NASA’s OSIRIS-REx is getting nearer, bodily and temporally, to its major objective. The spacecraft arrived at Bennu on the finish of 2018, and for simply over a yr it has been finding out the asteroid, looking for an appropriate sampling website.
To do this, it is getting nearer and nearer.
OSIRIS-REx stands for Origins, Spectral Interpretation, Useful resource Identification, Safety-Regolith Explorer. The guts of the mission is the pattern it will acquire from asteroid Bennu. That pattern will ultimately make its means again to Earth for examine.
The OSIRIS-REx crew chosen a sampling website very fastidiously. When the spacecraft arrived at asteroid Bennu, NASA discovered that the floor of the asteroid was more difficult than they thought. Although the floor comprises an abundance of the suitable sized materials for the spacecraft’s sampling mechanism, there are many hazards to be averted.
Ultimately, the OSIRIS-REx crew got here up with an inventory of 4 potential sampling websites. They then did extra fly-overs of the 4, to take a good nearer look.
From there, they selected two sampling websites: a major website and a secondary website. All 4 of the websites acquired avian-themed names, and on the finish of the method, NASA selected Nightingale as the first website, and Osprey because the backup website.
All through the positioning choice course of, OSIRIS-REx reconned Bennu in three phases: Recon A, B, and C. Throughout every section, it received progressively nearer to the floor, gathering extra element on every website.
Now, in recon section C, the spacecraft has carried out its closest flyover but. On March third, it flew over Nightingale at an altitude of solely 250 meters (820 ft).
The spacecraft’s safe-orbit peak is one km (zero.6 miles), however for about 5 hours, OSIRIS-REx left that security behind. The Nightingale website is in a crater, and it is about 16 meters (52 ft) broad. In the course of the maneuver, all the science devices had been aimed on the sampling website.
Whereas all the science devices had been working, this flyover is generally concerning the spacecraft’s PolyCam imager. PolyCam is a 20.Three-cm (Eight-inch) telescope, and the nearer it will get to Bennu, the upper decision photographs it acquires.
After the flyover OSIRIS-REx returned to its secure house orbit, however in the wrong way. Now it is prepared for its subsequent massive maneuver, the sampling rehearsal.
There will be two sampling rehearsals, and the primary one is scheduled for April 15. The spacecraft will make its closest strategy then, coming to inside 125 meters (410 ft) of Bennu’s floor. Nevertheless it’s not achieved there.
At that altitude it will carry out what’s known as the Checkpoint maneuver. It will descend even nearer to the Nightingale website, and after descending for about 10 minutes, it will cease its descent at 50 meters (164 ft) and start backing away from the asteroid.
Then in June OSIRIS-REx will carry out its second rehearsal. However this time, it will get just a bit nearer, to between 25 to 40 meters (82 to 131 ft) earlier than backing away.
As OSIRIS-REx performs every strategy, it will be gathering extra information on the sampling website. It will even be “coaching” its Pure Characteristic Monitoring (NFT) system. The NFT makes use of photographs of Bennu’s floor to information itself, evaluating onboard photographs with real-time digital camera enter to keep away from hazards and nail its sampling operation.
The precise sampling maneuver is scheduled for late August 2020. At the moment, OSIRIS-REx will come shut sufficient that its sampling mechanism touches the floor. Then it will fireplace a cost of nitrogen fuel to kick-up some regolith, and seize a few of it. Then it will again away.
Mission operators will not be shocked if the spacecraft’s NFT system cancels the sampling try. The system has a built-in fail-safe. OSIRIS-REx can carry out a number of sampling makes an attempt, so there isn’t any have to decide to a maneuver that’s deemed unsafe by the spacecraft’s automated programs.
If the primary try at Nightingale would not work, OSIRIS-REx can both try to acquire from Nightingale once more, or transfer to the backup website, Osprey.
Ultimately, if all goes nicely, OSIRIS-REx will return to Earth and launch the Pattern Return Capsule (SRC) into Earth’s environment, the place it would deploy a parachute and float right down to the floor. It is anticipated to land on the Utah Testing and Coaching Vary, the place it will likely be retrieved.
This text was initially revealed by Universe At present. Learn the unique article.