Flyby puts Juno spacecraft on a course for Jupiter
By David Szondy
October 10, 2013
Online observatory Slooh has streamed live pictures of NASA’s Juno space probe flyby. The feed from the robotic half-meter telescope in the Canary islands gave visitors a ringside seat as the probe passed within 347 mi (559 km) of Earth in a slingshot maneuver designed to take it all the way to Jupiter.
The Juno space probe was launched in 2011 and since then has been carrying out a series of orbital maneuvers to give it enough speed to reach the planet Jupiter, where it will go into orbit as part of a mission to learn more about the structure and nature of the deep atmosphere of the giant planet.
Having traveled out beyond the orbit of Mars, Juno returned to Earth for a flyby this week. In an interview with Stephen Cox of Slooh that accompanied the live feed, JPL scientist Steven Levin, speaking from mission control in Denver, explained how this worked.
“We could not afford a big enough rocket to launch Juno with enough energy, enough speed to get all the way to Jupiter," said Cox. "So, we’re using a technique called gravity assist … The basic idea is to latch onto an object and use its gravity to give it a boost. It’s a bit like coming up to a truck on the highway and grabbing onto the truck for a bit to get extra speed.”
On Wednesday at 3:21 PM EDT, the unmanned, US$1.1 billion Juno probe passed within 347 mi (559 km) of Earth as it hurtled over South Africa. For 20 minutes, the spacecraft was in the shadow of the Earth, which is the only time during the mission when it drew no power from the massive solar panels designed to work while in orbit around Jupiter, which lies five times the distance of the Earth from the Sun.
In Wednesday’s interview, Dr Levin explained that NASA provided no press releases or any other information on the flyby because of the partial shutdown of the US government due to budget disputes. “The good news is that because of the nature of what we were doing, we were granted an exception to the shutdown, so the people who were necessary to make sure that the spacecraft was safe and we collected the data we need to collect, and so forth were all allowed to keep working.
"The bad news from the point of view of the government shutdown is that anything to do with press releases and sending the information out to the public and so forth is not part of what’s considered essential activity that’s granted that exception. All of NASA’s usual procedures for seeing what we’re doing shut down and the word’s getting out a little bit through avenues like this and people who work with us, but the real release ‘here’s everything we did’ will have to wait until the government is operating again.”
The only apparent hitch on Wednesday came as Juno completed the slingshot maneuver. NBC News reports that when Juno came out of the Earth’s shadow, it was in safe mode, indicating that it had encountered some sort of malfunction. The craft is en route to Jupiter as scheduled while NASA engineers try to determine the cause.
The video below shows some of the image feed from the Canary Islands as Juno flew by.