The under secretary of defense for weapons development, the chairman of the Joint Chiefs of Staff and several other senior officials are scheduled to meet at the Pentagon March 2 to determine the fate of a controversial advanced Air Force missile called Maverick.

The Air Force eventually wants to spend $5 billion for 61,000 new Mavericks--a heat-seeking missile with a long record of expensive troubles, delays, and failure. Congressional testimony and Air Force tests raise serious questions about whether one of the major weapons U.S. forces are likely to get over the next decade will work under combat conditions.

Richard D. DeLauer, the under secretary for research and development and the person chairing the March 2 meeting, said he will keep an open mind about approving purchase of the Maverick. But in a moment of candor in a recent interview he said, "You know, it's a go-ahead now, there's no question about it, the question is at what pace . . . ."

Late yesterday--aware that the Washington Post was beginning a series of articles on the Maverick--the Air Force announced that it was slowing down the pace. A spokesman said the Air Force has been dissatisfied with the latest test results and would order more tests before committing itself to full production of the missile.

Meetings to review new military hardware are being held almost daily as the Reagan administration prepares to carry out its pledge to improve the nation's defense, reduce waste, and restore competence and credibility to U.S. forces. At each of these meetings rigorous, critical questions are supposed to be asked to determine if the weapon works and if it's worth the money.

The March 2 meeting will deal with the Air Force's request for the initial production of several hundred new Mavericks, an eight-foot-long, non-nuclear guided missile carried on U.S. tactical aircraft and designed to destroy ground targets, primarily enemy tanks.

Because of the importance of the antitank mission--especially in Europe--and because the Air Force has no other weapon as an alternative to Maverick, a number of civilian and military experts said that not only will the Air Force inevitably win approval next Tuesday, but it also eventually will be allowed to go on to buy all 61,000 new Mavericks.

The Air Force already has spent $173 million developing the new Maverick, which has tested poorly even in favorable conditions that do not come close to the rigor of combat.

Over the last 14 months, the Air Force has conducted three rounds of tests. Because of unexpected problems, each test was suspended and the missile modified. Five live firings were planned between last October and Jan. 31; one aborted, two failed, and the other two have been postponed.

"These shots have not gone well," said Maj. Gen. James H. Marshall, the officer in charge of the Maverick's development. Nonetheless Marshall is convinced that the Air Force can make it work and he has a team of officers devoting full time to the task.

The Maverick's supporters and critics alike agree on the importance of a missile that can be fired at long range against ground targets. Some military strategists have argued that the absense of an effective antitank weapon increases the possibility that tactical nuclear or neutron weapons would be used.

In 1964, the Air Force issued an "operational statement" outlining the need for a precision guided weapon to give close air support to Army ground operations.

The "smart" missiles seemed most promising. With miniaturized video or other sensing equipment in the nose, a smart weapon fired from an Air Force jet can detect the target, hold it in its sights (called a "lock on") after it is fired as the sensing system guides the missile at supersonic speeds toward its target.

It was with this directive that the Air Force began experimenting with the Maverick. In spite of its poor test record over the years, the first generation Maverick was developed and produced; there currently are 20,000 of them stockpiled in Europe and elsewhere as the primary antitank weapon. And now the Air Force wants the advanced, second generation Maverick with a new sensing device.

"It fills a need no other system can fill," said Marshall. "You know, we got a lot of money invested in a solution. There's no other solution hanging on the horizon to grab."

This series of articles is a study of how the Air Force decided both on the old and the new Maverick and how the missile has been tested and developed over the years.

"It ain't been the best but it ain't the worst . . . somewhere in the middle . . . somewhat of a typical example," said DeLauer.

Though the missile's supporters and critics don't agree on its capabilities and promise, they all seem to agree it is somewhat typical of the Pentagon's system of conceiving, developing, testing and buying weapons.

It is this Pentagon system that the Reagan administration will use--or will have to modify--for a large part of the $1.6 trillion in defense spending it plans over the next five years.

The Maverick is both an old and a new weapon. In the earlier version produced in the 1970s, the Maverick used a television guidance system that homed in on the visual contrast offered by a target. Its successor, the new Maverick now being tested, has an advanced sensor that can detect and home on heat produced by enemy tanks.

Thousands of pages of reports, testimony, inquiries and test data have been compiled during its 18-year history. The missile's career also has been witnessed by hundreds of military officers, civilians, officials, pilots, weapons testers and analysts and others in many parts of the government.

The Maverick record shows:

A history of failure. The old TV-guided Maverick failed when it was used in Vietnam. Gen. John W. Vogt, who commanded air operations in Vietnam said, "Clearly it didn't do the job out there." And in bad weather, he said, "this kind of weapon craps out completely."

It is not an all-weather missile. Pentagon officials and Gen. Marshall acknowledge that it will not work in heavy fog or heavy rain.

Problems finding the target. The new Maverick sensor can see only about 3 degrees of the field of view in front of it. "It is like looking at the world through the end of a drinking straw," said one former weapons analyst. Air Force Maj. Grant G. Nicolai, the program requirements manager for Maverick and an accomplished jet pilot who has tested the missile, agrees: "Your comment about looking through a straw is valid. It is a 3-degree field of view. There's no two ways about that." He added that other detection devices and intelligence should help the pilot find the target.

Problems identifying the target. The chief advantage of the new heat-seeking Maverick is that it is supposed to allow the pilot to fire the missile from as far as six to eight miles away. Spotting a tank at six miles is almost impossible. Most pilots and officials interviewed said that positive identification of a ground target--unless there is some other intelligence or identification system--requires the pilot's own eyes. Most said a pilot cannot identify a target unless he is from one to two miles away. DeLauer said: "You probably can see four to five kilometers three miles , depends on the weather . . . ."

This means it is difficult to distinguish an enemy tank from a friendly tank, or from a sun-heated rock or burning bush. Even if it is clear the targets belong to the enemy, it is hard to tell if the $70,000 Maverick is going to be fired at a tank or a $10,000 enemy jeep, generally not a cost-effective action.

Unrealistic tests. The tanks in the 1977 and 1978 tests of the new Maverick traveled the same routes, enabling the pilots of the airplanes carrying the Maverick test missiles to anticipate the placement and movement of the tanks. Still, the records show that the test results were poor. While the pilots are trying to find tanks, they are constantly in jeopardy from enemy surface-to-air (SAM) missiles that have been perfected in combat experience like Vietnam.

Because of problems with the missile in recent months and the need to balance safety and realism, Col. Roger W. Engebretson, system program director of Maverick, said, "So we have very controlled conditions . . . it's very controlled, not realistic operational environment" for the development tests.

Yet in order to speed up testing many of the required operational tests that are supposed to be realistic have been combined with the tests in which the missile is still being developed and perfected.

To all of this grim diagnosis and history, the Air Force and Pentagon officials have responses.

Whatever occurred in the past, said Marshall, who has been Air Force director of development and production for 18 months, the current Maverick testing program is "purposely stressful" and meets rigorous standards. "We set up some terrible scenarios," said Marshall. "Based on what we see in the tests, we are confident that it's going to work . . . yes, sir. Absolutely."

In addition, Air Force officials give this defense:

The new Maverick will work at night if there is no heavy fog or heavy rain; the Air Force needs such a capability. Testing setbacks will be overcome. The missile just needs to be fine tuned; the concept is sound; pilots will learn to identify targets and know the silouettes on the cockpit video screen; additional sensing devices now in development will help target identification; the Air Force has no reason to spend $5 billion on a missile that won't perform; there have been some tests that show high performance.

To an extent, some Air Force officers argue that they are simply doing their duty; the Pentagon has established a requirement for it to cope with an enemy tank threat.

Marshall said: "Weapons are getting more expensive all the time . . . obviously, the missile is complex. It spends most of its life in a can in storage , so you got to have reliability; when it come out of the can it needs to work. Any system like this has a series of things that have to work right for it to hit the target. That goes all the way from the missile in the can to the delivery system to the pilot to the training aspects--all that is necessary to make the system work.

"Now I don't call those negatives, necessarily. They're complexities, perhaps," said Marshall, noting that the Air Force has few alternatives.

Marshall summarized: "There's a threat. There's a requirement, and we think we have a solution. Now, if the decision makers say we don't have a solution, I frankly don't know where we'd turn right now."

But if the decision makers say yes, can the new Maverick fill the bill? Marshall rephrases the question and answers it: "Do we see light at the end of the tunnel now? Yes."

Still, the Maverick has many critics. "I don't think it's totally useless," said Russell Murray, who was the assistant secretary of defense for program analysis and evaluation in the Carter administration. "It's just not the right choice."

Based on his detailed evaluation of the advanced heat-seeking missile, Murray said, the pilot will in fact be handicapped as he tries to find and hold a target on a small five-inch screen while trying to fly the single-seat tactical airplane.

"It makes the aircraft more vulnerable, not less," Murray said.

Col. John M. Verdi, a retired officer who took the first Marine Corps aircraft squadron into Vietnam, goes further: "It's a waste."

Under the so-called "Carlucci initiatives"--named after Deputy Defense Secretary Frank C. Carlucci--designed to streamline the rearming program of the Reagan administration, if the Air Force gets its go-ahead for the initial Mavericks on March 2, the full production decision--scheduled to be made later this year--will be delegated to the Air Force itself.

And the Air Force is the strongest advocate for the missile.

So the Air Force and the American taxpayer seem almost certain to get the new Maverick.