Ілюстрація, яка показує космічний корабель Europa Clipper на орбіті Юпітера
Jupiter’s icy moon Europa is considered one of the most promising places in the solar system to search for signs of life.
The Europa Clipper spacecraft launched aboard a SpaceX Falcon Heavy rocket on Monday (the launch was delayed for several days due to Hurricane Milton) and marked the beginning of the mission’s long 5-year journey to Jupiter. There, the ship will explore the planet’s icy moon Europa, which is of interest to scientists because of what the ocean may contain under the frozen crust.
«This is an epic mission. The chance for us not to explore a world that might have been habitable billions of years ago, but a world that might be habitable right now,» said Kurt Niebuhr, Europa Clipper program scientist.
The first images of Jupiter up close sent NASA probes «Voyager» in 1979, while a follow-up mission called «Galileo» orbited the planet for almost eight years until the early 2000s and found signs of ocean presence on its satellite.
As noted by Ars Technica Europa Clipper concepts tried to continue the research, but all were canceled, while former U.S. Congressman John Culberson actively promoted the mission, demanding that it be included in NASA’s budget. Eventually, the Obama administration and the space agency officially supported the project, which became known as Europa Clipper in 2015.
Europa Clipper is the largest spacecraft NASA has ever sent to explore a planetary body (weight 5.7 tons at launch). It is equipped with two solar panels that can capture weak sunlight from a long distance (5 times the distance from the Earth to the Sun).
It is also the most expensive planetary mission in NASA’s history, costing $5.2 billion — about half the cost of the James Webb Space Telescope and twice as expensive as the last Mars rover of the US space agency.
The power of the Falcon Heavy allowed the Europa Clipper to reach the trajectory along which it will eventually reach Jupiter. SpaceX used all the fuel to provide the necessary speed for the spacecraft, so there was no room left to restore the accelerators. According to John Edwards, vice president of the space company, The Falcon Heavy reached a speed of 45,648 kilometers per hour — the highest speed ever achieved by a SpaceX rocket.
To reach Jupiter, Europa Clipper will have to travel 2.9 billion kilometers — next year the mission will approach Mars, while in 2026 it will return to Earth. These flybys will use the gravity of each planet to «push» the spacecraft further away from the Sun and direct it to Jupiter.
Europa Clipper is scheduled to reach Jupiter in April 2030. Then the mission will run its engines for 6–8 hours to consume most of its fuel and slow down in the planet’s orbit. In this way, the spacecraft will set itself up to launch a series of 49 «close calls» with Europe.
«To be clear, we are not landing on Europe. We are coming very close, 25 kilometers above the surface. These overflights cover both hemispheres of the satellite and different latitudes,», — says project manager Jordan Evans.
NASA’s «Galileo» spacecraft approached Europe a dozen times, but had scientific instruments from the 1980s. Whereas, Europa Clipper boasts a 21st century payload package — with nine instruments to study Jupiter’s icy moon, from its ocean to the surrounding atmosphere.
«Europa Clipper contains the most sophisticated set of instruments we’ve ever sent to the outer solar system,» says Bob Pappalardo, project scientist. «It has a radar that can traverse ice and works like a computed tomography scanner, providing ultra-high resolution images. We’ll also be able to look for warm spots and plumes in Europe — all these great techniques that come together to tell us if the satellite could be the place that can support life today.»
The best of the Europa Clipper cameras will be able to recognize elements up to 50 cm in size on the satellite’s surface in certain areas. These images will be 12 times sharper than the most detailed images taken by «Galileo».
The rest of the spacecraft’s sensors will determine the composition of Europa’s crust and rarefied atmosphere, look for columns of water (previously detected by the Hubble telescope) that emerge through cracks in the icy shell, and scan for small pools of water that could potentially be on Europa’s surface.
Scientists will use magnetic and gravitational field measurements from the Europa Clipper to determine the depth and salinity of Europa’s ocean According to rough estimates, the depth of the ocean is 100-120 km, and the thickness of the ice shell is about 15-30 km.
The second goal of Europa Clipper is to find places on the satellite’s surface that might be worth sending a lander to.
«Sometimes people ask me what I would like to see happen in Europe. What would be the best result?”» — says Pappalardo. «For me, — is to find some kind of oasis with evidence of liquid water near the surface, evidence of organic matter. This could be a place where NASA can send a lander in the future and literally look for signs of life».
Source: NASA, Ars Technica