WASHINGTON: NASA’s first mission to retrieve an asteroid sample and return it to US soil is expected to reach a perilous finale on Sunday with a descent into the Utah desert. Scientists hope the material — possibly the most ever retrieved by such a mission — will provide humanity with a better understanding on the formation of our solar system and how Earth became habitable.
The US space probe OSIRIS-REx, launched in 2016, scooped up the sample from an asteroid called Bennu almost three years ago.
Touchdown is scheduled for Sunday at around 9 am local time at a military testing site in the western state. Some four hours earlier, at about 108,000 kilometres away from Earth, the Osiris-Rex probe will release the capsule containing the sample. The final descent lasts 13 minutes: the capsule enters the atmosphere at a speed of around 43,000 kilometres per hour and reaches a maximum temperature of 2,800 degrees Celsius, NASA said.
If all goes well, two successive parachutes will bring the capsule to a soft landing on the desert floor, where it will be retrieved by prepositioned staff. Hitting the target area of 650 square kilometres is like “throwing a dart across the length of a basketball court and hitting the bullseye”, Rich Burns, OSIRIS-REx project manager at NASA, told a press conference last month.
The night before landing, controllers will have a final opportunity to abort if conditions are not correct. If so, the probe would then circle the Sun before its next attempt — in 2025. “Sample return missions are hard. There’s a number of things that can go wrong,” said Sandra Freund, Lockheed Martin’s OSIRISREx program manager. Teams have meticulously prepared for the capsule’s return — even a “hard landing scenario” according to Freund — in order to preserve the asteroid material in its pristine form.
A final dress rehearsal took place in August, with a replica capsule dropped from a helicopter. Once the capsule is on the ground, a team will check its condition before placing it in a net, which will be lifted by helicopter and taken to a temporary “clean room”. The next day, the sample will be flown to a highly specialised laboratory at NASA’s Johnson Space Centre in Houston, Texas. Scientists will open the capsule and separate pieces of the rock and dust over a period of days. Some of the sample will be for studies now, with the rest stored away for future generations equipped with better technology — a practice first started during the Apollo missions to the Moon. NASA is expected to unveil its first results during a press conference on October 11. – AFP
