Three high-precision, Canadian-built lasers are at the centre of a NASA-led proposal to land an unmanned probe on a distant asteroid that’s expected to yield crucial clues about the origins of the Earth — and, possibly, about how to prevent it from crashing into our planet 160 years from now.
The planned trip to retrieve samples from the 600-metre-wide space rock — dubbed “1999 RQ36” by the astronomers who discovered it 11 years ago, and classified as a “potentially hazardous asteroid” for Earth — is among three candidate projects selected in December for a chance to receive up to $650 million U.S. in NASA funding and a launch-pad “go” in 2016.
The proposed OSIRIS-Rex mission — to be partly funded by the Canadian Space Agency — would include a set of LIDAR laser instruments supplied by B.C.-based aerospace firm MacDonald, Dettwiler and Associates and the Toronto-area company Optech.
The imaging devices would be used to create a precise topographical profile of the 4.5-billion-year-old asteroid and to help land the OSIRIS spacecraft on the massive rock, which experts believe has a 1-in-1,800 chance of striking Earth in the year 2170.
The potential impact, says University of Calgary meteorite expert Alan Hildebrand — the principal Canadian investigator on the project — would be equivalent to hundreds of times the explosive power of all of the nuclear devices on Earth, and would leave a crater 10-km wide.
The LIDAR lasers would be used to “derive the shape of the asteroid — effectively to map it,” says Hildebrand, and to guide the spacecraft gently to a safe landing.
“The purpose of this mission is to land on the asteroid and bring back a sample,” he told Canwest News Service on Friday. “You can appreciate that asteroids are pretty lumpy things, so if you don’t understand the shape, you can’t land.”
The Canadian lasers would come into play during what Hildebrand calls the “very tentative dance” at the end of the OSIRIS spacecraft’s 400,000-km voyage to intercept RQ36 (about 60,000 kilometres on the far side of the moon), when it will spend months orbiting the asteroid and attempting to figure out how to land.
The target is considered particularly important for scientists because RQ36 appears to have survived the formation of the universe relatively intact — with little surface melting or subsequent deterioration.
“You can’t overestimate the value of a pristine sample,” Cutlip stated, noting that meteorites — chunks of asteroids that reach Earth — are “toasted on their way through Earth’s atmosphere. Once they land, they then soak up the microbes and chemicals from the environment around them.”
Another NASA scientist, Joseph Nuth, added that, “with a pristine sample — especially one from an asteroid type not available in NASA’s meteorite collections — scientists will learn more about the time before the birth of our solar system, the initial stages of planet formation, and the source of organic compounds available for the origin of life.”
The original OSIRIS project was a top-three finisher in a previous NASA competition for full mission funding in 2007. The latest version of the plan, including the additional Canadian components, has again earned a top-three, $3.3-million development grant from NASA ahead of its decision on full funding in a year.
Key to the project pitch this time around is the plan to learn more about the impact of solar radiation on an asteroid’s precise trajectory. The findings, says Hildebrand, are deemed crucial to accurately predict whether RQ36 — or other asteroids expected to come close to Earth — will actually strike the planet.
Four Canadian universities — the University of Toronto, University of Winnipeg, University of Calgary and University of British Columbia — are signed on to the project, with Hildebrand and his fellow scientists slated to receive bits of dirt scooped from the asteroid’s surface to help unravel mysteries about both the composition of the object and the origins of the universe.
If all goes according to plan, samples from the asteroid would be returned to Earth in 2023.
“Like the Moon rocks from the Apollo missions, samples of RQ36 will keep on giving. They’ll be analyzed for decades after the mission is complete, using new techniques we can’t even imagine now, to test new theories of how we came to be,” said Nuth.
Canwest News Service