The mission marks the first U.S. attempt to sample an asteroid, a hunk of debris left over from the dawn of our solar system some 4.5 billion years ago. Scientists have long eyed asteroids as storehouses of knowledge regarding the formation of the solar system and the origins of life.
Telescope surveys of RQ36 have already revealed carbon-rich materials that could act as the building blocks of life, said the lead scientist on the mission, Michael Drake of the University of Arizona. When the Earth was young, asteroids bombarded our planet, possibly depositing the compounds that later joined up to make the first life-forming molecules.
RQ36 is about five football fields long, and astronomers say it has a 1-in-1,800 chance of hitting the Earth in 2182. After the probe arrives at the asteroid, it will begin a delicate, months-long survey to find a suitable landing site.
“The trickiest thing will be learning to navigate so we can select a site on the surface and sample it,” Drake said.
OSIRIS-REx will then match the asteroid’s rotation, and a probe will dance down to its surface and make contact for just five seconds. During the brief landing, which Drake called a “kiss,” a puff of gas will blow dust into a collector that the scientist likened to a car’s air filter. This collector can hold nearly five pounds of material — enough for decades of scientific study.
A high-definition camera will broadcast the maneuver so that earthbound space buffs can “go along for the ride to collect that sample,” Drake said.
Last summer, the Japanese space agency JAXA successfully returned a whiff of an asteroid in a small capsule dropped onto Australia from its Hayabusa probe.
So-called sample return missions are tricky, though. The Japanese craft developed navigational problems, and a NASA craft sent to sniff the solar wind, Genesis, crash-landed in Utah in 2004 when its parachute failed to open.
The Goddard Space Flight Center in Greenbelt will receive $128 million to manage the project, which beat out missions to the moon and Venus for funding from NASA’s New Frontiers program for small-to-medium robotic probes.
The agency is struggling with a reduced budget in an era of austerity on Capitol Hill, but NASA’s decision to push ahead with the mission shows it “still has a very healthy planetary exploration program,” said Ralph McNutt of the Applied Physics Laboratory at Johns Hopkins University.
President Obama identified asteroids last year as attractive destinations for human exploration, setting a target date of 2025 for an asteroid landing. No such mission has been announced, but NASA is developing a capsule, the Multi-Purpose Crew Vehicle, to send humans beyond Earth after the space shuttle program shuts down this summer.