Columbia -- and the role of the shuttle -- are up in the air

Space shuttle Columbia lifted off Sunday atop a massive column of flame -- and a thick cloud uncertainty.

With this fourth two-man space mission, launch of the chunky cargo ship has almost become routine for the army of technical and scientific support personnel on the ground.

Columbia went through its paces with split-second perfection June 27. Its launch at 11 a.m. EDT was the first ''on-time'' getaway in the shuttle test flight program.

(The perfection of the launch was marred by the loss of the two spent solid rocket boosters. Meant to be reused, they were supposed to have been recovered after falling into the sea. At this writing, NASA was reporting the both boosters were apparently lost in 3,500 feet of water.)

Three earlier Columbia flights have virtually assured that the Space Transportation System's fourth mission, STS-4, will provide all the data needed to complete the test phase of the decade-old, $15-billion shuttle program. STS-5 , set for November, should inaugurate operation of the shuttle in the way its designers intended -- hauling heavy cargo into space with airline-style regularity and cost-efficiency.

As well as carrying military equipment for the first time, STS-4 launches the operational phase by carrying the program's first commercial payload. This potentially money-making package designed to process biological samples is described by shuttle-builder Rockwell International as ''the first of many steps leading to possible commercial operation in space of 'space factories.' ''

But the STS-4 flight is carrying more than hardware aloft. A variety of questions accompany the Columbia as it circles the globe.

If all goes smoothly with STS-4, the 7-day flight will end with a flag-waving July 4th landing at Edwards Air Force Base in California. President Reagan plans to be on hand to greet shuttle commander Thomas K. Mattingly and pilot Henry W. Hartsfield. However, complete ''success'' for the NASA/STS team will be realized only if Mr. Reagan uses the occasion to announce full support for both the shuttle program and NASA's hoped-for next step, a manned space platform.

Any flight problems could delay the President's reported plan to deliver a major speech on national space policy including several new space projects.

One indication of the economic challenge facing NASA is that the shuttle program has been cut back by the Reagan administration. Overall, NASA won only an 11 percent increase from 1982's $5.98 billion to $6.6 billion in the 1983 budget, in spite of intensive lobbying. STS-related projects will account for a building four shuttle vehicles rather than the five planned earlier, which the Department of Defense, among others, wants.

This move creates problems in realizing shuttle pay-off. Early plans called for flying up to 55 missions per year to bring profitability to the STS program. Current plans call for only 24 flights per year by 1988. That's well below the 30 flights considered the break-even volume, where fares charged to commercial customers would at least equal costs including amortization of the program.

NASA and aerospace contractors hope for enough of a budget boost in future years to start the 12-year project of building the 8- to 12-person Space Operations Center. This $8.5 billion space station would provide a long-term, stable platform orbiting 200 miles above the earth and able to carry a wide variety of scientific and military equipment.