The European Space Agency's Rosetta probe is set to make history by landing its robot craft Philae on a comet, SIA reports.
The lander separated from Rosetta earlier on Wednesday and headed towards the surface of the comet Churyumov-Gerasimenko 67P which is moving at the speed of more than 80,000 miles (128,747 kilometers) per hour.
ESA tweeted: "SEPARATION CONFIRMED, Safe journey Philae2014."
The probe has covered a distance of approximately 3.7 billion miles (six billion kilometers) and is now 10 years into its mission.
The Philae lander is scheduled to touch down at 10.35 a.m. (EST) on Wednesday and confirmation is expected at 11:03 a.m. after ground controllers in Darmstadt, Germany, gave it the green light to part from its mothership and start a nail-biting seven-hour descent.
Watch the Webcast live from mission control and follow the updates at http://rosetta.esa.int/
The probe's touchdown is the most critical part of the mission, Stephan Ulamec, a senior manager at ESA posted online.
According to the official Rosetta blog at blogs.esa.int/rosetta/ ,Philae could miss its landing site and crash into rocks or cliffs on the comet's surface if there are any errors.
The agency’s senior science advisor Mark McCaughrean said: "Everyone's nervous, everyone's on tenterhooks, but we know the risk is worth taking. The rewards are enormous.
"You won't get anything without taking risks. Exploration is all about going to the limits."