NASA’s OSIRIS-REx breaks record for smallest space object ever orbited
What in news:
· OSIRIS-REx spacecraft successfully orbited around asteroid Bennu.
· NASA’s OSIRIS-REx spacecraft broke a record after successfully entering into orbit around the asteroid Bennu — the smallest cosmic object ever to be orbited by a spacecraft.
· While many on Earth prepared to welcome the New Year, NASA’s OSIRIS-REx spacecraft, 110 million kilometres away, carried out a single, eight-second burn of its thrusters, NASA said in a statement.
· “With the navigation campaign coming to an end, we are looking forward to the scientific mapping and sample site selection phase of the mission,” said Laurette.
· Inching around the asteroid at a snail’s pace, OSIRIS-REx’s first orbit marks 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.
· 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 it
· The spacecraft will circle Bennu about 1.75 kilometres from its centre, closer than any other spacecraft has come to its celestial object of study.
· Previously the closest orbit of a planetary body was in May 2016, when the Rosetta spacecraft orbited about seven kilometers from the center of the comet 67P/Churyumov-Gerasimenko.
· The comfortable distance is necessary to keep the spacecraft locked to Bennu, which has a gravity force only 5-millionths as strong as Earth’s.
· The spacecraft is scheduled to orbit Bennu through mid-February at a leisurely 62 hours per orbit.
· Now that the OSIRIS-REx spacecraft is closer to Bennu, physical details about the asteroid
· orbit design is highly dependent on Bennu’s physical properties, such as its mass and gravity field.
· As the team learned more about the asteroid,they incorporated new information to hone in on the final orbit design.
· The simulations have played a critical role. The OSIRIS-REx mission, after all, was designed based on complex computer programs that predicted the properties of Bennu and how the spacecraft’s trajectory would behave.
· This diligent preparation allowed the team to navigate the vehicle safely to Bennu in December and put some questions to rest and to fly over its poles and equatorm.
· 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.
· The OSIRIS-REx is a NASA asteroid study and sample-return mission.
· The mission's main goal is to obtain a sample of at least 60 grams from 101955 Bennu, a carbonaceous near-Earth asteroid, and return the sample to Earth for a detailed analysis.
· Bennu is a carbonaceous asteroid in the Apollo group discovered by the LINEAR Project on 11 September 1999.
· Asteroid Bennu has a roughly spheroidal shape, resembling a spinning top. The direction of rotation about its axis is retrograde with respect to its orbit.
· Preliminary spectroscopic surveys of the asteroid's surface by OSIRIS-REx spacecraft, detected the presence of the hydroxyl group likely bonded in the clay material of the asteroid.
Expected prelims question
Consider the following statements
1. OSIRIS-Rex spacecraft was launched by NASA
2. OSIRIS-REx spacecraft was launched over asteroid Bennu.
Which of the above statements are correct.
a) Only 1
b) Only 2
c) Both 1 and 2
d) None of the above
Ans – c
Expected mains question
Describe the features of Bennu Bennu asteroid. Analyse why do most of space explorations Carried out over asteroids and meteors.