The first asteroid sampling mission coordinated by NASA is rapidly approaching a triumphal success. In less than two weeks the Osiris-REx spacecraft will reach the Bennu asteroid as it is currently travelling through the remaining twenty million miles that separate it from its target.
The spacecraft was launched in September 2018 and it has spent most of its time tracking down the 1,640-foot-wide Bennu asteroid as the latter orbits around the sun.
In a span of two years Osiris REx was able to reach an impressive distance and it recently scored another milestone while following the asteroid. In an official press release NASA notes that the probe has reached the two-billion miles landmark, with more than 1.25 billion miles spent on the trajectory towards Bennu.
In order to mark Thanksgiving, the official Twitter of the spacecraft posted a tweet that mentions the milestone and a delightful ‘’I’m thankful for hydrazine and sunshine’’ message.
The last and final approach maneuvers took place on November 12 and if all goes according to plan the spacecraft should be able to reach Bennu on December 23.
After Osiris REx will reach the target destination point the next phase will be initiated. During the Preliminary Survey Base a series of flybys will take place in order to accurately map the surface and other important traits of the asteroid-like its mass and location. During this stage the spacecraft will go within three miles of the asteroid in order to observe the surface of the rock.
These steps are vital since the data collected will be used in order to identify a suitable zone that will allow the spacecraft to collect a reasonable amount of regolith. In the last two years the spacecraft has already practiced some of the moves that will be used during the process, including the extension of a robotic arm that will grab the samples. It is estimated that the spacecraft has enough nitrogen reserves in order to attempt the task three times. A fourth one will leave it grounded on the asteroid forever since the blast systems will no longer function.
It is estimated that OSIRIS-REx will return to Earth in the summer of 2023.