NASA Probe to Drop Off Asteroid Samples After 7 Years in Deep Space

Sharon Adarlo
Tue, September 19, 2023 


Pay Dirt

After a monumental journey through outer space that took years and countless miles, NASA's OSIRIS-REx spacecraft is scheduled to release a "mini-fridge size capsule" over the Utah desert this week, according to the space agency.

The capsule contains truly precious cargo, about 8.8 ounces of rock and dust from asteroid Bennu tens of millions of miles away.

If carried off successfully, it could mark the first time NASA has nipped a sample of asteroid and taken it back to Earth in an extraordinary delivery. First-time honors in bringing an asteroid sample back to Earth belong to the Japanese spacecraft Hayabusa, which had taken minute samples of the asteroid Itokawa back in 2010.

Many scientists are eager to study this asteroid sample from Bennu because they believe it contains materials that date back to the earliest days of the solar system, according to OSIRIS-REx deputy project manager Michael Moreau. It could also contain organic molecules that scientists think hitched rides on meteorites that slammed into Earth and helped seed life on our planet.

Touch and Go

OSIRIS-REx first embarked on its mission on September 8, 2016, and arrived two years later at Bennu, an asteroid that has a diameter of around 1,614 feet and orbits the Sun every six Earth years.

The asteroid is interesting because it's extraordinarily old, with material dating back to at least 4.5 billion years. Bennu is also relatively close to Earth compared to the solar system's many asteroids, which primarily reside in the asteroid belt between Mars and Jupiter, making it a tantalizing object of study.

When OSIRIS-REx first arrived at Bennu, it orbited the asteroid for two years, and then in 2020, it made a bold maneuver — a "Touch-And-Go" move — that saw the spacecraft land on the asteroid briefly, collect samples, and then used its on-board thrusters to launch itself off of the rock.

In 2021, after a last flyby around the asteroid, OSIRIS-REx finally started journeying back to Earth.

Even after it releases its return capsule over Earth in less than a week, NASA says OSIRIS-REx's job is not quite complete. When it makes its payload delivery, the spacecraft will not stop to land on our planet but will instead veer its path towards the asteroid Apophis, where it is scheduled to arrive in 2029.

More on OSIRIS-REx: Watch Nasa's Spacecraft Touch Down On A Tiny Asteroid

How asteroid Bennu caught NASA's OSIRIS-REx spacecraft by surprise and nearly killed it along the way

Tereza Pultarova
Mon, September 18, 2023

 
A mass of gravel and dirt ejected from the surface of asteroid Bennu by the touchdown of NASA's OSIRIS-REx probe.


When the OSIRIS-REx probe arrived at asteroid Bennu, it found a body that looked and behaved quite differently from what scientists had expected.

When NASA started planning its first mission to snatch an asteroid sample, the space rock science community was abuzz with excitement over another asteroid mission — Japan's Hayabusa. In 2010, for the first time in history, that mission triumphantly delivered to Earth a fragment of an asteroid, a space rock called Itokawa. A few years earlier, Hayabusa, had mapped the whole of Itokawa, revealing a landscape strewn with boulders but also featuring smooth beach-like plains, or ponds, of gravel and sand.

It was these images of Itokawa that guided the design of NASA's OSIRIS-REx mission. But as it turned out, despite some superficial resemblance, the asteroid that OSIRIS-REx was to head for turned out to be completely different.

Related: Queen legend Brian May helped NASA ace its asteroid-sampling mission, new book reveals

"The strategy for planning with OSIRIS-REx was to take Itokawa and all of the observations of asteroid Bennu that we had made of it before," Kevin Walsh, a planetary scientist at Southwest Research Institute and lead scientist of the Regolith Development Working Group of the OSIRIS-REx mission, told Space.com. "So we would look at the different way [the two asteroids] reflect light and the different way they reflected radar, and every indication was that Bennu would have more ponds of fine grains than Itokawa."

It wasn't until OSIRIS-REx arrived at asteroid Bennu, two years after its 2016 launch from Kennedy Space Center at Cape Canaveral, Florida that the mission team discovered that their assumptions were "totally wrong," said Walsh. Instead of wide plains of sand and gravel interspersed with accumulations of boulders, the spacecraft's cameras revealed a "bouldery hellscape" that had none of the smooth open areas on which they envisioned OSIRIS-REx to touch down and collect its sample.

The mission's chief scientist Dante Lauretta told Space.com in an earlier interview that the team had concerns the sample collection might not be possible at all.

"When we designed the spacecraft, we had a design targeting accuracy [for the landing] of about 50 meters [164 feet]," Lauretta said. "The thermal properties, also the radar properties [of Bennu], really looked like a smooth surface. So when I first saw that [the surface was completely different], I really thought we might be in trouble there."

A stereoscopic image of a rocky outcrop on the surface of asteroid Bennu.

As the team grappled with the question whether their precious spacecraft could possibly safely touch down amid the towering boulders that rose against Bennu's feeble gravity into heights unseen on Earth, they received support from an unexpected source. Legendary guitarist of the rock band Queen and well-known astronomy aficionado Sir Brian May reached out to Lauretta to express his interest in the mission. May, who holds a PhD in astronomy, which he famously completed after a 30-year hiatus enforced by Queen's rise to fame in the 1970s, is also known for his interest in stereoscopic imaging. It was this skill he offered to the OSIRIS-REx team, which was at that time struggling to find a boulder-free-enough area to land the spacecraft on.

Stereoscopic imaging replicates the ability of human eyes to perceive surrounding space in three dimensions. Dedicated stereo cameras help Martian rovers navigate their exploration site. But the OSIRIS-REx spacecraft wasn't fitted with a stereo camera. May, however, knew his way around this issue by selecting images of various spots on Bennu taken from different angles and processing them for 3D viewing.

"Once you have a stereo image of that particular potential landing site, you can really make that instinctive judgment as to whether things are going to work out," May told Space.com in an earlier interview. "You see that there is this boulder, how much slope there is, how dangerous it is to get on and to get off."

With May's help, the OSIRIS-REx team eventually identified a sufficiently obstacle-free crater to attempt the sample collection. Still, the team had to remotely reprogram the spacecraft to accomplish the feat. Instead of the originally envisioned 164-foot-wide (50 m) landing side, the van-sized spacecraft had to squeeze into the merely 33-foot-wide (10 m) Nightingale Crater.


Asteroid Bennu turned out to be completely different from what scientists had expected.

"When we launched, we planned to use a laser altimeter for the guidance down to the asteroid because we were expecting these big smooth areas," Lauretta said. "We just thought that we would need to know that we were coming down at the right rate towards the surface. Instead, we had to completely change the strategy, using the onboard cameras and performing an extensive mapping campaign, sometimes mapping features as small as a couple of centimeters to put into the spacecraft's memory so that it could make real decisions and guide itself down to the safe location."

The descent was smooth. But when OSIRIS-REx's sample collection device pressed into the asteroid's surface, something unexpected happened. Contrary to expectations, the surface behaved almost like a swamp. Within a few seconds, the spacecraft sank 19 inches (50 cm) deep into Bennu. As the sample collection head sucked in the sample and the spacecraft's backaway thrusters fired, a huge wall of debris rose from the crater, engulfing the ascending spacecraft.

The OSIRIS-REx team only learned about what happened when images from on-board cameras reached Earth. The researchers later admitted that the stirred-up gravel could have damaged the retreating spacecraft.

Walsh described the touchdown as "scientifically interesting, although operationally challenging." Just like the team misjudged Bennu's surface, it turned out that they also misjudged its density. The surface layer was unexpectedly fluffy, behaving more like water than solid material, something the analysis of measurements from Bennu's orbit didn't indicate.

Related stories:

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— Farewell, Bennu! NASA spacecraft leaves asteroid to bring pieces of space rock to Earth

"When we did our calculations, initially we were taking the density of all of Bennu, which is 1.1 grams per cubic centimeter," said Walsh. "But our models showed afterwards that to be able to compress the surface so much and drive the tag head so deep into the surface, the surface density would have to be like 0.4 grams per cubic centimeter. And so it was less than half as dense as the entire body."

Scientists still don't know why Bennu's surface has this waterlike quality. Walsh thinks that smaller sand-like particles may have filtered through the gaps between the bigger rock fragments into the asteroid's interior, leaving a lot of empty space in the asteroid surface layer. That would explain the unexpectedly low density of the surface, but also the overall density of the asteroid that appears to be much higher than that of the surface.

Despite the challenges, OSIRIS-REx collected much more of the asteroid material than the mission aimed for, and the spacecraft will drop off this cargo at Earth on Sunday, Sept. 24. Lauretta hopes to release the first scientific results from the sample analysis by the end of this year. And chances are that Bennu will surprise researchers again.

OSIRIS-REx: Purdue scientist will be one of the first to examine asteroid material

Noe Padilla, Lafayette Journal & Courier
Tue, September 19, 2023 

WEST LAFAYETTE, Ind. — After more than a decade of work, NASA’s OSIRIS-REx asteroid-study project is scheduled to return to Earth on Sept. 24 landing in the Utah desert with pieces of the asteroid Bennu.

Once it lands, the spacecraft’s sample return capsule will be sent off to a clean lab at NASA’s Johnson Space Center in Houston, and while there, Michelle Thompson, an associate professor of earth, atmospheric, and planetary sciences at Purdue’s College of Science, will be one of the first six lead investigators from the science team to study the samples.

More: Purdue's 'Cradle of Astronauts': Now 28 Boilermakers who have traveled into space

“This is a truly once-in-a-lifetime — maybe a once-in-several-lifetime — experience,” Thompson said in a press release.

“OSIRIS-REx was selected in 2011, the year I started my PhD, and launched in 2016, the year I got my PhD. It reached Bennu in 2018, the year I came to Purdue. And now I am going to be one of the first humans to get to study it. Bennu is a treasure trove of information; this is literally the project of my career.”

Prior to NASA’s OSIRIS-REx’s return, there were two other missions with the goal of retrieving asteroid samples for scientists to study back on Earth, Hayabusa and Hayabusa2, which were both launched by the Japan Aerospace Exploration Agency.

Michelle Thompson, planetary scientist and expert in space weathering, will be one of the first six humans — and the first woman — to analyze samples of asteroid Bennu brought to Earth by OSIRIS-REx.

 (Purdue University photo/Rebecca Robiños)

Both missions returned with small amounts of samples, the first mission returned with less than a milligram of material, while the second one returned with 5.4 grams of material.

The OSIRIS-REx mission obtained potential return with more than 100 grams of material according to camera observations from Bennu, a carbonaceous asteroid that passes within 186,000 miles of Earth, closer than the moon.

After its arrival, Thompson and five other scientists will have 72 hours to analyze and evaluate the samplers to determine the initial characteristics of the asteroid materials.

Thompson's research focuses on the process called space weather or in other words, she analyzes the alteration of planetary materials after their formation, specifically the evolution of airless body surfaces.

She’s previously studied samples of moondust brought to Earth by the Apollo missions and spent months at Johnson Space Center preparing for the asteroid samples’ arrival.

By understanding the material's surface — the very top few millimeters of rock and dust, called regolith — Thompson hopes it will shed light on the composition of asteroids and how their properties change and reflect their makeup.

OSIRIS-REx’s name stands for Origins, Spectral Interpretation, Resource Identification and Security — Regolith Explorer, which encapsulates the program’s goal. Scientists are hoping that the results of the mission and study will help give the scientific community insight into the origin of the planets and the earliest history of the solar system.

“Observing asteroids from spacecraft and telescopes is incredibly important, but nothing can replace analyzing samples in the laboratory,” Thompson said.

“Sample return missions are a cornerstone of planetary science, and this close-up look at Bennu material will give us details we couldn’t see from orbit and help us understand how to interpret what we’re seeing on other faraway asteroids. It makes our understanding more comprehensive, more three-dimensional.”

Beyond the notion of studying the asteroid’s material for the sake of science, by coming to understand what asteroids are made of, it could help future humans and explorers to discover if asteroids could contain materials to mine for future vehicles, missions and habitats.

Scientists are also hoping to gain a deeper understanding of asteroids’ physical chemistry and how their orbit is changing with time, particularly of asteroids like Bennu that come close to Earth.

“Asteroids are relics of the early solar system,” Thompson said. “They’re like time capsules. We can use them to examine the origin of our solar system and to open a window to the origin of life on Earth.”

Although scientists have examined materials from asteroids that have entered Earth’s atmosphere before, the material collected from this mission will be unlike anything those scientists have seen before.

Due to the friction from the atmosphere, asteroids that don’t burn up and are able to make it to the Earth’s surface no longer resemble the material floating in space.

By escorting the material in an insulated still-pristine condition, scientists will get to look at the asteroid as it was in its original environment, lending understanding to a wide range of planetary science.

“These samples have been on their way back to us for a couple of years,” Thompson said.

“We have had years to prepare for what we might find and how we might study the sample.

“Looking at the organic molecules from Bennu, we’re going to get an understanding of what kinds of molecules could have seeded life on early Earth.

“Information about what compounds, what elements are there, and in what proportions. We won’t find life itself, but we’re definitely looking at the building blocks that could have eventually evolved into life.”

This article originally appeared on Lafayette Journal & Courier: Purdue scientist will be one of the first to examine asteroid material


What if NASA's OSIRIS-REx asteroid-sample capsule crashes to Earth this weekend?

Elizabeth Howell
Tue, September 19, 2023 

A sample space capsule parachuting to Earth in a test.

After seven years flying through space, a spacecraft capsule carrying a precious asteroid sample will touch down on Earth under parachutes this weekend. But what if it crashes?

A crash of NASA's OSIRIS-REx descent capsule on Sept. 24 is "the stuff of my nightmares," the mission's principal investigator, Dante Lauretta of the University of Arizona, said recently. (OSIRIS-REx stands for "Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer.")

"If that parachute doesn't open and we're in the 'hard landing' contingency, fortunately we have a backup team member who will help me with the emotional state and also, probably be the one I send out there to go deal with it," Lauretta said of the asteroid mission during a livestreamed press conference on NASA Television on Aug. 30. "We've got a great plan."

OSIRIS-REx made the first-ever visit to the near-Earth asteroid Bennu in 2020. In October of that year, the probe swooped down to snag samples in a touch-and go maneuver that almost saw the spacecraft swallowed up by the surprisingly spongy asteroid.

Related: Asteroid Bennu nearly swallowed up NASA's sampling spacecraft

OSIRIS-REx survived that sampling run and is now in the home stretch of its asteroid-delivery effort. If all goes to plan, the return capsule will touch down gently on Sunday morning under parachutes in the Utah desert.

But sometimes things don't go to plan. So the recovery team has been practicing for numerous other scenarios, to preserve as much of the sample as possible in the event of a landing anomaly. The OSIRIS-REx team wants to get as much scientific return as possible from the $1 billion mission no matter what happens on Sunday.

Lauretta said that, if a crash occurs, the team will take the sample into a clean room, which he called "a safe environment," to reduce contamination as much as possible. Contingency supplies will also be available on site if the recovery team needs them, he said.

"We practice beforehand to optimize accuracy and minimize the chances of mistakes during the capsule's Earth arrival," Sandra Freund, OSIRIS-REx program manager at the aerospace company Lockheed Martin, added in an Aug. 17 NASA blog post. "By simulating different scenarios, our team can anticipate challenges and work through contingency plans to effectively address them."

The recovery practice has been ongoing for years, and culminated with a series of simulations in Utah in the zone where the spacecraft should touch down. In April, a practice capsule was placed in the field in different positions to allow the team to practice retrieving it. Then the team ramped up the effort by using a truck in July, and then a helicopter in September, to simulate dropping off the capsule at higher and higher speeds.

The recovery professionals were then timed to see how quickly they could take out the sample and bring it back to a local lab in the first of a long series of processing steps. "The faster the better," Richard Witherspoon, OSIRIS-REx ground recovery lead at Lockheed Martin, wrote in another NASA blog post in May.

There have only been a few other spacecraft that have brought asteroid samples back to Earth, and each one of these missions gives us a little more information about how the early solar system was formed. NASA is taking lessons learned from its other missions that sent space samples to Earth, sometimes not entirely successfully.

Related: Dramatic sampling shows asteroid Bennu is nothing like scientists expected

side-by-side images showing a spacecraft's robotic arm about to contact a gravelly asteroid (left) and stirring up lots of dirt and rock after contact (right).

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Famously, the agency's Genesis capsule crashed in 2004 due to four switches being installed backward in its re-entry system. Fortunately, however, the ions (charged particles) of the solar wind that it snagged were still lodged deep within the capsule, underneath the damaged collector surfaces. Scientists were able to use the sample to reveal several insights about planetary formation — for example, the Genesis sample suggested that Earth lost some of its atmosphere early in its history, according to NASA.

Two years later, the Stardust spacecraft had more success landing in the Utah desert. Investigations of the samples it picked up from Comet Wild-2 in 2004 continue to yield intriguing insights. For instance: Aside from numerous comet bits, probable interstellar particle tracks were detected by a team led by principal investigator Don Brownlee, of the University of Washington.

Other robotic sample return missions over the decades include several Soviet Luna spacecraft that visited the moon, the Chinese Chang'e-5 lunar sample return mission, and the Hayabusa and Hayabusa2 missions from the Japan Aerospace Exploration Agency. As always, NASA reviews the available documentation from such missions to form procedures and inform its own planning.

In whatever shape the descent capsule arrives, investigators on Earth will be kept busy for years — indeed, decades — with the samples returned by OSIRIS-REx. Meanwhile, the original spacecraft will go on to a new mission. Its next task will be to examine another near-Earth asteroid, Apophis, in 2029 under an extended mission known as OSIRIS-APEX.

Nasa ‘in final leg’ of mission to halt asteroid armageddon

Sarah Knapton
Sat, September 16, 2023

An Atlas V rocket carrying the OSIRIS-REx spacecraft lifts off from Cape Canaveral in 2016 on seven-year journey - the first US mission to sample an asteroid - Nasa

On 24 September 2182, there is a chance that an asteroid named Bennu will hit Earth with the force of 22 atom bombs.

The Empire State Building-sized space rock swings close to our planet every six years but will have its closest shave 159 years from now.

Although the odds of a catastrophic strike are 1 in 2,700, Nasa was concerned enough to launch a spacecraft to Bennu seven years ago to collect samples, in case an Armageddon-style deflection mission is required.

Asteroid samples from the OSIRIS-REx mission will finally reach Earth next week, touching down in the Utah desert on Sept 24 - the same date as the future apocalypse Nasa is seeking to avert.

“We are now in the final leg of this seven-year journey, and it feels very much like the last few miles of a marathon, with a confluence of emotions like pride and joy coexisting with a determined focus to complete the race well,” said Rich Burns, project manager for OSIRIS-REx at Nasa’s Goddard Space Flight Center in Greenbelt, Maryland.

Bennu is about a third of a mile wide, so it is not big enough to cause a planet-wide extinction. For comparison, the asteroid which wiped out the dinosaurs was six miles wide.

However, Nasa estimates that it could cause a six-mile wide crater and wreak devastation over a 600-mile radius.

Overall there is a 1-in-1,750 chance that Bennu could collide with Earth between now and 2300.

This artist’s conception shows the OSIRIS-REx spacecraft extending its sampling arm as it moves in to make contact with the asteroid Bennu - This artist’s conception shows the OSIRIS-REx spacecraft extending its sampling arm as it moves in to make contact with the asteroid Bennu. 

Credits: NASA/GSFC

The space agency is taking the threat from space rocks seriously and last year carried out its first asteroid deflection test, showing it could alter the orbit of the small moonlet Dimorphos.

The samples, which are contained in a fridge-sized capsule, will be fired to Earth from the OSIRIS-REx spacecraft once it reaches a distance of 63,000 miles from the planet.

On board are an estimated 8.8 ounces, or 250 grams, of rocky material collected from the surface of Bennu in 2020. Although the Japanese Hayabusa mission has brought samples back from an asteroid before, it is Nasa’s first asteroid sample and the largest amount ever collected in space.

The capsule will enter Earth’s atmosphere at around 3.42 pm BST on September 24, traveling at nearly 28,000 mph, and reaching temperatures twice as hot as lava.

Parachutes will then deploy to slow the capsule down to 11 mph so it can land safely at the Department of Defense’s Utah Test and Training Range southwest of Salt Lake City.

Recovery teams participate in field rehearsals in preparation for the retrieval of the sample return capsule from Nasa's OSIRIS-REx mission - Keegan Barber/Nasa

The recovery team must retrieve the capsule from the ground as quickly as possible to avoid contaminating the sample with Earth’s environment.

Once located, the capsule will be flown to a temporary clean room on the military range, where it will undergo initial processing in preparation for its journey to Nasa’s Johnson Space Center in Houston for study.

As well as helping protect the planet, samples from Bennu - named for the ancient Egyptian phoenix - could also hold secrets about the origin of life on Earth.

The spinning-top-shaped space rock is more than four and a half billion years old and is a leftover relic from the formation of the Solar System which has been perfectly preserved in the vacuum of space.

This Nov 16, 2018, image provide by Nasa shows the asteroid Bennu after a two-year chase - Nasa/Goddard/University of Arizona

Scientists have long suspected that the ingredients for life on Earth may have been delivered to our planet by asteroids, and so are keen to find out whether there are life-forming compounds in the samples.

Professor Dante Lauretta, leader of the OSIRIS-REx mission said: “The return of samples from Bennu is the culmination of over a decade of intense effort by thousands of people around the world.

“These samples will be analyzed by hundreds of researchers to unravel the history of our Solar System, the formation of the Earth, and, possibly, the nature of the building blocks of life.”

Bennu is thought to be rich in organic molecules, which are made of chains of carbon bonded with atoms of oxygen, hydrogen, and other elements in a chemical recipe that makes all known living things. Scientists expect it to also contain water and minerals and possibly precious metals.

Nicola Fox, associate administrator of Nasa’s Science Mission Directorate in Washington: “Pristine material from asteroid Bennu will help shed light on the formation of our Solar System 4.5 billion years ago and perhaps even on how life on Earth began.”

Twenty minutes after the capsule drop-off, the OSIRIS-REx spacecraft will fire its thrusters to divert past Earth to visit another asteroid Apophis under a new mission name OSIRIS-APEX.

Apophis was also predicted to get dangerously close to Earth in 2068, but experts have since revised their calculators and no longer see it as a risk.