From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ej1-x62e.google.com (mail-ej1-x62e.google.com [IPv6:2a00:1450:4864:20::62e]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id D88863B29E for ; Sat, 12 Feb 2022 18:08:44 -0500 (EST) Received: by mail-ej1-x62e.google.com with SMTP id p14so5734262ejf.11 for ; Sat, 12 Feb 2022 15:08:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=reKjDGK1N47cy7nWb3VqdNT4ji0Tq9kS61IuQVttC7Y=; b=eVYpBNJPy9IOVlYhxFygt+FkYn+cbcJF4fzNoQhjQ6MEBMVu28H2L+ZwcoxbYUe4aL 01Trwljq+iSNZg4gPFS7HhNi+u5L1Y1u9HOCfqRDt8mSSP9HqdtqdLgkFQJ1mWGtQtUE FYrx0E+UUXY+8TWWEMtUMtm42Ejt6jVTLYLhrQQiYj9UTC+0w4gyo+BqkaLCGyMw7CXC I6wnEFuK5LXm+UsIZq9NTCYlLMgwXu4CKx0oJyDCp+vVWRhnxtKnFqgukzHgK6kNRPa9 Dbi4TSuLeLs+qPlApweCjKtzJmJlLlhtIvFaXwOzlc0wBNN51OrBr/Qi/PTdRrM7lHhN D8hA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=reKjDGK1N47cy7nWb3VqdNT4ji0Tq9kS61IuQVttC7Y=; b=NJcZerWGZ9vUBmXasInP5u1WGNIc5T2laRb36Ccv2L9BhnCpydNmthIjBEEFg7bZZg mW1fBXlYHuFOzQBD9kj+8SCOGolrSzRvRMUaOqDdtuQOAaPrm9WtYx33vINDp92zi2Ps Kgeu5Gti9mzg9v123c6T4XSozluIuhyhW3ZAv5Gh5fUqIIBBktSlWqLRYFnG+NbstWVl vzx1J8q09h0ugcoKl+clu+kNN7P9+crbN7LsxcktuzOZGR6iwiFaBiDjkE6UF9Hksrt8 eDQWtH7uNSFifaNU7cgfHhbMrf4NLvy9jn1ivfR4fEOW8T2VNJVLrW1tuLmW4fVKajHA Zojw== X-Gm-Message-State: AOAM530wwfGfOs07CtUvltuM4AFLb5Ad2Q2bsIgV9ABB+8FgHT6yx/Z7 bOiz7a/DLfNrH5d10J50yQW0DC/s2BbVPVtJYZ1J/qGTGBA= X-Google-Smtp-Source: ABdhPJx3SpZwx+lkYOYvfEY304y64oEGHpjiwryXA3fpVPBKR45XrYgzPJwpAWvZRZtCPi1D8iqQOsW3TdNuCYQ/a4k= X-Received: by 2002:a17:907:a41f:: with SMTP id sg31mr6012866ejc.645.1644707323572; Sat, 12 Feb 2022 15:08:43 -0800 (PST) MIME-Version: 1.0 References: <20220212103610.576e44b1@spidey.rellim.com> In-Reply-To: From: Dave Taht Date: Sat, 12 Feb 2022 15:08:31 -0800 Message-ID: To: David Lang Cc: "Gary E. Miller" , starlink@lists.bufferbloat.net Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [Starlink] saving ship 20 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: Sat, 12 Feb 2022 23:08:45 -0000 thx all. I still think that attempting re-entry with a known-busted heatshield is kind of a waste, but... btw, the alt.space mailing list I had been on for a decade or three (on one of my retired accounts) is "arocket", which has participants such as henry spencer (https://en.wikipedia.org/wiki/Henry_Spencer), the original founder of the L5 society, and a few other notables. https://www.freelists.org/post/arocket/FW-NASA-HQ-News-NASA-Awards-Artemis-= Contract-for-Future-Mega-Moon-Rocket-Boosters,3 Just spent an enjoyable hour catching up there. On Sat, Feb 12, 2022 at 2:04 PM David Lang wrote: > > On Sat, 12 Feb 2022, Dave Taht wrote: > > > Having a pause to inspect the lost tiles, and assess the damage before > > even attempting re-entry strikes me as a good idea. I hope they've > > lined up some good telescopes this time to take a peek at it. Always > > sad we didn't get that done for columbia. > > for this first flight, they are deliberatly not going into an orbit that = would > clear the ground (they are going high enough, and fast enough, but not ro= und > enough), so that they don't need to deal with the complications of a zero= -g > restart (settling the fuel, etc) > > They have lined up the NASA aircraft that has a big telescope on it to wa= tch it > during reentry, and unlike everyone else, they put lots of cameras on and= in > their rockets (spectacular PR and very useful to figure out what went wro= ng) > > Odds are that something will go wrong before reentry on the first flight,= but > they have the timeline go all the way to a landing burn above the ocean, = but I > don't think anyone is expecting it to be intact by the time it spashes do= wn. It > would be an absolutly spectacular win if it does survive to that point. > > > Developing the capability to do on-orbit repair, also is a good goal. > > > > A small robot to do external inspection? > > > > It seems pointless to attempt re-entry if you determined it was going t= o > > fail and seems better to plan on exploring other options. > > until we have a lot more access to space, people are more afraid of 'spac= e junk' > than interested in accumulating resources in space. > > Even if they end up missing some tiles and get a burn-through during reen= try, > it's worth doing the reentry to learn how the skydiver approach works com= pared > to what every other spacecraft has done. There has never been anything cl= ose to > this big that's attempted reentry, they don't know how well the computer = models > actually match reality. Given that it will be years before there is manne= d > flight that would be able to use it if they left it up there, odds are go= od that > it would come down first anyway, just in an uncontrolled fashion. > > I'll point out that the bigelow inflatable module on the ISS is only bein= g used > for storage, NASA doesn't trust inflatables. > > >> > >> And, as we have seen many times, getting back in one piece is the hard= est > >> part to get right. > > > > So why not have a plan B involving staying in orbit, rather than burnin= g up? > > if you never attempt reentry, you can never succeed. > > >> > >> > Do they not have enough thrust, even with an empty payload bay, to > >> > stay up there? > >> > >> I'm sure they do, but to stay up they would need a course corrction > >> or two. > > > > testing restart seems smart. > > these are gen-1 raptor engines, given how much more complicated they are = than > the gen-2 raptors, how useful would it be? and it would add a LOT of > complication. Also, unless you boosted it up above the ISS, it will deorb= it > fairly quickly. Starlinks are higher and denser, and they have a lifetime= of 5 > years or so without reboost. > > David Lang --=20 I tried to build a better future, a few times: https://wayforward.archive.org/?site=3Dhttps%3A%2F%2Fwww.icei.org Dave T=C3=A4ht CEO, TekLibre, LLC