December 2011

Notes & Queries 12/14/11

December 14, 2011

I normally scan through various news items for the Notes & Queries posts, but in this case I’ve been trying to catch up on my reading. In particular, I’ve been looking at books that could be useful in inspiring young people to get interested in astronomy and engineering. Here’s a look at three titles that […]

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A Path Forward for Beamed Sails

December 13, 2011

Minimizing the cost of a project is no small matter because, as Jim Benford points out in the paper we’ve been examining over the past several days, cost determines how we decide on competing claims for resources. In the case of a beamed sail mission and its infrastructure, the cost is largely the reusable launcher […]

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Obousy Appearance on TV Tonight

December 13, 2011

Be aware that the History Channel show The Universe will air an episode at 2200 EST tonight (December 13) in which Richard Obousy will discuss interstellar propulsion concepts. The air time will probably vary depending on your cable provider, so be sure to check. Richard, once project leader of the Icarus effort and still actively […]

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Optimizing Interstellar Mission Costs

December 12, 2011

Although we frequently talk about beamed sails for interstellar missions, the fact is that spacecraft on the scale Robert Forward used to talk about that could take us to Alpha Centauri in 40 years won’t come out of nowhere. The evolution of the solar sail into the beamed sail will involve all kinds of experimentation […]

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The Case for Beamed Sails

December 9, 2011

There is a natural path through solar sails, which are now flying, toward beam-driven propulsion, and it’s a path Jim Benford has been exploring for the last eighteen years. In my Centauri Dreams book I described how Jim and brother Gregory ran experiments demonstrating that carbon sails could be driven by microwave beams back in […]

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Detecting a ‘Funeral Pyre’ Beacon

December 8, 2011

Beamed propulsion continues to be a particular fascination of mine, which is why I want to start a discussion tomorrow of Jim Benford’s latest paper on beamed sails and how they might be optimized for both performance and cost. Reading through Benford’s work, however, I also came across Chris Wilson’s recent articles in Slate, which […]

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New Worlds Targeted by Allen Telescope Array

December 7, 2011

The on-again, off-again SETI search at the Allen Telescope Array is back in business as Jill Tarter and team focus in on some of the more interesting worlds uncovered by the Kepler space telescope and follow-up observations. You’ll recall that last April the ATA was in hibernation, having lost its funding from the University of […]

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Kepler-22b: A ‘Super-Earth’ in the Habitable Zone

December 6, 2011

It’s fun to see Kepler-22b — an intriguing new world that lies 600 light years from us toward Lyra and Cygnus — being referred to as the ‘Christmas planet’ in the newspapers this morning, the latter a nod to Kepler chief scientist William Borucki, who said he thought of the planet that way, as a […]

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Terraforming: Enter the ‘Shell World’

December 5, 2011

If we ever achieve manned missions to the stars, one of the assumptions is that we will find planets much like Earth that we might live on and colonize. But what if the assumption is flawed? There are surely many Earth analogues in the Milky Way, but we don’t know how widely they are spaced, […]

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Interstellar Flight: Equations and Art

December 2, 2011

Les Johnson (MSFC) always says that the coolest job title he ever had in his long career at NASA was Manager of Interstellar Propulsion Research. Think about it — if going to the stars is your passion and you have a title like that, you must feel that you have really arrived. These days he […]

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