Sail Concepts

Beamed Sails: The Problem with Lasers

August 25, 2014

We saw on Friday through Jim Benford’s work that pushing a large sail with a neutral particle beam is a promising way to get around the Solar System, although it presents difficulties for interstellar work. Benford was analyzing an earlier paper by Alan Mole, which had in turn drawn on issues Dana Andrews raised about […]

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Sails Driven by Diverging Neutral Particle Beams

August 22, 2014

Is it possible to use a particle beam to push a sail to interstellar velocities? Back in the spring I looked at aerospace engineer Alan Mole’s ideas on the subject (see Interstellar Probe: The 1 KG Mission and the posts immediately following). Mole had described a one-kilogram interstellar payload delivered by particle beam in a […]

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Electric Sail Concept Moves Forward

August 11, 2014

Just how we follow up on the investigations of New Horizons remains an open question. But we need to be thinking about how we can push past the outer planets to continue our study of the heliopause and the larger interstellar environment in which the Sun moves. I notice that Bruce Wiegmann, writing a precis […]

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A Spacecraft in Your Pocket

July 22, 2014

Last week we looked at Mason Peck’s ideas on ‘Sprites,’ tiny spacecraft the size of computer chips that could be sent in swarms to targets near and far. I was particularly interested in Peck’s idea of using Jupiter as a massive particle accelerator, bringing huge numbers of Sprites up to speeds in the range of […]

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‘Smart Pellets’ and Interstellar Propulsion

July 16, 2014

When Clifford Singer proposed in his 1980 paper that a stream of pellets could be used to drive an interstellar vehicle, the idea emerged at a time when Robert Forward had already drawn attention to a different kind of beamed propulsion. Forward’s sail missions used a beamed laser from an array near the Sun, and […]

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Clifford Singer: Propulsion by Pellet Stream

July 15, 2014

Small payloads make sense if we can extract maximum value from them. But remember the problem posed by the rocket equation: It’s not just the size of the payload that counts. A chemical rocket has to carry more and more propellant to carry the propellant it needs to carry more propellant, and so on, up […]

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Reflections on the LightSail Project

July 10, 2014

I was delighted to see Doug Stetson, the program manager for The Planetary Society’s LightSail effort, quoting Johannes Kepler in last night’s webcast. If you missed the Pasadena event, which took place at the KPCC Crawford Family Forum in Pasadena, CA, you can watch the recorded session here, and I highly recommend it. Kepler’s 1610 […]

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Focus on LightSail-A

July 9, 2014

As Cosmos 1 demonstrated, launching solar sails isn’t always easy. The Planetary Society’s sail perished thanks to a malfunctioning Volna booster not long after launch in 2005. When NASA attempted to launch its NanoSail-D in 2008, a problem aboard the Falcon 1 booster destroyed the craft. And when the agency launched the backup, NanoSail-D2, in […]

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Cosmos 1 in Context

July 8, 2014

We’re coming up on the tenth anniversary of Centauri Dreams, and it doesn’t surprise me even remotely that two of the earliest stories I ever wrote for the site involve solar sails. August 17, 2004’s Solar Sail Test by Japan talks about the Japanese Institute of Space Astronautical Science testing sail deployment strategies, and the […]

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Sailing to Halley’s Comet

July 7, 2014

We have interesting solar sail news coming up later this week, so it seems a good time to lead into it with some thoughts on NASA’s early solar sail work. For the theoretical work for a sail rendezvous with Halley’s Comet was well along in the 1970s, when Louis Friedman, later a founder and executive […]

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