NASA’s OSIRIS-REx spacecraft simply gained one of the vital epic video games of tag in human historical past. Final month, the plucky little craft reached out and high-fived Bennu, a diamond-shaped asteroid roughly the dimensions of a skyscraper, snatching a pattern of its floor within the course of.
Orbiting the hunk of rock greater than 200 million miles from Earth, the spacecraft prolonged its robotic arm and blasted the asteroid’s floor with pure nitrogen gasoline. It then used a pattern assortment head to hoover up the disturbed materials.
However OSIRIS-Rex’s assortment head could have labored too properly. It snagged a lot rocky materials that it couldn’t shut its assortment flap securely. Treasured rocks leaked out into area, making a dilemma about how the spacecraft ought to go about storing its cargo.
“That is the mission that retains on shocking us,” mentioned Dante Lauretta, College of Arizona planetary scientist and principal investigator of the OSIRIS-REx mission throughout a information convention three days after the gathering. “We couldn’t have carried out a greater assortment experiment: It was profitable, we collected 100s of grams of samples, however the greatest concern is that particles are escaping.”
Pictures and video beamed again from the spacecraft confirmed that its assortment head contained a hefty stash of asteroid rubble, together with some pretty bigger items of rock. Lauretta mentioned these bulkier pebbles have been simply massive sufficient to forestall that flap from closing. This discovery pressured the mission crew to utterly change its plans. As a substitute of taking the time to measure how a lot pattern was collected, the crew needed to race to retailer the rocks earlier than an excessive amount of was misplaced to area—a meticulous course of that took a number of days to finish.
Scientists say the contact and go maneuver resulted not solely in a profitable pattern assortment but in addition offered new details about the layer of unfastened rocks which will cowl the surfaces of many small planetary our bodies, like asteroid Bennu. The fabric, beforehand regarded as akin to strong bedrock, is definitely extra like a playground ball pit.
The crew is anxious to get their fingers on the pattern, however gained’t know for certain precisely how a lot materials they’ve till the craft returns to Earth in three years. However scientists are very assured that they grabbed greater than the minimal mission requirement of 60 grams. Primarily based on photos beamed again, Lauretta and his crew suppose they’ve grabbed at the very least 400 grams of fabric.
Regardless of the uncertainty, OSIRIS-REx did one thing that no different NASA spacecraft has completed: attain out and contact the floor of an asteroid. This daring maneuver has been a long time within the making.
NASA scientists began planning the mission in 2004. 4 years in the past, OSIRIS-REx launched on its journey to Bennu. OSIRIS-REx, which is brief for Origins Spectral Interpretation Useful resource Identification Safety and Regolith Explorer, is designed to reply various basic questions together with “The place did we come from?” Asteroids are scientific treasure troves as a result of they include items of the earliest supplies that shaped our photo voltaic system. Moons and planets change over time, however most asteroids don’t, which makes them completely preserved galactic fossils. “They will present useful details about how planets, like our personal, got here to be,” mentioned Lori Glaze, NASA’s director of planetary science, in a information briefing.
Earth has an environment and energetic plate tectonics. Because of this, its oldest rocks are sometimes weathered or are pushed deep into the mantle. So, researchers usually use items of asteroids that land right here—referred to as meteorites—to study extra in regards to the composition of the photo voltaic system and historical Earth.
Asteroids can include carbon and different natural compounds, together with the constructing blocks of life, not discovered on meteorites. To essentially perceive how life on Earth began billions of years in the past, scientists say we have to go someplace the place no life exists but—like Bennu.
OSIRIS-REx arrived at Bennu in 2018 and started its orbit, spending almost two years extensively mapping the asteroid utilizing a laser altimeter, a tool that makes use of laser beams to measure the floor of planets and different rocky our bodies. Primarily based on preliminary information, Lauretta and his crew anticipated to see a sandy floor, however have been shocked to seek out Bennu was coated in boulders. This offered a problem, because the crew initially deliberate to land the craft on the asteroid and accumulate samples. Since Bennu is basically a floating cosmic rubble pile, the crew determined to forego a touchdown, and as a substitute selected an method utilizing that robotic arm.
Regolith, the grime and rubble discovered on an asteroid, is rather like the grime discovered on Earth, however in outer area, conventional technique of scooping and digging it up gained’t work due to the shortage of gravity. Engineers at Lockheed Martin in Colorado, the place the spacecraft was constructed, wanted to determine how you can accumulate the pattern. Jim Harris, a Lockheed engineer, helped give you the concept of vacuuming up regolith. Utilizing a solo cup and an air compressor in his driveway, he examined out a really rudimentary prototype.
Initially dubbed Muucav (vacuum spelled backwards), a refined model of Harris’ contraption was constructed and referred to as the Contact And Go Pattern Acquisition Mechanism, aka TAGSAM. The system consists of that robotic arm and a vacuum that appears like an enormous, spherical showerhead. However as a substitute of water taking pictures out, the top blasts Bennu’s floor with gasoline, sucks up materials and shops it. TAGSAM, which was loaded with three containers of gasoline, had three probabilities to gather a minimal of 60 grams (2 oz) of asteroid. The gathering capsule far exceeded that on the primary strive, which the scientists deducted once they noticed the gathering head couldn’t shut.
Initially, the crew had deliberate to measure how a lot rock was within the pattern head by commanding the spacecraft to spin round in place with its robotic arm prolonged. The extra collected materials, the extra pressure it will take to hurry up OSIRIS-REx’s rotation, permitting researchers to estimate the quantity of pattern to inside just a few grams. Because the flap couldn’t shut, the crew wished to attenuate the quantity of pattern misplaced to area, so that they selected to skip the measurement step and concentrate on stowing the pattern head as quickly as potential.
The crew very rigorously moved the pattern head—open flap and all—to a storage container and gingerly positioned it inside. Two locking mechanisms secured it. The arm then gently tugged on the top to ensure it was set.
OSIRIS-REx will keep in orbit round Bennu till March, when it is going to depart the asteroid. The return journey to Earth will take roughly two-and-a-half years. At that time, the pattern assortment canister will separate from the spacecraft and parachute down, touchdown within the Utah desert in September 2023. It could possibly be carrying the most important extraterrestrial pattern because the Apollo period.
Researchers around the globe are already prepping their labs to check this materials. One cause Bennu was chosen as a goal is as a result of scientists consider it’s a fraction of what was as soon as a a lot bigger area rock. As a physique that broke off throughout a collision between two asteroids early in our photo voltaic system’s historical past, the 4.5 billion-year-old rubble pile is a wonderfully preserved cosmic time capsule.
In a sequence of papers revealed within the journal Science on October 8, Lauretta and a crew of researchers found that Bennu contained a cosmic prize: thick veins of natural minerals referred to as carbonates, which type in hydrothermal methods. The collected samples may assist scientists higher perceive the function asteroids performed in bringing water and prebiotic materials to Earth, offering the constructing blocks for all times.
Jamie Elsila, a analysis scientist at NASA Goddard House Flight Heart, is particularly focused on amino acids—which type proteins—that advanced inside Bennu’s grime. Life on Earth makes use of 20 amino acids, however many extra have been recognized inside meteorite samples which have fallen to the bottom. These samples may have been affected by their journey by way of the environment. Bennu’s samples are pristine, which implies they may assist scientists pinpoint which amino acids have been current within the early photo voltaic system—and deduct how they might have influenced life on Earth.
Finding out bits of Bennu may even have broader implications for all times all through the universe. “If this type of chemistry is occurring within the early photo voltaic system, it in all probability occurred in different photo voltaic methods as properly,” Lauretta says. “It may assist us assess the probability of life all through the galaxy and, finally, the universe.”