On Saturday, December 5th (Sunday December 6th local time in Australia), Japan’s Hyabusa2 successfully returned samples gathered from the asteroid 162173 Ryugu.
It marked the culmination of a six-year mission to reach the asteroid, gather samples and then make a return to Earth – although as I mentioned in my last Space Sunday update, the return of the samples does not mark the end of the road for Hyabusa2.
Travelling at 43,190 km/h – too fast to enter orbit – the spacecraft released the 40 cm sample return capsule on the night of Friday December 4th, 2020, whilst still some 220,000 km away. With its cargo duties discharged, Hyabusa2 performed an engine burn to start it on its way for a rendezvous with asteroid (98943) 2001 CC21 in 2026, before flying on to meet with 1998 KY26, in 2031.
With no means to slow down, the sample capsule slammed into the upper reaches of Earth’s atmosphere at 17:28 GMT on Saturday, December 5th (the earlier hours of Sunday December 6th in Japan and Australia). Following re-entry, that helped the capsule to slow to supersonic speeds, the capsule dropped to an altitude of 10 km before deploying its landing parachute, touching down in Australia at 17:47 GMT (04:17 a.m. local Australian time on December 6th), JAXA officials said.
Radio tracking systems deployed around the expected landing site were able to follow the capsule down allowing its landing point to be triangulated accurately so that recovery helicopters could quickly move in and retrieve the capsule and its cargo.
Following recovery, work started on capsule assessment and preparations to transfer it to the Japanese Space Agency’s (JAXA) Extraterrestrial Sample Curation Centre, a purpose-built facility designed to house and study cosmic material brought home by space missions. Here some of the samples – believed to measure just a few grams – will be studied by Japanese scientists, and some will be distributed to laboratories around the world, where scientists will study it for clues about the solar system’s early days and the rise of life on Earth.
The mission marks only the second time a dedicated sample return mission has brought samples of an extra-terrestrial body back to Earth, the first being the original Hyabusa mission, which returned samples from asteroid 25143 Itokawa in 2010. However, it will not be the last. China’s Chang’e 5 mission will shortly be on its way back to Earth with samples gathered from the Moon (see below for more), and NASA’s OSIRIS-REx will be returning samples from asteroid from 101955 Bennu in 2023.
When it came, it came suddenly and without warning – yet purely by chance, a drone was on hand to capture the event as it happened.
I recently wrote about the fact that, having lost a primary and secondary support cable that were helping to keep its receiving platform aloft, the Arecibo observatory had been declared unsafe and was to be decommissioned, the replacement of the primary load-bearing cables – one of three in total – being determined to be both difficult and dangerous.
Due to the risk of the 900-tonne receiving platform collapsing onto the dish, built into a hilltop karst sinkhole, it had been hoped the telescope could be decommissioned and dismantled, possibly through the use of controlled demolition, sooner rather than later, lest further cables – including one of the two remaining primary cables – gave way.
But on December 1st, before decommissioning plans could be finalised, one of the remaining suffered a catastrophic failure, sending the receiving platform plummeting into the telescope’s 305-metre diameter dish.
The event took place shortly before 07:30 in the morning, local time – and by chance, engineers were monitoring the telescope’s cable system from the main control room and via an aerial drone positioned above the cable housings on the receiving platform when the cable failed. As a result, the entire collapse was caught on camera from two locations – although the drone had to be hastily moved away from the receiving platform as the collapse started.
Swinging towards the ground on the remaining support cables, the receiving platform disassembled as it fell, the bulk falling the 150m into the aluminium dish, the support frame swinging to smash into the the side of dish, the trailing cables also doing considerable damage. Such was the force of the failure, the mass of the platform tore away the top section of one of the support towers and brought about the complete collapse of another.