4:05 A.M. EST UPDATE:
Philae probe separation from Rosetta spacecraft confirmed.
3:45 A.M. EST UPDATE:
The Philae lander should have separated from the Rosetta spacecraft. It will take the radio signals from the transmitter on Rosetta 28 minutes and 20 seconds to reach Earth for separation confirmation.
Earlier this morning, it was discovered that the active descent system, which provides a thrust to avoid rebound at the moment of touchdown, cannot be activated.
At touchdown, landing gear will absorb the forces of the landing while ice screws in each of the probe’s feet and a harpoon system will lock Philae to the surface. At the same time, the thruster on top of the lander is supposed to push it down to counteract the impulse of the harpoon imparted in the opposite direction.
“The cold gas thruster on top of the lander does not appear to be working so we will have to rely fully on the harpoons at touchdown,” says Stephan Ulamec, Philae Lander Manager at the DLR German Aerospace Center.
The European Space Agency’s Rosetta spacecraft was launched over a decade ago from Europe’s spaceport in Kourou, French Guiana. During this long voyage, Rosetta had to make three gravitational sling shot maneuvers around the Earth and one around Mars to gain enough speed to catch up with Comet 67P/ Churyumov-Gerasimenko.
Rosetta reached the icy comet on August 6, 2014. After several months of maneuvering the spacecraft into a precise orbit, Rosetta is now set to launch its Philae probe today. Separation of the probe is planned for 4:03 a.m. Eastern Standard Time (09:03 GMT). Philae should touch down on the comet about seven hours later at 1:02 p.m. EST (16:02 GMT).
Image Credit: ESA