From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gndrsh.dnsmgr.net (br1.CN84in.dnsmgr.net [69.59.192.140]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 23AED3CB37 for ; Thu, 27 Apr 2023 10:09:21 -0400 (EDT) Received: from gndrsh.dnsmgr.net (localhost [127.0.0.1]) by gndrsh.dnsmgr.net (8.13.3/8.13.3) with ESMTP id 33RE9FxP099939; Thu, 27 Apr 2023 07:09:15 -0700 (PDT) (envelope-from starlink@gndrsh.dnsmgr.net) Received: (from starlink@localhost) by gndrsh.dnsmgr.net (8.13.3/8.13.3/Submit) id 33RE9EUf099938; Thu, 27 Apr 2023 07:09:14 -0700 (PDT) (envelope-from starlink) From: "Rodney W. Grimes" Message-Id: <202304271409.33RE9EUf099938@gndrsh.dnsmgr.net> In-Reply-To: <2o06n7s5-9547-13pn-1659-s509p837o1on@ynat.uz> To: David Lang Date: Thu, 27 Apr 2023 07:09:14 -0700 (PDT) CC: "Rodney W. Grimes" , Dave Taht , Dave Taht via Starlink X-Mailer: ELM [version 2.4ME+ PL121h (25)] MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII Subject: Re: [Starlink] some post Starship launch thoughts X-BeenThere: starlink@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Starlink has bufferbloat. Bad." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 27 Apr 2023 14:09:22 -0000 > On Wed, 26 Apr 2023, Rodney W. Grimes via Starlink wrote: > > > Now that water cooled steel plate, if you treat it like a sacrificial > > anode in a water heater, ie you expect it to be erroded over time it > > could get interesting. > > They are designing towards hourly launches, so I don't expect it to be planned > as a wear item. The way it was introduced (prior to the launch) was that even > steel plate would wear if it wasn't water cooled. They had best consider that as a wear item. Those steal plates are going to rust, no mater what they do, and at those temperatures I expect the surface rust rate to be rather high. Even if you water cool the back side the exposed surface is going to get very hot, anyone have the exhaust gas temperatures of starship? While findin that temperature I found: Kennedy 39A and 40 did have flame trenches lined with fire bricks, until successive Shuttle launches blew them out and for some distance. Both flame trenches are now lined with a thin layer of replaceable fireproof concrete. So seems NASA has done this science.... I hope SpaceX is paying attention! That temperature is suppose to be 2810C, steel melts at ~1500C, and vaporizes at 2860C, I would say they better plan on regular replacement of those plates, even water cooled. Its probably time to let this thread die... and wait to see what they come up with. -- Rod Grimes rgrimes@freebsd.org