NASA has high hopes for Jupiter’s moon Europe, and the US space agency has just dotted the i’s and crossed the t’s on the spacecraft that will fly there to see if it can really support life. Europa Clipper faces a long journey as Jupiter orbits the sun on a far more elliptical path than Earth, but what he can find there can make it all worth it.
This is because Europe, unlike what we have seen from other planets and moons in the solar system, shows signs that it is very conducive to supporting life. There is twice as much liquid water there as on earth, mostly for a large, salty ocean. It is warming up by tidal warming and is expected to be filled with minerals from the rocky moon of the moon.
In short, as potential places where life can develop or even flourish, Europe can be a relative haven before our doorstep, astronomically speaking. The Europa Clipper project is the way NASA is sure to figure it out, with the agency confirming that the spacecraft has now completed its Critical Design Review. This is the process by which the complete design – including everything from propulsion to scientific instruments, to the complex radiation shielding required – is assessed before the final spacecraft is signed off to begin.
The design is not simple. Europe may have a lot of water, but it also occupies a particularly treacherous part of space. Radiation levels are high and surface temperatures are low; this means Europe Clipper must be both tough enough to survive those conditions, but also instruments sensitive enough to get the data NASA and its scientists need.
The plan is seemingly straightforward. Once it reaches Jupiter, Europa Clipper will orbit the planet on an elliptical path and graze near the moon each time to take readings. “Science includes collecting measurements of the internal ocean, mapping its surface composition and geology, and hunting for plumes of water vapor that can emerge from the icy crust,” NASA explains.
Although the final design may have only just been approved, there has been some time going on to build many of the individual components that are in the spacecraft. This is because NASA has given all the green light to some of the subsystems and instruments, such as the nearly 10-foot-wide high-gain antenna. This is the large dish that will be used to communicate with the earth and reflect the data that Europa Clipper collects.
Similarly, the solar wings – 100 feet long and covering 960 square feet of solar panel surface – are also being built. The Johns Hopkins Applied Physics Lab (APL) in Laurel, Maryland, is working on the propulsion module with its 16 rocket engines, and the whole thing will be assembled in the NASA Jet Propulsion Lab. The computer hardware, as well as the shielded safe, are being built, which scientists hope will protect the hardware and other components from radiation.
There are a number of different tools on board. Heat image sensors measure surface temperatures, signs of hot ice and surface roughness; NASA hopes to use it to develop a future lander for Europe. A magnetometer will look at the direction, strength and time-changing nature of magnetic fields around the moon, in addition to the depth and composition of Europe’s ocean.
The Europa Imaging System consists of two visible light cameras – one wide-angle, one narrow-angle – to obtain high-resolution images of the surface. With a resolution of about 20 inches, they can detect evidence of recent or even current geological activity. An ultraviolet spectrograph will be similar to UV light, while the Mapping Imaging Spectrometer will collect infrared light and be used to detect the distribution of ice, salts and organic matter.
A mass spectrometer will collect gases from across the moon and find out their composition, while a plasma instrument will detect things like the thickness of the ice cap, the depth of the ocean and the oxalate content. Instruments to measure surface dust that are distributed in the nearby space – and possibly water and other particles – will also be on board. Eventually, there will be a radar system that can penetrate up to 18 miles into the ice to try to figure out what may be below the surface.
Ironically, in addition to making sure that Jupiter’s radiation is not a problem, the Europa Clipper team must also make sure that the instruments it carries are not colliding either. “We are currently ensuring that the instruments can all work simultaneously without electromagnetic interference,” explains Robert Pappalardo, Europe Clipper project scientist at JPL.
By the end of 2021, all the components – from instruments to solar panels and rockets – should have arrived at JPL. From 2022 onwards, the challenge will be to put them together like a big, very expensive jigsaw. The launch is expected to take place sometime in 2024.