The largest spacecraft NASA has ever built for planetary exploration has just received its “wings”: giant solar arrays that will power it on its journey to Jupiter’s icy moon Europa.
NASA’s Europa Clipper spacecraft was recently outfitted with a series of giant solar arrays at the agency’s Kennedy Space Center in Florida. The arrays are each about 46 feet (14.2 meters) long and 13 feet (4.1 meters) tall, making them the largest NASA has ever designed for a planetary mission. They need to be large so they can capture as much sunlight as possible during the spacecraft’s study of Jupiter’s moon Europa, which is five times farther from the sun than Earth.
The arrays were folded up and attached to the main body of the spacecraft for launch, but when deployed in space, Europa Clipper will have a wingspan of more than 100 feet (30.5 meters) — a few feet longer than a professional basketball court. The “wings,” as engineers call them, are so large that they could only be opened one at a time in the clean room at Kennedy’s Payload Hazardous Servicing Facility, where teams are preparing the spacecraft for its launch, which begins Oct. 10.
Photo credit: NASA/JPL-Caltech/KSC/APL/Airbus
In the meantime, engineers are continuing to evaluate tests conducted on the radiation resistance of the transistors on the spacecraft. Longevity is crucial because the probe will be traveling for more than five years to reach the Jupiter system in 2030. As it orbits the gas giant, the probe will fly past Europa several times, using a range of scientific instruments to find out whether the ocean beneath its icy shell has conditions that could support life.
Power for these flybys, in a region of the solar system that receives only three to four percent of Earth’s sunlight, will be provided by five-panel solar arrays each. They were designed and built at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, and at Airbus in Leiden, the Netherlands. They are much more sensitive than the solar arrays used on homes, and the highly efficient spacecraft will make the most of the power they generate.
On Jupiter, Europa Clipper’s solar cells will generate a combined 700 watts of electricity, about as much as a small microwave or coffee machine needs to run. On the spacecraft, batteries will store the power for all electronics, a full payload of scientific instruments, communications equipment, the computer, and a complete propulsion system with 24 engines.
The arrays have to work in extreme cold. In the shadow of Jupiter, the temperature of the hardware drops to minus 400 degrees Fahrenheit (minus 240 degrees Celsius). To ensure that the panels work in these extremes, the engineers tested them in a special cryogenic chamber at the Liège Space Center in Belgium.
“The spacecraft is cozy. It has heaters and an active heat loop that keep it in a much more normal temperature range,” said APL’s Taejoo Lee, the product delivery manager for solar arrays. “But the solar arrays are exposed to the vacuum of space without heaters. They’re completely passive, so those are the temperatures they reach no matter what the environment is.”
About 90 minutes after launch, the arrays will unfold from their folded position in about 40 minutes. About two weeks later, six antennas attached to the arrays will also unfold to their full size. The antennas are part of the radar instrument that will search for water in and under the moon’s thick ice layer. They are enormous and unfold perpendicular to the arrays to a length of 17.6 meters.
“At the beginning of the project, we really thought it would be almost impossible to develop a solar array strong enough to support these gigantic antennas,” Lee said. “It was difficult, but the team approached the challenge with a lot of creativity and we succeeded.”
More about the mission
Europa Clipper’s three main scientific objectives are to determine the thickness of the Moon’s icy shell and its interaction with the underlying ocean, study its composition, and characterize its geology. The mission’s detailed exploration of Europa will help scientists better understand the astrobiological potential for habitable worlds beyond our planet.
NASA’s Jet Propulsion Laboratory, managed by Caltech in Pasadena, California, is leading development of the Europa Clipper mission in partnership with APL for NASA’s Science Mission Directorate in Washington. APL designed the spacecraft’s main 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 the Langley Research Center in Hampton, Virginia. The Planetary Missions Program Office in Marshall is conducting program management of the Europa Clipper mission.
NASA’s Kennedy-based Launch Services Program manages launch services for the Europa Clipper spacecraft, which will launch on a SpaceX Falcon Heavy rocket from Launch Complex 39A at Kennedy.
For more information about Europe, see:
europe.nasa.gov
Gretchen McCartney
Jet Propulsion Laboratory, Pasadena, California.
818-393-6215
[email protected]
Karen Fox / Alana Johnson
NASA Headquarters, Washington
202-358-1600 / 202-358-1501
[email protected] / [email protected]
2024-112
