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Raumfahrt - OSIRIS-REx - ASTEROID SAMPLE RETURN MISSION -Update 11

25.10.2018

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NASA’s OSIRIS-REx Executes Second Asteroid Approach Maneuver

October 15, 2018 -

NASA’s OSIRIS-REx spacecraft executed its second Asteroid Approach Maneuver (AAM-2) today. The spacecraft’s main engine thrusters fired in a braking maneuver designed to slow the spacecraft’s speed relative to Bennu from 315 mph (141 m/sec) to 11.8 mph (5.2 m/sec). Likewise, the spacecraft’s approach speed dropped from nearly 7,580 miles (12,200 km) to 280 miles (450 km) per day.

Artist’s conception of NASA’s OSIRIS-REx spacecraft during a burn of its main engine. Credit: University of Arizona

The mission team will continue to examine telemetry and tracking data and will have more information over the next week. This burn marked the last planned use of the spacecraft’s main engines prior to OSIRIS-REx’s departure from Bennu in March 2021.

The OSIRIS-REx spacecraft is in the midst of a six-week series of maneuvers designed to fly the spacecraft through a precise corridor toward Bennu. AAM-1, which executed on Oct. 1, slowed the spacecraft by 785.831 mph (351.298 m/sec) and consumed 532.4 pounds (241.5 kilograms) of fuel. AAM-3 is schedule for October 29. The last of the burns, AAM-4, is scheduled for November 12 and will adjust the spacecraft’s trajectory to arrive at a position 12 miles (20 km) from Bennu on December 3. After arrival, the spacecraft will perform a series of fly-bys over Bennu’s poles and equator.

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Bennu Rotating at 13 Pixels

This set of images, taken with OSIRIS-REx’s PolyCam camera on Oct. 23, 2018, shows three views of asteroid Bennu as it rotates over a span of five hours. At the time the images were taken, Bennu was about 1,800 miles (3,000 km) away from the spacecraft and appears about 13 pixels across in the camera’s field of view. In this set of images, the spacecraft’s camera is beginning to detect noticeable differences on each side of Bennu as the asteroid rotates.

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Date Taken: Oct. 23, 2018

Instrument Used: OCAMS (PolyCam)

Credit: NASA/Goddard/University of Arizona

Queklke

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Update: 1.11.2018

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Bennu at 50 Pixels

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This image of Bennu was obtained by NASA’s OSIRIS-REx spacecraft from a distance of approximately 480 miles (770 km) on Oct. 28, 2018. The spacecraft is now close enough to Bennu that the asteroid occupies about 50 pixels in the PolyCam camera’s field of view, and the image’s scale shows about 10 meters per pixel.

The image is oriented so that Bennu North is at the top of the image and Solar System North is at the bottom, as the asteroid rotates in a retrograde motion. Features on Bennu’s surface are beginning to be detectable, including what appears to be a large boulder formation in the southern hemisphere.

Date Taken: Oct. 28, 2018

Instrument Used: OCAMS (PolyCam)

Credit: NASA/Goddard/University of Arizona

Quelle: NASA

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Update: 3.11.2018

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NASA’S OSIRIS-REx Spacecraft Zooms in on Bennu

zoom in from a few pixels to an asteroid

This set of 16 images shows the OSIRIS-REx spacecraft’s steady approach toward the asteroid Bennu during the last half of October 2018. From Oct. 12 to Oct. 29, the long-range PolyCam camera took one optical navigation image per day, except on Oct. 16 and 17 when PolyCam was not scheduled to take images. The spacecraft was approximately 27,340 miles (44,000 km) from Bennu for the first image – a distance several thousand miles greater than the circumference of the Earth. The last image was taken from a distance of around 200 miles (320 km), or slightly less than the distance between Los Angeles and Las Vegas.

Quelle: NASA

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Update: 9.11.2018

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OSIRIS-REx Sees Bennu from 'All Sides'

animated images of asteroid

This set of images shows the asteroid Bennu rotating for one full revolution. Over a four-hour and 11-minute period on Nov. 2, the PolyCam camera on NASA’s OSIRIS-REx spacecraft acquired a 2.5-millisecond image for every 10 degrees of the asteroid’s rotation. At the time of imaging, Bennu was approximately 122 miles (197 km) from the spacecraft, and appeared approximately 200 pixels wide in PolyCam’s frame.

Quelle: NASA

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Update: 18.11.2018

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TAGSAM Testing Complete: OSIRIS-REx Prepared to TAG an Asteroid

animation showing spacecraft deploying arm

On Nov. 14, NASA’s OSIRIS-REx spacecraft stretched out its robotic sampling arm for the first time in space. The arm, more formally known as the Touch-and-Go Sample Acquisition Mechanism (TAGSAM), is key to the spacecraft achieving the primary goal of the mission: returning a sample from asteroid Bennu in 2023.

 

As planned, engineers at Lockheed Martin commanded the spacecraft to move the arm through its full range of motion – flexing its shoulder, elbow, and wrist “joints.” This long-awaited stretch, which was confirmed by telemetry data and imagery captured by the spacecraft’s SamCam camera, demonstrates that the TAGSAM head is ready to collect a sample of loose dirt and rock (called regolith) from Bennu’s surface.

 

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This image shows the OSIRIS-REx Touch-and-Go Sample Acquisition Mechanism (TAGSAM) sampling head extended from the spacecraft at the end of the TAGSAM arm. The image was obtained by the SamCam camera on Nov. 14, 2018 as part of a visual checkout of the spacecraft’s sample acquisition system. This is a rehearsal image for an observation that will be taken at Bennu during the moment of sample collection to help document the asteroid material collected in the TAGSAM head. There are two witness plate assemblies on the top perimeter of the TAGSAM head, one of which is entirely visible in this image. These witness plates record the deposition of material on the TAGSAM head over the duration of the mission, giving scientists a record of material on the TAGSAM head that is not from Bennu.
Credits: NASA/Goddard/University of Arizona

“The TAGSAM exercise is an important milestone, as the prime objective of the OSIRIS-REx mission is to return a sample of Bennu to Earth,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona, Tucson. “This successful test shows that, when the time comes, TAGSAM is ready to reach out and tag the asteroid.”

 

Years of innovation

Lockheed Martin engineers spent more than a decade designing, building, and testing TAGSAM, which includes an 11-foot (3.35-meter) arm with three articulating joints, a round sampler head at the end of the arm that resembles the air filter in a car, and three bottles of high-pressure nitrogen gas.

 

This test deployment was a rehearsal for a date in mid-2020 when the spacecraft will unfold the TAGSAM arm again, slowly descend to Bennu’s surface, and briefly touch the asteroid with the sampler head. A burst of nitrogen gas will stir up regolith on the asteroid’s surface, which will be caught in the TAGSAM head. The TAG sequence will take about five seconds, after which the spacecraft will execute small maneuvers to carefully back away from Bennu. Afterward, SamCam will image the sampler head, as it did during the test deployment, to help confirm that TAGSAM collected at least 2.1 ounces (60 grams) of regolith. 

 

 

 

 

n mid-2020, the OSIRIS-REx spacecraft will use its TAGSAM device to stir up and collect a sample of loose material from asteroid Bennu’s surface. That material will be returned to Earth for study in 2023.
Credits: NASA/Goddard/University of Arizona

The TAGSAM mechanism was designed for the key challenge unique to the OSIRIS-REx mission: collecting a sample from the smallest planetary body ever to be orbited by a spacecraft. “First-of-its-kind innovations like this one serve as the precursor for future missions to small bodies,” said Sandy Freund, systems engineer manager and Lockheed Martin OSIRIS-REx MSA manager. “By proving out these technologies and techniques, we are going to be able to return the largest sample from space in half a century and pave the way for other missions.”

 

A month of testing

The unfolding of the TAGSAM arm was the latest and most significant step in a series of tests and check-outs of the spacecraft’s sampling system, which began in October when OSIRIS-REx jettisoned the cover that protected the TAGSAM head during launch and the mission’s outbound cruise phase. Shortly before the cover ejection, and again the day after, OSIRIS-REx performed two spins called Sample Mass Measurements. By comparing the spacecraft’s inertial properties during these before-and-after spins, the team confirmed that the 2.67-pound (1.21-kilogram) cover was successfully ejected on Oct. 17.

A week later, on Oct. 25, the Frangibolts holding the TAGSAM arm in place fired successfully, releasing the arm and allowing the team to move it into a parked position just outside its protective housing. After resting in this position for a few weeks, the arm was fully deployed into its sampling position, its joints were tested, and images were captured with SamCam. The spacecraft will execute two additional Sample Mass Measurements over the next two days. The mission team will use these spins as a baseline to compare with the results of similar spins that will be conducted after TAG in 2020 in order to confirm the mass of the sample collected.

 

 

 

Over the past month, the OSIRIS-REx team conducted a series of tests to ensure that TAGSAM, the spacecraft’s sampling mechanism, is ready to collect a sample from Bennu in 2020. This rehearsal marked the first time since launch that the TAGSAM arm has moved through its full range of motion.
Credits: NASA/Goddard/University of Arizona

 

Although the sampling system was rigorously tested on Earth, this rehearsal marked the first time that the team has deployed TAGSAM in the micro-gravity environment of space.

 

"The team is very pleased that TAGSAM has been released, deployed, and is operating as commanded through its full range of motion." said Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. "It has been restrained for over two years since launch, so it is gratifying to see it out of its shackles and performing well."

 

OSIRIS-REx is scheduled to arrive at Bennu on Dec. 3. It will spend nearly one year surveying the asteroid with five scientific instruments so that the mission team can select a location that is safe and scientifically interesting to collect the sample.

 

“Now that we have put TAGSAM through its paces in space and know it is ready to perform at Bennu, we can focus on the challenges of navigating around the asteroid and seeking out the best possible sample site,” said Lauretta.

Quelle: NASA

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Update: 19.11.2018

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NASA OSIRIS-REx Flexes Its "Arm" Before Arriving At Asteroid Bennu
- NASA's OSIRIS-REx spacecraft completes critical engineering maneuver campaign to test out sample return mechanism - developed by Lockheed Martin.
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TAGSAM, or Touch-and-Go Sample Acquisition Mechanism, completed a successful practice deployment in space on Nov. 14—an important milestone in the OSIRIS-REx mission to the asteroid Bennu. TAGSAM is the first-of-its-kind robotic arm and sampling head invented by Lockheed Martin.

Lockheed Martin engineers on the Mission Support Area (MSA) team moved TAGSAM's arm through the full range of motion of all its "joints"—shoulder, elbow and wrist. The maneuver demonstrates that TAGSAM is ready to collect surface material (regolith) from Bennu.

"Our team has been providing spacecraft operations since launch and has been conducting various checkouts over the past two years," said Sandy Freund, Lockheed Martin OSIRIS-REx MSA manager. "This was a very important milestone in checking out the hardware required to collect an asteroid sample." 

Lockheed Martin engineers spent more than a decade designing, building and testing TAGSAM. The mechanism meets the unique challenges of trying to collect samples from the smallest planetary body that a spacecraft has ever orbited.

The OSIRIS-REx spacecraft cannot land on Bennu because of its small size—just 0.3 miles (500 meters) in diameter--and its microgravity environment—100,000 times less than Earth's. Instead, TAGSAM will extend its 11-foot-long (3.35-meter) arm from the spacecraft to Bennu's surface and "tag" the asteroid.

The round sampler head will agitate the surface and loosen regolith with a jet of nitrogen gas, allowing the suspend­ed particles to pass through a filter into the sampler head. The entire operation will take about five seconds, with the TAGSAM head bouncing against the surface in a pogo-stick-type motion.

If necessary, TAGSAM can make up to three sampling attempts to collect at least 2.1 ounces (60 grams) of regolith.

"First-of-its-kind innovations like this one serve as the precursor for future missions to small bodies," said Freund. "Proving out these technologies and techniques, we are going to be able to return the largest sample from space in half a century and pave the way for other missions."

TAGSAM began its journey aboard OSIRIS-REx on Sept. 8, 2016. The spacecraft is scheduled to reach Bennu on Dec. 3, 2018, and complete a survey of the asteroid over the next two years. The window for the touch-and-go sampling operation opens on July 4, 2020. Once enough sample is collected, the TAGSAM head will be stowed and sealed in the spacecraft's sample return capsule (SRC) for the return trip to Earth, with expected arrival on Sept. 24, 2023.

NASA Goddard Space Flight Center in Greenbelt provides overall mission management, systems engineering and safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission's science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and is currently providing spacecraft operations. OSIRIS-REx is the third mission in NASA's New Frontiers Program. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages New Frontiers for the agency's Science Mission Directorate in Washington.

Quelle: Lockheed Martin

 

 

 

 

 

 

 

 

 
 
 

 

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