Roughly the size of a football field the International Space Station ISS is by far the largest human-made structure placed into orbit Most of its parts were delivered by the now-retired Shuttle fleet The ISS is a triumph of space engineering and a model of international cooperation
INTRODUCTION Since the first space station launched in 1971 human presence in orbit has been almost constant Yet living in space poses massive challenges in technology biology and funding How do we build in orbit How are astronauts provided with life support and protected from extremes of heat and cold microgravity and radiation Solving these problems costs vast sums and tests our ingenuity But our orbital foothold is precious for science and spaceflight and as an inspiring human achievement The Russian space station Mir circled the planet in Low Earth Orbit LEO Space stations are typically placed here below an altitude of 300 miles 482 km LEO is near enough for ferry craft to reach but high enough to minimize atmospheric drag
SPACE COLONIES In the early 1950s NASA scientist Wernher von Braun imagined an inflated wheel of reinforced nylon as a potential space station From the 1950s to the early 1970s ideas for space stations stimulated the imagination of scientists and space planners They envisioned giant space wheels and even cities in the skies WHEEL LIFE The 1975 Stanford Torusdesign was a donut-shaped ring 1 mile 1 6 km in diameter which rotated once every minute to provide Earth-like gravity Sunlight was controlled by a giant mirror placed at an angle to the ring which housed 10,000 people and had agricultural areas for growing crops The Torusconcept came from a question posed by Princeton physicist Gerard K O'Neill Is the surface of a planet really the right place for an expanding technological civilization Calculations showed it was more economical to build self-sustaining space colonies mine the Moon and asteroids for raw materials and harness the incredible power of the Sun out in space This imaginary scene shows astronauts fitting the final pieces of radiation shielding to the outer ring of a Stanford Torus The station would lie at a gravitational balance point between Earth and the Moon to avoid the need for orbit-adjusting engines 06
Finding high-quality living space for a world population that is doubling every 35 years The answer space-colonization Dr Gerard K O'Neill The power and cost of Earth-launched rockets limits the size of objects put into space A mass driver electric catapult on the Moon which has one-sixth of Earth’s gravity could launch parts made there more economically SPHERES OF INFLUENCE Like the Torus a Bernal Sphereworks like a planet turned inside out Everything is built on an axis that rotates producing centrifugal force to simulate gravity At the end of each axis are low-gravity manufacturing plants and docking ports The outside of the habitation sphere is built from lunar waste slag to shield radiation then terraformed with a river running through the middle its beaches made of softened lunar sand The Bernal Sphere’s crops and livestock lie in a separate compartmentalized torus where lower gravity and unfiltered sunlight aid plant growth The Space Colony DREAMERS were inspired by APOLLO to see the MOON as a future RESOURCE 2 1 BERNAL SPHERE 1 DOCKING PORT 2 RADIATORS Remove excess heat 3 EXTERNAL AGRICULTURAL TORUS 4 FACTORIES In a microgravity environment 5 MIRRORS To reflect sunlight into the habitation sphere Arrays of solar panels not shown provide electricity 6 SHIELDED HABITAT Land space for 10,000 humans 3 4 5 6 The center of the habitation sphere would house a low-gravity recreation area for zero gee sports and human-powered flight 07
