NASA's Osiris-Rex spacecraft enters orbit around ancient asteroid Bennu

MacNut

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More big space news to start the new year.
https://www.dailymail.co.uk/science...d-Bennu-ahead-2020-sample-return-mission.html
A NASA spacecraft has gone into orbit around an ancient asteroid, setting a pair of records.

The Osiris-Rex spacecraft entered orbit Monday around the asteroid Bennu, 70 million miles (110 million kilometers) from Earth.

It's the smallest celestial body ever to be orbited by a spacecraft.

Bennu is just 1,600 feet (500 meters) across.

The spacecraft's laps are barely a mile (1.6 kilometers) above the asteroid's surface, another record.

NASA's OSIRIS-REx spacecraft has found water locked deep inside the asteroid it hopes to bring a sample from back to Earth.

The craft finally arrived at asteroid Bennu last month, more than two years after blasting off from Cape Canaveral Air Force Station.

Now, NASA says it 'made the right decision' choosing its target.

'Recently analyzed data from NASA's Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) mission has revealed water locked inside the clays that make up its scientific target, the asteroid Bennu,' NASA said.

'The presence of hydrated minerals across the asteroid confirms that Bennu, a remnant from early in the formation of the solar system, is an excellent specimen for the OSIRIS-REx mission to study the composition of primitive volatiles and organics,' said Amy Simon, OVIRS deputy instrument scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

'When samples of this material are returned by the mission to Earth in 2023, scientists will receive a treasure trove of new information about the history and evolution of our solar system.
 

neutrino23

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This is awesome. It is amazing that we can send probes to make observations of objects like this that are so far away and so small and so old.
 

Mac'nCheese

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Dumb question maybe but how much more difficult is it to land on an asteroid than a planet or the moon?
 

MacNut

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Dumb question maybe but how much more difficult is it to land on an asteroid than a planet or the moon?
I think the real difficulty is catching up to an object so small. It depends on the rotation, orbit and speed of the asteroid. The goal is to retrieve samples and bring them back to earth.
[doublepost=1546740555][/doublepost]Here is some information from the mission website.
https://www.asteroidmission.org/status-updates/

“The gravity of Bennu is so small, forces like solar radiation and thermal pressure from Bennu’s surface become much more relevant and can push the spacecraft around in its orbit much more than if it were orbiting around Earth or Mars, where gravity is by far the most dominant force,” he said.

The OSIRIS-REx navigation team will use “trim” maneuvers to slightly thrust the spacecraft in one direction or another to correct its orbit and counter these small forces. If the spacecraft drifts away from Bennu, or some other problem forces it into safe mode, it has been programmed to fly away from the asteroid to stay safe from impact.

“It’s simple logic: always burn toward the Sun if something goes wrong,” said Coralie Adam, OSIRIS-REx lead optical navigation engineer at KinetX. Engineers can navigate the spacecraft back into orbit if it drifts away, Adam said, though that’s unlikely to happen.
 
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