Planning for the next NASA mission to Jupiter began in 1977, just as the two Voyager probes were launched. Rather than performing a flyby of the Jupiter system like all the missions preceding it, the "Galileo" spacecraft would orbit Jupiter to perform close-up observations of the planet and its many moons, including Io, as well as deliver a Jovian atmospheric probe. Originally scheduled to be launched via the Space Shuttle in 1982, delays resulting from development issues with the shuttle and upper-stage motor pushed the launch back, and in 1986 the "Challenger" disaster delayed "Galileo's" launch even further. Finally, on October 18, 1989, "Galileo began" its journey aboard the shuttle "Atlantis". En route to Jupiter, the high-gain antenna, folded up like an umbrella to allow the spacecraft to fit in the shuttle cargo bay, failed to open completely. For the rest of the mission, data from the spacecraft would have to be transmitted back to Earth at a much lower data rate using the low-gain antenna. Despite this setback, data compression algorithms uploaded to "Galileo" allowed it to complete most of its science goals at Jupiter.