US President Barack Obama on Thursday pledged to send astronauts to Mars, as he outlined a vision for the future of US space flight that eschews earlier plans to return to the moon in favour of boosting commercial flights and reaching deep space. Obama travelled to the Kennedy Space Centre in Cape Canaveral, Florida, to defend controversial budget plans for NASA that rely heavily on creating a commercial spaceflight option and which some had said amounted to the killing of US dominance in space. He pledged to send astronauts into deep space by 2025 - reaching an asteroid or other distant object - after first conducting a series of test missions early in the next decade. "A landing on Mars will follow and I expect to be around to see it," he said, vowing humans could touch the surface of the Red Planet by the mid-2030s. In February, Obama's administration announced it would scrap plans started under former president George W Bush for a next-generation spacecraft to return astronauts to the moon and eventually travel to Mars and beyond. That programme was behind schedule and over budget, and officials argued it would never achieve its goals with current funding levels. Instead Obama planned to transfer the transporting of US astronauts to the International Space Station (ISS) to commercial providers. Obama on Thursday defended the use of commercial vehicles as freeing up the space agency to focus on long-term goals such as reaching Mars, but also revived parts of the programme he had cancelled for being bloated and behind schedule. He backtracked on plans to completely kill the so-called Constellation programme of spacecraft and rockets to replace the shuttle. Instead, he announced that the capsule will be retooled as an emergency escape vehicle for the ISS, while still handing over routine transport work to the commercial firms. His plans include work to begin on a heavy-lift vehicle that could carry astronauts outside of low-Earth orbit to a series of destinations such as asteroids seen as a stepping stone for a mission to Mars. Humans have not left low-Earth orbit since the moon missions of the 1970s. The speech comes at a critical moment as NASA prepares for the retirement of the space shuttle programme later this year. One shuttle is currently in orbit and just three more flights remain once it returns home. The retirement of the shuttle fleet will leave Russian Soyuz capsules as the only means to get humans into orbit.
