STEERING SYSTEM LEAK WON'T LIMIT SHUTTLE'S DOCKING WITH MIR.

Byline: Associated Press 

Space shuttle Atlantis sprang a leak in its steering system during liftoff Friday, but NASA said the problem isn't serious enough to cut short a docking with the Russian space station Mir.

Officials of the National Aeronautics and Space Administration said neither the crew nor the shuttle was in any immediate danger from the leak of hydraulic fluid. Mission Control assured Shannon Lucid and her five crew mates that the docking was still on. Lucid is supposed to be dropped off at Mir - along with more than 5,000 pounds of supplies - for a five-month stay.

As the shuttle raced after Mir for a linkup tonight, flight controllers pored over the data to make sure the leak would not worsen and that the escaped fluid, nonflammable but corrosive, would not damage any equipment.

The leak was in only one of three identical hydraulic systems used to control wing flaps, the rudder and landing gear. Only two systems are needed for landing.

Lead flight director Bob Castle said the red, oily fluid began leaking a few minutes before Atlantis was launched, but the seepage was too slight to be detected by ground-control computers. The launch would have been scrubbed had the leak been detected, he said.

About a quarter of the fluid, or 1-1/2 gallons, seeped out before astronauts turned off the hydraulic systems, as usual, when Atlantis reached orbit.

Castle said there is no evidence of further leakage, and the fluid is believed to be confined to the engine compartment in the form of a harmless oily film covering shuttle components.

NASA engineers spent Friday considering more than 100 possible scenarios to determine if the fluid could harm shuttle components.

"None of those are felt to be of significant risk at all," Castle said. "The risks to the system . . . are essentially zero, so there's no reason to shorten the flight for this. We think we have a very manageable situation."

Flight managers decided to allow Atlantis to remain docked with Mir for the full five days, as planned, rather than drop off Lucid and return home sooner.

NASA and Russian space officials are still discussing any risk the leaked fluid could pose for the Mir. The Russians, fearful of damage to Mir, almost nixed a close approach by the shuttle Discovery a year ago because of a leaking thruster.

"We don't expect a problem," Castle said. "We don't think that if anything was getting out of the aft compartment it's going to affect the Mir, but we're going to go review all that and make sure that the Russians are all comfortable with that as well."

NASA rules stipulate that if a hydraulic system leaks excessively and the leak cannot be isolated, a shuttle should complete its major objectives and then return to Earth.