LDEF was supposed to stay in space one year before returning to Earth. But the Challenger accident in early 1986 left LDEF stranded in orbit until the shuttle Columbia rescued the 12.7-ton space platform this past January.

The laboratory contained more than 50 experiments, mostly samples of metal, plastic and glass that were tested to determine how well they withstood the wear and tear of space.

The tomato seeds, however, were of particular interest because scientists wanted to know whether solar radiation would alter their genetic make-up.

The results are important to NASA because future space explorers may have to grow some of their own food as part of a lunar colony or during long journeys to such places as Mars.

When LDEF was brought back to Earth five months ago, about 10 million of the seeds were distributed to 67,000 student groups throughout the country to be planted and nurtured. Researchers, universities and space-related corporations also received some of the seeds to grow.

So far the plants are maturing well in window boxes, greenhouses and outdoor gardens.

One of those who got seeds, Gay Perry of Lockheed Space Operations Co., planted them indoors. But the sprouts grew so quickly that Perry, who trains shuttle technicians at Kennedy Space Center, transplanted them into pots outside a KSC warehouse.