Sail Concepts

Project Dragonfly: The case for small, laser-propelled, distributed probes

September 5, 2014

Andreas Hein is a familiar figure in these pages, having written on the subject of worldships as well as the uploading of consciousness. He is Deputy Director of the Initiative for Interstellar Studies (I4IS), as well as Director of its Technical Research Committee. He founded and leads Icarus Interstellar’s Project Hyperion: A design study on […]

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Thinking about Magnetic Sails

August 28, 2014

Magnetic sails — ‘magsails’ — are a relative newcomer on the interstellar propulsion scene, having been first analyzed by Dana Andrews and Robert Zubrin in 1988. We saw that the particle beam concept advanced by Alan Mole and discussed this week by Jim Benford would use a magsail in which the payload and spacecraft were […]

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A Response to Comments on ‘Sails Driven by Diverging Neutral Particle Beams’

August 27, 2014

Jim Benford’s article on particle beam propulsion, published here last Friday and discussed in the days since, draws from the paper he will soon be submitting to one of the journals. I like the process: By running through the ideas here, we can see how they play before this scientifically literate audience, with responses that […]

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Beaming to a Magnetic Sail

August 26, 2014

Jim Benford’s work on particle beam propulsion concepts, and in particular on the recent proposal by Alan Mole for a 1 kg beam-driven interstellar probe, has demonstrated the problem with using neutral particle beams for interstellar work. What we would like to do is to use a large super-conductor loop (Mole envisions a loop 270 […]

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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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