Published: May 15, 2010 5:49 PM EDT

CAPE CANAVERAL, Fla. (AP) - Atlantis' astronauts ran into trouble with a camera system Saturday and had to temporarily put off a safety survey of their ship as they sped toward a weekend rendezvous with the International Space Station.

Flight controllers, meanwhile, were monitoring some space junk that was threatening to come too close to the space station. They were going to decide Saturday evening whether to move the station into a slightly lower orbit.

Even if the station has to dodge out of the way, it won't delay Sunday morning's scheduled docking by Atlantis. A NASA spokesman said the stalled shuttle survey also would not affect the docking.

The inspection is a standard - and essential - procedure the day after liftoff. A 100-foot boom is used to survey the heat shield on both wings and the nose in a hunt for launch damage. On Saturday morning, however, the astronauts could not move the bundle of laser sensors and TV camera on the end of the pole.

After zooming in with a handheld camera, the astronauts discovered that one cable was pinched by camera equipment at the end of the boom. They said they didn't think they could free it.

"Oh come on, man, we've got faith in you," Mission Control said. "Can't crack the whip with a little centrifugal acceleration?"

"Need to pull some G," replied commander Kenneth Ham, referring to gravity forces. "Spin her up," joked Mission Control.

Ham said it probably would be a simple spacewalk job to free the tangled cable. The astronauts used cameras and binoculars to beam down close-up pictures, so engineers on the ground could see what's wrong. The cable was dented where it was being squished, Ham reported.

Finally, in late morning, Mission Control asked the crew to work around the problem by using a condensed, backup survey method. The day-after-launch shuttle inspections were put in place following the 2003 Columbia disaster. Columbia shattered during re-entry because of a hole in the left wing; it was left there by insulating foam that broke off the fuel tank during liftoff.

Only a few small pieces of foam were spotted coming off Atlantis' tank Friday. Nonetheless, the wings and nose still need to be checked.

This is Atlantis' last planned flight after a quarter-century of service. Its six astronauts are hauling fresh batteries and a new Russian compartment to the space station. Three spacewalks are planned to plug in the batteries and other equipment.

Only two more shuttle flights remain, by Discovery and Endeavour. NASA is ending the program so it can focus on presidential-ordered trips to asteroids and Mars.