Astronaut walking in space

Two astronauts walked outside the International Space Station (ISS) to remove a urine container and install a replacement bottle.

Two astronauts Rick Mastracchio and Clayton Anderson begin to make an outer space walk on April 9.Photo: Reuters.

AP said, Rick Mastracchio and Clayton Anderson - two members of Discovery's crew - made a total of three walks.

In addition to replacing urine containers, Mastracchio and Anderson also have to collect data for a scientific test and replace a broken device.

According to the plan, Discovery and crew of 7 will stay in ISS next Friday. But they may have to spend an extra day due to the ship's main antenna failure. The US Aeronautics Agency asked astronauts to check if the ship was damaged by collisions with meteorites before leaving the ISS. So Discovery will return to Earth on April 19.

After this flight, the US shuttle fleet will only make three more flights before it stops operating later this year.

Below is a bunch of astronauts walking in space:

Rick Mastracchio astronaut leaves ISS on April 9.Photo: Reuters.

Photo: Reuters.

Photo: Reuters.

Photo: AP.