After months grappling with the rugged fact of asteroid Bennu’s ground, the team main NASA’s first asteroid sample return mission has selected Four doable web sites for the Origins, Spectral Interpretation, Helpful resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft to “label” its cosmic dance accomplice.
Since its arrival in December 2018, the OSIRIS-REx spacecraft has mapped the total asteroid in dispute to call the most accumulate and most accessible spots for the spacecraft to build up a sample. These Four web sites now would possibly be studied in extra detail in dispute to make a alternative the final two web sites – a major and backup – in December.
The team within the starting up had planned to steal the final two web sites by this level within the mission. Preliminary prognosis of Earth-primarily primarily based observations suggested the asteroid’s ground likely contains good “ponds” of gorgeous-grain enviornment topic. The spacecraft’s earliest images, on the other hand, revealed Bennu has an particularly rocky terrain. Since then, the asteroid’s boulder-crammed topography has created a scenario for the team to call protected areas containing sampleable enviornment topic, which need to be beautiful sufficient – decrease than 1 poke (2.5 cm) diameter – for the spacecraft’s sampling mechanism to ingest it.
“We knew that Bennu would shock us, so we came ready for regardless of we would accumulate,” said Dante Lauretta, OSIRIS-REx main investigator on the University of Arizona, Tucson. “As with all mission of exploration, coping with the unknown requires flexibility, resources and ingenuity. The OSIRIS-REx team has demonstrated these needed traits for overcoming the unexpected all the blueprint through the Bennu advance across.”
The celebrated mission time desk deliberately incorporated more than 300 days of beyond bizarre time for the duration of asteroid operations to cope with such unexpected challenges. In a demonstration of its flexibility and ingenuity in response to Bennu’s surprises, the mission team is adapting its plight selection course of. In its put of down-selecting to the final two web sites this summer time, the mission will spend an additional Four months studying the Four candidate web sites in detail, with a explicit kind out identifying areas of gorgeous-grain, sampleable enviornment topic from upcoming, excessive-resolution observations of every plight. The boulder maps that citizen science counters helped make through observations earlier this yr had been faded as one in every of many pieces of data regarded as when assessing every plight’s safety. The records gentle would possibly be key to selecting the final two web sites easiest fitted to sample sequence.
In dispute to extra adapt to Bennu’s ruggedness, the OSIRIS-REx team has made other adjustments to its sample plight identification course of. The celebrated mission belief envisioned a sample plight with a radius of eighty two toes (25 m). Boulder-free web sites of that dimension kind now not exist on Bennu, so the team has in its put identified web sites starting from sixteen to 33 toes (5 to 10 m) in radius. In dispute for the spacecraft to precisely design a smaller plight, the team reassessed the spacecraft’s operational capabilities to maximize its efficiency. The mission also has tightened its navigation requirements to data the spacecraft to the asteroid’s ground, and developed a new sampling technique called “Bullseye TAG,” which makes utilize of images of the asteroid ground to navigate the spacecraft the total manner to the right ground with excessive accuracy. The mission’s efficiency to date has demonstrated the brand new standards are inside its capabilities.
“Even supposing OSIRIS-REx changed into once designed to build up a sample from an asteroid with a sea accelerate-love dwelling, the unprecedented in-flight efficiency to date demonstrates that we’re going to be ready to meet the scenario that the rugged ground of Bennu affords,” said Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Rental Flight Heart in Greenbelt, Maryland. “That unprecedented efficiency encompasses now not easiest the spacecraft and instruments, but additionally the team who continues to meet every scenario that Bennu throws at us.”
The Four candidate sample web sites on Bennu are designated Nightingale, Kingfisher, Osprey, and Sandpiper – all birds native to Egypt. The naming theme complements the mission’s two other naming conventions – Egyptian deities (the asteroid and spacecraft) and mythological birds (ground facets on Bennu).
The Four web sites are diverse in every geographic space and geological facets. Whereas the amount of sampleable enviornment topic in every plight has yet to be definite, all Four web sites had been evaluated totally to be obvious the spacecraft’s safety as it descends to, touches and collects a sample from the asteroid’s ground.
Nightingale is the northern-most plight, positioned at 56 degrees north latitude on Bennu. There are more than one conceivable sampling areas on this plight, which is web page in a microscopic crater encompassed by the next crater 459 toes (140 m) in diameter. The positioning contains largely beautiful-grain, dark enviornment topic and has the lowest albedo, or reflection, and ground temperature of the Four web sites.
Kingfisher is found in a microscopic crater conclude to Bennu’s equator at Eleven degrees north latitude. The crater has a diameter of 26 toes (Eight m) and is surrounded by boulders, though the positioning itself is freed from good rocks. Amongst the Four web sites, Kingfisher has the strongest spectral signature for hydrated minerals.
Osprey is web page in a microscopic crater, Sixty six toes (20 m) in diameter, which is also located in Bennu’s equatorial web page at Eleven degrees north latitude. There are several conceivable sampling areas all the blueprint through the positioning. The diversity of rock types within the encircling dwelling means that the regolith inside Osprey will also additionally be diverse. Osprey has the strongest spectral signature of carbon-rich enviornment topic among the many Four web sites.
Sandpiper is found in Bennu’s southern hemisphere, at Forty seven degrees south latitude. The positioning is in a somewhat flat dwelling on the wall of a great crater 207 feet (sixty three m) in diameter. Hydrated minerals are also present, which signifies that Sandpiper will also comprise unmodified water-rich enviornment topic.
This fall, OSIRIS-REx will start detailed analyses of the Four candidate web sites for the duration of the mission’s reconnaissance half. At some level of the main stage of this half, the spacecraft will carry out excessive passes over every of the Four web sites from a distance of Zero.Eight miles (1.29 km) to substantiate they are protected and comprise sampleable enviornment topic. Closeup imaging also will plot the facets and landmarks required for the spacecraft’s self sustaining navigation to the asteroid’s ground. The team will utilize the records from these passes to make a alternative the final main and backup sample sequence web sites in December.
The second and 1/3 stages of reconnaissance will start in early 2020 when the spacecraft will agree with passes over the final two web sites at decrease altitudes and steal even greater resolution observations of the bottom to call facets, equivalent to groupings of rocks that would possibly be faded to navigate to the bottom for sample sequence. OSIRIS-REx sample sequence is scheduled for the latter half of 2020, and the spacecraft will return the asteroid samples to Earth on Sept. 24, 2023.
Goddard affords overall mission management, systems engineering, and safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the main investigator, and the University of Arizona leads the science team and the mission’s science commentary planning and records processing. Lockheed Martin Rental in Denver built the spacecraft and is providing flight operations. Goddard and KinetX Aerospace are guilty for navigating the spacecraft. OSIRIS-REx is the 1/3 mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Rental Flight Heart in Huntsville, Alabama, for the company’s Science Mission Directorate in Washington.
For more data about OSIRIS-REx, talk over with: http://www.nasa.gov/osiris-rex
Uncover the final Four candidate web sites in detail: http:// www.asteroidmission.org/candidate-sample-web sites