NASA’s Juno mission to Jupiter arrives in just about a day, after a 5 year journey that began in August of 2011 aboard an Atlas V rocket. The Juno mission is primarily concerned with studying the magnetic fields, particles, and structure of Jupiter. Finding out how Jupiter works, and what its core is made of are some of Juno’s goals. None of the experiments need a camera, but NASA decided, in the interest of public outreach and education, that if you are going to spend $1 billion to send a probe to Jupiter, it probably should have a camera. Energetic particle detectors, Magnetometers, and Auroral Mappers are great for science, but what the public is inspired by is pretty pictures of wild and distant worlds.
Juno is powered by a now familiar computer, the BAE RAD750 PowerPC radiation hardened computer. It operates at up to 200MHz (about the processing power of a mid 1990’s Apple Computer) and includes 256MB of Flash memory and 128MB of DRAM. It (and the other electronics) are encased in a 1cm thick titanium radiation vault. Flying in a polar orbit around Jupiter, Juno will experience intense radiation and magnetic fields. The probe is expected to encounter radiation levels in the order of 10Mrads+. The vault limits this to 25krads, within what the electronics can handle. It should be noted that a dose of 10krads is fatal in most cases. This intense of radiation will degrade the prober, even with shielding, resulting in a mission life of only 37 orbits (a little over a year) before the probe will be gracefully crashed into Jupiter.