CAPE CANAVERAL — What began as a concept scribbled on a cocktail napkin in a Tucson bar 12 years ago — sending a spacecraft to an asteroid and retrieving a pristine sample to bring back to Earth for study — becomes reality Thursday with the launch of NASA’s OSIRIS-REx mission.
At the Arizona Inn, three men having drinks one night in 2004 first dreamed of proposing an asteroid sample return to NASA, the first U.S.-led mission of its kind ever attempted, in the search to find the origin of life.
“We seek samples that date back to the very dawn of our solar system, and we want to get those samples back to our laboratories to understand the processes that may have led to life and to the habitability of our planet,” said Dante Lauretta, a University of Arizona professor and one of the mission’s three founders from that fateful evening.
“OSIRIS-REx is bringing back samples (from) the likely candidates that delivered these key prebiotic compounds to our Earth, and (will) help us understand why we are here, how we are here and how likely this process of origin and evolution of life occurred elsewhere in the solar system and even throughout the galaxy.”
After writing a formal proposal for a mission called OSIRIS, the team submitted it during NASA’s calls for new Discovery-class mission projects a decade ago. They didn’t get picked.
Giving it another shot in a subsequent round ended with the same disappointing result.
The guys’ growing team then tried again under NASA’s New Frontiers program. It would offer twice the budget to pull off the daunting sample return voyage.
“When we moved up to New Frontiers, Bill Cutlip in the back of the room was our proposal manager — now the (launch segment) manager on the spacecraft side — sent an email that said ‘OSIRIS-REx: An adventure in New Frontiers,’” recalls Lauretta.
“We all saw that and we laughed, and though that was pretty funny, then thought that actually sounds pretty cool. It kind of sounds like a dinosaur, and we all know how the dinosaurs’ days ended. Since we’re an asteroid mission, it just stuck. That’s where OSIRIS-REx came from.”
On December 29, 2009, OSIRIS-REx was one of three proposals selected by NASA for more study under its New Frontiers program. Then, on May 25, 2011, the mission was picked to fly, beating out a probe to land on Venus and a sample return mission to the Moon’s south pole.
The Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer, or OSIRIS-REx, was go.
OSIRIS-REx became the third New Frontiers mission, following New Horizons spacecraft that successfully flew by Pluto last year and Juno that entered orbit around Jupiter on July 4.
The target: Asteroid Bennu, a dark, unexplored, carbon-rich world 1,600 feet across that orbits near Earth and grazes past at lunar distance every 6 years.
“I started my career in meteorite science,” said Lauretta, but added that studying space rocks that fall to Earth is often a frustrating profession. Osiris-Res will change that.
“Meteorites are uncontrolled samples — we don’t know where the came from, they have to pass through Earth’s atmosphere, they experience alteration as a result of that very energetic and dynamic process,” he said.
“Our science objectives are about ultra-trace organic compounds and really understanding the role these might have played in the origin of life. I compare it to a forensic investigation. With OSIRIS-REx, we will have control of the evidence from the time it was on the surface of the asteroid until it gets into our laboratories.”
Just four months after the mission was selected, however, the leader of OSIRIS-REx died following a battle with cancer and receiving a liver transplant.
“Dr. Michael Drake, who was the director of the Lunar and Planetary Laboratory. He invited me to be the deputy principal investigator back in 2004, and he and I worked side-by-side for seven years to win the program. He passed away in September 2011, four months after we won the contract, and I had to step up into a leadership role,” said Lauretta, who ascended to the title of principal investigator of the OSIRIS-REx mission.
“It was not a role I was expected that early in career, so I really poured my heart and soul into being the leader of this team, keeping positive attitude, reminding everybody of their critical roles no matter what it was and making this mission a success.”
The spacecraft has a microchip, which is carrying messages to Asteroid Bennu, with Drake’s likeness on it and a plaque that reads:
“We are humbled to follow in the footsteps of Dr. Michael Drake, who inspired and led us to develop OSIRIS-REx. This mission will help us understand ‘where did we come from?’ and ‘where are we going?’ We are proud to carry on his legacy as we embark on our journey to Bennu and return with samples of the early solar system. We will keep Mike’s words of wisdom close in our hearts. ‘The team must remain united as we face the challenges and discoveries that Bennu has to offer.’ KISS!”
“When Mike and I decided we were going to lead this program, we committed to being a model development for NASA. I feel like we have delivered on that,” Lauretta said.
“We are coming in substantially under-budget, on time, with no issues, clean spacecraft, fully capable with everything we expected to have on this. The pride, the honor, the remembering of Mike, it’s all kind of coming together in a huge swirl of emotion.”
In April 2014, NASA completed a review of the OSIRIS-REx design and gave approval to start building the spacecraft at Lockheed Martin in Denver.
That solidified the satellite blueprints that began with a contest a decade ago among engineers to develop the best method to retrieve a sample of surface material off an asteroid.
The winning concept was first demonstrated in the engineer’s driveway with a plastic disposable cup and an air compressor to form a reverse vacuum.
The Touch-and-Go Sample Acquisition Mechanism, or TAGSAM, was born.
“Over the past 10 years, it’s come a long way from a Solo cup in the driveway to what you see now,” said Rich Kuhns, OSIRIS-REx program manager at Lockheed Martin Space Systems.
Jim Harris, a mechanical engineer at Lockheed Martin, is created for inventing the device OSIRIS-REx will use in the extreme microgravity environment on Bennu.
“Imagine a cup with air injected on one side, then holes on the other side and a filter outside of the holes,” Harris said. “We used a compressor to blow air against the ground. As the air went out through the holes and through the filter, we collected particles.”
Alternative ideas such as landing the spacecraft on the asteroid or using a scoop to excavate a sample were deemed too risky to try on Bennu.
“The problem is that you have all of this loose material on a surface with very low gravity,” Harris said. “You can’t think of it as gravel in a driveway. As soon as you touch it, the particles may scatter.”
The 11-foot-long articulated arm will reach the asteroid with a 12-inch-diameter disk-shaped sampler head that gives Bennu a quick high-five, firing a jet of nitrogen gas to stir up loosen regolith that is captured in the collection chamber.
“I watched the TAGSAM development from those early days where it was a Solo cup and an air compressor to the phenomenal flight unit we have today,” Lauretta said.
The arm also doubles as a pogo stick, helping to push OSIRIS-REx away from the asteroid after the sample retrieval.
“The purpose of the pogo is to keep us in contact with the asteroid for the three-to-five seconds it takes to give the asteroid a gentle high-five. We then release the gas, which is actually how we collect the material from the asteroid,” Kuhns said.
“We’ve tested the technology over a wide-range of different materials — lightweight materials, dense materials, difference sizes of materials — to understand how wide of a range of material we’ll be able to collect. Throughout that testing, we’ve collected significantly more than we intend to collect, with an average of over 300 grams as opposed to our target of 60 grams.”
The spacecraft will obtain at least 2.1 ounces (60 grams) and as much as 4 4 pounds (2 kilograms) of the asteroid.
“Sixty grams, I’ve never seen a test that low,” Lauretta said of Earth-based testing. “They actually designed it to pick up 150 grams to give us a lot of margin, and routinely picking up several hundred grams. So five to six times the amount of material that scientists require to get our mission objective.”
After retreating to a safe distance, the spacecraft will perform a spin maneuver to measure the mass of material added to OSIRIS-REx. The craft has enough nitrogen for up to three sample attempts, if needed.
“Once we confirm we have enough material, we are able to stow it in the Sample Return Capsule and place ourselves on a trajectory back to Earth,” Kuhns said.
OSIRIS-REx is scheduled to approach at Bennu in August 2018. It will appear first as just a single pixel in camera images taken more than a million miles away before the robotic visitor comes face-to-face with the mountain-sized space rock. By October, a detailed mapping campaign commences with its cameras, laser and spectrometer instrument suite, beginning 5,000 feet above the asteroid’s surface before dropping down to 3,300 feet.
“We are going to be identifying key organic molecules on the surface of the asteroid to guide our sample-site selection,” said Lauretta.
After selecting the scientifically-best site to sample, the probe will grab the specimen in July 2020. Departure in March 2021 begins the trip back to Earth.
“We can’t leave Bennu before March of 2021, just because we’ve got to wait for the orbital mechanics to line up. So that’s over two-and-a-half years of operations at the asteroid,” Lauretta said.
“We’re going to be formation flying with the asteroid, so we only touch the asteroid for that brief, five-second sampling contact. We are going to do everything we can to make sure we get the sample on the first attempt.”
Landing of the parachute-equipped sample container at the Utah Test and Training Range is planned for Sept. 24, 2023, a Sunday morning, around 9 a.m. Mountain Time.
The samples, the largest cache of extra-terrestrial materials returned to Earth since the Apollo moonrocks, will be taken to the Johnson Space Center in Houston for curation.
More recently, NASA’s Genesis spacecraft returned atoms of the solar wind in 2004 and Stardust landed with particles captured from Comet Wild 2 in 2006. Japan’s first Hayabusa sample return mission visited Asteroid Itokawa and returned microscopic grains and particles in 2010. A second Hayabusa is currently en route to Asteroid Ryugu and will return in 2020 with a gram of sample material.
About 20 percent of the returned Bennu specimen will be studied by the OSIREX-REx team, while four percent is given to Canada for providing the mission’s laser altimeter. A half-percent goes to Japan under cooperative agreement with that country’s Hayabusa asteroid missions.
And three-quarters of the sample will be set aside for future study by instruments not yet invented.
“Sample return is the gift that keeps on giving. We are going to analyze it for our science and we are going to have future generations looking at these materials for decades,” said Lauretta.
“We are going after compounds that are literally at the parts-per-billion level in these materials. We have to get these samples into our laboratories so that we can bring cutting-edge analytical techniques, the kinds of things you just can’t fly on a spacecraft — because they weigh too much or require too much power or require a very careful lab technician to make the analysis possible.”
Two years of post-flight science investigations into the samples will count as part of the $800 million OSIRIS-REx project before its official end-of-mission on Sept. 30, 2025.
For Lauretta, that will be 21 years after the cocktail napkin in a Tuscon bar.
“2025, in September, it’ll be lights out, we’re done with the program, the science papers have been published. That’s 21 years of my career. I was 33 years old when I got involved in the program and I’ll be 54 when it’s over. So it’s pretty much my professional life! said Lauretta.
“It’s been a long journey. We spent the first seven years writing the proposals. I lost a dear friend in 2011. That chokes me up when I think about Mike, and how much fun he would be having right now.”
A United Launch Alliance Atlas 5 rocket will boost OSIRIS-REx on its expedition this Thursday. Liftoff is planned for 7:05 p.m. EDT (2305 GMT) from Cape Canaveral.
Given the time-critical nature of the launch, the Air Force-controlled Eastern Range has reserved three consecutive days for OSIRIS-REx instead of the usual two days before negotiating for more, if needed. This year’s planetary alignment window extends only to Oct. 12, and missing this period would delay the launch for a year until the next window opens.
Sept. 8: 7:05 p.m. EDT (2305 GMT)
Sept. 9: 7:10 p.m. EDT (2310 GMT)
*Sept. 10: 7:05 p.m. EDT (2305 GMT)
Liftoff will be available at each five-minute interval during daily windows that vary between 115 and 120 minutes in length per day, giving 24 or 25 launch opportunities every evening to put OSIRIS-REx on the proper interplanetary trajectory. Officials picked five-minute blocks to simplify the number of targeting cases to devise and analyze.
The flight will use a strange-looking rocket — the Atlas 5’s 411 variant — with only one strap-on solid-fuel booster to give just the right amount of liftoff power. The configuration has successfully flown three times before.
It will take nearly an hour for the launch sequence to be performed, accelerating OSIRIS-REx and then releasing the 4,650-pound craft on the proper flight path.
“We’ve got an incredibly capable vehicle,” Lauretta said. “I just want to see this thing get out on the road. It’s like buying a brand new car. The first thing you want to do is get out on the highway and see what it’s got. We’re really looking forward to trying it out.”
See earlier OSIRIS-REx coverage.
Our Atlas archive.
from Spaceflight Now ift.tt/2c75ecG