Osiris rex" is the first probe from the u.S. Space agency nasa to take a sample from an asteroid – and later deliver it to earth.
In a complicated manover lasting several hours, the probe is to approach the asteroid bennu to within a few meters and then take the sample with a kind of robotic arm.
The robotic arm, called "tagsam" (touch-and-go sample acquisition mechanism), will touch the surface of the asteroid for about five seconds and eject nitrogen under pressure. This is supposed to make the surface swirl. Then a sample of about 60 to 2000 grams is to be sucked up before the entire probe moves away from bennu again.
The U.S. Space agency nasa has successfully tested the manover twice before. Because "osiris rex" is currently about 290 million kilometers from the earth, nasa’s control signals take about 16 minutes to reach the probe.
"Osiris rex" was launched from cape canaveral spaceport in september 2016 and arrived at bennu about two years later. Since then, the six-meter-long, 2100-kilogram probe (its acronym stands for: origins, spectral interpretation, resource identification, security-regolith explorer) has been orbiting the asteroid and studying it with its scientific instruments and cameras.
The jet-black bennu, named after an ancient agyptian deity, has a diameter of about 550 meters and was able to come quite close to the earth in more than 150 years. Even though the risk of impact is very low, nasa considers bennu to be one of the most dangerous asteroids currently known – and therefore wants to study it very closely.
In addition, the scientists hope that the mission, which will cost around one billion dollars, will provide insights into the formation of the solar system more than 4.5 billion years ago. Because asteroids are remnants of it.
"Osiris rex" is the first U.S. Craft to set out for an asteroid, take a sample and bring it back to earth. The capsule is expected to arrive on earth in around three years.
In 2005, the japanese space probe "hayabusa" landed on an asteroid and in 2010 brought the first soil samples ever collected from such a celestial body to earth. There have been other flights to asteroids – but no other probe has so far brought material back to earth.