by All space missions require split-second precision, but the ambitious journey from Europa to Jupiter has a tighter schedule than usual.
The Juice mission, which searches for signs of extraterrestrial life on the Jovian moons Europa, Ganymede and Callisto, has a minuscule one-second window to enter orbit when it launches in April.
The European Space Agency’s orbiter needs to take advantage of the gravitational forces of Earth, Mars and Venus to launch it towards its target, and the planets must line up perfectly, or the spacecraft could end up badly off course.
By comparison, when the Artemis I mission launched to the Moon last November, it had a quiet two hours to lift off.
Juice, which stands for Jupiter Icy Moons Explorer, will launch on April 13 from the European spaceport in Kourou, French Guiana, aboard an Ariane 5 rocket.
Justin Byrne, head of Earth exploration and science missions at Airbus Defense and Space UK, which built the spacecraft, said: “The rocket is not powerful enough to send the mission directly to Jupiter, so we have to use energy from somewhere else, so we steal it from the planets.
“Those planets will only align twice a year, in April and at the end of summer. But when that aligns with Earth’s rotation, we only have a one-second launch window each day where the physics of the entire universe aligns, so it’s quite a complicated thing.”
Jupiter is about 391 million miles from Earth, on average, and it will take the spacecraft eight years to reach its destination.
The system is believed to be one of the best places to search for extraterrestrial life because its icy moons are believed to contain vast icy oceans.
Once there, the orbiter will fly 125 miles over Callisto, observing the oldest moon in the Solar System, before making two flybys of Europa.
Beneath Europa’s ice crust is believed to lie a huge ocean of liquid water, or mud ice, containing twice as much water as Earth’s oceans combined.
This vast, deep body of water is widely considered the most promising place to search for life in the Solar System, and instruments aboard Juice will search for biosignatures such as methane, which could indicate life thrives below the icy surface. .
On Earth, extremophile life forms have been found thriving near subterranean volcanoes and deep-sea vents, raising hopes that they may also exist in the subterranean oceans of Jupiter’s moons.
After Europa, the mission will spend eight months circling Ganymede, the first time a spacecraft has orbited a moon other than our own.
Ganymede is the only moon in the Solar System known to generate its own magnetic field, so scientists are eager to find out how it is doing so.
Like Europa and Callisto, it harbors a hidden ocean, so researchers will also be looking for signs of habitability.
“Ganymede is the one that really interests everyone, because it has a magnetic field and it must have a molten core, but the other two have liquid below the surfaces and there is potentially life on all three,” Byrne added.
“There are definitely signatures that we can see. When the data starts coming back, it’s going to be really intensive, with new bang, bang, bang results. We will be inundated with new information.”
The magnetic field surrounding Ganymede has proved a challenge for spacecraft engineers who had to build a lead-lined core to protect the electronics.
Byrne added: “It has a massive magnetic field, 10,000 times stronger than Earth, so it’s really the worst place to put a spacecraft. If you wanted to kill him, this is what you would do.”
In all, Juice will make 35 flybys of all three moons, before finally carrying out a controlled crash on Ganymede. The team also wants to learn more about Jupiter, particularly why its famous Red Spot is shrinking.
Experts believe the one-second window is achievable, but worry that weather could ruin the launch. Too much wind or storms could cause delays and mean waiting for the next time the planets align.
If the first window is missed, there are several more opportunities in April, but after that, the team will have to wait until August.
