The Discovery shuttle will undock from the International Space Station (ISS) one day later than previously planned, the space agency said on its website, RIA Novosti reported.
"Space shuttle and International Space Station managers decided today to extend the STS-133 mission by an additional day, providing more time for the shuttle crew to help unpack and outfit the Leonardo Permanent Multipurpose Module and fill the Japanese Kounotori2 H-II Transfer Vehicle with trash," NASA said on its website.
The spacecraft is scheduled to undock from the space station at 15:03 Moscow time [12:03 GMT].
During the mission, the crew is to deliver and install the Permanent Multipurpose Module, the Express Logistics Carrier 4 and provide critical spare components to the International Space Station.
STS-133 is shuttle Discovery's 13th and final docking to the space station. After this mission, the shuttle will be retired and placed in a museum. According to NASA, Discovery has flown 38 missions to date - more missions than any other shuttle - and made more than 5,600 trips around the Earth.