OSIRIS-REX MISSION. After seven years of travel, NASA’s Osiris-rex probe is about to return to Earth. Its arrival marks the end of its journey through space, but above all the return of the samples taken from the asteroid Bennu.
Launched on September 8, 2016, Osiris-rex is a NASA probe designed to collect asteroid samples and return them to Earth. After two years of travel, the craft had reached its target in 2018: the asteroid Bennu. The probe was then placed in orbit around the latter during an approach phase. In October 2020, the rock samples were taken using a robotic arm and stored in a capsule. The Osiris-rex probe finally began its return journey in May 2021 and is now preparing to return to Earth with its precious cargo.
The teams must now prepare for the sample return phase, which is the last stage of this mission. The challenge is to successfully land the capsule, which must pass through the atmosphere and protect its precious contents from the heat and vibrations that this dizzying fall to the ground entails. Then the scientists will have to unpack the pieces of rock, taking care not to contaminate them. The next few months will therefore be dedicated to fine-tuning and rehearsing these protocols.
The mission of the Osiris-rex probe began on September 8, 2016 when it launched from the Cape Canaveral launch base aboard an Atlas V rocket. The probe then had one objective: to reach the near-Earth asteroid Bennu, including take a rock sample and bring it back to Earth.
For this, the probe made a two-year journey before placing itself in orbit around Bennu in 2018. On site, it carried out a long work of photography, cartography and study of the asteroid. The information collected allowed him to identify landing sites and choose one. On October 20, 2020, the probe approached and used its robotic arm to sample rock. The sample was then placed safely in a capsule before the probe began its return journey in May 2021.
The Osiris-rex probe is now on its way to Earth. The journey, which began in May 2021, is expected to take just over two years. NASA has made available to the public a tool to visualize the position of the spacecraft in the solar system on their website.
With a mass of two tons, the space probe has several instruments as well as a capsule which accommodates rock samples taken from the asteroid. She also has a robotic arm measuring over three meters in length. During sampling, a blast of nitrogen was blasted onto the asteroid’s surface to kick up rock dust. The latter was then captured in the cylinder located at the end of the arm before being placed in a capsule which should be brought back to Earth.
The Osiris-rex probe has five scientific instruments needed to study the asteroid Bennu during the approach phase. It is a series of three cameras which made it possible to take photographs of the star and to map it. The probe also has a laser altimeter thanks to which Osiris-rex was able to acquire a very precise knowledge of the terrain. Three spectrometers are also on board to study the composition of the soil.
The asteroid targeted by the Osiris-rex mission is 500 meters in diameter and was discovered in 1999. Known as Bennu, the object intrigues astronomers because it is expected to pass close to Earth in 2135. Indeed , it is a near-Earth asteroid, which means that it evolves not far from the Earth. It belongs to the category of Apollo-type asteroids. In other words, its trajectory is such that it approaches very close to the Earth on a certain portion of its orbit. Luckily, the risks of collision are extremely low according to NASA, which is closely monitoring the asteroid.
The Osiris-rex probe, which left the asteroid Bennu in May 2021, is about to return to Earth. Scheduled for September 24, 2023, the return of the samples is a crucial step in the mission. The scientists involved in the project are fine-tuning the protocols that will surround this event and ensure the safety of the cargo brought back by the probe.
The capsule containing the asteroid samples will be dropped by the probe and will land on land belonging to the Ministry of Defense. It will then be necessary to quickly recover the object and place it in a clean room to extract the samples without contaminating them. After that, they will be transported to a NASA laboratory built for the occasion at the Johnson Space Center in Houston.
Only a small part of the samples thus collected will be used by the mission teams. The rest will be carefully preserved and can benefit future generations who will certainly have more advanced scientific instruments than those we have today.
