NASA launched OSIRIS- RExseven years ago from Cape Canaveral, Florida to orbit the asteroid Bennu. Two years later and 200 million miles from the earth, the SUV-sized autonomous spacecraft arrived at the giant space rock. Dante Lauretta, a planetary scientist at the University of Arizona and principal investigator of the OSIRIS-REx, mission, said Bennu is about the size of the Empire State building.
“It’s almost like a droplet of liquid, it’s a pile of rubble that’s floating in microgravity. So, it’s boulders, it’s gravel and it’s the result of a cosmic collision about a billion years ago in the main asteroid belt,” said Lauretta.
And it’s the most dangerous rock in the solar system. Lauretta said it has the highest probability of impacting the earth than any object scientists know of.
“But I don’t want you to panic, because the odds are low. It's 1 in 1,750 chances. I like to say you cross the street with those odds. And if the impact is going to occur it's going to be in the late 22nd century. So, I like to think of this as a bit of an insurance policy. This is a risk, the likelihood is low, consequences are high. We have to do something to understand it," said Lauretta.
For Lauretta, Bennu is a scientific time capsule because the minerals and chemicals that make up this asteroid formed over 4.5 billion years ago, at the dawn of our solar system.
“We picked Bennu because of its carbon rich composition and we are particularly interested in understanding if objects like Bennu delivered the prebiotic seeds to our planet,” said Bennu.
Space Dynamics Laboratory at Utah State University has been a long-time partner of the mission, in fact, since 2011. SDL helped build the camera and electronic systems onboard.
“The SDL space electronics systems are what enable all the communication from the spacecraft back to earth,” said Jed Hancock.
Jed Hancock is President of Space Dynamics Laboratory. He said these systems collect the photons, or the light, and the electronics once converted to electrical signals create the images that we can see and understand.
“So the electronics, they truly are the nervous system. It’s where the brains of the sensors in the operation are. They are vitally important to the operation of the entire mission,” said Hancock.
The images first helped navigate the spacecraft to the asteroid and while in orbit, the cameras took pictures in many colors of its surface, which helped the team determine where to safely collect the sample. In 2020, using a mechanism that is basically an air filter, the spacecraft scooped up asteroid material into the sample return capsule (that actually looks like a mini-UFO). But things did not go as planned. Lauretta said Bennu behaved like a fluid and the spacecraft just sunk in.
“Fortunately, the back-away thrusters fired. If we had not fired those engines to back away from Bennu I think we would have just sunk in like quicksand and the spacecraft would have disappeared. It was such a shocking result, a response of the surface, nothing that we expected," said Lauretta.
He believes this sample, comprised of what the team called fragile and fluffy rocks, would not survive earth’s passage to land as meteorites.
“So I think we are bringing back something that is distinct from our material in our collections today.”
Lauretta has been involved in this mission since 2004, when he said the concept was first formulated on a cocktail napkin at a drinkery in Tuscon, Arizona. It’s now on course to set multiple records in space flight history.
“Including the closest in orbit and the smallest object ever orbited. Of course, it will be the largest sample to be returned from beyond the earth moon system,” said Lauretta.
The spacecraft is now headed back to earth to drop the capsule with the precious sample, expected to land at the U.S. military's Utah Test and Training Range on September 24.
Once it’s retrieved, it will be transferred to a "clean room" at UTTR, where crews will extract the cannister that contains the sample. The following day, it will be flown to NASA’s Johnson Space Center in Houston, where it will be analyized and preserved for the future. More than 200 scientists will have the opportunity to study the material.
"Watch with excitement over the next couple of years what happens. We are going to learn about the formation of the solar system and possibly how life came to be on earth," said Jed Hancock.
