Johnson Space Center, Houston — As the fruit of his agency's labor orbits some 135 miles over the eastern Pacific, Michel Bignier leans forward in his chair and draws a quick comparison: ''When the Spacelab program was negotiated in 1972 and all the agreements signed in '73, European industry had no competence at all with manned space activities. But today, I see in the POCC (the payload operations control center here) two men at each computer point - one from ESA and one from NASA.''
To Mr. Bignier, director of space transportation systems for the European Space Agency (ESA), American and European controllers sitting side by side on a manned spaceflight mission has a special meaning. It is an indication of how the Spacelab project has helped Western Europe to carve a niche beside the United States and the Soviet Union in developing the know-how for manned spaceflight.
The 10-year, $920 million Spacelab project has not been without its critics in Europe. They argue, among other things, that the return on ESA's investment hasn't justified that investment. The agreement between the National Aeronautics and Space Administration (NASA) and ESA stipulates that ESA deliver the first spacelab free of charge, and that NASA is obligated to buy a second lab and any additional pallets and spare parts from ESA.
Critics also contend that ESA's money would have been better spent on lofting a series of unmanned exploratory missions.
''The money spent on the Spacelab program is not justified, if you consider only the very short-term view,'' counters Bignier. ''But if you have a longer view, I think that the cost of the program is not excessive at all.''
And what is that long-term view?
''During the next 20 years, and more in the 21st century, it is clear that a space station will be built, and manned space activity will take on more and more importance in the future,'' he says. ''Not to be involved in manned space activity is, for me, to practically close a door.''
Bignier says that the technical expertise and the degree of cooperation with the United States gained during the Spacelab project puts ESA in a good position to make a major contribution to a space-station effort.
As for the relative advantage of manned over unmanned research in space, that depends on one's objectives.
''Take, for example, materials processing (developing new manufacturing processes) in space. I am convinced that the presence of man is needed. If we speak of astronomy, I am a little less convinced. Astrophysics and astronomy could probably well be explored without Spacelab. But in certain fields, the presence of man is extremely important,'' he says.
For ESA, the Spacelab project represents the largest cooperative space project, both within Western Europe itself and between the US and Western Europe.
Bignier, a former director-general of the Centre National d'Etudes Spatiales, the French equivalent to NASA, points out that up until the billion-dollar Spacelab, the most that the agency had ever invested in one payload was $300 million for a satellite. And while five or six countries are cooperating on the Ariane program, Spacelab drew on the resources of 10 Western European nations and 50 European contractors.
As for previous US-European cooperation, he says, Europe had provided some subsystems for previous NASA space projects. And the Europeans were infuriated three years ago when the US withdrew support for its half of the International Solar-Polar Mission, in which a European and an American satellite were to orbit the sun and return data on its poles.
But, says ESA Director-General Eric Quistgaard, that wound has healed.
For now, at least, ESA officials appear to be pinning their hope for a slice of the action on a manned space station on the US.
NASA is urging President Reagan to put $200 million in seed money for a space station in the fiscal 1985 budget. Estimates of the total cost for such a project range from $20 billion to $30 billion. NASA's timetable would place the station in orbit by 1992.
''It is clearly the European wish that if NASA undertakes a space-station project, then we would like to make it a joint venture,'' Bignier says.
While acknowledging that the US hasn't decided yet whether to proceed with a space-station project, Bignier says, ''The question for me is not if there will be a space station. The question for me is when. So long as the Americans have not taken the decision, Europe will not take its own decision.
''If the NASA decision is relatively fast, we would be in a position to start negotiations immediatiely,'' he says.
If NASA doesn't decide within the next three or four years to build a space station, ESA has plenty of other projects in the hopper to keep it busy and to prevent dispersion of the expertise that has been built up during the last 10 years.
One of those projects is EURICA, a free-flying, reusable pallet designed to be used in conjuncion with the space shuttle. It would be able to hold 1.2 tons of experiments. The first of these pallets is scheduled to fly either in late 1987 or early 1988, Bignier says.
''At the same time, we will try to increase European use of Spacelab. We are also very interested in the international microgravity laboratory program, which will be dedicated to microgravity experiments in life and materials sciences. And if NASA makes improvements in the shuttle that will allow 20- to 30-day flights, obviously ESA will update the Spacelab for 20- to 30-day flights.''
There is a potential hitch, however, that might prevent the kind of tight cooperation on a space-station project that ESA and NASA enjoy on Spacelab. That factor is potential US military participation in building a US space station.
While defense officials say publicly they do not foresee a need to take part in a space station, studies have been conducted within the US Defense Department on possible military uses for a manned space station, especially in conjunction with proposed space-based antiballistic missile systems.
It's not clear whether the Defense Department would look kindly on sharing such a project with the West Europeans. And of the Europeans, such a project might prove difficult because ESA's charter mandates that the agency's efforts be directed exclusively toward the peaceful use of outerspace.