A (real) Space Odyssey
GALILEO WAS AN AMAZING SPACECRAFT. Launched in 1989, it arrived at Jupiter just under 6 years later and orbited for 7 years. Over 20 years after sending Galileo, we are about to launch his younger sister, Juno, on her way to Jupiter on August 5, and I get to be at Kennedy Space Center to send her on her way.
Yet another achievement for our last space shuttle, Atlantis, she was responsible for launching the Galileo probe to Jupiter on STS-34. The was only the second time a probe leaving our local neighborhood was launched from the space shuttle, the first having been the Magellan probe to Venus that was launched by Atlantis during STS-30 earlier in 1989. Galileo’s path would take her around Venus in 1990 and then around Earth twice, in 1990 and 1992, in order to use the gravitational assist to build up enough velocity to get to Jupiter. Even along the way, she had plenty of work to do, examining asteroids and determining if it was possible to detect life on Earth from space. This was accomplished through a series of experiments devised by Carl Sagan during Galileo’s first flyby of Earth. And it was not a trip without problems, either, as her high-gain antenna failed to open. This forced us to rely on her low-gain antenna, which was only intended to transmit at 8 to 16 bits per second (whereas the high-gain antenna would have transmitted at 134 kilobits per second, over 8000 times faster). The NASA engineers, resourceful as always, were able to boost this to 160 bits per second by utilizing compression and receiver upgrades. Just before arriving in Jupiter orbit, Galileo launched an atmospheric probe that made a death dive into Jupiter, collecting 58 minutes worth of data about the weather and composition of the atmosphere. In total, Galileo returned about 30 GB of data and around 14,000 images before performing her own dive into Jupiter (to prevent any possibility of introducing Earth bacteria to Europa).
Juno, with the benefit of 20 years of additional engineering advances, will perform almost as many orbits (32) as Galileo (35) in just a single Earth year, and will perform much more sophisticated science. Once she arrives at Jupiter, in 2016, she will provide a better estimate of Jupiter’s core mass and precisely explore the planet’s magnetic and gravitational fields. She will also fill in many of the gaps in our knowledge of the atmospheric composition. You may ask why we really care. Why would we bother using our resources to send another probe to Jupiter, rather than exploring our closer neighbors? But Jupiter was probably one of the first planets to form in our solar system, and its giant mass has a huge effect on the rest of the planets, including Earth. By understanding Jupiter, we will learn more about how our solar system, and our planet, formed.
The science is exciting, but even more exciting and immediate for me is that NASA has invited me down to Kennedy Space Center to learn more about Juno, and Jupiter, from the experts and to witness her launch on August 5th. As part of NASA’s Tweetup program, where they open up events to some of their social media followers in an effort to increase awareness of NASA’s work, 150 people have been invited down to KSC for a two day event around Juno’s launch. My first NASA Tweetup experience was for Sun-Earth Day at Goddard Space Flight Center, in Maryland, earlier this year, and I am honored to have been selected again to go down for this launch. At GSFC, we were able to participate in NASA Edge, their unscripted webcast, as well as take a tour of the GSFC facilities and go down to the Smithsonian National Air and Space Museum to observe the sun and meet with other experts. I can only speculate on what we will be involved in at KSC, based on previous (shuttle) launch Tweetups, and I am so excited to find out!