Everything about NASA’s Juno mission to Jupiter is big: the destination (giant planet, duh!), the cost ($1.1 billion), the travel time (five years to cruise 1.8 million miles), even the solar panels (totaling 635 square feet in area, about the size of a one-bedroom apartment).
And one of the biggest things for us Earthlings is that you can use the small screen on your smartphone to watch the mission reach its climax while you’re waiting for the Fourth of July fireworks to begin.
NASA will be providing live video coverage of Juno’s orbital insertion maneuver, starting at 7:30 p.m. PT Monday. Mission managers at NASA’s Jet Propulsion Laboratory in California expect to hear that the bus-sized spacecraft successfully executed Monday’s key engine burn at 8:53 p.m. PT.
If the engine firing goes wrong, the probe could zoom uselessly past Jupiter, or enter the wrong orbit around the planet. But a successful maneuver will set the stage for 20 months’ worth of meticulously planned orbital observations.
Juno and its scientific instruments are designed to study the giant planet’s magnetic field, its flux of energetic particles, its auroras and its interior structure at close range. At its closest, the orbiter will pass within 3,100 miles of the cloud tops.
“NASA has been to Jupiter before, but never this close,” Diane Brown, NASA’s Juno program executive, said Thursday at a news briefing.
That’s the key difference between Juno and Galileo – NASA’s other big mission to Jupiter, which orbited the planet and studied its moons from 1995 to 2003. The kinds of measurements that Juno is meant to provide are best done from deep within Jupiter’s magnetosphere.
Even during the approach, Juno’s detectors have been tracking the “roar” of radiation as the spacecraft plows through the magnetic field. Here’s a video that converts the blasts of plasma waves into a horror-movie soundtrack:
Juno’s microwave radiometers should be able to trace the presence of an exotic material known as liquid metallic hydrogen – and reveal whether Jupiter has a rocky core far beneath its clouds. The instruments can also analyze the composition of the Jovian atmosphere, keying in on the abundance of water and ammonia.
All those readings will help flesh out the picture that scientists have of the solar system’s creation more than 4.5 billion years ago. How did Jupiter and the other planets condense from the cloud of gas and dust that surrounded our infant sun? How prevalent were the chemicals that eventually gave rise to life on Earth? Those are the sorts of questions Juno’s data could answer.
There’s a camera aboard the spacecraft, of course. But because Juno orbits so close to Jupiter, don’t expect the wide-angle shots of Jupiter and its moons that we saw during the Galileo mission. Instead, JunoCam will be sending back full-color, medium-resolution views of the giant planet’s clouds.
“JunoCam is a unique element of the payload on this spacecraft, because from the outset, its reason for being on the payload was to do outreach to the public,” JunoCam co-investigator Candy Hansen, a researcher at the Planetary Science Institute, said in a video about the experiment. JunoCam’s scientists will be working with amateur astronomers to decide where to point the camera.
JunoCam isn’t the mission’s only public outreach angle: Three Lego figurines, representing Jupiter, Juno and Galileo, have been placed aboard the spacecraft just for fun. And Apple Music has teamed up with NASA to produce a music video celebrating the mission, titled “Visions of Harmony.” Apple is also offering a selection of songs with Juno connections in a “Destination: Jupiter” section of iTunes.
Spaceflight always presents challenges, but Juno is working under more than the usual share.
When the spacecraft was being built, mission managers opted to go with solar power, rather than the more expensive and harder-to-acquire plutonium power packs that are typically used for probes heading to the outer solar system. That mean the folks who built the spacecraft at Lockheed Martin and Spectrolab (a Boeing subsidiary) had to push the envelope on solar-cell performance. Thanks to the probe’s three 30-foot-long solar arrays, Juno is the farthest-out mission to rely on the sun rather than radioactivity for its energy.
The other big challenge has to do with a different kind of radiation: the blast of energetic particles whipped up by Jupiter’s magnetic field.
“Over the life of the mission, Juno will be exposed to the equivalent of over 100 million dental X-rays,” Rick Nybakken, Juno’s project manager at JPL, said in a NASA mission preview. Juno is equipped with titanium shielding and radiation-hardened wiring to cope with the blast. But NASA doesn’t expect the spacecraft to last much longer than the 20 months that have been planned for the primary mission.
When Juno’s work is done, the spacecraft will be programmed to plunge into Jupiter’s clouds, setting off a final round of fireworks.