HOUSTON, United States (AFP) -- Discovery's astronauts will inspect the shuttle for micrometeorite impacts and pack trash from the International Space Station into its cargo bay before heading back to Earth.

The Discovery crew have used the shuttle's robotic arm to scan it for possible damage caused during liftoff and NASA analysts found nothing that would prevent the spaceship from safely flying home on Monday.

But for the first time in a shuttle mission, the astronauts will conduct another safety check before they pull out of the ISS to ensure that Discovery's heat shield was not cracked by space particles in just the second flight since the 2003 Columbia tragedy.

"I am confident that if there is any impact that we will detect it," mission specialist Stephanie Wilson said in a U.S. press interview this week.

Before the inspection, the astronauts will finish putting ISS rubbish and unused equipment into a container that they will transfer into the shuttle's payload bay.

The Discovery shuttle had brought food, clothes and equipment inside the container, a cylindrical logistics module dubbed "Leonardo." As they transferred the cargo into the ISS, they placed trash in the module to be taken back to Earth.

The two women and four men, who arrived at the ISS last week, bid farewell to the orbiting laboratory's three crew members on Saturday and leave on a two-day journey back to the Kennedy Space Center in Cape Canaveral, Florida.

The nine space colleagues took the day off Thursday, taking time to admire the view of Earth 350 kilometers (220 miles) below while the conjoined spacecraft circled the planet every 90 minutes.

"We have been so busy, we haven't had much time to really have a whole lot of fun," astronaut Mike Fossum said in a television interview.

"But today (Thursday) has been the first day we have had a chance to have a little bit of down time to look out the window a little bit and appreciate where we are," Fossum said from the space station.

NASA television showed the six Discovery astronauts and their three ISS counterparts enjoying dinner together, picking food out of cans or taking bites out of food floating in zero gravity.

The last two shuttle flights since the Columbia accident are aimed at improving space flight safety before NASA resumes regular launches to finish building the ISS by 2010, when the three-shuttle fleet is retired.

"It's of course a very important mission and we feel like we are getting the program back on track for all the missions after this to follow, and we are very happy about that," astronaut Lisa Nowak said.

Fossum and fellow astronaut Piers Sellers successfully performed three key spacewalks, spending more than 21 hours outside, to test shuttle repair techniques and fix equipment critical to the construction of the ISS.

NASA officials hailed the 13-day mission's three spacewalks as successes.