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Bennu Blast 

The UA teams up with NASA to send a spacecraft on an asteroid hunt

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Robots don't come much cooler than OSIRIS-REx.

The $800 million asteroid hunter, designed and run by a team at the UA Lunar and Planetary Lab in partnership with NASA and Lockheed Martin, is set to lift off on Thursday, Sept. 8, to launch a seven-year mission that will aims to bring back primordial space dust.

The spacecraft—about the size of an SUV—will spend the next two years chasing down the near-earth asteroid Bennu. Once OSIRIS-REx catches up with Bennu in October 2018, it will start relaying images and other data back to Earth about the makeup of the asteroid so the team can map it. The science team will use that info to plot a course so that sometime around Independence Day 2020, OSIRIS-REx can scoot right on up next to Bennu and reach out with an arm to blast about two ounces of of asteroid dust into a container. In 2021, OSIRIS-REx heads back to Earth and in September 2023, a capsule with the asteroid dust pops loose and lands in the Utah desert. From there, the science teams will be off to the races with their analysis of a pristine sample from the dawn of the solar system.

The science mission's principal investigator is UA Professor of Planetary Science Dante Lauretta, who has spent the summer at Kennedy Space Center as OSIRIS-REx was being prepped for its placement aboard a mighty Atlas-V rocket for its upcoming launch.

"I've very anxious to see this thing go," Lauretta said the day after he got final launch approval from NASA in late August. "To see all the technological progress that's happening here at the very end is awe-inspiring."

OSIRIS-REx—an acronym for Origins • Spectral Interpretation • Resource Identification • Security • Regolith Explorer—is part of NASA's New Frontiers program. Earlier New Frontier missions include the New Horizon probe that sent back images of Pluto in 2015 and is now off to the Kuiper Belt, and Juno, which remains in orbit around Jupiter.

The Origins part is all about the sample of asteroid dust. But, as the acronym suggests, the mission is more that:

• The Spectral Interpretations angle is all about using the spacecraft's various instruments to not only map of Bennu, but also understand its composition—and by doing so, to better understand the composition of other asteroids.

Resource Identification is about finding out what these asteroids are made of—and whether it makes sense to mine them.

Security is all about studying the asteroid to learn more about how to best prevent an asteroid collision with the Earth. Of particular interest is something called the "Yarkovsky effect." Without getting too deep into the science, Russian engineer Ivan Yarkovsky has theorized that the amount of sunlight that asteroids absorb subtly affect their orbits through the release of thermal energy—so if an asteroid were headed toward earth, there might be a way to deflect it without trying to, say, blow it up with a nuclear missile. (Lauretta doesn't advise that option: "Blowing up something the size of a mountain is not an easy task and the real analogy is: Would you rather be hit by a cannonball or a shotgun blast? Blowing it up doesn't change the mass or the orbit, really, it just changes the nature of the particles that are coming at you.")

BTW, there is a 1-in-1,420 chance that Bennu will collide with Earth sometime between the years 2169 to 2199. Lauretta says it's "way over the top" to say the collision would destroy the planet, but depending on where it hit, it would likely be a "major natural disaster."

"I like to say, you don't need to go out and buy asteroid insurance," Lauretta says. "There is no imminent danger. But we're going to contribute substantially to NASA's mission to catalogue the hazards of near-earth objects."

• The Regolith Explorer gets back to the asteroid dust, which is called "regolith" by science guys like Lauretta.

To get those jobs done, OSIRIS-REx is equipped with a range of instruments, including:

• The UA-designed OSIRIS-REx Camera Suite (or OCAM), a three-camera unit that will serve as the eyes of the mission. OCAM will send back images so the asteroid can be mapped and researchers can determine the best spot to gather a sample.

• The OSIRIS-REx Thermal Emission Spectrometer. Built by ASU, the OTES will use an infrared scanner to determine what minerals are on the surface of Bennu.

• The Sample Acquisition and Return Assembly (or SARA). SARA has both the Touch-and-Go Sample Acquisition Mechanism (TAGSAM) arm that will reach out to grab the sample of asteroid dust and the capsule that will rocket back to earth once OSIRIS-REx returns to Earth.

• The OSIRIS-REx Visible and Infrared Spectrometer (or OVIRS), from the Goddard Space Flight Center. The OVIRS will break down the light bouncing off Bennu into spectral components in order to study the chemistry of the asteroid to better determine an ideal spot to gather a sample.

• The Canadian Space Agency's OSIRIS-Rex Laser Altimeter (or OLA), which uses a laser to precisely measure distances and develop a topographical map of Bennu.

• The Regolith X-ray Imaging Spectrometer (or REXIS), which was developed by MIT and Harvard students to capture X-rays that can identify different elements on Bennu's surface.

The OSIRIS-REx design mashes up two previous NASA missions: The spacecraft itself is similar to the Mars Reconnaissance Orbiter and the Juno spacecraft, while the sample-return technology came from the 2006 Stardust mission, which used a similar capsule to collect dust from a comet.

As the instruments were completed by the various partners, they were assembled at Lockheed-Martin's Denver headquarters, where OSIRIS-REx underwent its "shake-and-bake" testing to ensure it could survive both liftoff and the long travel through the cold vacuum of space to Bennu.

Bennu is named for an Egyptian god, after a North Carolina third-grader suggested it as part of a global contest. The asteroid was picked for a variety of reasons, including the possibility that it could collide with Earth. But it's also your typical carbon-rich asteroid that's in the right orbit around the sun. Bennu has been the subject of a lot study, making it the "best understood asteroid not yet visited via spacecraft," according to Christina Richey, NASA's deputy program scientist for OSIRIS-REx.

"For primitive, carbon-rich asteroids like Bennu, materials are preserved from over four and a half billion years ago," says Richey. "We're talking about the start of the formation of our solar system. And these primitive materials could contain organic molecules that may be the precursors to life here on Earth or elsewhere in our solar system."

The OSIRIS-REx mission got official approval from NASA in 2011, but it had been in the works for much longer. Back in 2004, Lauretta got a call in 2004 from Michael Drake, who was then the head of the Lunar and Planetary Lab. Some guys from Lockheed Martin wanted to bring back an asteroid sample and Drake wanted to know if Lauretta wanted in.

"It really launched my career, so I owe him a great debt of gratitude," Lauretta says. "We worked together tirelessly for seven years to convince NASA that we were the team to fund, and to select our mission for flight. We won the contract from NASA in May 2011 and, unfortunately, Mike passed away in September of that year. So he was there when we won and celebrated with us and he was ecstatic."

OSIRIS-REx is the latest in a long line of space missions that the Lunar and Planetary Lab has played a key role in, including the 2008 Phoenix Mars Lander, which dropped a robotic lab on the Arctic plains of Mars, and the HiRISE Camera aboard the Mars Reconnaissance Orbiter, which has been sending back photos of the surface of Mars and other targets for more than a decade.

"OSIRIS-REx is the most ambitious program that the University of Arizona has ever taken leadership of," Lauretta said. "But it really is standing on the shoulders of giants. All of those great past accomplishments are what allowed us to take on the challenge like we have. The Lunar and Planetary Laboratory at the University of Arizona has been at the forefront of planetary exploration for more than 50 years. Our history goes all the way back to the dawn of the space age and NASA's awesome Apollo program."

OSIRIS-REx is picking up where the Phoenix mission left off. It's being run out of the same low-key building north of downtown that the UA purchased when it won the contract to manage the Phoenix Mars Lander mission, which dropped a robotic lab on the arctic plains of Mars in 2008, now named the Michael J. Drake building in honor of Lauretta's old mentor.

Lauretta says Drake is much missed as the launch preparations are underway at Florida's Kennedy Space Center in recent months.

"I can tell you that I'm missing him a lot these days," Lauretta says. "He would be having the time of his life down here in Florida and seeing all this activity taking place. All that we do and what we work for is in tribute to his memory and I know he'd be extremely proud of the team here."

Lauretta himself has "always been an explorer at heart. When I was a young kid, it was the deserts of Arizona and going off into the mountains on my own or with my buddies and trying to find the most amazing, beautiful, isolated places that I could get into. I've always had that desire to go someplace that nobody has ever been before."

While studying math and physics as a UA undergrad, Lauretta got "hooked on planetary science."

"I wasn't sure what direction I wanted my career to go and I got an undergraduate research space grant," he recalls. "I was assigned to the search for extraterrestrial intelligence. That's blew my mind. I was thinking about talking to aliens on other planets orbiting around other stars in other galaxies and I decided I really wanted to understand what was the likelihood that there actually is somebody else out there. And that led me to understanding the origins of our planet and how life formed here and ultimately to the study of meteorites and asteroids and looking at the kind of science we're doing with OSIRIS-REx."

After a dozen years on his asteroid chase, Lauretta is eager for next week's launch. But he knows it's just the first step toward getting a little bit of Bennu back here to Earth so scientists can learn a little bit more about what how our planet came together—and whether the Bennu will offer off clues as to the origin of life.

"To me, the mission is driven by the return of pristine organic molecules from the early solar system so I'm really hopeful that we can get some unique material that isn't in our meteorite collections," Lauretta said. "It really is a great adventure. We're going out into the unknown and bringing back scientific treasure. I'm looking forward to the day in 2023 when we open up that sample return capsule."

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