros may be the more important mission. Solar sails are not the quickest way to travel through space, but they are cheap. They draw their energy from sunlight (the light exerts a small pressure on the sail, driving it forward) and therefore need no fuel. They are difficult to deploy, though, because they need to be thin, huge and tightly folded for launch. The unfurling of Ikaros, which has an area of 200 square metres, is therefore no mean feat. It will now be put through its paces to see just how much photonic puff it can provide.
Ikaros was launched on May 21st (it hitched a lift on a JAXA mission to Venus). Hayabusa was launched in 2003 and matched orbits with Itokawa in 2005. The intention was to get close, fire a projectile into the surface and grab some of the ensuing dust. That does not seem to have happened, but the probe did sit on the asteroid’s surface for about half an hour, so there is a chance some material, if only a few milligrams of dust, made its way into the grab and will thus be sitting in the return capsule, waiting to be examined.
If it is, it will be only the fourth sort of extraterrestrial material returned to Earth by a spacecraft—the others being the moon rocks brought back by the Apollo missions and three unmanned Russian Luna craft, the material from comet Wild 2 picked up by the Stardust mission in 2004, and the samples of solar wind collected between 2001 and 2004 by the Genesis mission. Of course, nature delivers extraterrestrial material to Earth every day, in the form of meteorites, most of which are, in effect, tiny asteroids, so whether anything truly new will be discovered by looking at Hayabusa’s trove is moot.
Woomera, the place JAXA chose to land Hayabusa’s capsule, is also the site from which the Black Knight, Black Arrow and Blue Streak rockets of Britain’s aborted space programme were launched in the 1950s to the 1970s. Japan’s space programme has, so far, been a lot more successful than Britain’s was. Thoughtful Japanese though, looking at their country’s debt and wondering what might be cut to reduce it, may regard the coincidence as a bad omen.
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