In this news, we discuss the Touch-and-go: US spacecraft sampling asteroid for return.
After nearly two years circling an ancient asteroid hundreds of millions of miles away, a NASA spacecraft will attempt this week to descend to the treacherous, boulder-filled surface and pull out a handful of rubble. The drama takes place on Tuesday as the United States makes its first attempt to collect asteroid samples for return to Earth, a feat so far accomplished only by Japan.
Bursting with names inspired by Egyptian mythology, the Osiris-Rex mission seeks to bring back at least 60 grams of asteroid Bennu, the largest otherworldly transport beyond the moon. The van-sized spaceship targets the relatively flat middle of a tennis-court-sized crater named Nightingale – a place comparable to a few parking spots here on Earth. Boulders as large as buildings loom above the target hit area.
“So, to have a little perspective, the next time you park your car in front of your house or a cafe and walk inside, think about the challenge of navigating Osiris-Rex in one of these places in 200 million kilometers, “said Mike Moreau, deputy director of the NASA project. Once it emerges from its half-mile high (0.75 kilometer high) orbit around Bennu, the spacecraft will deliberately take four hours to descend, just above the surface.
Then, the action accelerates as Osiris-Rex’s 3.4-meter arm reaches out and touches Bennu. The contact should last five to 10 seconds, just long enough to spray pressurized nitrogen gas and suck up churned dirt and gravel. Programmed in advance, the spacecraft will operate autonomously during the unprecedented tactile maneuver. With an 18-minute delay in radio communications each way, ground controllers at spacecraft manufacturer Lockheed Martin near Denver cannot intervene.
If the first attempt does not work, Osiris-Rex can try again. Samples collected will not reach Earth until 2023. Although NASA has returned comet dust and solar wind particles, it has never attempted to sample any of the nearly one million. Known asteroids hidden in our solar system so far.
Japan, meanwhile, expects to get samples from asteroid Ryugu in December – in milligrams at most – 10 years after bringing back spots from asteroid Itokawa. Bennu is a heaven for asteroid gatherers. The large, black, rounded, carbon-rich space rock – taller than New York’s Empire State Building – existed around the time our solar system was formed 4.5 billion years ago. Scientists see it as a time capsule full of immaculate building blocks that could help explain how life formed on Earth and possibly elsewhere.
“It’s about understanding our origins,” said lead scientist on the mission, Dante Lauretta of the University of Arizona. There are also selfish reasons to get to know Bennu better.
The solar orbiting asteroid, which oscillates around Earth every six years, could target us at the end of the next century. NASA puts the odds of an impact at 1 in 2,700. The more scientists know about potentially threatening asteroids like Bennu, the safer Earth will be.
When Osiris-Rex took off in 2016 on a mission worth over $ 800 million, scientists envisioned stretches of sand at Bennu. The spacecraft was therefore designed to ingest small pebbles less than an inch (2 centimeters) in diameter. Scientists were amazed to find massive rocks and coarse gravel everywhere when the spacecraft arrived in 2018. And pebbles were sometimes seen shooting the asteroid, falling back and sometimes ricocheting again in a cosmic game of ping-pong. pong.
With so much rugged terrain, engineers scrambled to aim for a spot that was narrower than originally intended. Nightingale Crater, the primary target, appears to have the greatest abundance of fine-grained, but rocks are still abundant, including the one dubbed Mount Doom. Then COVID-19 hit.
The team fell behind schedule and pushed back the second and final touch-and-go dress rehearsal for the spacecraft until August. This pushed the taking of samples until October. “It is difficult to return a sample,” said NASA chief science officer Thomas Zurbuchen. “COVID has made things even more difficult.” Osiris-Rex has three bottles of nitrogen gas, which means he can land three times – no more.
The spacecraft will automatically reverse if it encounters unexpected dangers such as large rocks that could tip it over. And there is a chance that it lands safely, but fails to collect enough rubble. Either way, the spacecraft would return to orbit around Bennu and try again in January at a different location.
With the first try finally here, Lauretta is worried, nervous, excited “and confident that we have done everything possible to ensure safe sampling.”
- The drama takes place on Tuesday as the United States makes its first attempt to collect asteroid samples for return to Earth, a feat so far accomplished only by Japan. Bursting with names inspired by Egyptian mythology, the Osiris-Rex mission seeks to bring back at least 60 grams of asteroid Bennu, the largest otherworldly transport beyond the moon.
- Touch-and-go: US spacecraft sampling asteroid for return