The OSIRIS-REx or the Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer was launched by NASA on 8th September 2016. Its main mission is to map and collect the samples from the surface of asteroid “Bennu“. It was launched on a United Launch Alliance Atlas V from Cape Canaveral. It is specifically designed to follow asteroid Bennu and bring the samples collected back to Earth, but why was asteroid Bennu selected?
Asteroid Bennu is a near Earth asteroid. This asteroid has pristine carbonaceous materials present on it which are known because of their presence in organic molecules and they are necessary for life. This asteroid was also chosen as it is expected to collide with Earth in the near future.
OSIRIS-REx which reached near asteroid Bennu on 3rd December 2018 is mapping and analyzing it’s surface while you are reading this. It will spend more than 500 days collecting data and mapping the surface of Bennu to find a perfect place from where it can easily collect a sample without even landing! For this, the spacecraft will be using a robotic arm that extends to the surface of Bennu and then sucks up the stones and dust weighing approximately 60 grams by using nitrogen. This arm which is known as TAGSAM or the Touch-And-Go Sample Acquisition Mechanism will collect the sample within 5 seconds of it’s contact with Bennu then the sample will be reviewed and if it isn’t approved, the arm will stretch again to collect the sample. TAGSAM will extend at a speed of 0.2m/s, after reaching the surface a burst of nitrogen gas will be released to collect the samples and after collecting them, the spacecraft will drift away from the asteroid. If the collected sample isn’t good enough, OSIRIS-REx will again carry out the process to replace the samples. The Spacecraft will also carry instruments like OCAMS, OLA, OVIRS, OTES AND REXIS.
The OCAMS or the OSIRIS-REx Camera Suite will be responsible for collecting hig resolution images of the asteroid. It will map the surface of Bennu and will tell us about it’s shape, structure and a perfect site for collecting the samples. It is further divided into 3 instruments based on the type of information they acquire.
OLA on the other hand will provide us with topographical details of Bennu’s surface. OLA or OSIRIS-REx Laser Altimeter has a prime motive of creating local and global maps of the asteroid so we can know it better. It consists of a high and low energy laser which will be used to map the asteroid and to learn more about it’s gravitation and centre of mass.
The OVIRS or OSIRIS-REx Visible and IR Spectrometer is as it’s name suggests, a spectrometer. Each element has a unique spectrum and it is OVIRS job to study the spectral lines coming from Bennu to know more about its composition. This would tell us about the elements, minerals and the compounds present on the asteroid which at the end will help scientists to decide a spot from where the spacecraft will collect samples.
REXIS or the Regolith X-ray Imaging Spectrometer will be creating a map using X-ray spectroscopy which would be stored in a way that it occupies minimum space and can be accessed when it reaches back to Earth.
OSIRIS-REx will be reaching back to Earth in 2023 after successfully completing its task. It would be collecting samples from the asteroid, then it would map the properties of elements and minerals present on it which will give us a more wide idea about the asteroid’s geography as well as topology. Interestingly, the spacecraft was named after the Greek god of underworld known as OSIRIS and the REx stands for ruler or king in latin. This name was chosen as the asteroid has a probability of hitting Earth in the near future. This mission is important as it might just save humans from extinction as knowledge is our ultimate key of survival and by obtaining more information on such asteroids, we can think of a proper method to save us from becoming dust.