NASA’s NEO Surveyor is seen in this illustration against an infrared
observation of a starfield made by the agency’s WISE mission. More than 100
asteroids can be seen as red dots, with some of them visible in a track that
shows how they were captured at different times as they marched across the sky.
Credits: NASA/JPL-Caltech/University of Arizona
NEO Surveyor is the first purpose-built space telescope that will advance
NASA’s planetary defense efforts by finding and tracking hazardous near-Earth
objects.
A space telescope
designed to search for the hardest-to-find asteroids and comets that stray into
Earth’s orbital neighborhood, NASA’s Near-Earth Object Surveyor (NEO Surveyor) recently passed a rigorous technical and programmatic review. Now the mission is transitioning into
the final design-and-fabrication phase and establishing its technical, cost,
and schedule baseline.
The mission supports the objectives of
NASA’s Planetary Defense Coordination Office (PDCO) at NASA Headquarters in Washington. The
NASA Authorization Act of 2005 directed NASA to discover and characterize at
least 90% of the near-Earth objects more than 140 meters (460 feet) across that
come within 30 million miles (48 million kilometers) of our planet’s orbit.
Objects of this size are capable of causing significant regional damage, or
worse, should they impact the Earth.
“NEO Surveyor represents the next
generation for NASA’s ability to quickly detect, track, and characterize
potentially hazardous near-Earth objects,” said Lindley Johnson, NASA’s
Planetary Defense Officer at PDCO. “Ground-based telescopes remain essential
for us to continually watch the skies, but a space-based infrared observatory
is the ultimate high ground that will enable NASA’s planetary defense
strategy.”
Find
Them First
Managed by NASA’s Jet Propulsion
Laboratory in Southern California, NEO Surveyor will journey a million miles to
a region of gravitational stability – called the L1 Lagrange point – between Earth and the Sun, where the
spacecraft will orbit during its five-year primary mission.
From this location, the NEO Surveyor will
view the solar system in infrared wavelengths – light that is invisible to the
human eye. Because those wavelengths are mostly blocked by Earth’s atmosphere,
larger ground-based observatories may miss near-Earth objects that this space
telescope will be able to spot by using its modest light-collecting aperture of
nearly 20 inches (50 centimeters).
NEO Surveyor’s cutting-edge detectors are
designed to observe two heat-sensitive infrared bands that were chosen
specifically so the spacecraft can track the most challenging-to-find
near-Earth objects, such as dark asteroids and comets that don’t reflect much
visible light. In the infrared wavelengths to which NEO Surveyor is sensitive,
these objects glow because they are heated by sunlight.
In addition, NEO Surveyor will be able to
find asteroids that approach Earth from the direction of the Sun, as well as
those that lead and trail our planet’s orbit, where they are typically obscured
by the glare of sunlight – objects known as Earth Trojans.
“For the first time in our planet’s
history, Earth’s inhabitants are developing methods to protect Earth by deflecting hazardous
asteroids,” said Amy Mainzer, the mission’s survey director at the University
of Arizona in Tucson. “But before we can deflect them, we first need to find
them. NEO Surveyor will be a game-changer in that effort.”
The mission will also help to characterize
the composition, shape, rotation, and orbit of near-Earth objects. While the
mission’s primary focus is on planetary defense, this information can be used
to better understand the origins and evolution of asteroids and comets, which
formed the ancient building blocks of our solar system.
When it launches, NEO Surveyor will build
upon the successes of its predecessor, the Near-Earth Object Wide-field
Infrared Survey Explorer (NEOWISE). Repurposed from the WISE space telescope after that
mission ended in 2011, NEOWISE proved highly effective at detecting and
characterizing near-Earth objects, but NEO Surveyor is the first space mission
built specifically to find large numbers of these hazardous asteroids and
comets.
Already
in the Works
After the mission passed this milestone on
Nov. 29, key instrument development got under way. For instance, the large
radiators that will allow the system to be passively cooled are being
fabricated. To detect the faint infrared glow of asteroids and comets, the
instrument’s infrared detectors need to be much cooler than the spacecraft’s
electronics. The radiators will perform that important task, eliminating the
need for complex active cooling systems.
Additionally, construction of the
composite struts that will separate the telescope’s instrumentation from the
spacecraft has begun. Designed to be poor heat conductors, the struts will
isolate the cold instrument from the warm spacecraft and sunshield, the latter
of which will block sunlight that might otherwise obscure the telescope’s view
of near-Earth objects and heat up the instrument.
Progress has also been made developing the
instrument’s infrared detectors, beam splitters, filters, electronics, and
enclosure. And work has begun on the space telescope’s mirror, which will be
formed from a solid block of aluminum and shaped by a custom-built
diamond-turning machine.
“The project team, including all of our
institutional and industrial collaborators, is already very busy designing and
fabricating components that will ultimately become flight hardware,” said Tom
Hoffman, NEO Surveyor project manager at JPL. “As the mission enters this new
phase, we’re excited to be working on this unique space telescope and are
already looking forward to our launch and the start of our important mission.”
More
About the Mission
The mission is tasked by NASA’s Planetary
Science Division within the Science Mission Directorate; program oversight is
provided by the PDCO, which was established in 2016 to manage the agency’s
ongoing efforts in planetary defense. NASA’s Planetary Missions Program Office
at Marshall Space Flight Center provides program management for NEO Surveyor.
The project is being developed by JPL and is led by survey director Amy Mainzer at the University of Arizona. Established aerospace and engineering companies have been contracted to build the spacecraft and its instrumentation, including Ball Aerospace , Space Dynamics Laboratory, and Teledyne. The Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder will support operations, and IPAC-Caltech in Pasadena, California, is responsible for processing survey data and producing the mission’s data products. Caltech manages JPL for NASA.
More information about NEO Surveyor is
available at: https://solarsystem.nasa.gov/missions/neo-surveyor
No comments:
Post a Comment