Europa Clipper’s radar instrument received echoes of
its very-high-frequency radar signals that bounced off Mars and were processed
to develop this radargram. What looks like a skyline is the outline of the
topography beneath the spacecraft.
NASA/JPL-Caltech/UT-Austin
The agency’s largest interplanetary probe tested its radar during a Mars
flyby. The results include a detailed image and bode well for the mission at
Jupiter’s moon Europa.
As it soared past Mars in March,
NASA’s Europa Clipper conducted a critical radar test that had been impossible
to accomplish on Earth. Now that mission scientists have studied the full
stream of data, they can declare success: The radar performed just as expected,
bouncing and receiving signals off the region around Mars’ equator without a
hitch.
Read more
about Europa Clipper's radargram at Mars
Called REASON (Radar for Europa Assessment and Sounding: Ocean
to Near-surface), the radar instrument will “see” into Europa’s icy shell,
which may have pockets of water inside. The radar may even be able to detect
the ocean beneath the shell of Jupiter’s fourth-largest moon.
“We got everything out of the flyby that we dreamed,” said Don Blankenship, principal investigator of the radar instrument, of the University of Texas at Austin. “The goal was to determine the radar’s readiness for the Europa mission, and it worked. Every part of the instrument proved itself to do exactly what we intended.”
In this artist’s concept, Europa Clipper’s radar
antennas — seen at the lower edge of the solar panels — are fully deployed. The
antennas are key components of the spacecraft’s radar instrument, called
REASON.
NASA/JPL-Caltech
The radar will help scientists understand how the ice may capture materials
from the ocean and transfer them to the surface of the moon. Above ground, the
instrument will help to study elements of Europa’s topography, such as ridges,
so scientists can examine how they relate to features that REASON images
beneath the surface.
Limits of
Earth
Europa Clipper has an unusual radar
setup for an interplanetary spacecraft: REASON uses two pairs of slender
antennas that jut out from the solar arrays, spanning a distance of about 58
feet (17.6 meters). Those arrays themselves are huge — from tip to tip, the
size of a basketball court — so they can catch as much light as possible at
Europa, which gets about 1/25th the sunlight as Earth.
The instrument team conducted all
the testing that was possible prior to the spacecraft’s launch from NASA’s Kennedy Space Center in Florida on Oct. 14, 2024. During development,
engineers at the agency’s Jet Propulsion Laboratory in Southern California even
took the work outdoors, using open-air towers on a plateau above JPL to stretch
out and test engineering models of the instrument’s spindly high-frequency and
more compact very-high-frequency antennas.
But once the actual flight hardware
was built, it needed to be kept sterile and could be tested only in an enclosed
area. Engineers used the giant High Bay 1 clean room at JPL, where the spacecraft was assembled, to
test the instrument piece by piece. To test the “echo,” or the bounceback of
REASON’s signals, however, they’d have needed a chamber about 250 feet (76
meters) long — nearly three-quarters the length of a football field.
Enter Mars
The mission’s primary goal in
flying by Mars on March 1, less than five months after launch, was to use the
planet’s gravitational pull to reshape the spacecraft’s trajectory. But it also presented opportunities to calibrate the spacecraft’s infrared camera and perform a dry run of the radar instrument
over terrain NASA scientists have been studying for decades.
As Europa Clipper zipped by the
volcanic plains of the Red Planet — starting at 3,100 miles (5,000 kilometers)
down to 550 miles (884 kilometers) above the surface — REASON sent and received
radio waves for about 40 minutes. In comparison, at Europa the instrument will
operate as close as 16 miles (25 kilometers) from the moon’s surface.
All told, engineers were able to
collect 60 gigabytes of rich data from the instrument. Almost immediately, they
could tell REASON was working well. The flight team scheduled the full dataset
to download, starting in mid-May. Scientists relished the opportunity over the
next couple of months to examine the information in detail and compare
notes.
“The engineers were excited that
their test worked so perfectly,” said JPL’s Trina Ray, Europa Clipper deputy
science manager. “All of us who had worked so hard to make this test happen —
and the scientists seeing the data for the first time — were ecstatic, saying,
‘Oh, look at this! Oh, look at that!’ Now, the science team is getting a head
start on learning how to process the data and understand the instrument’s
behavior compared to models. They are exercising those muscles just like they
will out at Europa.”
Europa Clipper’s total journey to
reach the icy moon will be about 1.8 billion miles (2.9 billion kilometers) and
includes one more gravity assist — using Earth — in 2026. The spacecraft is
currently about 280 million miles (450 million kilometers) from Earth.
More About
Europa Clipper
Europa Clipper’s three main science
objectives are to determine the thickness of the moon’s icy shell and its
interactions with the ocean below, to investigate its composition, and to
characterize its geology. The mission’s detailed exploration of Europa will
help scientists better understand the astrobiological potential for habitable
worlds beyond our planet.
Managed by Caltech in Pasadena,
California, NASA’s Jet Propulsion Laboratory in Southern California leads the
development of the Europa Clipper mission in partnership with the Johns Hopkins
Applied Physics Laboratory in Laurel, Maryland, for NASA’s Science Mission
Directorate in Washington. APL designed the main spacecraft body in
collaboration with JPL and NASA’s Goddard Space Flight Center in Greenbelt,
Maryland, NASA’s Marshall Space Flight Center in Huntsville, Alabama, and
Langley Research Center in Hampton, Virginia. The Planetary Missions Program
Office at NASA Marshall executes program management of the Europa Clipper
mission. NASA’s Launch Services Program, based at NASA Kennedy, managed the
launch service for the Europa Clipper spacecraft. The REASON radar
investigation is led by the University of Texas at Austin.
Find more information about Europa
Clipper here:
https://science.nasa.gov/mission/europa-clipper/
Source: NASA’s Europa Clipper Radar Instrument Proves Itself at Mars - NASA
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