In anticipation of its December rendezvous with Bennu, the 1,640-foot-wide space rock chosen by NASA as the target of its first asteroid sample return mission, the OSIRIS-REx spacecraft has just performed its first asteroid approach maneuver (AAM), the mission’s website announced earlier today.
According to Erin Morton, OSIRIS-REx communications lead at the University of Arizona, which helms the unmanned NASA mission, the spacecraft fired its main engine thrusters to execute a braking maneuver that allowed it to slow down and adjust its course.
This particular maneuver, dubbed AAM-1, served to reduce the space probe’s speed relative to Bennu from about 1,100 mph (491 m/sec) to 313 mph (140 m/sec).
“The mission team will continue to examine telemetry and tracking data as they become available and will have more information on the results of the maneuver over the next week,” stated Morton.
As the Inquisitr previously reported, OSIRIS-REx began adjusting its course three months after its launch with a deep space maneuver (DSM-1) executed on December 28, 2016. The spacecraft performed a second deep space maneuver on June 28 of this year, which put it on course for today’s AAM-1.
“Today I’m executing Asteroid Approach Maneuver-1, which is the first in a series of braking maneuvers that will slow my speed as I approach asteroid Bennu. My cruising speed before AAM-1 is about 1,100 miles per hour (490 meters per second),” the mission’s Twitter account disclosed a few hours ago.
Today I'm executing Asteroid Approach Maneuver-1, which is the first in a series of braking maneuvers that will slow my speed as I approach asteroid Bennu.— NASA's OSIRIS-REx (@OSIRISREx) October 1, 2018
My cruising speed before AAM-1 is about 1,100 miles per hour (490 meters per second). https://t.co/rACre4nDe4 pic.twitter.com/RVl9b328DL
In a brief update posted on Twitter an hour later, the OSIRIS-REx team revealed that the preliminary results of the AMM-1 showed the maneuver was “executed as expected.”
The preliminary results are in, and my first Asteroid Approach Maneuver executed as expected! ???? This main engine braking burn was designed to slow my speed from about 1,100 mph (491 m/sec) to 313 mph (140 m/sec). My team will have more details this week. https://t.co/zxaSViv5xX pic.twitter.com/aV0GpbiGN1— NASA's OSIRIS-REx (@OSIRISREx) October 1, 2018
OSIRIS-REx will be conducting three more asteroid approach maneuvers by mid-November. These procedures are “designed to fly the spacecraft through a precise corridor during its final slow approach to Bennu,” which is scheduled to take place on December 3, explained Morton.
The final maneuver is slated for November 12 and help will steer the spacecraft into an observational position 12 miles (20 kilometers) from the asteroid’s surface on the day of the rendezvous.
Built by Lockheed Martin Space Systems in Denver, the spacecraft set out on a seven-year journey to Bennu and back, with the goal of returning a sample from this carbon-rich space rock — a near-Earth asteroid located about 54 million miles from our planet and which “is one of the most potentially hazardous asteroids, with a relatively high probability of impacting Earth late in the 22nd century,” notes the University of Arizona.
Once OSIRIS-REx arrives at Bennu’s orbit two months from now, the spacecraft will begin asteroid proximity operations by conducting flybys of the space rock’s poles and equator. This will bring it within 4.4 miles (seven kilometers) of Bennu’s surface and help reveal more about the space rock’s mass and features, the Inquisitr reported in August, when the spacecraft snapped its first-ever image of the asteroid from a distance of 1.4 million miles (2.2 million kilometers).
At first, the probe will orbit Bennu for a period of two years, studying its features from space. After the team gathers enough data to choose a landing site, OSIRIS-Rex will descend to Bennu’s surface in July 2020, hovering over the designated area to retrieve a sample of regolith, or the layer of rock-strewn dust covering the asteroid. The spacecraft will head back to Earth in March 2021 and is expected to deliver its precious cargo in September 2023, the Inquisitr recently reported.