Hayabusa2 Spacecraft Completes Mission, Returns Asteroid Sample to Earth
The Japanese Hayabusa2 spacecraft launched a few years back with an ambitious mission ahead of it: orbit an asteroid, deploy rovers, shoot the asteroid, and collect samples for return to Earth. In the last couple of years, Hayabusa2 has accomplished every single one of those objectives. After six years in space, the Hayabusa2 sample container landed on Earth, providing scientists with the first significant samples collected directly from an asteroid.
The Japan Aerospace Exploration Agency (JAXA) launched Hayabusa2 in 2014. It took about two years for the probe to rendezvous with a space rock known as Ryugu, which is a rare spectral type Cb asteroid, with qualities of both a C-type and B-type asteroids. Asteroids like Ryugu have remained mostly unchanged since the earliest era of the solar system. So collecting a sample could allow us to look back in time and learn about this part of our history. Getting pristine samples from an asteroid is no simple feat, though.
Hayabusa2 reached Ryugu in summer 2018 and spent the next several months gathering data so the team on Earth could evaluate sample collection locations. The team found that Ryugu was much more craggy than expected, a finding confirmed when NASA’s OSIRIS-REx probe reached the asteroid Bennu. Along the way, Hayabusa2 dropped off its robotic surface explorers and mapped the entire surface of Ryugu.
Last year, Hayabusa2 dropped down to the surface and fired a tantalum slug into the asteroid. This launched the regolith upward into the collection mechanism. Later, the probe deployed its Small Carry-on Impactor (SCI), which fired an explosive-accelerated impactor into the surface to produce a small crater. After bombing the asteroid, Hayabusa2 dropped down to get another sample from the newly uncovered area.
Capsule collection! The helicopter team immediately flew to the location identified by the DFS team. They searched for the fallen capsule by using radio waves and maps. Thank you very much!
(Collection Team M)#Hayabusa2#はやぶさ２#AsteroidExplorerHayabusa2 #HAYA2Report pic.twitter.com/KSyEbnU3Yd
— HAYABUSA2@JAXA (@haya2e_jaxa) December 6, 2020
Hayabusa2 began the journey home in late 2019, using its ion engines to leave Ryugu behind forever. The spacecraft reached Earth over the weekend and released the 35-pound (16 kilograms) sample return capsule. As planned, the container entered Earth’s atmosphere over Australia, deploying its parachute as it descended in the Woomera test range. Teams recovered the capsule after spotting its parachute snagged on a bush.
The team set up a “quick look” facility at Woomera to inspect the payload. They siphoned off gas from the inside of the container, but it’s unclear at this time if the gas came from the asteroid. The mission was designed to collect about 100 micrograms of material — that might not sound like a lot, but it’s by far the most asteroid material we’ve ever had to analyze. JAXA will send some of the samples to NASA (among others), which will have its own asteroid samples in a few years when OSIRIS-REx returns to Earth. That mission may have collected several kilograms of material from Bennu, so scientists will have plenty of material to conduct experiments.