NASA’s New Frontiers program is a set of solar system exploration missions designed to address “strategic goals in planetary science through a series of moderate size space missions” (you can read the entire program plan here). New Frontiers consolidates a number of long-term space missions into a single program that share a funding source, management structure, and goals, yet maintain their independent identities. New Horizons, NASA’s recent mission to Pluto and the Kuiper Belt, is considered the first mission of the New Frontiers program. The second mission is named Juno. Launched in 2011 with its sights set on our solar system’s red-spotted giant, Juno is poised to arrive at Jupiter on July 4, 2016. Let’s take a look at the mission and what we can expect to learn.
Juno: What’s In a Name?
Juno takes its name from Greek and Roman mythology. NASA draws the connection between the spacecraft and the myths as such:
Jupiter drew a veil of clouds around himself to hide his mischief. It was Jupiter’s wife, the goddess Juno, who was able to peer through the clouds and reveal Jupiter’s true nature. The Juno spacecraft will also look beneath the clouds to see what the planet is up to, not seeking signs of misbehavior, but helping us to understand the planet’s structure and history.
(It’s probably for the best that they left out the part about how Juno was, in addition to being Jupiter’s wife, also his sister.)
Launch and Earth Fly-by
Juno launched atop the reliable and powerful Atlas V rocket engine on August 5, 2011. This engine contained five solid rocket boosters, along with a Centaur upper stage engine. The launch was flawless. After the solid rocket boosters were expended and jettisoned, the Centaur upper stage ignited and burned for six minutes, placing Juno in a parking orbit around the Earth. Juno coasted for thirty minutes towards the destination for the second Centaur burn. 40 minutes after lift-off from Cape Canaveral, the second Centaur burn was executed. It burned for nine minutes as it accelerated Juno on a trajectory to escape Earth’s orbit. From there, the Centaur engine separated from the spacecraft and Juno was on its own. Juno unfurled her solar panels and settled into a five-year journey to her mythical partner.
Juno underwent a series of deep space maneuvers that brought it back near Earth, two years and two months into its voyage. By now, Juno had already traveled 1.6 billion kilometers (994 million miles). Juno came within 559 kilometers (347 miles) of Earth, borrowing our planet’s gravity to boost its speed with an additional 3.9 kilometers per second (8,800 miles per hour). By the time Juno reaches Jupiter, it will have traveled more than 2,800 million kilometers (1.7 billion miles).
While near Earth, Juno did more than just steal some of our velocity. Juno’s science team activated a number of the spacecraft’s instruments and pointed them at Earth, acting as a sort of dress rehearsal for Jupiter.
Juno will be the second spacecraft to orbit and study Jupiter, preceded by the Galileo mission that performed from 1989 to 2003.
Once Juno arrives at Jupiter on July 4, 2016, it will begin conducting its primary mission objectives. Juno will orbit Jupiter in a highly-elliptical orbit that will take it sweeping in close to the planet over one of its poles, zipping past the other pole in about two hours, before heading out beyond the orbit of Jupiter’s moon Callisto, repeating every 14 days.
Juno is loaded with instruments that will measure the oxygen and hydrogen ratios in Jupiter’s atmosphere, determine the mass of Jupiter’s core, map the gas giant’s magnetic and gravitational fields, and other important observations and experiments. These will allow us to determine how Jupiter formed, determine its structure below the clouds, and establish the source of the planet’s magnetic field.
Juno is also equipped with a visible light camera named JunoCam. Due to Jupiter’s damaging radiation and magnetic fields, JunoCam is only expected to operate for about 7 or 8 orbits; however, while it’s alive it’s expected to produce some fantastic images. Its specific targets will include Jupiter’s polar region and lower-latitude cloud belts, and will boast a resolution of 15 kilometers (9.3 miles) per pixel.
One of the best things about JunoCam is its strong emphasis on education and public outreach. For months now, a JunoCam website has been accepting images of Jupiter captured by amateur astronomers. These images will be publicly discussed during the next couple of months before a round of voting occurs to select the locations on Jupiter for JunoCam to image. Once the images have been captured and sent to Earth, the raw data will be posted on the JunoCam website for anyone to process and share.
If you want to stay up-to-date with the mission, you can watch the program page or follow the Twitter account below:
Tweets by @NASAJuno
While you’re at it, you should follow TheStarSplitter Twitter account as well! Stay informed on Juno, and everything else space related.
Tweets by @thestarsplitter