Regular readers of this blog will find the content of today's 365 Days of Astronomy Podcast familiar, because it's an update on what the solar system exploration spacecraft are up to, based on my monthly "what's up" updates.
April 2011 will see MESSENGER begin the science phase of its orbital mission at Mercury, and should, I think, also see the start of Dawn's approach observations of Vesta. At Mars, Opportunity is back on the road again, rolling inexorably toward Endeavour. At Saturn, Cassini will continue its focus on Saturn and Titan science.
Today the Dawn imaging team released a photo from the main camera, the Framing Camera, symbolizing that they're preparing to start Dawn approach science; the other two science instruments, a spectrometer and a neutron detector, are also being turned on and checked out.
Deep in the asteroid belt, Dawn continues thrusting with its ion propulsion system. The spacecraft is making excellent progress in reshaping its orbit around the sun to match that of its destination, the unexplored world Vesta, with arrival now less than five months away.
Dawn continues its flight through the asteroid belt, steadily heading toward its July rendezvous with Vesta, where it will take up residence for a year. On January 10, Dawn performed some of the activities that it will execute in its low altitude mapping orbit (LAMO) at Vesta.
Dawn is now so far from the sun that even with its tremendous solar arrays, it does not receive enough sunlight to generate sufficient electrical power to operate all systems and still achieve maximum thrust.
Dawn usually interrupts ion thrusting once a week for about eight hours to point its main antenna to Earth. On November 30, however, instead of resuming thrusting, it dutifully followed different instructions that were stored onboard.