Juno (spacecraft)

This article is about the spacecraft. For the launch vehicle, see Juno I.

Juno at Jupiter

Juno is a NASA mission to Jupiter planned to cost roughly $700 million (FY03) and scheduled to launch August 2011.^[1] The spacecraft will be placed in a polar orbit in order to study the planet's composition, gravity field, magnetic field, and polar magnetosphere. Juno will also be searching for evidence to help scientists understand how Jupiter formed. Specific questions that relate to the origin of planets in our solar system include the determination of whether Jupiter has a rocky core, the amount of water present within the deep atmosphere, and how the mass is distributed within the planet. Juno will also study Jupiter's deep winds (which can reach speeds of 600 km/h). It will be the first mission to Jupiter using solar panels instead of radioisotope thermoelectric generators.

Mission summary

Juno, which is set for launch August 2011, is a New Frontiers mission to study the planet Jupiter. Juno's trajectory to Jupiter utilizes a gravity assist from Earth. This is accomplished through an Earth flyby two years after launch. At arrival at Jupiter in 2016, approximately 5 years after launch, the spacecraft will perform an orbit insertion burn to slow the spacecraft enough to allow capture into Jupiter orbit. The spacecraft will then orbit Jupiter about its poles with an 11 day orbital period. Its mission will conclude in 2017, after completing 32 orbits around Jupiter. Data analysis may occur during 2018.

Current status

Currently the mission is in the early planning stages. Although the price of the mission is lower than for most other spacecraft, a launch vehicle must be ready for Juno to be launched. The Atlas V rocket has been chosen to launch Juno in the Atlas V-551 configuration.

Solar panels

Unlike the Galileo Orbiter, Juno will use solar panels rather than radioisotope thermoelectric generators. The reason for this is the significant advancement in solar cell technology and efficiency over the past several decades, which now makes it economically feasible to use solar panels of practical size to provide sufficient power at such a great distance from the sun. In addition, RTGs are in short supply, limiting their availability for space missions. Also, by using solar energy, NASA avoids the protests associated with launching RTGs into space (due to accusations of public safety risks, which NASA refutes in detailed scientific reports); however, it should be noted that NASA plans several more projects involving RTGs,^[2] and the decision to use alternate technology on this mission is more practical and economical than political.

References

External links

• Official web site
• Juno Mission Profile by NASA's Solar System Exploration
• NASA Selects New Frontiers Concept Study: Juno Mission to Jupiter at NASA Jet Propulsion Laboratory
• The Juno Mission to Jupiter at Space.com