Jupiter spacecraft mounted atop bloody big rocket

[American Patriot]

Jupiter spacecraft mounted atop bloody big rocket



Juno to ride the thrust of five mighty strap-ons
By Lester Haines • Get more from this author
Posted in Space, 28th July 2011 10:46 GMT
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NASA's Juno spacecraft has been mated to an United Launch Alliance Atlas V 551 rocket ahead of its forthcoming trip to Jupiter.
The "most powerful Atlas rocket ever made" is sitting on the launchpad at Cape Canaveral Air Force Station while technicians carry out "a final flurry of checks and tests" to see if all is well for a first launch opportunity on 5 August.
Juno principal investigator Scott Bolton declared: "We're about to start our journey to Jupiter to unlock the secrets of the early solar system. After eight years of development, the spacecraft is ready for its important mission."
Juno will arrive at Jupiter in July 2016 and orbit the gas giant's poles 33 times. It's solar powered, and since it'll be operating at a considerable distance from the Sun, requires plenty of solar panel area to catch some rays.

NASA explains: "Three solar panels extend outward from Juno’s hexagonal body, giving the overall spacecraft a span of more than 66 feet (20 metres). The solar panels will remain in sunlight continuously from launch through end of mission, except for a few minutes during the Earth flyby. Before launch, the solar panels will be folded into four-hinged segments so that the spacecraft can fit into the launch vehicle."

The panels will power an array of kit which includes a six-wavelength microwave radiometer, plasma and energetic particle detectors, and ultraviolet and infrared imager/spectrometers. Juno is also carrying a colour camera, promising Earthlings "the first detailed glimpse of Jupiter's poles".
Before that, however, Juno has to slip the surly bonds of Earth. The Atlas V 551 entrusted with the job will be lifted from the pad by a standard dual chamber RD-180 motor burning kerosene and liquid oxygen.
In this case, the RD-180 will be assisted by five solid rocket boosters, and the task of getting Juno into its final trajectory will fall to a Centaur upper rocket stage powered by hydrogen and liquid oxygen.
This configuration is reflected in the designation "551" (5-metre diameter payload fairing + five boosters + one Centaur). There's more on the myriad possible configurations of the Atlas V in United Launch Alliance's handy guide (pdf).
A similar 551 set-up lifted NASA's New Horizons mission to Pluto back in 2006 (see pic). Lockheed Martin has more here.
As we recently reported, NASA is eyeing the Atlas V as a possible vehicle for getting people into low-Earth orbit as part of its Commercial Crew Program. The agency is keen to offload International Space Station taxi duties to the private sector, while it concentrates on more distant horizons for manned space exploration. ®

[American Patriot]

CORRECTED - NASA probe poised for launch to Jupiter







Thu Jul 28, 2011 8:53am EDT

* Juno spacecraft to spend a year orbiting Jupiter's poles
* Mission aims to learn how Jupiter, solar system formed
* Journey to Jupiter will take five years
(Corrects 10th paragraph to say "minutes," not "seconds")
By Irene Klotz
CAPE CANAVERAL, Fla., July 27 (Reuters) - A NASA satellite was hoisted aboard an unmanned Atlas 5 rocket at Cape Canaveral Air Force Station on Wednesday in preparation for launch next week on an unprecedented mission to the heart of Jupiter.
The robotic probe called Juno is scheduled to spend one year cycling inside Jupiter's deadly radiation belts, far closer than any previous orbiting spacecraft, to learn how much water the giant planet holds, what triggers its vast magnetic fields and whether a solid core lies beneath its dense, hot atmosphere.
"Jupiter holds a lot of key secrets about how we formed," said lead scientist Scott Bolton, with the Southwest Research Institute in San Antonio, Texas.
Scientists believe Jupiter was the first planet to form after the birth of the sun, though exactly how that happened is unknown. One key piece of missing data is how much water is inside the giant planet, which circles the sun five times farther away than Earth.
Jupiter, like the sun, is comprised primarily of hydrogen and helium, with a sprinkling of other elements, like oxygen. Scientists believe the oxygen is bound with hydrogen to form water, which can be measured by microwave sounders, one of eight science instruments on Juno.
Jupiter's water content is directly tied to where -- and how -- the planet formed. Some evidence points to a planet that grew in the colder nether-regions of the solar system and then migrated inward. Other computer models show Jupiter formed at about its present location by accumulating ancient icy snowballs.
LARGER THAN SISTER PLANETS
However it grew, Jupiter ended up with a mass more than twice all its sister planets combined, giving it the gravitational muscle to hang on to nearly all of its original building materials.
"That's why it's very interesting to us if we want to go back in time and understand where we came from and how the planets were made" -- which Juno can help NASA do, Bolton said.
Juno's journey to Jupiter will take five years. Upon arrival in July 2016, Juno will thread itself into a narrow region between the planet and the inner edge of its radiation belt. The solar-powered probe will then spend a year orbiting over Jupiter's poles, coming as close as 3,100 miles (5,000 km) above its cloud tops.
Only an atmospheric probe released by Galileo, NASA's last Jupiter spacecraft, has come closer, though that spacecraft was able to relay data for only 58 minutes before succumbing to the planet's crushing pressure and intense heat.
Juno's electronic heart is protected in a vault of titanium, but it too will fall to the harsh Jovian radiation environment after about a year. Juno's last move will be to dive into the planet's atmosphere to avoid any chance of contaminating Jupiter's potentially life-bearing moons.
Juno's launch is scheduled for Aug. 5. The spacecraft was built by Lockheed Martin Astronautics of Denver, Colorado. The mission, the second in NASA's lower-cost, quick-turnaround New Frontiers planetary expeditions, will cost $1.1 billion. (Editing by Jane Sutton and Philip Barbara)