Jupiter probe Juno
Jupiter probe Juno NASA

NASA is set to launch the "Juno" space probe that will travel to Jupiter, the largest planet in our solar system, to help scientists discover how the planets were formed.

United Launch Alliance, a commercial launch services firm owned by Boeing and Lockheed Martin, will launch Juno on Aug. 5 at 11:34 a.m. EDT. The space probe was fitted above an Atlas V rocket at Cape Canaveral Air Force Station’s Launch Complex 41 in Florida on Wednesday.

Earlier this month, the probe completed hydrazine fuel loading, oxidizer loading and final tank pressurizations. The Juno mission is part of the New Frontiers Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala.

Once the probe is out in space, "It's a five-year cruise to Jupiter," said Project Manager Jan Chodas. When it reaches Jupiter, it will then orbit over Jupiter's poles at 160,000 mph (the fastest man-made object in history) and fly as close as 3,100 miles above the planet's atmosphere.

The solar-powered probe, which weighs about 8,000 pounds, then will deploy eight scientific instruments to determine how much water Jupiter holds, a key factor in finding out where the planet was formed.

According to Juno project scientists, "Possibly the single most important measurement Juno is going to make is going to be the global water content of Jupiter," because if the planet was formed roughly where it is positioned today, scientists expect Jupiter to hold nine times more water than the sun. But if the planet was formed farther out in the solar system where it's colder, the amount of water might be three times more than solar levels.

Figuring how and where Jupiter was formed will help scientists determine how other planets in our solar system ended up in the positions they are today.

However, Juno also has other major tasks to perform. For instance, the probe will map Jupiter's gravity as well as its magnetic force field (which will be analyzed by two redundant Flux Gate Magnetometer instruments) besides analyzing the composition, temperature and cloud motions of the planet's atmosphere. It will also capture images of Jupiter's ultraviolet aurora.

For long scientists have wondered about Jupiter, which together with dozens of moons and an enormous magnetic field, virtually forms a kind of mini solar system. Juno's mission will help scientists determine the core of the planet's surface and in the process how it came to be formed - according to competing theories, Jupiter either have formed out of a collapsing mass of gas and dust, much like a star, or it begun as a "dirty snowball" whose growing gravitational muscle pulled matter from its surroundings and helped it become the largest planet in our solar system.

Juno's space mission is exciting but a dangerous one too as its predecessor Galileo can testify. Galileo descent module managed to get closer to Jupiter's surface than Juno will attempt but it lasted only 58 seconds before the planet's heat and pressure pulverized it.

Juno will be clothed with a stronger body - the probe will be layered with titatium - than Galileo but it is expected to survive not more than a year because of Jupiter's harsh radioactive environment.

At the end of its life span, Juno will make a suicidal plunge into Jupiter's atmosphere to avoid possible contamination of the planet's potentially life-bearing moons.