The Io Observer is a New Frontiers Class mission

The Io Observer is a New Frontiers Class mission

Io is Jupiter's  5th moon (3rd largest and slightly larger than our moon) orbiting at around 422,000 Km.   The significance of Io is that it is the most geologically active body in the solar system, with over 400 active volcano's many the height of Everest.  The highest recorded magma temperatures ~ 1800 degrees Celsius, far higher than that recorded on the earth, suggesting the magma is more primitive and that there is a magma ocean beneath the surface. Possibly duplicating conditions that existed on earth before life began.

The Io Observer mission is designed to determine the internal structure of Io and to learn about its volcanic activity which could have real applications to the nature of volcanoes here on earth.  The mission will be funded by NASA, including the cost of the launch.   None of the four proposed options require new technology and, two of the proposals fall within the new frontiers cost cap, the other two are marginally higher.

Because Io is situated within Jupiter's radiation belt it presents significant challenges to the engineers involved, but the benefits from solving these problems now will result in payback, in the near future, when even more challenging missions are contemplated.  The Io Observer is, as its name implies to be a remote observation mission, under the guidance of the National Research Council's (NRC's) Satellites Panel.   They have four suggested study options using similar equipment to investigate variations in payload, power systems, and mission duration.  Those options are as follows:

1. An advanced Stirling radioisotope generator (ASRG)-powered remote sensing spacecraft.  This will involve ten flybys.
2. A solar-powered remote sensing spacecraft.  This will involve ten flybys.
3. A Solar-powered remote sensing spacecraft with one less instrument and a shorter observational period compared to option 2.   This will involve six flybys.
4. A Solar-powered remote sensing spacecraft with one more instrument compared to option 2.   This will involve ten flybys.

For all options the spacecraft will enter into a highly elliptical orbit of Jupiter, to minimise radiation exposure, while performing periodic Io flybys; this will allow for multiple viewing of Io's polar regions.  A series of close flybys would enable higher resolution mapping and details of the magnetic field, species in the atmosphere and plume to be analysed and allow greater understanding of the internal stresses, strains, put on Io's internal structure by the gravitational pull of Jupiter.   This phase would last approximately 60 days, and would include:

• A redundant 3-axis stabilized spacecraft carrying a narrow-angle camera (NAC), to measure peak lava temperatures with near-simultaneous colour imaging to tightly constrain peak lava temperatures.
• A thermal mapper, to map & monitor temperatures & heat flow patterns related to the internal structure and tidal heating mechanisms.
• A pair of fluxgate magnetometers (FMG's), to detect magnetic induction and an internal field (if the latter is present).
• In addition, options 1, 2, & 4 will carry an ion and neutral mass spectrometer (INMS), to determine composition and spatial distribution neutrals, that control energy input into the Io plasma torus; determine the composition of Io's atmosphere, volcanic plumes and a whole host of other things.
• Option 4 will also carry a fast-imaging plasma spectrometer (FIPS), to measure the energy, angular, and compositional distributions of the low-energy components of the ion distribution.  The solar-powered versions will require an instrument scan platform that will enable the solar arrays to continually face towards the sun while data collection is in progress. 

Previous missions to the Jupiter system were:

1.     Pioneer 1 & 2 1973/74

2.     Voyager 1 ~ 1979  first reported volcanic eruption.

3.     Voyager 2 ~ 1990  confirmed volcanic activity.

4.     Galileo      ~ 2000  confirmed the volcanic nature of Io.

5.     New Horizons ~ 2007 due to flyby 2016

There is a high Electrical current set up between Io and Jupiter in a cylinder of highly concentrated magnetic flux known as the Io flux tube, of two trillion watts output.  This is comparable to the total power produced on earth. 

The Short Version:

Most of the above technical data goes way over my head.  I understand that there have been six missions that have visited the Jupiter system.   They obtained a lot of information about the Jovian moons some of it was about the anomaly that is Io.  One of the sixty-seven moons (last count), It appears to be a double for earth 4.5 billion years ago.  It's unlikely that it will ever spawn life as we know it, but given enough time anything is possible.   It would be interesting to watch it and draw parallels between the geological activity on Io & Earth.   There are a lot of forces in action between Io & Jupiter, sometime in the future that awesome energy in the Io flux tube (two trillion watts) might be harnessed; anything is possible.   It may sound like science fiction, but if we don't study it we won't learn anything, and Homo sapiens are a curious species.