NASA asked for $19.092 billion for funding activities in the current financial year, which trimmed back quite a few programmes, ended some and pushed a few out many years. One of the programmes pushed out was the Europa Clipper project, which is planned to send a spacecraft loaded with sensors to do multiple passes of Europa to gain a better understanding of this active moon around Jupiter.
The US government agreed to fund NASA more than they asked with $20.736 billion, significantly more than was planned. This opened the ability to fund a lot of programmes that were in jeopardy. It’s great news that the Europa Clipper programme is back being fully funded (and also the Wide Field Infrared Survey Telescope, WFIRST. The deal with the WFIRST doesn’t mean it’s certain to happen it just means it isn’t dead, Congress wants a report on the full lifecycle costs of the telescope within 60 days.)
The big news and what we are very excited about is the $2.2 billion for the planetary science programme, this is $300 million more than asked for and includes $595 million for the Europa Clipper mission and the lander that is supposed to follow that mission. The plan is for the Space Launch System (SLS) to launch the Europa Clipper in 2022 followed by the lander mission in 2024. We’ll be watching nervously for any delays to the SLS programme that will have a detrimental effect on the missions to Europa. The good news is the funding bill also fully funds the SLS and Orion programmes at $2.15 billion and $1.35 billion each, hopefully that’s enough to keep them both on track. Another aspect which is also really positive is $350 million set aside for a second mobile launch platform, which will mean there is less of a risk in a delay between the EM-1 and EM-2 missions. Any delay early in the programme, beyond what has already occurred of course, will have a compounding effect on the planetary science missions utilising the SLS. It’s not expected that the funding bill will have any problems getting through the two houses.
With this good news, we have a little more confidence that the Europa Clipper mission will actually get off the ground and it’s probably timely to have a closer look at what this mission is planned to achieve. The overarching objective of the mission is to conduct a detailed look at Jupiter’s moon Europa and see if the big ball of ice could harbour the conditions for life. Europa is of interest to scientists because it probably has an ocean of water underneath the icy surface. Recent work looking at plumes from the surface of the moon have indicated that there may well be conditions in that ocean that could be favourable for life, such as around hydrothermal vents on the ocean floor. The plumes were examined from data collected by the Hubble Space Telescope that imaged water plumes on the southern part of the moon. The plan is to send the spacecraft to orbit Jupiter on a long looping orbit that will enable it to pass by Europa on repeated close flypasts. This will enable the sensor package on the spacecraft to collect data for analysis back on Earth.
Europa was first observed by Galileo back in 1610 and is about 5.2 AU from the Sun. Voyager 1, Voyager 2, Galileo, Cassini and Hubble Space Telescope. Speculation that Europa had an ocean beneath its surface was following the analysis of data collected by the Galileo spacecraft. This excited speculation that there could be life or at least the conditions for life on the moon. The importance of this is that there are a few moons in the Solar System with possible oceans under a surface of ice so if we find evidence for the conditions for life on Europa is raises the possibility for the same on those moons.
To figure out what is going on in Europa the spacecraft will have a complex payload of scientific instruments that we determined last year. This payload will include nine instruments. The Plasma Instrument for Magnetic Sounding (PIMS) will work in concert with the magnetometer and will be used to determine the thickness of the icy surface, the depth of the ocean and the salinity of the ocean. The Interior Characterisationof Europa using Magnetometry (ICEMAG) will be used to measure the magnetic field near Europa and work in concert with PIMS. The Mapping Imaging Spectrometer for Europa (MISE). This instrument will look at the composition of Europa including, organics, salts, acid hydrates, water ice and anything it finds. The Europa Imaging System (EIS) include wide and narrow angle cameras to map the on at 50m resolution and selected areas at about 5cm resolution. The Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) is a dual frequency ice penetrating radar to try and figure out the structure of the icy surface and the boundary with the ocean beneath. The Europa Thermal Emission Imaging System (E-THEMIS) is basically a thermal imager that will be used to detect hot spots on the moon such as erupting plumes. The Mass Spectrometer for Planetary Exploration/Europa (MASPEX) will measure any atmosphere to determine what has been ejected into it by plumes. The Ultraviolet Spectrograph/Europa (UVS) will look at small plumes using the same technique that was developed for the HubbleSpace Telescope (HST) to look at Europa’s plumes. Finally the Surface Dust Mass Analyzer (SUDA) will directly analyse material ejected from the surface for the moon by collecting material and analysing it during the close flypasts.
The funding for Europa Clipper and the SLS programme, that will launch it, is great news for astrobiology. The follow on rover project that is also planned is also quite exciting.
