A spacewalk is planned at the International Space Station, Nasa has announced.
Two of space shuttle Discovery's visiting crew will float outside the orbiting facility, spending several hours moving a broken ammonia pump to a better location, installing an extension cable while completing other chores.
One of the astronauts going out is Stephen Bowen, who was assigned to the job just last month.
The original lead spacewalker, Timothy Kopra, was injured in a bicycle accident and pulled off the flight.
Kopra, who is still on crutches, will help direct the spacewalk from Mission Control.
This is the last flight for Discovery. After it returns to Earth next week, it will be retired and sent to the Smithsonian Institution.
Only two other shuttle missions are planned.