A few hours ago NASA’s OSIRIS-REx blasted off atop an Atlas 5 411 rocket from Cape Canaveral. After nearly 55 minutes it successfully separated from the rocket’s Centaur last stage, after a few more minutes it deployed its solar panels and started communicating with the mission control center. At that point it started its journey to the asteroid 101955 Bennu to collect a sample and take it back to Earth.
The mission of the OSIRIS-REx (Origins Spectral Interpretation Resource Identification Security Regolith Explorer) space probe is part of the New Frontiers program, consisting of a series of very specialized space missions and follows New Horizons and Juno. In this case, it’s not only one of the various exploration of a place in the solar system but also the taking of samples to be brought back to Earth.
In early 2014, NASA officially called on people around the world to register their names with the “Messages to Bennu” program. All the names of the people who answered that call were recorded on a microchip that will travel aboard the OSIRIS-REx spacecraft.
The Bennu asteroid has an average diameter of about 500 meters and after being discovered in 1999 was the subject of many observations, also to assess the likelihood of an impact with Earth, which according to some calculations could take place between 2169 and 2199. the actual chances of an impact seem very little but to have more precise calculations they need more information on Bennu’s physical characteristics so the fact that it was selected as the target of the OSIRIS-REx mission is positive.
The task of the OSIRIS-REx space probe will be complex because it includes a period of study, a sampling and a return to Earth. The approach to the asteroid Bennu is scheduled for August 2018 using a series of maneuvering thrusters for the rendezvous and at that point the most complex part of the mission will start.
Bennu’s survey will last more than a year during which the asteroid will be studied with various instruments and mapped to allow NASA’s scientists to identify the most suitable area to take samples. When the decision is made, the robotic arm TAGSAM (Touch-And-Go Sample Acquisition Mechanism) will use a nitrogen gas burst to stir up materials from Bennu’s surface allowing the equipment on the arm’s head to catch them. The nitrogen is enough for three pickup attempts to collect between 60 and 2,000 grams (between 2 and 70 ounces) of samples.
In March 2021 the window for for the OSIRIS-REx space probe to depart will will open and that will be the start of the new journey that will last about two and a half years. The arrival in Earth’s orbit is scheduled for September 2023. The capsule that will contain the samples will separate from the probe to physically return the samples to the surface.
This mission has scientific purposes because it will allow to learn more about the composition of asteroids, an interesting goal from various points of view. It will be easier to assess asteroid hazards but the hope is that the samples contain organic materials and in general pristine materials from the birth of the solar system. They’ll give us new information about that era and the origins of the biochemistry who led to the emergence of life forms on Earth.
In addition to these goals, there’s the testing of technologies that will be further developed over the years to explore asteroids with very practical purposes. There are several asteroid mining projects and from this point of view the OSIRIS-REx mission represents a first step.