Space shuttle Discovery closed in on the International Space Station on Sunday to deliver a Japanese research laboratory, a new crew member and a repair kit for the outpost's faulty toilet, Reuters reported.
The spaceship was scheduled to arrive at the station shortly before 2 p.m. EDT (1800 GMT) on Monday. The shuttle and seven astronauts blasted off from the Kennedy Space Center in Florida on Saturday for a 14-day mission.
The shuttle lost about five pieces of insulating foam from its fuel tank during lift-off, the same problem that triggered the 2003 loss of Columbia in which seven astronauts died.
Analysis of the debris lost during Discovery's launch was under way but NASA's top space operations manager told reporters there was no cause for concern.
"We don't consider those a big deal to us," said space flight chief Bill Gerstenmaier.
NASA spent more than $1 billion and two years fixing the tank to minimize debris and added a suite of inspection tools to check for damage after launch.
Because of the shuttle's design, NASA says it will never completely solve the debris issue but it does expect any fly-away foam will be too small and occur too late during the climb to orbit to do any damage.
As the shuttle ascends, there is less atmosphere to transport debris and less energy for it to impact the shuttle.
Because the Japanese laboratory in Discovery's cargo bay is so large, Discovery is flying without an inspection boom routinely used since Columbia to scour the ships for damage. The last shuttle to visit the space station left its boom behind for the Discovery crew to use and return to Earth.
On Sunday, the Discovery astronauts began a limited inspection of the ship's wings and nose cap using a camera on the end of the shuttle's 50-foot robot arm.
The arm is only long enough for the crew to take images of the upper surfaces of the wings' leading edges. The boom adds another 50-feet of manoeuvring room. A more thorough inspection is planned for later in the mission.
MAIN GOAL
The main goal of NASA's 123rd space shuttle flight is to deliver Japan's lab, named Kibo, which means "hope."
The lab's launch had been on hold for years due to delays in the construction of the station. NASA now has just two years to complete assembly, which began in 1998, in advance of the shuttle fleet's retirement.
Seven construction missions and two resupply flights are pending. The U.S. space agency also plans a final servicing call to the Hubble Space Telescope in October.
The Discovery crew is also carrying a new pump for the station's sole toilet, which has been working erratically for the past week or so. Crew members have been manually flushing the commode with water four to five times a day to push urine through a system that separates liquids from gases.
The solid-waste system is not affected by the problem.
Helping with the toilet repair may be one of the first jobs for incoming station flight engineer Greg Chamitoff, who is being ferried to his new home by the Discovery crew.
He replaces Garrett Reisman who will be returning aboard the shuttle after a 2 1/2-month mission. Chamitoff is scheduled to remain in orbit for six months.