STS-87 Mission Specialists Kalpana Chawla, right, from Karnal, India, and Leonid Kadenyuk, from Chernivtsi region of the Ukraine, smiles as they see family members and friends near the Space Shuttle Columbia Tuesday Nov. 18, 1997 at Kennedy Space Center, Fla. AP Photo/Chris O'Meara

Doing the twist: Columbia will flip in space shuttle first

Web posted November 19, 1997

Associated Press

CAPE CANAVERAL, Fla. -- It's a 180-degree flip that normally would have NASA flipping out.

In a space shuttle first, Columbia will roll from belly-up to belly-down -- and the crew from heads-down to heads-up -- six minutes after liftoff Wednesday while traveling at about Mach 13, or 13 times the speed of sound.

The twist is designed to put the rocket ship in radio contact with communication satellites.

In the past, such a tricky maneuver would have been used only if a shuttle had to make an emergency landing overseas -- something never attempted -- because of a failed engine or loss of cabin pressure.

In this case, it's a money-saving move.

NASA can no longer afford its tracking station in Bermuda, which for 16 years has provided uninterrupted communication between Mission Control and ascending space shuttles.

Columbia will twist to keep its external fuel tank from obstructing the radio antenna that links the spaceship to NASA's communication satellites. The switchover from a Kennedy Space Center tracking station to the satellites should be smooth, with only a momentary gap in coverage.

The shuttle normally would switch over to the satellites upon reaching orbit 8 1/2 minutes after liftoff.

NASA stressed that the maneuver is safe and has been certified for emergency use ever since Columbia made the first shuttle flight in 1981.

``This is something we've studied at great length,'' said flight director Bill Reeves. ``We feel very comfortable with it or we wouldn't be performing it.''

Columbia's computers automatically will start the maneuver once the shuttle reaches a speed of more than 8,300 mph some 70 miles above the Atlantic Ocean, well after the twin rocket boosters have peeled away.

By then, Columbia will have passed from the atmosphere into space, eliminating any danger from undue aerodynamic stresses, said launch manager Donald McMonagle, a former shuttle commander.

It will take 40 seconds for the main engines on NASA's oldest shuttle to twist the ship 180 degrees, wider than it usually rolls after clearing the launch pad.

Commander Kevin Kregel and the five others on board won't know in advance whether will Columbia flip to the right or to the left. The computers will choose the shortest way at the last moment. The shuttle will stay in this position for the remaining two-minute ride to orbit.

If the test goes well, NASA will close its Bermuda station following Columbia's 16-day science mission, saving NASA $5 million a year. And all shuttles launched toward the east, from then on, will do the twist.

Shuttles launched toward the northeast -- to Mir or the future international space station, for example -- won't have to twist because of all the tracking stations up the East Coast.

Kregel expects it to be ``an E-ticket ride.''

``It will be exciting because it will be different,'' he said, ``but I don't think we have any fears about it not working correctly.''