The transistors on the Europa Clipper spacecraft are already installed, and removing them for inspections or replacement would delay the mission’s launch until late next year.
Europa Clipper has a 21-day launch window beginning October 10 to begin its journey into the outer solar system.
That’s roughly half of the total weight of the Europa Clipper spacecraft, the largest probe NASA has ever built for planetary exploration.
If that happens, Europa Clipper’s instruments will get a taste of the chemistry of Europa’s ocean.
“This is an epic mission,” said Curt Niebur, Europa Clipper’s program scientist at NASA Headquaters.
It appeared for a while earlier this summer that NASA’s flagship mission, Europa, which is designed to study Jupiter’s icy moon, might not launch this year.
Because radiation is a constant danger to any probe circling Jupiter, engineers expressed concern in May that transistors installed throughout the spacecraft might be vulnerable to damage. Located within the spacecraft’s circuitry, the transistors have about 200 distinct uses. Many of these are vital to the mission’s survival as it orbits Jupiter and frequently passes by Europa, using nine science instruments to investigate the frozen moon.
The Europa Clipper spacecraft already has transistors installed; taking them out for maintenance or replacement would push back the mission’s launch date to late 2019. Starting on October 10, Europa Clipper will have a 21-day window for launch to start its journey into the outer solar system.
Engineers discovered that the transistors on Europa Clipper could survive the intense radiation the spacecraft would encounter around Jupiter after four months of testing similar transistors on Earth, all without altering the mission’s flight plan or trajectory.
According to Jordan Evans, the project manager for Europa Clipper at the Jet Propulsion Laboratory (JPL), “one big challenge was analyzing how those transistors on the spacecraft would handle the radiation environment at Jupiter.”. “The Europa Clipper project and I are confident that we can successfully execute the initial mission to explore Europa as planned, having tested and analyzed the transistors extensively. “.
On Monday, senior NASA officials decided to concur with the JPL team’s evaluation of the Europa Clipper team.
“It’s amazing to be here with really good news,” NASA’s Science Mission Directorate Associate Administrator Nicky Fox said. “Everyone here is really content. As of right now, we have completed a critical milestone review for the Europa Clipper mission. the final major review before we truly get into launch fever, and we’re thrilled to report that they passed it with flying colors today. ****.
Later this week, teams at Kennedy Space Center in Florida, which are preparing Europa Clipper for launch, will start loading roughly 3 metric tons (6,600 pounds) of propellant into the spacecraft with permission from NASA headquarters. That is approximately half of the weight of NASA’s largest-ever planetary exploration probe, the Europa Clipper spacecraft. The probe will then be enclosed inside the launcher fairing by NASA and SpaceX technicians, and it will be connected to a Falcon Heavy rocket for launch the following month.
“We are confident that our beautiful spacecraft and capable team are ready for launch, operations, and our full science mission at Europa,” stated Laurie Leshin, JPL center director. “I am thrilled to write that.”.
This mission is really awesome.
Europa Clipper will arrive at Mars in February 2025 for a gravity assist flyby in order to accelerate its journey to Jupiter, after departing Florida’s Space Coast the following month. Europa Clipper will reroute its trajectory after another flyby of Earth in December 2026 to cross Jupiter’s orbit in April 2030. At that time, the probe will ignite its engines to slow down and become trapped by the powerful gravitational field of the massive planet.
After that, Europa Clipper will align itself on a course to fly 49 times across roughly four years, getting as close as 16 miles (25 kilometers) to the icy surface of the moon. By mapping the majority of the moon’s icy crust, Europa Clipper’s instruments will look for clues suggesting that Europa’s subterranean ocean of liquid water could support life. If the scientists are fortunate, the spacecraft may also pass through plumes that are erupting from the surface of Europa; these eruptions may contain pure materials from the ocean beneath its cryoprotective shell. Should it occur, the instruments aboard Europa Clipper will be able to sample the ocean’s chemistry.
Curt Niebur, NASA Headquarters’ program scientist for Europa Clipper, declared, “This is an epic mission.”. The opportunity presents itself for us to investigate a world that could potentially support life not just billions of years from now, but also one that exists now. “.”.
Europa, which is roughly 90% the size of the Moon, orbits Jupiter in the radiation belts that surround the planet, where charged particles have the potential to destroy any spacecraft that ventures near them.
Europa Clipper’s most delicate electronics are housed inside a vault with aluminum-zinc alloy walls to protect the parts from Jupiter’s radiation. While some of the spacecraft’s transistors are housed inside this vault, others are found in science instruments that are situated outside the craft.
Because of a self-healing characteristic called annealing, the transistors can recover a significant portion of their capacity following exposure to high radiation. In order to give the transistors time to heal themselves in between close flybys of Europa, where the radiation is highest, Europa Clipper spends the majority of its orbit around Jupiter in a radiation-free environment. Mission managers will only modify the heater settings on two instruments outside the vault to address some of the suspect transistors on Europa Clipper. The components can self-heal more effectively in warmer climates.
Evans explained that these devices were metal oxide field effect transistors, which functioned similarly to electrical switches that could be closed by applying a voltage”.
When a switch activates a tiny 1-watt decontamination heater, Evans stated, “that’s really not a big deal to the mission.” However, in certain situations, the switch essentially stays on all the time. It would be more concerning, though, if that circuit is informing the spacecraft that it must enter safe mode. The significance is immense. We thus examined each of those circuits to see how resilient and tolerant they were to failing transistors, and we came to the conclusion that we had enough margin in each circuit to confidently complete this flagship mission. “.
