NASA's Juno spacecraft poised for attempt to orbit Jupiterhttp://www.cbc.ca/news/technology/juno-jupiter-1.3663200
A solar-powered spacecraft is spinning toward Jupiter for the closest encounter with the biggest planet in our solar system.
NASA's Juno spacecraft fires its main rocket engine late Monday to slow itself down from a speed of 250,000 kilometres per hour and slip into orbit around Jupiter.
With Juno on autopilot, the delicately choreographed move comes without any help from ground controllers.
Confirmation of whether Juno, the only solar-powered spacecraft ever dispatched to the outer solar system, had successfully placed itself into polar orbit around Jupiter was not expected until 11:53 p.m. ET (New York time)
CBCNews.ca will carry a NASA livestream of the event starting 10:30 p.m. ET.
Launched from Florida nearly five years ago, Juno must be precisely positioned, ignite its main engine at exactly the right time and keep it burning for 35 minutes to shed enough speed so it can be captured by Jupiter's gravity.
"This is really the most up close and personal we've ever been with Jupiter," Michelle Thaller, assistant director of science communications at NASA Goddard Space Flight Centre, said in an interview with CBC News.
The spacecraft is travelling through a hostile radiation environment and rings of debris and dust, "making for very serious hazards," Juno chief scientist Scott Bolton said during a morning briefing. But Juno should be able to withstand the harsh conditions because it's "built like an armoured tank," he said.
Thaller said, "We are actually diving the spacecraft underneath the radiation belt and coming out the other side, so that has to work just right."
Juno's camera and other instruments were switched off for the arrival so there won't be any pictures at the moment the spacecraft reaches its destination. Scientists have promised close-up views of Jupiter when Juno skims the cloud tops during the 20-month mission
But NASA released a series of images taken last week during the approach, showing Jupiter glowing yellow in the distance, circled by its four inner moons:
Juno's mission: To peer through Jupiter's cloud-socked atmosphere and map the interior from a unique vantage point above the poles. Among the lingering questions: How much water exists? Is there a solid core? Why are Jupiter's southern and northern lights the brightest in the solar system?
What Juno's about is looking beneath that surface," Bolton said. "We've got to go down and look at what's inside, see how it's built, how deep these features go, learn about its real secrets."
There's also the mystery of its Great Red Spot. Recent observations by the Hubble Space Telescope revealed the centuries-old monster storm in Jupiter's atmosphere is shrinking.Juno will enter into this highly elliptical polar orbit and complete it 36 times before burning up in Jupiter's atmosphere in 2018: