NASA confirms that the next phase of the Europa Clipper mission is underway, which will send a spacecraft to the icy moon Europa. This moon of Jupiter is a very good candidate in our solar system to find life.
The current decision to proceed to the next phase means that the final design can be completed. Then construction and testing can begin. It is not yet entirely clear when the probe will be launched, but NASA says it has set a goal to have the spacecraft ready by 2023.
However, the plan assumes an external launch readiness of 2025. So it could take another six years before the probe sets course for Europe. A 2025 launch date seems more likely, as the Europa Clipper mission is to be launched with the US Space Launch System rocket, or SLS. It is not yet completed. Its design involves the necessary delays and cost overruns. Each launch is estimated to cost more than $1 billion.
Switching to SpaceX’s much cheaper Falcon Heavy could theoretically be an option, but that will not only meet with political objections. Joan Salute of the Europa Clipper program tells Scientific American that there is also a technical objection. Europe can be reached with the less powerful Falcon Heavy, but then there will be at least three years of travel time. The SLS can guarantee a direct flight from Earth to Jupiter, but with the Falcon Heavy, a gravitational pendulum from Venus is needed to generate enough speed. This automatically entails some additional risks.
“We are very pleased with the decision that brings the Europa Clipper mission one step closer to discovering the mysteries of this ocean world,” said Thomas Zurbuchen of NASA’s Science Mission Directorate. “We are building on scientific insights from the Galileo and Cassini spacecraft and are working to increase our understanding of our cosmic origins and life elsewhere.”
Zurbuchen does not mention Galileo for nothing. This Jupiter probe flew past Europa 11 times between 1995 and 2003 to make measurements. Based on the 20-year-old data from this probe, NASA found evidence for the existence of water geysers on Europa in May last year. They blow plumes of water into space. There were already indications of its presence after Hubble took pictures of the moon in 2012 and 2016.
Europa is covered with a substantial layer of ice and it is thought that the water plumes originate from a large saltwater ocean that lies below the ice layer. In addition to water, there are, for example, also carbon and an energy source on the moon. The energy comes from the tidal action of Jupiter’s gravity, generating enough heat to keep water liquid. These elements are seen by scientists as crucial to the possibility of life.
The idea of the mission is for the Europa Clipper to enter orbit around Jupiter and pay Europa several visits. During each fly-by, data will be collected on the ice sheet and the likely ocean. Orbiting Europa was not chosen because the probe would then be exposed to the full spectrum of Jupiter’s radiation bands for too long. These are charged particles thrown off by Jupiter’s strong magnetic field, which could theoretically destroy the probe’s electronics and nine different instruments. This risk is limited by making short stops in the orbit around Jupiter and Europa. No landing on the moon is planned for the Europa Clipper mission, but a second mission, which will involve landing to collect samples, is in development.
Incidentally, the ESA is also planning a mission to visit Europe. The JUpiter ICy moons Explorer of Juice is due to launch in 2022 and will explore three of Jupiter’s 79 moons: Ganymede, Callisto and Europa. The maiden flight of the European probe over Europe will not take place until 2030, as several time-consuming gravitational swings must take place.