HOUSTON (Reuters) - Spiders flying as an educational project aboard the International Space Station seem to have gotten the hang of weightlessness.

Their first orbital webs were messy, disorganized affairs. But a week into their flight, television images beamed back to Earth showed surprising progress.

"We noticed the spider made a symmetrical web," space station commander Mike Fincke told ground controllers on Friday. "We're really amazed that the spider could adapt to space so quickly."

Flight directors replied that the spider video had become the favorite form of entertainment for engineers overseeing the station's science experiments from Earth.

"We used to be your major form of entertainment," Fincke replied. "We've been overtaken by spiders."

The orb-weaving spiders were delivered by the crew of the space shuttle Endeavour, which lifted off from Florida last Friday on a 15-day mission.

The spiders will remain aboard the space station so schoolchildren -- and flight directors -- can watch their progress. Their chamber includes a supply of fruit flies and, of course, a video camera.