From owner-freebsd-chat Mon Aug 25 17:54:25 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id RAA25515 for chat-outgoing; Mon, 25 Aug 1997 17:54:25 -0700 (PDT) Received: from xmission.xmission.com (softweyr@xmission.xmission.com [198.60.22.2]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id RAA25509 for ; Mon, 25 Aug 1997 17:54:22 -0700 (PDT) Received: (from softweyr@localhost) by xmission.xmission.com (8.8.5/8.7.5) id SAA08910; Mon, 25 Aug 1997 18:53:29 -0600 (MDT) From: Wes Peters - Softweyr LLC Message-Id: <199708260053.SAA08910@xmission.xmission.com> Subject: Re: Anarchists decry 72lbs plutonium launc To: mike@smith.net.au (Mike Smith) Date: Mon, 25 Aug 1997 18:53:26 -0600 (MDT) Cc: chat@freebsd.org In-Reply-To: <199708250412.NAA01430@word.smith.net.au> from "Mike Smith" at Aug 25, 97 01:42:44 pm X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-chat@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > > PS: any takers on a guess as to whether or not 72lbs is over critical > > mass for Plutonium? That would depend on the purity of the plutonium, now wouldn't it? I was once told by somebody who probably knows that with weapons- grade material, you could get a chain reaction with less than a mole of plutonium. He didn't say which isotope this needed to be. > My understanding (Brian Handy, are you listening here?) is that the > plutonium is used as a heat source to provide electrical power. I have > a hard time imagining 30+ kilos of the stuff being required for > anything on the scale of a satellite. It depends on the power budget and lifetime of the satellite. These devices, once known as SNAP generators, are about as bone-head simple as you can get: a bottle of low-grade plutonium straight out of the garbage bins at Rocky Flats, wrapped with thermocouple wires. They produce little power, but don't decay (that 50,000 yr half-life). If you've got nice, big boosters to get them out of Earth's gravity well, they're a reliable cheap source of power out beyond the gravel patch (planetary disk). -- "Where am I, and what am I doing in this handbasket?" Wes Peters Softweyr LLC http://www.xmission.com/~softweyr softweyr@xmission.com