Astronomy Picture of the Week – Necklace Nebula
The Necklace Nebula consists of a bright ring, measuring nearly 20 trillion kilometers across, with dense, bright knots of gas spread out in a way that resembles the diamonds in a necklace. The knots are not stars, they only glow due to the absorption of ultraviolet light from the two stars located in the center of the nebula.
Non-Rocket Spacelaunch – Launch Loop
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. The launch loop concept was first described by Keith Lofstrom in November 1981 Reader’s Forum of the American Astronautical Society newsletter, and in the August 1982 L5 News. Another pioneer of the concept was Paul Birch. In 1982 he published a series of papers in the Journal of the British Interplanetary Society which described orbital rings and described a form of launch loop which he called Partial Orbital…
