JAXA has confirmed the engine burn to allow Ryugu to capture Hayabusa 2. Up close, the asteroid doesn’t look quite as clearly octahedral, but it’s still showing a remarkable diamond silhouette. The surface is battered, but not in the manner we’re used to seeing with larger bodies. The craters have soft edges, and the surface in general looks more like a clump of fine particles with occasional rocks stuck in it, probably reflecting a relatively loose composition.
The spacecraft is expected to stay at Ryugu for 18 months, during which it will make a series of daring touch-and-go landings, deploy a series of landing vehicles, and even launch an impactor at the asteroid. It will also attempt to collect material using a feed horn device similar to that used on the original Hayabusa. At the end of its stay, Hayabusa 2 will fire its engines to leave orbit around Ryugu and head back to Earth, with arrival scheduled for 2020. The original mission returned only a tiny amount of material, but enough to make comparisons to what Hayabusa 2 will return. The exciting part of the mission is only just beginning!
The second Japanese asteroid sample return mission is underway, and it’s spotted its target, the Apollo-group asteroid 162173 Ryugu. And what do you know? Most asteroids so far have looked like potatoes, but this one makes me think of an eight-sided die:
These images, taken with the ONC-T (Optical Navigation Camera – Telescopic) instrument at ranges from 330 to 240 km as the spacecraft approaches the asteroid, show that Ryugu is spinning like a top, completing one revolution every 7.6 hours.
Hayabusa 2 is expected to enter orbit around Ryugu next week, and will commence a lengthy period of orbital observations leading up to a series of daring landings in which it will sample material from the asteroid. It will also deploy a number of mini spacecraft, including an impactor (with an explosive charge) to excavate fresher material for sample, a German/French hopping lander named MASCOT and partially based on the design of Philae (the piggyback lander from the Rosetta mission), and three Japanese rovers. It’s an ambitious mission, and we’ll soon start to get into the interesting bit. 😉
The Atlas V launch of the OA-4 Cygnus flight was scrubbed due to bad weather at the Cape — mostly rain and fog at the launch site. They will try again tomorrow, but there is only a 30% chance of favorable weather. The forecast remains gloomy for several days, after which they start running into conflicts with ISS scheduling as there are other vehicles scheduled to visit the ISS this months. Cross your fingers!
But the Vega launch of LISA Pathfinder was a complete success! The technology demonstrator for the upcoming multinational LISA gravity probe mission is on its way to L1.
And last of all, the Japanese Hayabusa 2 probe visited Earth today, zipping on past to tweak its course to asteroid 162173 Ryugu. This is a follow-on from the partially successful Hayabusa probe, which performed the first sample return from an asteroid, but incorporating lessons learned from that spacecraft, so this one should perform even better. Here’s an animation of the flyby:
And here’s a view of Earth and Moon taken by Hayabusa 2 while on a approach a few days ago: