Sample return missions are increasingly in vogue, as evidenced by NASA OSIRIS-REx Mission and the Chinese current Chang’e 5 drilling operation on the moon. But they are not easy. In February 2019, Hayabusa2 landed on the surface and fired two small bullets into the asteroid to agitate a cloud of particles from which the sampling arm could collect debris. He fired a bigger projectile in April of the same year, dive to the surface a few months later to recover even more ejected material.
While the first Hayabusa mission was only able to bring back a millionth of a gram thanks to this approach, there is optimism that Hayabusa2 will bring in a lot more. “I am proud of this success, even if I do not yet know that the start of the [of the sample capsule] will be successful, ”says Eri Tatsumi, a planet specialist at the University of La Laguna in Spain who has worked directly with data from Hayabusa2 so far.
Asteroids are like time capsules of ancient space history because their physical and chemical makeup is much better preserved over time than, say, that of a planet (whose internal heating and magnetic field and potential atmosphere encourage continued activity). In this case, studying Ryugu’s material can help us understand what the early solar system looked like when massive amounts of gas and dust coalesced into different asteroids, moons, and planets, including habitable worlds like Earth. .
“What we would like to know is what are the processes that shaped the solar system,” says Tatsumi. “I would like to know what kind of organics are in Ryugu – if it has the building blocks for life.” She believes studying the Ryugu samples could allow scientists to “add another page to our knowledge of early solar system materials” and the types of elements and compounds that may have been delivered to early Earth. via meteorite impacts. Ryugu himself seems too fragile to survive a current entry into Earth’s atmosphere, so he’s probably quite different from the meteorite remnants on Earth that we’ve been able to analyze so far.
Additionally, there are some peculiar things about Ryugu’s story that require the kind of context you can only get from lab analysis. Tomokatsu Morota, a planetary scientist at the University of Tokyo, led a team that studied the Ryugu surface using images captured by Hayabusa2 cameras. The team noticed surface alterations caused by solar heating. “This suggests a scenario where Ryugu underwent an orbital excursion near the sun,” he says. A closer look at the rock fragments could help confirm whether or not this happened.
Hayabusa2 will drop off the Ryugu material sample capsule in just a few days. He must survive a fiery re-entry before landing in Australia. The spacecraft itself, however, will depart for an extended mission – first to asteroid 2001 CC21 for a flyby in July 2026, then an official rendezvous with asteroid 1998 KY26 in July 2031. Between these times strong, the spacecraft will make a pair of swings around the Earth trying to make observations of distant exoplanets.
The success of Hayabusa2 will also extend into future sample return missions. JAXA is planning one for the Martian moon Phobos, called Martian Moon eXploration, or MMX. “MMX is technically made from much of the legacy established by Hayabusa and Hayabusa2,” says Tatsumi. “And the Hayabusa2 project involved many young scientists and engineers who will lead the missions of the next generation. Based on these experiences, JAXA may launch more complex and important missions in the future. “