Scheduled to launch in 2024 and orbit Jupiter in flybys of its moon, Europa, NASA’s ‘Europa Clipper’ satellite will carry a suite of instruments to measure the moon’s magnetic field and look for subsurface lakes and the moon’s thick icy crust. In the search for life in our solar system, Jupiter’s moon, Europa – a bit smaller than our Moon – has long been considered a potential home for alien life. Recent evidence suggests there is an ocean below the moon’s icy crust, possibly with water that has the right chemical cocktail for life.

“Bigger than a basketball court”

After the completion of last year’s final design phase, development of the Europa Clipper is now being completed, including design and construction of the satellite’s crucial instruments. Final assembly and testing will be carried out by NASA’s Jet Propulsion Laboratory in partnership with Johns Hopkins Applied Physics Laboratory.

“Europa Clipper is a huge spacecraft packed with scientific instruments to scan Europa’s surface and underlying structure,” says Martin Greuter, Sector Manager Coating, Scientific Instruments and Research at VAT. “The solar panels alone span over 22 meters – longer than a basketball court!”

Europa Clipper’s payload also includes cameras, ice penetrating radar (to measure thickness of the icy shell), a magnetometer (to measure strength/direction of the moon’s magnetic field), a thermal surface-measuring device (to survey for eruptions of warmer water) and additional instruments (to detect any water or particles in the atmosphere).

Extremely precise and robust

During the project’s development phase, VAT collaborated with the Southwest Research Institute (SwRI) in Texas (USA) to develop and build a valve for the satellite’s mass spectrometer, which will help determine the chemistry of Europa’s surface. Because Jupiter’s intense radiation belt could quickly fry the satellite’s electronics, the spectrometer needs to be both extremely robust and precise – parameters that apply to the customized VAT valve as well. The VAT valve is one of the only all-metal valves that can be repeatedly closed hermetically – to meet the required <1E-10 mbar-l/sec leak rate, featured a relatively high conductance (which determined its size), and contained no polymers or hydrocarbons, as those materials would be sensed by the instrument.

The VAT team engineered the valve for the mass spectrometer to be extremely precise, much more precise than standard valves. The tight tolerances are driven by the compact design of the instrument and the need to minimize any chance of failure – since the valve will be operating about 390 million miles from the nearest VAT engineer! The design team also worked closely with VAT Production to ensure the tolerances were maintained.

Keeping it clean

A very precise timeline is also crucial for the design and development of the VAT valve and the mass spectrometer. The teams of experts and resources that are dedicated to the assembly of the analytical instrument and prepare it for launch have been scheduled for a long time; the 2024 rocket launch was also set years in advance.

“Because there is no room for error in the project schedule, VAT had to meet the engineering challenge and deliver a flawless solution right on schedule,” adds Joshua LeBeau, VAT General Vacuum Channel Manager USA. “Both SwRI and NASA trusted the VAT team to meet that challenge.”

VAT precision technology will ensure that once the Europa Clipper satellite enters Europa’s atmosphere, the spectrometer valve will open, gather samples, then close for measurement. During the design and manufacture of the valve, special attention was paid to cleaning any potential terrestrial elements, which could contaminate the measurement samples, from the valve surfaces.

“Europa Clipper is an extremely exciting project,” adds Martin Greuter. “The VAT team involved in the NASA mission are proud to see their expertise heading into outer space – and take part in the search for extraterrestrial life!”