This year, a rather exciting spacecraft is going to take flight. In September, NASA’s OSIRIS-REx spacecraft will launch, beginning its journey to the asteroid Bennu. From this asteroid, it will return the largest sample from space to Earth since the days of the Apollo Moon landings.

The mission is scheduled to launch on September 8, with arrival at the asteroid expected in 2018. Just recently, NASA began the final preparations for the launch, which will take place on an Atlas V rocket from Cape Canaveral in Florida.

“This team has done a phenomenal job of assembling and testing the spacecraft,” said Dante Lauretta, principal investigator for OSIRIS-REx at the University of Arizona, Tucson, in a recent statement. “As we begin the final preparations for launch, I am confident that this spacecraft is ready to perform its science operations at Bennu. And I can’t wait to fly it.”

^{OSIRIS-REx is seen here at the Kennedy Space Center in Florida. NASA/Dimitri Gerondidakis}

Bennu is known as a near-Earth asteroid, orbiting between 1.356 and 0.897 astronomical units (AU) from the Sun (one AU is the distance from Earth to the Sun). Once it arrives, the spacecraft will eventually lower its position around the asteroid so that it is hovering just meters away from its surface. It will then deploy a robotic arm that will contact the surface for five seconds, firing a burst of nitrogen gas. This maneuver is expected to take place in 2020.

The burst will enable OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) to collect a sample of between 60 grams and 2 kilograms (0.13 and 4.4 pounds), the biggest sample ever collected by a robotic mission. In 2023, this sample will be returned to Earth and studied by scientists in order to learn more about the Solar System.

This will not be the first time a sample from an asteroid’s surface has been returned to Earth – that honor belongs to Japan’s Hayabusa spacecraft, which returned to Earth in 2010 after a troubled mission. But Hayabusa returned less than a milligram of material from asteroid Itokawa; OSIRIS-REx’s sample size will be much more impressive.

Scientists hope that by studying Bennu, they may learn more about the origins of the Solar System, and possibly discover if asteroids played a part in delivering water and organic molecules to Earth. With less than 100 days until launch, there’s plenty of reason to get excited about this fascinating mission.