Reawakened after three long years in a deep space slumber, Europe’s Philae lander has began the newest phase in its mission to land on the surface of a comet later this year. The Philae lander is being transported on the back of the Rosetta satellite, to save fuel. The Rosetta satellite was re-activated just this past January.
The German space agency (DLR) acknowledged that they had received confirmation from the Rosetta satellite that contact had been re-established with it. Over the next few weeks, Philae will be reawakened to an even greater extent, and will be put through its paces to ensure that all will go well when it reaches its destination.
What comet is the ultimate destination of the Philae lander?
Launched 10 years ago, the Rosetta satellite and its freeloading passenger, the Philae lander, are on their way to their ultimate destination, the Comet 67P/Churyumov-Gerasimenko. If all continues to go well, the Rosetta satellite and Philae lander will meet up with and orbit the icy comet this August. Scientists are counting on learning a lot about comets from this much-anticipated rendezvous, especially when Philae will be released from the Rosetta satellite and attach itself to the comet next November.
The “Jupiter-class” comet with the difficult-to-pronounce name was named after Svetlana Gerasimenko and Klim Churyumov, the scientists who discovered it back in 1969. It takes 6.45 years to make just one orbit around the sun.The icy core of the Comet 67P/Churyumov-Gerasimenko is about two-and-a-half miles across and it rotates once every 12 hours.
Being so small, the comet’s gravity field is expected to be weak. The Philae lander will attempt to attach itself to the comet using harpoons and ice screws.
Why was the Rosetta satellite, transporting the Philae lander, shut down 31 months ago?
The Rosetta satellite was shut down, except for the basic necessities, 31 months ago because its solar panels got too far away from the sun to function properly in powering it further on its mission to the comet.
Now, however, the Rosetta satellite is getting closer to the sun once again.The scientists are carefully switching the all back on,
Now that Rosetta is moving closer to the sun again, those systems that were shut down — in particular, the various scientific instruments — are all being switched back on, one by one.
This will be a momentary arousal from sleep, though. Most of the Rosetta’s systems will be shut down once again to conserve its energy for later on, as it makes its approach to the comet.
However, one system that won’t be shut back down will be OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System), which is the imaging system that Rosetta uses. Rosetta will navigate its way towards the comet with the aid of OSIRIS, which will plot the comet’s path as it journeys across the skies.
May 21 will be another red-letter day for Rosetta and the Philae lander. On that day, the thrusters on the Rosetta satellite will begin a burn that will last for seven hours and 21 minutes.
This burn will mark the beginning of a further eight burns which will occur over the course of the summer as the Rosetta satellite and the Philae lander get ever closer to the comet.
The good news is that both the Rosetta satellite and the Philae lander have now reawakened and are still working and ready to complete their missions. The bad news is that, despite having traveled 655 km from Earth, they are still about 3.8 million miles away from Comet 67P/Churyumov-Gerasimenko.
Two images of the Rosetta satellite’s destination were taken by the spaceship on March 20 and March 21. Clearer images of the comet are expected to be taken by OSIRIS possibly as soon as May. The spacecraft is travelling at nearly 1800 mph.
OSIRIS is one of 11 of the scientific instruments aboard the Rosetta satellite. The job of these instruments will be to document and analyze data and samples that they collect from the comet. The instruments will be used to learn more about the comet’s gravity, internal structure, mass, shape, surface geology, atmosphere, plasma environment, and more.
By May, the photos OSIRIS takes will become clearer, and between May through August, when the Rosetta satellite will come within 100km of Comet 67P/Churyumov-Gerasimenko, we will be able to see some of the comet’s surface features.
The Philae lander has reawakened, prompting celebrations at the European Space Agency (ESA). Landing on a comet and analyzing one has been a major objective of space agencies around the world, and it looks as if the ESA will be the first such space agency to claim that honor.
What will the 11 scientific instruments aboard the Rosetta satellite and Philae lander discover about comets, to add to our knowledge about them? The next few months are certain to provide us with enough details about comets that we hadn’t previously known to write a book.
Written by: Douglas Cobb