Discovery's crew used highly sensitive cameras attached to a 50-foot boom Wednesday to carefully examine the space shuttle for any signs of damage from the previous day's launch. Nothing serious was reported, but it was much too early to draw any conclusions, officials said.
The only unusual thing found, at least for now, was a whitish splotch on Discovery's right wing that looked like a bird dropping. And there was one on the wing a few weeks ago at the launch pad, said flight director Tony Ceccacci.
Ceccacci said the imagery experts would study the splotch and make sure it was nothing more than a bird's shuttle signature.
Ceccacci said Discovery was on target for a Thursday linkup with the international space station. The astronauts were stepping through their chores in orbit and working hard to stay on schedule, he said.
Live video of Discovery's Independence Day launch had showed some small chunks of debris falling from the external fuel tank, at least one chunk hitting the shuttle.
Using new inspection techniques implemented after the 2003 Columbia disaster, the astronauts on Wednesday were taking more images with laser, digital and video cameras that can spot damage as small as an eighth of an inch.
As they hurtled toward a Thursday morning rendezvous with the space station, the astronauts maneuvered the boom, with the cameras attached, to inspect Discovery's right wing and nose cap. They had to work carefully — the boom could easily damage the shuttle's protective skin, but the radar camera needed to be within 10 feet to detect damage.
It was only the second time a shuttle crew had conducted such an intensive inspection, though NASA managers had said after reviewing the launch video that they weren't particularly worried.
"We saw nothing that gives us any kind of concern about the health of the crew or the vehicle," said Wayne Hale, shuttle program manager.
The seven-member Discovery crew awoke early Wednesday to sounds of "Lift Every Voice and Sing," sometimes referred to as the black national anthem.
"That one is particularly dear to my heart because ... after the day of our nation's independence, it's very fitting because it reminds us that anyone and everyone can participate in the space program," astronaut Stephanie Wilson, only the second black woman in space, radioed to Mission Control.
Astronaut Mike Fossum sent Mission Control video showing him, pilot Mark Kelly and specialist Lisa Nowak in the flight deck during Tuesday's launch.
First-time fliers Nowak and Fossum gave each other a gloved congratulatory handshake and thumbs up during the ascent. Once in orbit, Nowak, serving as flight engineer, took notes while Fossum and specialist Stephanie Wilson unstrapped themselves to photograph the external fuel tank as it fell away from the shuttle.
The Day 2 inspections, expected to take about 6 1/2 hours, were ordered after a chunk of hard insulating foam from the external fuel tank struck Columbia on liftoff in 2003 and damaged its wing, allowing fiery gases to enter the spacecraft during reentry. All seven astronauts were killed as the shuttle broke up over Texas.
Shuttle managers said early video images of Discovery's liftoff showing small pieces of foam breaking away — and one striking the spacecraft — were not troubling.
About three minutes after liftoff, as many as five pieces of debris were seen flying off the tank, and another piece of foam popped off a bit later, Mission Control told the crew. The latter piece struck the belly of Discovery, but NASA assured the seven astronauts it was no concern because of the timing.
Hale said Discovery was so high when the pieces came off that there wasn't enough air to accelerate the foam into the shuttle and cause damage.
The astronauts reported seeing what they described as a large piece of cloth tumbling away from Discovery soon after reaching orbit. It looked like one of the thermal blankets that protects the shuttle, they said, but Mission Control told them it was likely ice and that a similar observation was made during Discovery's flight a year ago.
The mission for Discovery's crew is to test shuttle-inspection techniques, deliver supplies to the international space station and drop off European Space Agency astronaut Thomas Reiter for a six-month stay. Astronauts Piers Sellers and Fossum plan to conduct two spacewalks, and possibly a third one, which would extend the 12-day mission by a day.