The pinpoint precision of the flight of the Columbia means at least one more space shuttle excursion into earth orbit this year, probably with two rookie astronauts aboard.

But that flight, scheduled for September or October, will be just a second routine step in what the National Aeronautics and Space Administration hopes will soon become voyages as common as those of a luxury ocean liner.

Two men who have never been in space -- Joe Engle, a 48-year-old Air Force colonel, and Dick Truly, a 43-year-old Navy captain -- are expected to map the next flight of the Columbia, which remains here in the dry clear air for a one-week checkout before being flown atop a specially designed Boeing 747 back to Cape Canaveral.

The shuttle seemed to have suffered no major damage from its punishing liftoff and its scorching return through the atmosphere. Budgetary questions still haunt NASA, however.

The space agency is committed to building four shuttle craft by 1984. The second, the Challenger, already is under construction at a Rockwell International assembly plant near this desert landing site.

Engle and Truly, almost certain to be the crew of the next trip, will stay in space about 4 1/2 days. They will take along a small kit of sensors and other equipment, the forerunners of future elaborate cargoes, for tests. They also will run the first crude tests of the shuttle's mechanical arm, which eventually will reach out of the craft to place satellites in orbit and retrieve them.

NASA plans to make the shuttle fully operational in September 1982. It has contracts with nine major American corporations, such as Bell Telephone and Comsat, and 15 foreign countries, including Canada and Indonesia, for the first industrial and scientific tests on about 50 military and commercial satellites through 1985.

The first 52 flights, through 1986, are booked up.

The Pentagon has assigned 14 of its communication, navigation and reconnaissance satellites to the space shuttle.

New customers who have booked space for communication satellites in the last six months on future shuttle flights include General Telephone Co. and Australia and India.

The average cost to carry a 10,000-pound communication satellite into-orbit is $14 million, less than half what it would cost using a conventional rocket.

A customer books space on the shuttle by paying NASA $100,000 in "earnest money" and telling it when it wants to fly its satellite and in what orbit. The customer must size the satellite to make it fit in the shuttle's cargo bay and meet safety requirements, such as not having sharp, protruding objects on the satellite that might injure astronauts.

About a dozen commercial customers have options for shuttle flights in the next five years they must exercise by June 1. NASA is planning a meeting about that time, and the meeting was described by one NASA official "as being a little bit like the player draft the National Football League conducts," meaning that some customers may trade dates to fulfill commercial requirements or arrange better financing.

NASA's schedule calls for almost 500 shuttle flights in the next dozen years. It also hopes eventually to get its space platform, the original justification for building a shuttle. The space station would remain in orbit, the shuttle bringing men and supplies up and down from earth.

But the question marks loom large. The Reagan administration budget cutters have the space agency nervous. The administration has recommended a $607 million cut in NASA's $6.7 billion budget.

Yesterday's moment of glory -- with all the flag-waving impact NASA hopes it will have on an American public tired of hearing of national failings instead of national strengths -- is clearly the space agency's budgetary hope.

As uneasy as NASA usually is in dealing with the military, the fact that the Department of Defense is touting the shuttle as a key in defense policy is expected to help.

In the past the space agency has gone to extraordinary lengths to stress that its mission in space has no military overtones, even if most astronauts were military officers.

Yesterday, almost every public comment by a high NASA official stressed first the magnificence of the accomplishment and then added that the Columbia strengthened America's defense posture.

That, as much as anything, told how nervous the space agency is about getting the money to go onward into space.