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The "Osiris-Rex" probe has been orbiting the asteroid for two years.
Photo by NASA / Goddard / University of Arizona
The NASA probe "Osiris-Rex" has been orbiting the asteroid Bennu for two years.
"Osiris-Rex" finally makes its grand entrance on Tuesday evening at 7:30 p.m. Central European Time: In a complicated maneuver lasting several hours, the probe is supposed to take a sample of the asteroid rock.
The probe is supposed to come within a few meters of Bennu and then extend a kind of robot arm.
It is said to touch the surface of the asteroid for about five seconds and expel pressurized nitrogen to stir the surface.
Then a sample of about 60 to 2000 grams should be sucked up before the entire probe moves away from Bennu.
The US space agency NASA had already successfully rehearsed the maneuver twice.
"Osiris Rex" is the first US missile that has made its way to an asteroid and - if the maneuver is successful - will take a sample and bring it back to Earth.
According to experts, if the mission is successful, Bennu's sample will be the largest amount of extraterrestrial rock that has been brought to earth since the moon landing 50 years ago.
Asteroid Bennu comes dangerously close to Earth
"Osiris-Rex" was launched from the Cape Canaveral spaceport in September 2016 and arrived at Bennu around two years later.
Since then, the "Osiris Rex" probe, which is around six meters long and weighs 2100 kilograms, has been orbiting the asteroid and examining it with its scientific instruments and cameras.
The more than 4.5 billion year old celestial body was carefully selected by NASA: it is relatively close to the earth, rich in carbon and, with a diameter of around 500 meters, has ideal dimensions.
In addition, when viewed through telescopes, it appeared to be covered by a layer of sand, which makes it easier to take samples.
The deep black asteroid could get quite close to Earth in more than 150 years.
Even if the risk of impact is very low, Nasa Bennu is one of the most dangerous asteroids currently known - and therefore wants to research it very carefully.
In addition, the scientists hope that the mission, which cost around one billion dollars, will provide information about the formation of the solar system more than 4.5 billion years ago.
"Osiris-Rex" is scheduled to start its return journey to earth in March.
In 2023, the small robot spaceship will then drop the container with the asteroid samples with a parachute over a desert in the state of Utah.
Then NASA researchers can evaluate the material.
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sug / afp / dpa-AFX
