shield tiles and fix any apparent problems. U.S. astronaut Stephen Robinson, 49, carried out an unprecedented spacewalk to remove cloth protrusions from between tiles on the shuttle underbelly. "We're in better shape and it's thanks to the Columbia crew and their sacrifice," Kelly said. Despite the triumph over return to space, there were hours of uncertainty after NASA officials delayed its return for a day, then redirected it to the other side of the United States. After a sonic boom signaled its approach, the shuttle roared down the runway at Edwards Air Force Base at 5:11 a.m. (1211 GMT) and deployed its speed-breaking parachute in a predawn landing. "You want to know how I feel? I feel fantastic," said shuttle programme manager Bill Parsons. "It's good to be us today." Even as NASA celebrated the successful mission, it was preparing to launch a new Mars exploration early Thursday - a day late - from Cape Canaveral to explore chances for robotic and human travel to the red planet. Discovery mission controllers in Houston, Texas, clapped as the shuttle made its first nighttime landing since 1991 and completed the first mission since Columbia broke up on re-entry in 2003, killing the seven astronauts aboard. "Welcome home, friends," mission control radioed to the crew. "It's good to be home," replied Collins. About two hours later, the blue-suited crew - coming off 219 orbits around the Earth - emerged into the California sun. They inspected the outside of the craft before Collins briefly talked to reporters. "We are so glad to be able to say we're back and we were successful," said Collins. The landing delays were caused by bad and stormy weather at Cape Canaveral. Despite a launch delay last month and an unprecedented in-space repair, Discovery's trip to the International Space Station (ISS) to deliver 15 tonnes of supplies has been a success for NASA. NASA administrator Michael Griffin, head of the U.S. space agency, called the mission "beyond fantastic". The 720-million dollar Mars probe to be launched Thursday will be the largest project ever sent to Mars, where it is to collect massive quantities of data on the Mars atmosphere. The spacecraft, due to reach the red planet by March next year and land in November 2006, will look for presence of water and suitable landing sites for robots and human beings. President Bush has set a deadline of 2020 for building a newly designed spacecraft capable of using the Moon as a platform for human space exploration to Mars and other planets.
