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After more than a year of carefully mapping the asteroid Bennu, a NASA spacecraft will attempt a historic “touch and go” to catch a precious sample of land to return to Earth. But we won’t know if it was fully successful for another 10 days, NASA officials said at a press conference on Monday (October 19).
The OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) spacecraft will begin its descent today (October 20), and you can watch it live here on Space.com, courtesy of NASA Television. Since it takes about 18 minutes for signals to travel between the spacecraft and mission controllers on Earth, all maneuvers are timed in advance and the spacecraft will transmit information as it progresses.
The first images of the asteroid will give a clue as to whether the scoop was successful, but only by comparing the mass of the spacecraft before and after the maneuver will engineers finally know how much asteroid debris is inside OSIRIS-REx. The maneuvers and analysis will take approximately 10 days, which means that the result of the spacecraft will not be known until at least the end of October.
OSIRIS-REx: NASA’s Asteroid Sample Return Mission in Pictures
But even landing will be a journey for team members, some of whom have been involved in mission planning for a dozen years or more.
“It will be four and a half hours of anxiety,” said Beth Buck, program manager for the OSIRIS-REx mission at Lockheed Martin Space, at a NASA-led news conference on Monday (October 19). That’s in contrast to the typical “seven minutes of terror” associated with a spacecraft landing on Mars, he added.
“The best result would be that we collect a massive sample,” said Heather Enos, deputy principal investigator for OSIRIS-REx at the University of Arizona, of what the team expects to see in about 10 days, when the gyro data is shown. spacecraft. changes in mass that will indicate whether there is asteroid material ready inside to be transported back to Earth in 2023.
While the mission design requires 1.7 ounces (50 grams) of fine-grained material, there is room for up to 4.4 pounds (2 kilograms), Enos said. “I would love for that capsule to be completely full,” he added.
Around 1:50 pm EDT (1950 GMT) on landing day today (Tuesday, October 20), controllers should receive telemetry from Bennu showing the spacecraft departed from orbit. OSIRIS-REx will carefully maneuver two more times on two burns to properly position itself on the surface and also, to verify that you are on the right track to pluck a scoop of regolith.
A “checkpoint” burn will transmit information to Earth around 5:50 pm EDT (2250 GMT), when the spacecraft is approximately 160 feet (50 meters) above the surface. Ten minutes later, OSIRIS-REx will transmit information from its third and final “hit point” that will prepare it for a smooth surface contact at 6:12 pm EDT (2312 GMT).
The descent will be more demanding than mission designers anticipated, with the main sampling area, nicknamed “Nightingale,” only 52 feet (16 m) in diameter, Kenneth Getzandanner, OSIRIS-REx flight dynamics manager at NASA’s Goddard Space Flight Center in Maryland. he said at the press conference.
The original mission design called for a landing “zone” about 150% larger than Nightingale, at 82 feet (25 m), but Bennu proved rockier than anyone expected, he said. Several months of precise laser mapping (up to 2-inch or 5-cm resolution) and simulations followed to change the OSIRIS-REx planning. From these discussions, the spacecraft will use improved guidance tracking to adjust the burn on the way to its target “tag” site, Getzandanner said.
At Nightingale, OSIRIS-REx will spend about 15 seconds trying to collect material before returning to space, Buck added. But there are ways to get out of the landing before landing if the area seems too rocky to do a safe pickup. Buck said the spacecraft is automatically prepared for aborts up to 410 feet (125 m) and as low as 16 feet (5 m) above the surface.
The chances of a firing are less than 6%, he added. If an abort occurs, OSIRIS-REx will eventually sample from a backup site, nicknamed “Osprey,” that will not be disturbed by any maneuvering by the spacecraft. When to make that second attempt will depend on the health of the spacecraft, Buck added.
OSIRIS-REx systems will focus on a safe landing and only low-speed data, such as your position, will be transmitted to Earth during and immediately after descent. Some of the images should go back sometime late Tuesday or early Wednesday. “We will know if we touch the asteroid, but we will not know if we have a sample,” Enos said. What comes next will depend on whether OSIRIS-REx actually collected material or not.
The spacecraft will send its precious cargo back to Earth in September 2023 for further analysis, with the goal of learning more about the small worlds that populate the small system. The collection’s applications will be diverse, including telling us more about the history of the solar system and helping future “planetary defense” engineers undertake missions to protect Earth from rogue asteroids, missions that depend on knowing the composition of asteroids. to better design diversion spaceships. .
“Something really amazing is about to happen tomorrow,” Thomas Zurbuchen, NASA associate administrator for science mission management, said at the news conference. “I couldn’t be more excited to be a part of this team and to be a part of this incredible event.”
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