NASA, European Space Agency go for Jupiter’s moons
By Leena Singh and Surendra P. Sharma|December 2024
The Space Exploration Integration Committee brings together experts on topics relevant to future human and robotic exploration missions.
In June, NOAA’s GOES-U, the Geostationary Operational Environmental Satellites-U, was launched aboard a SpaceX Falcon Heavy rocket. The fourth of four GOES-R series weather and environment monitoring satellites, GOES-U will monitor the Western Hemisphere, including the Americas, the Caribbean and the Atlantic Ocean to western Africa. After a fortnight’s transfer from delivery into geostationary transfer orbit, GOES-U was inserted into its checkout slot, about 35,700 kilometers altitude, and renamed GOES-19. Following an extended instrument checkout period that began in August, GOES-19 is to drift from checkout to its operational slot in 2025 to commence environmental monitoring with the rest of the GOES-R satellites. GOES-19 carries a new, highly sensitive Compact Coronagraph-1, which is to detect and characterize solar coronal mass ejections with high sensitivity, providing enhanced forecasting of impending geomagnetic storms on Earth.
In October, a Falcon Heavy launched NASA’s Europa Clipper toward Jupiter’s moon, Europa. The spacecraft left its assembly site at the Jet Propulsion Laboratory in California in May for launch preparations from NASA’s Kennedy Space Center in Florida. At Kennedy, final assembly included the installation of a high-gain antenna and two 46-foot-long solar panels, whose deployments were individually tested within Kennedy’s clean rooms. Clipper will see temperatures below minus 240 degrees Celsius during eclipse in Jupiter orbit, so engineers combed through thermal and environmental hardiness test data collected in specialized cryogenic chambers deep into the year. Europa Clipper is equipped with nine science instruments that are to collect detailed measurements through the moon’s icy crust during some 50 close flybys. Scientists have theorized a vast ocean is beneath Europa’s icy crust, and Clipper’s mission is to inspect Europa’s crust for its thickness, composition and geology. Clipper is scheduled to arrive in orbit around Jupiter in 2030.
Adding to collision concerns of Earth’s growing orbital debris volumes are environmental concerns from pollutants released into the stratosphere by reentering space objects. In February, the U.K. Space Agency awarded the University of Southampton the first “atmospheric ablation” research grant into potential climate, weather, astronomical and communications impacts from rocket bodies and defunct satellites disintegrating in the high atmosphere, releasing vast quantities of metal effluents. From multiple sample collection flights with a laser mass spectrometer onboard NASA’s WB-57 aircraft last year, NOAA scientists analyzed the 60,000-plus stratospheric particles collected. Their analysis, published in July in “Science” magazine, showed the world’s first definitive evidence of stratospheric pollution from metal alloys that bear markers of spacecraft reentry.
In August, the European Space Agency’s Jupiter Icy Moons Explorer, Juice, executed the first-ever double gravity-assist maneuver via another first, a lunar-Earth flyby, in a fuel-saving exercise to shortcut its rendezvous path to Jupiter’s moons in 2031. Juice’s near-perfect flyby execution demonstrated exquisite navigation and control precision and provided an opportunity to test its 10 scientific instruments. Among the instruments were the JANUS science camera and the NavCam vision-navigation sensor. NavCam will be critical for precise autonomous guidance, navigation and control in the Jupiter planetary system, and taking images of the flyby was an opportunity to conduct an early test of the sensors. After this double planetary assist, Juice is bound for a Venus gravity-assist slingshot, using a series of Venus-Earth/moon passes to save propellant.
Observations from ESA’s Solar Orbiter and NASA’s Parker Solar Probe processed this year answered long-standing questions about the source of energetics of solar winds. The two probes had intersected the same coronal stream from their distinct orbits one to two days apart; measurements of the time and space separated transits of the same phenomenon showed that energy gradients correlated to oscillations in the sun’s magnetic field. This analysis dispels some of the mysteries about our sun.
Contributors: Narayanan R. Ramachandran, Karen Rosenlof and Martin N. Ross
