Dawn - Mission autour de Cérès

montmein69 a écrit:Mais Micael l'a déjà dit :cheers: :cheers:

antoine34 a écrit:Dawn est donc le premier engin spatial à propulsion ionique ?

SkyLab a écrit:Superbe la premiere, il y a une version haute résolution?

Jet Propulsion Laboratory, Pasadena, Calif.
NASA Headquarters, Washington

STATUS REPORT: 2007-115 October 9, 2007

Dawn Mission Status: Spacecraft Tests Ion Engine

NASA's Dawn spacecraft successfully completed the first test of its ion propulsion system over the weekend. The system is vital to the success of Dawn's 8-year, 1.6 billion-kilometer (3-billion-mile) journey to asteroid Vesta and dwarf planet Ceres.

"Dawn is our baby and over the weekend it took some of its first steps," said Dawn project manager Keyur Patel of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We have two months more checkout and characterization remaining before Dawn is considered mission operational, but this is a great start."
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On Saturday, Oct. 6 at 6:07 p.m. Pacific Daylight Time (9:07 p.m. Eastern Daylight Time), the ion propulsion system began thrusting. Over the next 27 hours, spacecraft controllers and navigators at JPL monitored the engine's performance as it was put through its paces.

"We evaluated the engine's capabilities at five different throttle levels," said Jon Brophy, the Dawn project's ion propulsion manager at JPL. "From flight idle through full throttle, the engine performed flawlessly."

Dawn's ion engines are extremely frugal powerhouses. The 27 hours of thrusting from the ion engine resulted in the consumption of less than .28 kilograms (10 ounces) of the spacecraft's xenon fuel supply -- less than the contents of a can of soda. Dawn's fuel tank carries 425 kilograms (937 pounds) of xenon propellant. Over their lifetime, Dawn's three ion propulsion engines will fire cumulatively for about 50,000 hours (over five years) -- a record for spacecraft.
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