STS-129: Hatches Are Closed

All hatches connecting Atlantis and the ISS are now closed and sealed, marking the official end of the docked portion of the STS-129 mission. Atlantis is set to undock for the station at 4:53am EST Wednesday morning, back away to a safe distance and perform a flyaround to inspect their handiwork and video document the growth of the station.

With hugs and congratulations the two crews said their goodbyes and handed over the final piece of "cargo", Item 914, Astronaut Nicole Stott, who endured the final moments of the mission with a piece of paper with the number 914 on her back - just in case the crew forgot her.

The crews say their farewells

After undocking the Shuttle Atlantis will slowly separate from the vicinity of the station as it prepares to reenter the atmosphere and return to Earth. Unlike the Soyuz capsules that plunge into the atmosphere just a few hours after undocking, a Space Shuttle must be prepared for reentry by the crew. As an orbiting vehicle there are only two seats available for the commander and pilot as all of the other seats are stowed to provide more space for the astronauts to float around. This mission, one extra seat will be unpacked and installed for the returning Nicole Stott. The process of conversion from a space vehicle to an aircraft takes a couple of days and involves stowing all of the items transferred from the ISS during the mission, and along with the seats, unpacking and activating the landing suits that the crew all wears for the trip down. The payload bay doors are also closed and if needed, the robot arm and sensor boom are used one last time to inspect the heat shield tiles.

Strict weather requirements at the landing sites also play into the decision about when precisely to land. Storms, high winds, heavy clouds and rain are all considered no-go for landing, so often extra days are added to a mission as the weather on Earth is allowed to play out. The absolute final landing opportunity is determined by the consumables on board, and if the weather is unfavorable at all three landing sites, Kennedy, Edwards, and White Sands, the Shuttle will be forced to land at the site deemed safest.

Shuttle Atlantis approach as seen from ISS

So, can we see them both in orbit together then?
The few days after undocking is the best time to catch the two craft flying in formation across the sky. Just after undocking they will appear as two steady bright lights, one following the other in an unwavering path. As they separate they still follow, but because their orbits are diverging the plane is sometimes too different to catch them together. Now is the best time to click the Heavens-Above link to the right and enter your location to see if there is a visible pass where you are!

Happy Viewing Spacers!

Images credit: NASA TV, NASA

Digg this