The goal of the Europa Clipper spacecraft is to look for and investigate signs of habitability on one of Jupiter’s moons when it launches next month. NASA reports that the spacecraft achieved a significant milestone on Monday. Its launch window will open on October 10.
The mission has completed the critical planning phase known as “key decision point E,” which is the stage at which the mission’s launch status is determined. The Europa Clipper crew was happy to receive clearance following the discovery of a possible transistor issue with the spacecraft in May.
Engineers were concerned about transistors’ resistance to Jupiter’s intense radiation because they are crucial to managing the electrical flow inside the vehicle.
Extensive testing was conducted for four months at NASA’s Jet Propulsion Laboratory in Pasadena, California, the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, and NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
The team was able to complete the necessary testing on time, avoiding a 13-month delay in the launch of the mission to explore Europa, an ice-covered world that may harbor life in its salty underground ocean. Europa Clipper is carrying 10 scientific instruments that could determine whether life is possible anywhere in our solar system other than Earth. Europa Clipper was cleared for launch with no changes to the mission plan, objectives or trajectory.
“This is the last major review before we get into the excitement of launch, and we’re very pleased to say that it clearly passed that review today,” Nicola Fox, associate administrator for NASA’s Science Mission Directorate, said during a press briefing on Monday.
In May, the manufacturer of the transistors warned the mission team that the parts might not be as radiation-resistant as previously thought . The transistors are located throughout the spacecraft.
Jupiter is the largest planet in our solar system and has a magnetic field 20,000 times stronger than Earth’s. This magnetic field traps charged particles and accelerates them to high speeds. The fast-moving particles release energy in the form of intense radiation that bombards Europa and Jupiter’s other nearest moons.
Any spacecraft headed to Jupiter needs radiation-resistant electronics. “Jupiter is shrouded in more radiation than any other planet in our solar system, and that’s one of the reasons exploring the Jupiter system is so difficult,” said Jordan Evans, Europa Clipper project manager at JPL.
“Europa is located near the outer edge of the worst part of that radiation belt,” he added. “Flying close to Europa exposes us to this high flux of damaging particles, so mission engineers and Europa Clipper need to be confident that spacecraft components can survive that radiation environment for the duration of our four-year mission.”
Data from previous NASA missions to Jupiter, including the Juno spacecraft currently studying the planet and some of its moons, were used to validate the transistor testing process, Evans said.
The tests ran around the clock since May, simulating spaceflight conditions to see how the craft and its components would perform as the vehicle makes 49 flybys of Europa and ultimately 80 orbits around Jupiter over a four-year period. The team determined that the transistors can self-repair between flybys.
“We’ve come to the conclusion, after all this testing, that during our orbits around Jupiter, even though Europa Clipper goes into the radiation environment, once it comes out, it comes out long enough to give those transistors a chance to repair themselves and partially recover between flybys,” Evans said.
A radiation monitor installed on the spacecraft will allow the team to monitor the evolution of the transistors. “Personally, I have a lot of confidence that we can complete the original mission of exploring Europa as planned,” Evans said.
When Europa Clipper program scientist Curt Niebur joined NASA in 2003, he was faced with the task of launching a mission to Europa. Each year, the effort to design and build Europa Clipper seemed more difficult, he said.
“There hasn’t been a more challenging year than this one, and especially last summer,” Niebur said. “But through it all, we never doubted that it was going to be worth it. It’s an opportunity to explore, not a world that might have been habitable billions of years ago, but a world that might be habitable today – an opportunity to do the first exploration of this new kind of world that we’ve discovered very recently called an ocean world that is totally immersed and covered in an ocean of liquid water completely unlike anything we’ve seen before. That’s what awaits us on Europa.”
Europa Clipper is not a life detection mission, Niebur added.
The mission’s key goals focus on finding out whether Europa has the right ingredients for life as we know it: water, energy and chemistry. And without any scientific instruments that can directly determine the existence of life, Clipper can’t find conclusive evidence of it, he said.
“You can bet your bottom dollar that if Europa Clipper tells us yes, those ingredients are there, we’re going to be knocking on the door, fighting for a second mission to go look for life,” Niebur said.
Europa Clipper will be key in helping NASA determine where to send follow-up missions, such as to parts of the ice crust that may be thin and where subsurface ocean water could well up, said JPL director Laurie Leshin.
“If we get there and do this research, and the good news is that it has all the ingredients and it’s habitable, what that means is that there are two places in a solar system that have all the ingredients for life that are habitable right now, at the same time,” Niebur said.
“Think about what that means when you extend that result to the billions and billions of other solar systems in this galaxy,” he added. “Leaving aside the question of whether there is life on Europa, just the question of habitability itself opens up a huge new paradigm for the search for life in the galaxy.”
