NASA is preparing for the asteroid Bennu touchdown tomorrow, where it will take samples from the boulder-strewn space rock and bring them back to Earth by 2023.
The space agency announced that its OSIRIS-REx vehicle will land on the asteroid Bennu for a few seconds after a carefully coordinated 4.5-hour descent.
The ship, the size of a van, lands in an area called Nightingale, a rocky 52-foot location in the asteroid's northern hemisphere, on October 20 at 10:00 p.m. CET (5:00 p.m. CET).
After landing, a robotic arm attempts to collect samples of the surface, which it will save and return to Earth – a journey that is expected to take up to three years.
Scientists hope the mission will deepen our understanding of how planets and life form, and provide insights into asteroids that could affect Earth.
After a carefully coordinated 4.5 hour descent, OSIRIS-REx lands on the asteroid Bennu for a few seconds. The ship is the size of a van and will land in an area called Nightingale on October 20 at 10:00 p.m. CET (5:00 p.m. CET)
The 11-foot sampling arm of the OSIRIS-REx spacecraft (pictured) will take Bennu rock and soil samples when the spacecraft lands on space rock on Tuesday, October 20
The Nightingale site was chosen because it represents one of the clearest areas on the asteroid's surface with the best access to fine-grained material.
BUILDING BLOCKS OF LIFE CAN BE IN BENNU BOULDERS
The asteroid Bennu could contain the building blocks of life in its debris surface, and the body was once part of a much larger, water-covered world, scientists claim.
NASA's OSIRIS-Rex mission will land on Bennu on October 20 to collect samples of the space rock.
Bennu's boulders were found to contain a bright carbonate vein
In preparation for this mission, six research papers were published covering the history and composition of the near-Earth asteroid.
One such work found evidence of carbonaceous and organic materials that are common on the surface of Bennu.
These materials were found in veins running through rocks and had to be formed as a result of free flowing water that was on the larger, long-destroyed celestial body that Bennu created.
This is the first confirmed discovery of these building blocks of life on a near-Earth asteroid.
However, there are rock-sized buildings around the site, so there are few parking spaces available to land on.
If the landing goes even slightly wrong, OSIRIS-REx is in a treacherous area, NASA explained.
"The next time you park in front of your house or a coffee shop and go inside, think about the challenge of navigating Osiris-Rex to one of these locations from 200 million miles away," said Mike, NASA associate project manager Moreau.
Once it falls out of its 800 m high orbit around Bennu, the spaceship will purposely take four hours to make it all the way to the top to just above the surface.
Then the action turns when Osiris-Rex's 11-foot arm reaches for Bennu and touches him for about 10 seconds.
Bennu sits between Earth and Mars at a distance of approximately 334 million kilometers from our planet.
For this reason, it takes approximately 18.5 minutes for the signals to be transmitted between OSIRIS-REx and NASA headquarters.
The pre-programmed spaceship works autonomously during the unprecedented touch-and-go maneuver.
With a delay of 18 minutes in radio communications, ground controllers for spacecraft manufacturer Lockheed Martin near Denver cannot intervene.
This means that manual landing is impossible, with all hopes of a successful landing depending on the on-board autonomous system.
OSIRIS-REx is supposed to collect at least 57 grams of Bennu's rocky material to bring it back to earth.
This will be the largest sample selection since the Apollo missions, which had the bonus of a lot more money and people on the surface to aid the collection.
Should the collection of Bennu's surface material be successful, it will be returned to Earth on September 24, 2023.
While NASA brought back cometary dust and solar wind particles, it has never attempted to study any of the nearly 1 million known asteroids lurking in our solar system so far.
NASA is preparing for the asteroid Bennu touchdown tomorrow, where it will take samples from the boulder-strewn space rock and bring them back to Earth by 2023
Scientists hope the mission will deepen our understanding of how planets and life form, and provide insights into asteroids that could affect Earth
Japan, meanwhile, expects to receive samples – in milligrams at most – from the asteroid Ryugu in December – 10 years after it brought back spots from the asteroid Itokawa.
Bennu is an asteroid pickers paradise as it is large, black, plump, and full of carbon-rich boulders that may contain clues to past flowing water and the building blocks of life.
It was around the time our solar system formed 4.5 billion years ago. Scientists therefore view it as a time capsule full of pristine building blocks that could explain how life formed on Earth and possibly elsewhere.
"This is about understanding where we come from," said Mission Principal Scientist Dante Lauretta of the University of Arizona.
NASA revealed some details about how the OSIRIS-Rex vehicle will land on Bennu, and it has been broken up into three different maneuvers that together lasted 4.5 hours.
The first will involve firing the thrusters on OSIRIS-REx to remove them from orbit, approximately 770 meters above the surface.
This low altitude is due to the asteroid's tiny gravitational pull, which is less than half a mile in diameter.
At this point, the robotic sampling arm, the Touch-and-Go Sample Acquisition Mechanism (TAGSAM), unfolds and points down at Bennu.
The fragile solar panels move in a Y-wing orientation above the spaceship to safely avoid any danger.
The TAG head is the only part of the spacecraft that comes into contact with Bennu's surface.
"Years of planning and hard work by this team are largely due to the fact that the TAGSAM (touch-and-go sample acquisition mechanism) only comes into contact with the surface for five to ten seconds," said Mike Moreau, OSIRIS-REx assistant project Manager.
NASA revealed some details about how the OSIRIS-Rex vehicle will land on Bennu, and the 4.5-hour ordeal will be broken down into three different maneuvers. The first will involve firing the engines at OSIRIS-REx to remove them from orbit, approximately 770 meters above the surface
NASA previously discovered pieces of the asteroid Vesta, 5 to 14 feet in size, scattered across Bennu's southern hemisphere and near its center (picture).
NASA will approve the descent and allow OSIRIS-REx to take control of its own landing using a system called the Natural Feature Tracking (NFT) navigation system.
It uses all of the detailed images that the mission took of the asteroid's surface and creates a map showing all potential hazards.
NASA images of the asteroid Bennu show "extremely bright" pieces of another asteroid on the surface
NASA discovered pieces of the asteroid Vesta, 5 to 14 feet in size, scattered across Bennu's southern hemisphere and near its center.
The boulders were recognized in images by OSIRIS-Rex and appear much brighter than the surroundings with dark, rich carbon.
The team analyzed the chunks with an on-board spectrometer and found evidence of the mineral pyroxene – a known compound on Vesta.
NASA suspects that the material came from Bennu's parent asteroid, which was hit by a fragment from Vesta.
Hannah Kaplan of NASA's Goddard Space Flight Center in Greenbelt, Maryland said, "Our leading hypothesis is that Bennu inherited this material from his parent asteroid after a vestoid (a fragment of Vesta) struck the parents."
"Then when the parent asteroid was catastrophically destroyed, some of its debris accumulated under its own gravity in Bennu, including some of Vesta's pyroxene."
It is preprogrammed to abort the mission if it is outside of various pre-defined limits that may endanger it.
In this case, NASA will regroup and try the mission again at a later date, it said.
A slow and steady descent takes about four hours before a so-called checkpoint maneuver is carried out at an approximate height of 125 m.
The gradual decline is replaced by a steeper and faster approach to the surface after the engines detonate again.
About 11 minutes later, the third and final maneuver called "Matchpoint" will take place.
Here the computer system will use the engines and try to stabilize the vehicle only 54 m above the landing site.
OSIRIS-Rex slows down again and tries to adjust the rotation of the asteroid before it approaches.
According to NASA, it won't touch the surface for more than 16 seconds.
It will then expel gas from an on-board nitrogen cylinder to hurl debris from Bennu's surface.
The spaceship will attempt to collect some of this debris before firing its engines to retreat to the safety of orbit.
NASA will not know until the week after the landing whether it has managed to reach the target of 60 grams of material.
On October 22nd, an on-board camera took photos of the extendable arm to see if any material had been collected.
On October 24th, OSIRIS-REx will try to determine the mass of the material.
When deemed appropriate, it will be securely packaged in the Sample Return Capsule (SRC) for a trip to Earth.
If NASA is dissatisfied, they just go back and try again as OSIRIS-REx has enough nitrogen for a total of three attempts.
In that case, NASA would drop Nightingale and aim at the Osprey backup site and return in January 2021 at the earliest.
HOW WILL NASA'S OSIRIS REX MISSION TAKE SAMPLES FROM AN ASTEROID WORK?
Osiris-Rex is the first US mission to bring a piece of an asteroid back to Earth.
Scientists say the ancient asteroid may contain clues as to the origin of life.
It is believed to have formed 4.5 billion years ago, a holdover from the building blocks of the solar system.
The spacecraft launched aboard an Atlas V rocket at 7:05 p.m. EST on September 8, 2016.
After a careful study by Bennu to characterize the asteroid and pinpoint the most promising sample locations, Osiris-Rex will use its robotic arm to collect between 60 and 2,000 grams of surface material and bring the sample back to Earth via a detachable capsule in 2023.
To collect samples on the surface, the vehicle hovers over a certain area and is sent down at a speed of 10 cm per second (very slowly and gently).
The spaceship will also carry a laser altimeter, a set of University of Arizona cameras, spectrometers, and lidar similar to radar, which use light instead of radio waves to measure distance.
The asteroid Bennu, photographed by OSIRIS-REx, on December 2nd, 2018
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