NASA’s new record: spacecraft orbited around the smallest space object
Source :NewsBharati   Date :01-Jan-2019



Maryland, Jan 1: On December, 31, NASA’s OSIRIS-Rex, spacecraft entered into orbit around Bennu, and made Bennu, the smallest space object ever to be orbited by a spacecraft.

On New Year Eve, the world was engaged in celebrations, 70 million miles (110 million Kilometers) away, carried out a single, eight-second burn of its thrusters and broke a space exploration record. Spacecraft entered into orbit around the asteroid, Bennu became the smallest object ever to be orbited by a spacecraft.

Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona said, “The team continued our long string of successes by executing the orbit-insertion maneuver perfectly. With the navigation campaign coming to an end, we are looking forward to the scientific mapping and sample site selection phase of the mission.”

“With the navigation ‘entering orbit around Bennu is an amazing accomplishment that our team has been planning for years, the gravity of Bennu is so small, forces like solar radiation and thermal pressure from Bennu’s surface become much more relevant and can push the spacecraft around in its orbit much more than if it were orbiting around Earth or Mars, where gravity is by far the most dominant force” Dan Wibben, OSIRIS-REx Maneuver and Trajectory Design lead said.

OSIRIS-REx’s first orbit made a leap for humankind. Never before has a spacecraft from Earth circled so close to such a small space object-one with barely enough gravity to keep a vehicle in a stable orbit.

Now that the OSIRIS-REx spacecraft is closer to Bennu, physical details about the asteroid will leap into sharper focus, and the spacecraft’s tour of this rubble pile of primordial debris will become increasingly detailed and focused.

The Orbital A phase will help improve our detailed models for Bennu’s gravity field, thermal properties, orientation, and spin rate,” said Wibben. “This, in turn, will allow us to refine our trajectory designs for the even more challenging flight activities we will perform in 2019.”

The December 31 maneuver to place the spacecraft into orbit about Bennu is the first of many exciting navigation activities planned for the mission. The OSIRIS-REx team will resume science operations in late February.

At that point, the spacecraft will perform a series of close flybys of Bennu for several months to take high-resolution images of every square inch of the asteroid to help select a sampling site.

During the summer of 2020, the spacecraft will briefly touch the surface of Bennu to retrieve a sample. The OSIRIS-REx mission is scheduled to deliver the sample to Earth in September 2023.