Return-Path: Received: from [65.33.165.125] (account marv@lancaironline.net) by logan.com (CommuniGate Pro WebUser 4.2.5) with HTTP id 555599 for lml@lancaironline.net; Sat, 04 Dec 2004 01:46:28 -0500 From: "Marvin Kaye" Subject: Re: [LML] Cabin Pressurization in SpaceShipOne To: lml X-Mailer: CommuniGate Pro WebUser Interface v.4.2.5 Date: Sat, 04 Dec 2004 01:46:28 -0500 Message-ID: In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format="flowed" Content-Transfer-Encoding: 8bit Posted for "Neal Garvin" : The answer is so simple it's ingenious. It has no pressurization system or pressure control system as we typically know them. The spaceship is sealed up on the ground (or perhaps at 5000') and the pressure never escapes as the OAP drops to nearly zero. Onboard oxygen tanks supply oxygen to the pilot for the short duration flight. SpaceshipOne is a beautiful example of an ingeniously engineered design that is just enough and no more to meet the mission profile. The cockpit door doesn't even have a latch. It's just 'stuck" in place with Velcro or something and differential cabin pressure holds it shut tight and sealed. Rutan and his team had a lot of luck with them and they took very significant risks. Risks that you or I or most anyone else would not accept or allow Boeing or other "government" entities to take relative to our public transportation system and vehicles. That's why new commercial airliners have hundreds of "CPUs" and multiple redundant systems in them. It reduces risk. Not many people would fly on a 757 who's cabin door was "velcro'd" shut! """ The Lancair IVPs have a 5 PSI cabin differential. Airlines have 8 PSI differentials. SpaceShipOne is way up there in altitude, nearly zero atmospheric. Yet he wasn't wearing a pressure suit during the flight. Inside an astronaut EVA suit, there's ~10.5 PSI (versus our 14.5 PSI on terra firma). So, what is the cabin pressure differential inside SpaceShipOne? """