Preface
Space tethers. Unlike space rockets and space probes, it is not a topic many people are familiar with. You may wonder what tethers have to do with space, or what they would be doing there. You may also wonder why it would be interesting to read a book about them. On Earth, tethers, otherwise known as ropes or lines, are used primarily to bind things together and for climbing and pulling things up. Rock climbers and bungee jumpers use tethers, most elevators are based on them, and even people...
Artificial Gravity Assist
Interplanetary space probes often take advantage of the gravity pull of planets and large moons to alter course and gain speed. For these so-called gravity assist maneuvers, a spacecraft flies by a planet and uses its gravitational field and the planet's orbital velocity around the Sun to pick up speed and change direction. It can be somewhat compared to a Ping-Pong ball hitting a revolving fan the ball will bounce back at a much higher speed and in a different direction from which it was hit...
Safety Tethers
If tethers can be employed to keep satellites together, it is not a far stretch to imagine their use in securing astronauts to prevent them from drifting away. In the 1960s the first spacewalkers used tethers that not only secured them to Figure 1.8 Astronaut Ed White during his space walk in 1965. He was connected to the Gemini 4 spacecraft by a long tether. Courtesy of the National Aeronautics and Space Administration NASA . Figure 1.8 Astronaut Ed White during his space walk in 1965. He was...
Artificial Gravity
Microgravity, or weightlessness, exists inside an orbiting spacecraft because its contents including any astronauts are falling around Earth we call this free fall'' at the same speed as the spacecraft itself and not, as is often believed, because there is no gravity in space . It is like being inside a falling elevator, but without the hard landing at the end. Astronauts inside the International Space Station ISS can simply float through its many modules, have dinner on a wall, and sleep on...