NASA Asteroid Mission Uses Earth’s Gravity As A Slingshot

In its quest to find out how young Earth evolved and life on this planet began, NASA has used Earth’s gravity like a slingshot to propel a spacecraft into an orbit that will help it land on an asteroid and bring a sample back home.

The maneuver, which is being referred to as a “gravity assist,” happened on Friday, when the OSIRIS-REx spacecraft that launched last year passed within 11,000 miles of Earth — a point visible to viewers on the ground through a telescope — going 19,000 mph. During that pass, our planet’s gravity bounced the spacecraft’s orbital path 6 degrees, putting it in line with the 4.5-billion-year-old asteroid Bennu.

During its closest point to us, OSIRIS-REx was over Antarctica, although it flew over and was visible to other areas on Friday.

“A few weeks after the flyby we will assess the outgoing trajectory on its way to Bennu,” Dan Wibben, an expert from company KinetX Aerospace who led the design of the gravity assist maneuver, said in a NASA statement. “There is a maneuver planned in case we need to adjust the orbit just a little bit to push the spacecraft back on track.”

NASA’s Goddard Space Flight Center is working with KinetX Aerospace on the OSIRIS-REx navigation.

There are also further maneuvers required several months from now to push the spacecraft closer to the asteroid and then slow it down so it can meet the space rock.

“The asteroid’s small size and low gravity makes OSIRIS-REx the most challenging mission that I have worked on,” KinetX Aerospace’s navigation team chief Peter Antreasian said. “At roughly 500 meters in diameter, Bennu will be the smallest object that NASA has orbited.”

With Friday’s orbital readjustment complete, NASA said, the spacecraft was due to turn toward Earth and take images and spectrum data, “calibrating its instruments so that they are ready to study Bennu.”

That data collection, which included study of the moon as well, began four hours after the gravity assist.

The spacecraft won’t reach Bennu until 2018, but what OSIRIS-REx finds there could be worth the wait.

According to NASA, it will take a look around and map the surface and then use a robotic arm to collect a sample before firing itself up again to return to Earth.

OSIRIS-REx is scheduled to come back home in 2023.

Being able to study a sample from an asteroid that is orbiting our sun — particularly this one, which is almost as old as the solar system itself — could help scientists understand how Earth became a habitable world bursting with life.

“Scientists think asteroids like Bennu may have collided with Earth a long time ago, seeding our planet with the organic compounds that made life possible,” according to NASA. “That means that there’s a good chance Bennu contains answers to fundamental questions about the origins of life and how our solar system came to be. We sent OSIRIS-REx on a journey to investigate.”

The experts will be looking to analyze the chemical composition of the asteroid, searching for organic compounds that are the basis for life.