NASA’s very first asteroid tasting spacecraft is making last preparations to get a sample from asteroid Bennu’s surface area. Next week, the OSIRIS-REx objective will perform a 2nd wedding rehearsal of its goal series, practicing the sample collection activities one last time prior to touching down on Bennu this fall.
On August 11, the objective will perform its “Matchpoint” wedding rehearsal – the 2nd practice run of the Touch-and-Go (TAG) sample collection occasion. The wedding rehearsal will resemble the April 14 “Checkpoint” wedding rehearsal, which practiced the very first 2 maneuvers of the descent, however this time the spacecraft will include a 3rd maneuver, called the Matchpoint burn, and fly even better to sample website Nightingale – reaching an elevation of roughly 131 feet (40 m) – prior to pulling back from the asteroid.
This 2nd wedding rehearsal will be the very first time the spacecraft carries out the Matchpoint maneuver to then fly in tandem with Bennu’s rotation. The wedding rehearsal likewise offers the group an opportunity to end up being more familiar browsing the spacecraft through all of the descent maneuvers, while validating that the spacecraft’s imaging, navigation and varying systems run as anticipated throughout the occasion.
During the descent, the spacecraft fires its thrusters 3 different times to make its method to the asteroid’s surface area. The spacecraft will take a trip at a typical speed of around 0.2 miles per hour (0.3 kph) throughout the roughly four-hour adventure. Matchpoint wedding rehearsal starts with OSIRIS-REx shooting its thrusters to leave its 0.5-mile (870-m) safe-home orbit. The spacecraft then extends its robotic tasting arm – the Touch-And-Go Sample Acquisition Mechanism (TAGSAM) – from its folded, parked position out to the sample collection setup. Immediately following, the spacecraft turns to start gathering navigation images for the Natural Feature Tracking (NFT) assistance system. NFT enables OSIRIS-REx to autonomously browse to Bennu’s surface area by comparing an onboard image brochure with the real-time navigation images taken throughout descent. As the spacecraft approaches the surface area, the NFT system updates the spacecraft’s anticipated point of contact depending upon OSIRIS-REx’s position in relation to Bennu’s landmarks.
The spacecraft’s 2 photovoltaic panels then move into a “Y-wing” setup that securely places them up and far from the asteroid’s surface area. This setup likewise puts the spacecraft’s center of mass straight over the TAGSAM collector head, which is the only part of the spacecraft that will get in touch with Bennu’s surface area throughout the sample collection occasion.
When OSIRIS-REx reaches an elevation of roughly 410 feet (125 m), it carries out the Checkpoint burn and comes down more steeply towards Bennu’s surface area for another 8 minutes. At roughly 164 feet (50 m) above the asteroid, the spacecraft fires its thrusters a 3rd time for the Matchpoint burn. This maneuver slows the spacecraft’s rate of descent and changes its trajectory to match Bennu’s rotation as the spacecraft makes last corrections to target the goal area. OSIRIS-REx will continue catching pictures of Bennu’s landmarks for the NFT system to upgrade the spacecraft’s trajectory for another 3 minutes of descent. This brings OSIRIS-REx to its targeted location around 131 feet (40 m) from Bennu – the closest it has actually ever been to the asteroid. With the wedding rehearsal total, the spacecraft carries out a back-away burn, returns its photovoltaic panels to their initial position and reconfigures the TAGSAM arm back to the parked position.
During the wedding rehearsal, the one-way light time for signals to take a trip in between Earth and the spacecraft will be roughly 16 minutes, which avoids the live commanding of flight activities from the ground. So prior to the wedding rehearsal’s start, the OSIRIS-REx group will uplink all of the occasion’s commands to the spacecraft, permitting OSIRIS-REx to carry out the wedding rehearsal series autonomously after the GO command is offered. Also throughout the occasion, the spacecraft’s low gain antenna will be its only antenna pointing towards Earth, sending information at the extremely sluggish rate of 40 bits per second. So while the OSIRIS-REx group will have the ability to keep an eye on the spacecraft’s crucial indications, the images and science information gathered throughout the occasion won’t be downlinked till the wedding rehearsal is total. The group will experience these very same situations throughout the real TAG occasion in October.
Following Matchpoint wedding rehearsal, the OSIRIS-REx group will validate the flight system’s efficiency throughout the descent, consisting of that the Matchpoint burn properly changed the spacecraft’s descent trajectory for its goal on Bennu. Once the objective group identifies that OSIRIS-REx ran as anticipated, they will command the spacecraft to go back to its safe-home orbit around Bennu.
The objective group has actually invested the last numerous months getting ready for the Matchpoint wedding rehearsal while optimizing remote work as part of its COVID-19 action. On the day of wedding rehearsal, a restricted variety of workers will keep an eye on the spacecraft from Lockheed Martin Space’s center, taking proper security preventative measures, while the remainder of the group performs their functions from another location. The objective carried out a comparable procedure throughout the Checkpoint wedding rehearsal in April.
On Oct. 20, the spacecraft will take a trip all the method to the asteroid’s surface area throughout its very first sample collection effort. During this occasion, OSIRIS-REx’s tasting system will touch Bennu’s surface area for roughly 5 seconds, fire a charge of pressurized nitrogen to interrupt the surface area and gather a sample prior to the spacecraft pulls back. The spacecraft is set up to return the sample to Earth on Sept. 24, 2023.
NASA’s Goddard Space Flight Center in Greenbelt, Maryland offers general objective management, systems engineering, and the security and objective guarantee for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the primary private investigator, and the University of Arizona likewise leads the science group and the objective’s science observation preparation and information processing. Lockheed Martin Space in Denver developed the spacecraft and is offering flight operations. Goddard and KinetX Aerospace are accountable for browsing the OSIRIS-REx spacecraft. OSIRIS-REx is the 3rd objective in NASA’s New Frontiers Program, which is handled by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the company’s Science Mission Directorate in Washington.