Juno Missed It By *That* Much, But It's All Good
After a tremendous 1.7 billion mile, 5 year journey across the solar system, the 4 ton Juno spacecraft fired its engine for some 35 minutes to slow down enough to end up in mighty Jupiter's orbit - a first for a man-made craft. After all that, Juno ended within tens of miles of the exact spot it was supposed to, and there was much rejoicing July 5th back at NASA.
In reality, NASA also now sentenced its $1.1 billion (~£850M) spacecraft to die. Mission managers hope to get 37 orbits out of Juno over the next 20 months before radiation slowly breaks down its electronics and propulsion system. Even though a 1cm-thick wall of titanium encases the spacecraft’s electronics to provide some protection, a few of its nine instruments may begin to fail in as few as eight or 10 orbits. Before the spacecraft fails entirely engineers will place Juno into a slowly degrading orbit that will eventually force it to plunge into the planet. This is so that none of its potentially life bearing moons, such as Europa, might be contaminated.