The European Space Agency’s Philae lander as successfully detached from its mother ship Rosetta. The lander is now on its seven-hour long trip to the comet 67P. The 220-pound probe detached from Rosetta at 3:35 a.m. EST Wednesday. Scientists in the Rosetta control room in Germany exchanged handshakes and hugs after Philae set out on its nerve-wracking journey to the rugged terrain of the comet 67P.

Philae Lander Faces Thruster Glitch On Its 'Seven Hours Of Terror'

Philae needs some luck

If the probe descends successfully on the comet, it will be the first time in the history that a probe touched down on a comet. However, a problem in the thruster system has heightened the drama around the landing. Project scientist Claudia Alexander said the “seven hours of terror” has begun for the probe, suggesting the time it would take Philae to reach the surface of the comet.

At the end of its seven-hour journey, a thruster is supposed to fire up to hold Philae steady while harpoons secure it in place. However, mission managers said data from the lander indicated that the thruster system wasn’t activated properly. Philae lander manager Stephan Ulamec said that the thruster didn’t appear to be working. Philae will “need some luck” not to land on a steep slope or a boulder.

Control room re-establishes contact with Philae

As expected, the Rosetta control room lost contact with the probe upon separation. Two hours later, scientists said they had successfully re-established contact with the lander. The comet is traveling at over 85,000 miles per hour. Scientists have already zeroed in on the landing site for the probe. But the landing will be a big challenge as the comet’s surface has numerous boulder, steep slopes and cliffs.

Rosetta has been chasing the comet for more than 10 years. The $1.3 billion mission has traveled more than four billion miles to reach the comet 67P/Churyumov-Gerasimenko. Philae’s successful landing on the comet would give astronomers unprecedented insights into the comet. It is a 4.5 billion years old world of ice and dust. Scientists believe comets hold the secrets to the origin of solar system as they preserve leftovers from the solar system’s formation.