Picture yourself hitchhiking on a history-making, seven-year space mission.
You departed on Sept. 8, 2016. Your vehicle, called OSIRIS-REx, has solar panels for electricity. On your trip, you can share photos taken with the world’s finest set of space cameras, all made at the UA.
In 2018, you’ll reach your destination: a distant place that could reveal the origins of life and the universe itself. It’s a tiny asteroid named Bennu, a rocky target that would fit between Old Main and Arizona Stadium. Your mission will be to collect a sample of its surface material to return to Earth.
Why fly 800 million miles to sample an asteroid’s dirt?
UA scientists have long viewed the surfaces of asteroids as the next frontier in understanding the universe’s origin. Bennu, chosen because it swings near Earth now and then, may help determine whether asteroids dropped the essential molecules for life down to Earth.
Great fun, if you could ride along.
But sorry — no passengers on this flight! However, you can follow along with the UA’s biggest collaboration with NASA and grandest adventure ever by visiting asteroidmission.org. There, you can watch the story of OSIRIS-REx’s journey unfold day by day, starting at the Kennedy Space Center in Florida as the craft soars away at 10 miles per second.
Once the spacecraft launched, the UA became mission control, in charge of the science, for the rest of the mission. That’s a remarkable honor for a university. “To me, it doesn’t get any more exciting than that,” says Dante Lauretta, the UA’s principal investigator for the project.
The UA’s 50 years of dazzling space science helped in 2012 to convince NASA to fund the project, which will cost nearly $1 billion. Of course, the UA and NASA are no strangers: The University has played a key role in nearly every major NASA planetary sciences launch.
As OSIRIS-REx makes its way toward Bennu and sends back data on the asteroid’s surface, dozens of scientists — including UA graduate and undergraduate students — will track its progress from the UA’s high-security Michael Drake Building north of campus.
OSIRIS-REx is the biggest science venture in the history of the University of Arizona. Its nearly billion-dollar price tag will surpass the cost of the Phoenix Mars Lander mission ($386 million).
The UA team named the spacecraft OSIRIS-REx to spell out its mission: origins, spectral interpretation, resource identification, security, regolith explorer. “Regolith” refers to the surface material of certain planets, moons and asteroids — the prize OSIRIS-REx will be sending home from Bennu.
“Asteroids are interesting because they are the earliest remnants from the formation of the solar system and may have brought the water onto the Earth,” Lauretta says. “We think Bennu is a water-rich asteroid that contains platinum and other precious elements. Water and organic compounds together could be used for life support and rocket fuel.”
Because Bennu’s surface material has not been altered by forces like volcanoes and rain, it could represent a snapshot of our solar system’s infancy, he continues. “The asteroid’s regolith is also likely rich in carbon, a key element in the organic molecules necessary for life.
So by studying the sample we hope to find organic molecules that may have led to the origin of life on Earth and to inform the likelihood that life may have originated elsewhere in our solar system.”
In preparation for the mission, every part of the vehicle — from re-entry parachutes to telescopes, computers and gyros to guidance systems — has been tested and retested at the UA and its partner sites, including Lockheed Martin’s Colorado facility where the vehicle was built.
Guiding the spacecraft will be its $40 million package of three cameras, which can work as telescopes or microscopes. They were built for NASA at the UA’s Lunar and Planetary Lab, in part to map the surface of Bennu before the touchdown.
In examining the return sample, scientists will be watching for any signs of organic molecules or water bound up in the rocks. Water, of course, will be crucial when people begin to colonize space. Some say that may happen as early as the 2030s. Even before then, however — if water is found on Bennu — asteroids could become “filling stations” for future rockets, with the component hydrogen and oxygen converted to rocket fuel.
The late Michael Drake, UA Regents’ Professor of astronomy, head of the Steward Observatory and the principal investigator of the OSIRIS-REx mission until his death in 2011, once observed that the streaming video from OSIRIS-REx will let anyone on Earth tune in for the whole drama, including the moment of collecting the precious sample.
“That’s like the public going along for the ride,” he said.
Turns out you can hitch a ride after all.
Sept. 8, 2016
OSIRIS-REx was pushed into space by an Atlas V rocket, which fell away after its job is done, leaving the spacecraft to travel the rest of the 500 million miles on its own. An hour after takeoff, the craft will be tens of thousands of miles away, moving at 10 miles a second — the speed required to break out of Earth’s gravity.
September 2016-August 2018
After a year orbiting the sun, OSIRIS-REx will make a flyby of Earth. Earth’s gravitational field will pull the spacecraft toward the planet, where it can “borrow” a small amount of Earth’s orbital energy. This additional energy is used to increase OSIRIS-REx’s orbital inclination and sling it back into space for a rendezvous with Bennu.
OSIRIS-REx will match Bennu’s velocity as its cameras record the asteroid’s surface features. It will spend nearly a year on its survey, then the spacecraft’s rocket motors, powered by hydrazine, will emit tiny bursts to precisely maneuver into position over Bennu’s surface.
OSIRIS-REx will spend less than five seconds of its seven-year mission collecting anywhere from two ounces to two pounds of material in a round air filter.
At just the right moment, a robotic arm will reach down 11 feet and gather a handful of the precious regolith. The arm, called the “touch and go sample acquisition mechanism,” or TAGSAM, is a new approach for NASA. It will blow a puff of nitrogen at the surface and collect whatever it stirs up.
Sept. 24, 2023
The spacecraft will jettison the sample down to Earth in a special return capsule that will land at the Utah Test and Training Range in the desert west of Salt Lake City.