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.
This year we said goodbye to one of our most intrepid planetary explorers, the Opportunity rover. Take a look back at its storied 15-year mission on Mars, and how it revolutionized our understanding of not just the red planet, but our solar system at large.
Kevin explores life in orbit on board the Station. As Tim settles in to his new home he sends special reports about what it takes to live and work in space. Four hundred kilometres above the Earth, hurtling at a speed of 17,500mph, astronauts' bones and muscles waste away, the oxygen they breathe is artificially made, and they face constant threats from micrometeorites, radiation and extreme temperatures. If a medical emergency strikes, Tim is a very long way from home. In its 15-year lifetime, the International Space Station has never had a major accident. With a British astronaut in orbit, gravity-defying experiments and guest astronauts in the lecture theatre, Dr Fong shows us how to survive life in orbit.
Today we’re talking about our galactic neighborhood: The Milky Way. It’s a disk galaxy, a collection of dust, gas, and hundreds of billions of stars, with the Sun located about halfway out from the center. The disk has grand spiral patterns in it, formed by the traffic jams of stars and nebulae, where stars are born. The central region is shaped like a bar, and is mostly old, red stars. There’s also a halo surrounding us of old stars.