The OSIRIS-RX spacecraft has been orbiting the asteroid Bennu since the end of 2018. The mission – which is the original, Spectral Interpretation, Resource Identification, Security – Regolith Explorer – was launched in September 2016.
Since arriving in Bennu, the spacecraft and its cameras have been collecting and sending back data and images to help map out the best possible landing sites to learn more about the planet’s composition and collect samples.
The main event of the mission, called the Touch-and-Go Sample Collection, or TAG, is scheduled for October 20 at 5 p.m. ET.
Asteroids and spacecraft are currently about 207 million miles from Earth, which would cause a delay of about 18.5 minutes of communication. The NASA team will present live stream animations showing what is happening based on commands already sent to OSISIS-REx for the sample collection sequence.
Since live commands from Earth would not be possible the spacecraft would make a complete sequence of reaching the asteroid and collecting the sample autonomously.
Based on the data returned by the spacecraft, the mission team should be able to confirm whether the touchdown was successful on Tuesday.
The spacecraft has conducted two rehearsals without actually touching the planet, so its team is ready for this expected event.
However, Bennu’s scientists did not live up to expectations. The Nightingale landing site is surrounded by hazards, so the mission will need to be run with extreme precision.
The OSIRIS-Rex spacecraft will have to detect hazards and delay its own mission if there are any obstacles in the way of collecting samples. But if everything goes smoothly, the spacecraft and its precious specimens will embark on a long journey to Earth next year and take a sample to Earth in 2023.
Dodging building-sized boulders
Imagine a space that could hold 15 passengers flying out of space and come close to a cliff that has the height of the Empire State Building and rotates fast. That is Bennu’s Osiris-Rex mission.
Bennu has an orbit that brings it closer to Earth, which is why it is considered the closest planet to Earth. One of his future approaches could bring him dangerously close to Earth in the next century; It has 2,700 chances to affect our planet.
Bennu’s samples could help scientists understand not only about the asteroids that could affect the Earth, but also how the planets formed and how life began. In total, the spacecraft will collect about 2 ounces, or 30 packets of sugar from the planet.
Although this may seem small, according to Napo, the Apollo program is the largest sample return from that space since.
But first, OSIRIS-Rex will have to explore a small, narrow path to the Nightingale landing site inside the crater on the asteroid’s northern hemisphere.
The touchdown area has been reduced to about a tenth of the original plan, so accuracy is the key. On the eastern edge of the crater sits a building-sized boulder that could threaten the spacecraft as it retreats from the asteroid once the specimens have been collected.
Bennu “is not nearly as sandy a beach as we had hoped and expected,” Thomas Zurbuchen, associate administrator of the Science Mission Directorate at NASA, told a news conference in September.
Instead, scientists discovered that the asteroid was covered with house-sized rocks. The team used the spacecraft to map the entire planet and determine four possible landing sites. Nightingale was eventually chosen as the best.
“We chose Nightingale because it has the most excellent content from the four sample site candidates,” Dente Loretta, the mission’s chief investigator and professor at Arizona’s Lunar and Planetary Laboratory, said in September.
“We spent early reconnaissance passage at this site in early 2020, eventually imaging at one-eighth of an inch per pixel. We basically have incredibly detailed images covering the entire pit, and we’ve counted all those rocks.”
Going for a touchdown
The Niningal landing site is 52 feet in diameter, the size of some parking spaces where a van-sized spacecraft will briefly touchdown for just a few seconds. There is no room for error; Building-sized stones are just steps away.
The event will take about 4.5 hours to occur and the spacecraft will run three maneuvers to collect the sample.
The spacecraft will first drop the thrusters around its safe orbit around Aster to Ed, which is about 2,500 feet away from the surface, and will travel four hours before reaching just 410 feet away. Then, the spacecraft will adjust to position and speed to continue descending.
Next, the OSIRI will slow down its descent to target the IRS-Rex path so that it coincides with the rotation of the asteroid during contact. Its solar panels will be folded into the upper Y-wing alignment of the spacecraft for their protection.
Finally, OSIRIS-REx will touchdown for less than 16 seconds. The spacecraft will drop a pressurized nitrogen bottle into the asteroid using gas to lift the material from the surface of the bean.
The collector head of the spacecraft will capture the shaken material. Located on the arm of an 11-foot-long robotic specimen, the head is the only part of the spacecraft that touches Bennu. The team compares it to an older model car’s air filter, perfect for collecting nice stuff.
Small discs, which can collect dust like sticky pads, are also located on the head if part of the sample maneuver on the sample does not go as planned.
The camera on the spacecraft will take footage of my collection event.
“Whether we tilted or not, the gas flowed to the side, we can tell if the material is seasoned enough,” said Lure Retta. “We will also have a good indication of a specific location in the Nightingale where we have approached and we can compare it with our sampling map, to assess whether we have touched an area where there is an abundance of sampled goods or one of the beautiful locations. . “
After that, the spacecraft’s thrusters will fire and help remove it from Bennu’s surface and reach a safe distance once again.
The OSIRIS-Rex spacecraft will carry out the maneuver itself and ultimately determine whether it is safe. The spacecraft relies on its natural feature tracking navigation system, which actively takes images during landings and compares them with images stored in catalogs to make sure they are on the right track. This will affect every step of the lineage.
If it goes beyond the course, the spacecraft will drop the effort.
The navigation system also has a landing site hazard map, and if it detects that the spacecraft is approaching a hazard, it stops at 16 feet above the asteroid and will not continue the effort.
This means that OSIRIS-REx can stay safe and try another sample collection in the future.
Checking with Earth
During each step, the spacecraft will send data back to NASA researchers on Earth, allowing them to determine if the touchdown was successful. Due to the epidemic, only a limited number of people will be present at the Mission Support Area of Lockheed Martin Space, while others will be present at the site at different locations to monitor the event.
To make sure the spacecraft actually collects a sample, one of the OSIRIIRIS-Rex cameras will take images of the collection head on October 22nd. And on October 24, the spacecraft will spin to determine the mass of its collected material.
Although 2 ounces is the target, OSIRIS-REx can hold up to 4 pounds.
If the sample collection goes according to plan, the head and sample will be placed and sealed in the sample return capsule to return to Earth.
But if the collection fails or there is not enough material, there are two more nitrogen charges for future efforts at another site called sp spray in January 2021.
Together, team members will spend about a week evaluating what they have collected and making sure the spacecraft and its devices managed to survive the encounter.
“So far, the probable result that will come to us on October 20 is that we will approach the surface and take a large sample that exceeds our needs. But Bennu has already thrown us a number of turn balls, that’s why we absolutely” The Osprey (backup site) is ready to be tweaked if necessary, “Mike Moreau, deputy project manager at NASA’s Goddard Space Flight Center in Maryland, said in a statement.
Recently, scientists discovered that the fine material at the Nightingale site had only recently been exposed into space. This means that the material collected by OSIRIS-Rex will be some of the most ancient material on asteroids.
And the Bennu sample that will return to Earth will be nothing like the meteors on Earth, NASA scientists say, because what they have learned about Bennu is unexpected.
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