The Juno probe, already setting records for the most distant use of solar power, is nearing its giant target. Orbital insertion is scheduled for July 4. This is of course Independence Day in the US, but the timing is coincidental, dictated by the complex orbital mechanics required to get a payload this size all the way out to Jupiter with exactly the right amount of energy for Juno’s engines to get them into Jupiter orbit without being swallowed up by Jupiter. It’s been a long road, but the probe is nearly there. The probe’s primary mission revolves around invisible measurements: radio astronomy to probe Jupiter’s monstrous gravitational field, a microwave radar sounder to probe the clouds, a magnetometer, particle detectors, and cameras tuned to infrared and ultraviolet wavelengths. Yet although its primary mission is not to take pretty pictures, it still carries a color camera to provide the general public with the first images of Jupiter’s polar regions. (Given how surprising Saturn’s poles have been, Jupiter may have some real secrets hidden there.) Part of the reason imagery is not its primary focus is because the spacecraft is spin-stabilized; this will compromise exposure times, but is no problem for all the major instruments.
JunoCam will not be able to get much detail outside of the periodic close approaches the spacecraft will make in its long, looping orbits, but it just sent back our first real taste: a “family portrait” of Jupiter and the Galilean Moons taken just six days ago at a distance of 6.8 million miles:
Even at its worst, the pictures during the Jupiter tour will be better than this, so things are getting good. 😉 One week to insertion!