The attempt to send and land astronauts on Mars risks billions of dollars and the lives of those brave enough to attempt it. Is the possible benefit really worth the risk? And is it really achievable? Guiding us through this ethical and scientific minefield is Dr Kevin Fong. Kevin's diverse background in astrophysics, aeronautics and medicine makes him uniquely placed to understand the technical and human challenges of this perilous journey. With the help of the BBC's rich archive and a cast of supporting experts, Kevin leads us through the journey to Mars stage by stage. For Kevin, not only is this the toughest journey we will ever attempt, it is one that he feels we ultimately must make if we are to survive as a species.
With repeated triumphs and new challenges comes increasing risk, until loss breaks the pattern. The white-knuckle suspense thriller of Apollo 13's famous near-disaster is only a triumphant prelude to darker moments ahead. The launch of the space shuttle program promises routine trips to Earth orbit for many new astronauts. But just when that promise seems fulfilled, routine shuttle launches begin to bore the public. NASA responds by training a school-teacher to fly, in order to teach children lessons from space. Christa McAuliffe's life is tragically cut short as she and the rest of the crew perish aboard the shuttle Challenger. All missions are halted. Eventually the shuttle returns to orbit, for fifteen years of successful missions until disaster strikes again with the shocking loss of Columbia. It would be the beginning of the end for the shuttle.
Is there another Earth out there with liquid oceans, rocky continents and life like us? Astronomers seek the answer with spectroscopy, direct imaging and telescopes. They hope to find evidence of atmospheres, magnetospheres and signs of life.
After visiting the Moon, humanity seeks to explore deep space and learn to live beyond the Earth. This requires extensive experimentation, and the building of NASA's first space station - Skylab. Thus begins a new stage in space exploration, heralding the replacement of rivalry with partnership; The International Space Station unites over a dozen nations - with Japanese, Canadian and European astronauts aiming to complete it by 2010. Meanwhile NASA's greatest asset - the Hubble Space Telescope - reveals what is waiting for us deep in space, having begun its life as NASA's most famous mistake.
It was 30 years ago that the first space shuttle, Columbia, was launched. It was such a triumph of technology, engineering and organization that it's easy to forget the programme was primarily the product of an economy drive. The disposable Apollo missions had cost billions. A reusable craft was deemed more expedient.