NASA's OSIRIS-REX today arrived at its target asteroid, Bennu, an important step in its mission to collect a sample of the asteroid and return it to Earth.
OSIRIS-REx started on September 8, 2016 from Cape Canaveral. It carries five data acquisition tools, and scientists hope to learn more about the origin of the Solar System, and even about which asteroids can retain resources. Today's milestone marks the end of a two-year trip to Bennu, and the start of a 1.5-year period of study.
"For a long time it comes to the coming and we really rejoice in the next chapter of this mission," said Heather Enos, deputy chief researcher at OSIRIS-REx from the University of Arizona.
Today, scientists have set fire to safe OSIRIS-REx motors in their orbit around Bennu, 7 kilometers from the asteroid, with the closest approach. The spacecraft took over maneuvers from the summer to change its speed and prepare it for this approach and arrival.
Orbital asteroids (and connecting to them) is not easy – these rocks have very little gravity, and several missions for asteroid-orbiting encounter problems. Bennu will be the smallest astronomical object that ever orbited a spacecraft; it is only about 487.68 meters from end to end, on average.
"A low gravity environment is one of the most important challenges in implementing this mission," said Rees Burns, OSIRIS-REx project manager at NASA's Space Center Space Center in Goddard, in NASA's video. Even the heating of the Sun's energy the spacecraft can change its trajectory.
Asteroids are extreme interest for scientists. They are thought to contain unchanged records of the early solar system, and they could be the way some of Earth's water arrived on our planet in the first place.
That water or metals of the asteroid could one day serve as useful resources, so space explorers should not carry these heavy materials with them. And Bennu's orbit makes it a "potentially dangerous" asteroid, which means it is large and could endanger the Earth in the distant future, so scientists hope to characterize it further.
Scientists hope to have real parts of the asteroid here on Earth to analyze them. "I'm especially excited about the moment the sample is discovered," Neida Abreu, associate professor of geoinnovation and mathematics at Penn State DuBois Gizmodo. "We just scratched the surface when it comes to understanding asteroids." Abreu hopes that Bennu will discover different materials and terrains, while offering a safe landing place.
OSIRIS-REx is the first NASA asteroid mission to return the sample, and the largest specimen returns from Apollo returns the moon rocks. I hope to grab up to 2 kilograms of material. However, this is not the first return of asteroid samples, but Japan's first "problematic" mission from Japan brought significant 1,500 dust grains from the Ithacaid asteroid after considerable difficulty.
His predecessor, Hayabusa2, is in the middle of his mission to touch another asteroid, Ryugu.
The OSIRIS-REx team will now map the asteroid with extremely fine details and measure its mass. This will help them determine future orbits and where the asteroid will collect the sample, said Coralie Adams, a OSIRIS-REx flyer, during a NASA press conference.
The spacecraft is scheduled to return to Earth in September 2023.