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August 12, 2019 – After months grappling with the rugged actuality of asteroid Bennu’s floor, the staff main NASA’s first asteroid pattern return mission has chosen 4 potential websites for the Origins, Spectral Interpretation, Useful resource Identification, Safety-Regolith Explorer (OSIRIS-REx) spacecraft to “tag” its cosmic dance associate.
Since its arrival in December 2018, the OSIRIS-REx spacecraft has
mapped your entire asteroid in an effort to establish the most secure and most
accessible spots for the spacecraft to gather a pattern. These 4
websites now will likely be studied in additional element in an effort to choose the ultimate
two websites – a main and backup – in December.
The staff initially had deliberate to decide on the ultimate two websites by this
level within the mission. Preliminary evaluation of Earth-based observations
prompt the asteroid’s floor seemingly accommodates giant “ponds” of
fine-grain materials. The spacecraft’s earliest photographs, nonetheless, revealed
Bennu has an particularly rocky terrain. Since then, the asteroid’s
boulder-filled topography has created a problem for the staff to
establish protected areas containing sampleable materials, which should be effective
sufficient – lower than 1 inch (2.5 cm) diameter – for the spacecraft’s
sampling mechanism to ingest it.
“We knew that Bennu would shock us, so we got here ready for
no matter we would discover,” mentioned Dante Lauretta, OSIRIS-REx principal
investigator on the College of Arizona, Tucson. “As with all mission
of exploration, coping with the unknown requires flexibility, sources
and ingenuity. The OSIRIS-REx staff has demonstrated these important
traits for overcoming the surprising all through the Bennu encounter.”
The unique mission schedule deliberately included greater than 300
days of additional time throughout asteroid operations to deal with such surprising
challenges. In an indication of its flexibility and ingenuity in
response to Bennu’s surprises, the mission staff is adapting its website
choice course of. As a substitute of down-selecting to the ultimate two websites this
summer time, the mission will spend an extra 4 months learning the
4 candidate websites intimately, with a selected concentrate on figuring out
areas of fine-grain, sampleable materials from upcoming,
high-resolution observations of every website. The boulder maps that citizen
science counters helped create via observations earlier this yr
had been used as one among many items of information thought of when assessing every
website’s security. The information collected will likely be key to deciding on the ultimate two
websites greatest fitted to pattern assortment.
With a view to additional adapt to Bennu’s ruggedness, the OSIRIS-REx staff
has made different changes to its pattern website identification course of.
The unique mission plan envisioned a pattern website with a radius of 82
toes (25 m). Boulder-free websites of that measurement don’t exist on Bennu, so
the staff has as an alternative recognized websites starting from 16 to 33 toes (5 to
10 m) in radius. To ensure that the spacecraft to precisely goal a
smaller website, the staff reassessed the spacecraft’s operational
capabilities to maximise its efficiency. The mission additionally has tightened
its navigation necessities to information the spacecraft to the asteroid’s
floor, and developed a brand new sampling approach known as “Bullseye TAG,”
which makes use of photographs of the asteroid floor to navigate the spacecraft all
the best way to the precise floor with excessive accuracy. The mission’s
efficiency to this point has demonstrated the brand new requirements are inside its
capabilities.
“Though OSIRIS-REx was designed to gather a pattern from an
asteroid with a beach-like space, the extraordinary in-flight efficiency
so far demonstrates that we can meet the problem that
the rugged floor of Bennu presents,” mentioned Wealthy Burns, OSIRIS-REx
venture supervisor at NASA’s Goddard House Flight Middle in Greenbelt,
Maryland. “That extraordinary efficiency encompasses not solely the
spacecraft and devices, but in addition the staff who continues to fulfill
each problem that Bennu throws at us.”
The 4 candidate pattern websites on Bennu are designated Nightingale, Kingfisher, Osprey, and Sandpiper – all birds native to Egypt. The naming theme enhances the mission’s two different naming conventions – Egyptian deities (the asteroid and spacecraft) and mythological birds (floor options on Bennu).
The 4 websites are numerous in each geographic location and geological
options. Whereas the quantity of sampleable materials in every website has but
to be decided, all 4 websites have been evaluated totally to
make sure the spacecraft’s security because it descends to, touches and collects a
pattern from the asteroid’s floor.
Nightingale is the northern-most website, located at 56 levels north
latitude on Bennu. There are a number of potential sampling areas on this
website, which is ready in a small crater encompassed by a bigger crater 459
toes (140 m) in diameter. The positioning accommodates largely fine-grain, darkish
materials and has the bottom albedo, or reflection, and floor
temperature of the 4 websites.
Kingfisher is positioned in a small crater close to Bennu’s equator at 11
levels north latitude. The crater has a diameter of 26 toes (eight m) and
is surrounded by boulders, though the location itself is freed from giant
rocks. Among the many 4 websites, Kingfisher has the strongest spectral
signature for hydrated minerals.
Osprey is ready in a small crater, 66 toes (20 m) in diameter, which is
additionally positioned in Bennu’s equatorial area at 11 levels north latitude.
There are a number of potential sampling areas inside the website. The
range of rock sorts within the surrounding space means that the
regolith inside Osprey can also be numerous. Osprey has the strongest
spectral signature of carbon-rich materials among the many 4 websites.
Sandpiper is positioned in Bennu’s southern hemisphere, at 47 levels
south latitude. The positioning is in a comparatively flat space on the wall of a
giant crater 207 ft (63 m) in diameter. Hydrated minerals are additionally
current, which signifies that Sandpiper might comprise unmodified
water-rich materials.
This fall, OSIRIS-REx will start detailed analyses of the 4
candidate websites throughout the mission’s reconnaissance part. Throughout the
first stage of this part, the spacecraft will execute excessive passes over
every of the 4 websites from a distance of zero.eight miles (1.29 km) to verify
they’re protected and comprise sampleable materials. Closeup imaging additionally
will map the options and landmarks required for the spacecraft’s
autonomous navigation to the asteroid’s floor. The staff will use the
knowledge from these passes to pick the ultimate main and backup pattern
assortment websites in December.
The second and third levels of reconnaissance will start in early 2020 when the spacecraft will carry out passes over the ultimate two websites at decrease altitudes and take even increased decision observations of the floor to establish options, equivalent to groupings of rocks that will likely be used to navigate to the floor for pattern assortment. OSIRIS-REx pattern assortment is scheduled for the latter half of 2020, and the spacecraft will return the asteroid samples to Earth on September 24, 2023.
Goddard offers general mission administration, methods engineering, and
security and mission assurance for OSIRIS-REx. Dante Lauretta of the
College of Arizona, Tucson, is the principal investigator, and the
College of Arizona leads the science staff and the mission’s science
commentary planning and knowledge processing. Lockheed Martin House in
Denver constructed the spacecraft and is offering flight operations. Goddard
and KinetX Aerospace are accountable for navigating the spacecraft.
OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which
is managed by NASA’s Marshall House Flight Middle in Huntsville,
Alabama, for the company’s Science Mission Directorate in Washington.
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