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New "Juno" Mission To Jupiter Announced
Riding with Robots writes "Today NASA announced it is officially proceeding with the Juno robotic mission to Jupiter. Scheduled to launch in August 2011 and reach the largest planet in 2016, the spacecraft will orbit the planet 32 times, skimming about 4,800 kilometers over the planet's cloud tops for about a year. The mission will focus on Jupiter's structure and evolution, and not on Europa or the other icy moons that may hide oceans under their surfaces — a disappointment if you ask me. Then again, all planetary missions so far have turned up amazing images and surprising scientific discoveries, and I doubt this expedition will be any different." We discussed NASA's deliberation of its short list a few days back.
The mission will focus on Jupiter's structure and evolution, and not on Europa or the other icy moons that may hide oceans under their surfaces - a disappointment if you ask me.
... especially since we could be using those icy moons as giant particle detectors (PDF) for neutrinos and other cosmic rays.
Ok, why can't the seeds of life be found on Jupiter? As I see it, if Jupiter has any sort of life, then it becomes the largest biosphere (probably several orders of magnitude larger than the Earth's) in the Solar System with a strong chance of intelligent life.
That's not how orbits work. After the 32nd orbit, Juno will enter its 33rd orbit. Orbits are inertial, and only require fuel for station-keeping. On this orbit, however, no orbital perturbations will cleverly keep Juno out of the worst of Jupiter's tremendous magnetic fields, which trap cosmic rays, solar wind particles, and other ionizing radiation, and so Juno's electronics will begin to degrade. No longer able to speak to us, Juno will keep orbiting until the orbital trajectory itself begins to degrade and it spirals down into the planet to burn up in the atmosphere.
The thing is, we're so damn close on the moons of Jupiter. All we need to do is break the fucking ice and take a look. Odds are, if there's life, there's something obvious, not just unicellular (though we can easily check for that.)
I'm sure that Jupiter has a lot to teach us, but the moons are just about the only place we've found that actually have a reasonable chance of supporting extra-terrestrial life. I sort of feel like clearing that up is the next step, then we can go back to poking things and seeing what turns up. We probed the moons, we have a sense that there may be something of interest there, we should act on that suspicion before moving on to something else.
What they're trying to answer is "How did our planets form?" It's hard to imagine any findings on Europa (even life) that would significantly out-weigh an answer to this question, although some would probably rival it in importance. But given that this mission can almost certainly address the questions it's being sent up to answer and given that the technological hurdles of studying Europa properly are so high, this is a much more sensible mission to send at the moment, in my view.
So I took a few seconds to RTFA and I found (or didn't find):
It uses SOLAR PANELS to power this thing all the way to Jupiter. That'll beat the previous record holder (I think the DAWN mission to Vesta and Ceres) for use of solar power away from the sun. TFA says that other than a 10 min period in earth's shadow during a flyby it will always be in sunlight.
1) So does that mean it will be in a sun synchronous polar orbit at Jupiter? Won't that compromise the data collection opportunities it has? (It'll never be able to look "straight down" with the sun at its back).
I couldn't find any details about how it intends to enter and then adjust its jupiter-centric polar orbit. I see no mention of using gravity assist WITHIN the jupiter system using any of the galilean satellites to reduce the amount of delta V for insertion (and adjustments). Is this because they are going into a polar orbit and won't be in the plane of the satellite's orbits? Nor did I see any mention of some fancy aero-braking (like the Mars orbiters use). (Of course I guess ion drives (like those used in DAWN) wouldn't be practical because the probe would have to "linger" too long in Jupiter's radiation belts while it slowly shed velocity).
2) So will they be using some standard chemical propellents with a long storage time (like Cassini)? Will a large part of the spacecraft be fuel or does its "unique highly elliptical" orbit not require too much delta V to enter?
Anyway, sounds like a cool mission, that won't cost too much or take too long to get there (uses solar power so no expensive nukes, uses 1 gravity assist and a medium size Atlas booster). Hopefully the camera has a high enough resolution to take a picture of Medusa! (Please see Arthur C. Clarke's "Meeting with Medusa").
"It is probable that NASA would decide to deorbit the spacecraft at the end of mission by sending it in to Jupiter's atmosphere, rather than just let the orbit degrade. This was done to Galileo to prevent any contamination of Jupiter's moons, particularly Europa."
And Io. And this deorbit was particularly interesting considering that one cancelled mission plan would have maneuvered Galileo through a volcanic plume on Io.
"You're getting brutal, Sark. Brutal and needlessly sadistic."
"Thank you, Master Control"
-Sark and the MCP