With five flawless flights of the space shuttle Columbia behind it, NASA would seem to be in clover.

But there are persistent reports of new frictions between the Johnson Space Center in Houston, where the astronauts are trained and picked for shuttle assignments, and headquarters in Washington, where the political realities include staying on the good side of congressional budgetary committees. The latest frictions reportedly involve the choice of only two women among the 50 astronauts selected for the next 10 flights.

The women chosen were Sally Ride, who will be one of five astronauts on the seventh shuttle flight, and Judith Resnick, one of five to make the 12th flight. Of the five mission specialists who are not assigned a flight, four are women: Dr. Anna Fisher, Shannon Lucid, Kathryn Sullivan and Rhea Seddon.

"They're not happy and headquarters isn't happy," said a source at the Johnson Space Center who asked not to be identified. "Headquarters wanted at least four women on the flights where crews have been picked, and JSC decided two were enough. There's sort of a mini-war brewing between the two over this."

That isn't NASA's only or most serious problem these days. Its most serious problem is the second space shuttle, Challenger, which is sitting on the launch pad at Cape Canaveral waiting for a launch that was scheduled originally for Jan. 20 and now looks as if it will go no earlier than April 7.

Challenger's first flight was postponed four times because engineers found leaks in the fuel lines of the spaceliner's three main liquid-hydrogen engines. These engines, the most powerful ever built, run at chamber pressures of 60,000 pounds per square inch and burn fuel at nozzle temperatures exceeding 3,000 degrees Fahrenheit.

"If something catastrophic is going to happen on a shuttle flight," said one astronaut who asked not to be identified, "it's going to come from a failure of one of the hydrogen engines."

Just about the time the space agency thought it had the hydrogen leaks all fixed, a new and even more bizarre event took place to postpone Challenger's maiden flight a fifth time. On Feb. 28, a severe storm with wind gusts up to 70 mph hit Cape Canaveral directly from the east, an unusual direction for Cape storms of any kind.

The winds carried dust and grit that had not been vacuumed out of the payload checkout room, directly east of the shuttle's payload bay, where a $250 million tracking data and relay satellite was waiting to be launched. The wind also carried water and salt into the bay and contaminated the satellite.

The satellite had to be removed from the payload bay where it had sat for 38 days (28 days longer than planned) and cleaned with what amounted to space-age fine-tooth combs and vacuum devices.

Among the contaminants found in the satellite's delicate electronics and solar panel hinges were sand, metal chips, silica dust from the shuttle's protective tiles, salt, rust, man-made fibers, steel weld beads, zinc paint and titanium from an acrylic spray paint.

The delay of Challenger's first flight automatically affects at least the next two flights. Delays in the space business cost as much as $3 million a day in overtime paid to technicians working to correct the problems.