REx Mission Launches, Beginning 7-Year Asteroid Journey

“We’re not talking about an asteroid that could destroy the Earth”, explained chief scientist Dante Lauretta. “I can’t tell you how thrilled I was this evening, thinking of the people who played a part in this”. “We’re going to be answering some of the most fundamental questions that NASA works on”.

Scientists selected Bennu in 2008 for the mission because it met several criteria – flight-path stability and proximity to Earth, size and speed of rotation, and an unaltered, carbon-rich composition.

Asteroids are considered to be like time capsules from the earliest stages of the formation of the solar system, and may contain materials which helped lead to life beginning on Earth.

Researchers hope that studying the makeup of Bennu will provide some insight into the early days of the Solar System. That journey will include several passes around the asteroid as the spacecraft conducts a 2-year-long mapping mission and a particularly hard maneuver in which a 10-foot robotic arm will grab a dirt sample from above the asteroid.

Upon reaching its destination, Osiris will observe the asteroid for two years before retrieving a sample and returning to Earth.

But OSIRIS-REx won’t land. In 2023, just the container holding the sample will re-enter the atmosphere and fall down to Earth, aided by a parachute. NASA scientists are expecting to land it in Utah from where they will begin testing the sample.

The probe will get three chances to snag samples, and then the attachment will be tucked into a sample return capsule for safekeeping.

Bennu, which is about 1,600 feet in diameter, was picked because it’s big enough, it’s not rotating too quickly, and it’s pretty close to Earth. Lauretta said its orbit has changed by over 160 kilometers due to the Yarkovsky effect since it was discovered in 1999.

Nasa chose Bennu as the target of its asteroid sample mission because of its relative proximity to Earth. If the OSIRIS-REx mission is a success, if it is able to make the two year journey and collect a substantial sample from the rocky surface of Bennu it will be the most successful mission of it’s kind since the Apollo era.

To capture the dust sample on the surface, the space craft will “kiss” the asteroid with a robotic arm, gently touching the surface.