In fifty years of spaceflight, only 285 piloted spaceships were launched, carrying 1,154 travellers. Since some of them flew more than once, only 515 human beings have flown in space. And only two dozen Americans ventured beyond Earth orbit, up to the Moon, twelve of them having walked on it. Continue reading
Like the Moon, Mercury is also airless. Once its bulk density was determined I became less scientifically interested in it. Density is an important piece of data for modeling the evolution of the solar system. Continue reading
Unlike conventional rockets, launch loops can have many launches per hour, independent of weather, and are not inherently polluting. Rockets create pollution such as nitrates in their exhausts due to high exhaust temperature, and can also create greenhouse gases depending on propellant choices. Continue reading
Thirty-five years ago, Gerard K. O’Neill wrote: “We are so used to living on a planetary surface that it is a wrench for us even to consider continuing our normal human activities in another location”. He concluded that the best place for a growing industrial society is not on the Earth… Continue reading
Sky-Terra Towers Sprout Cities in the Skies As urban areas become more congested and dense, it becomes more challenging for city dwellers to spend time outdoors, exercise and relax. Buildings tower over public parks, blocking out the sun, while city … Continue reading
Ferengi smugglers shake in their boots as the first step towards tractor beams is announced. In the past, lasers have been used only to impart forward momentum to their targets. They hit objects with photons, and those objects move forward with the beam of light (or burst into flame). Continue reading
Wormholes are one of the stranger objects that arise in general relativity. Although no experimental evidence for wormholes exists, scientists predict that they would appear to serve as shortcuts between one point of spacetime and another. Continue reading
Lonely Earth-like planets with tumultuous cores could conceivably support life even if they had no stars, a new study says. Researchers Dorian Abbot and Eric Switzer at the University of Chicago have dubbed these theoretical worlds “Steppenwolf planets,” because… Continue reading
A launch loop (also known as a Lofstrom loop) is a proposed design for a very efficient non-rocket spacelaunch method. It is a much simpler concept than the space elevator, but still more complex than tether propulsion systems such as the rotovator. Continue reading
Astronomers have identified some 54 new planets where conditions may be suitable for life. Five of the candidates are Earth-sized. The announcement from the Kepler space telescope team brings the total number of exoplanet candidates they have identified to more than 1,200. Continue reading