<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto">On Jan 4, 2018, at 9:03 AM, spike <<a href="mailto:spike66@att.net">spike66@att.net</a>> wrote:<span style="font-family: Calibri, sans-serif; font-size: 11pt;"> </span><blockquote type="cite"><div class="WordSection1"><div><div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in"><p class="MsoNormal"><b>From:</b> extropy-chat [<a href="mailto:extropy-chat-bounces@lists.extropy.org">mailto:extropy-chat-bounces@lists.extropy.org</a>] <b>On Behalf Of </b>Dan TheBookMan<br><b>…</b><o:p></o:p></p></div></div><div><p class="MsoNormal"><o:p> </o:p></p></div><div><p class="MsoNormal">>…Not rocket engineer either... I think they’ve demonstrated some success with the modular scalable approach. Building a bigger engine would mean basically having to go through the whole design, develop, test, and use process again for just that one component…<o:p></o:p></p><p class="MsoNormal"><o:p> </o:p></p><p class="MsoNormal">Ja in spite of the scary number of nozzles, the whole notion is growing on me. Mass production is something the rocket industry needs desperately. There are so many one-time costs in space stuff, so many really big ones, where a facility was built and used for four or six units. If that can be spread across hundreds of units and we can tolerate a little lower reliability, this might be a great step forward.</p></div></div></blockquote><div><br></div><div>It already is a great step forward — given the number of engines they built and flown and now reflown. I imagine, too, recovered engines gave them some good data too. (I’m sure some of the flown Saturn F-1 and other engines were recovered and studied.)</div><br><blockquote type="cite"><div class="WordSection1"><p class="MsoNormal">Regarding reliability: with our Saturn 5-ish yankee approach, so much of the reliability model was educated guesswork. With clusters of instrumented engines, you get something the rocket guy loves: data, lots of performance data, frabjous day, callooh callay, reams of yummy data. <o:p></o:p></p><p class="MsoNormal"><br></p><p class="MsoNormal">I am still hoping for the best from the air-breathing crowd, but until the Skylon notion is ready to fly, this whole rocket cluster thing might be our best bet for heavy lift. I count myself as a reluctant Musk supporter.</p></div></blockquote><div><br></div><div>I hope SpaceX inspires more competition in this area. I’m skeptical of exotic approaches when the making things better and cheaper will do — and when the exotic approach requires huge up front investments though (as usual) promises to pay off if and when it works.</div><br><blockquote type="cite"><div class="WordSection1"><p class="MsoNormal">>…I believe we’re all hoping for success here. If it all goes well, SpaceX will have a Mars-ready rocket. That might mean that Musk’s aggressive plan to put people on Mars in a few years will come to pass. Dan<br><br>Dan I am reluctant to put a turd in the punchbowl, but that humans to Mars notion ain’t happening. Musk is doing and has done marvelous things. But that won’t fly.</p></div></blockquote><br><style><!--
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--></style><div>I’m skeptical myself — more of his aggressive schedule than of the overall outcome. To be sure, in terms of wanting to get more humans away from Earth, I’d much rather see space settlements than Mars settlements. Seems like much effort to me to simply stick people down another gravity well.</div><div><br></div><div><div style="line-height: normal;"><span style="line-height: 20px; background-color: rgba(255, 255, 255, 0);">Regards,</span></div><div style="line-height: normal;"><span style="line-height: 20px; background-color: rgba(255, 255, 255, 0);"><br></span></div><div><div style="line-height: normal;"><span style="line-height: 20px; background-color: rgba(255, 255, 255, 0);">Dan</span></div><div style="line-height: normal;"><span style="line-height: 20px; background-color: rgba(255, 255, 255, 0);"> Sample my latest Kindle book "Sand Trap":</span></div><div style="line-height: normal;"><font color="#000000" style="background-color: rgba(255, 255, 255, 0);"><a href="http://mybook.to/SandTrap" style="background-color: rgba(255, 255, 255, 0);">http://mybook.to/SandTrap</a></font></div></div></div><div style="line-height: normal;"><br></div></body></html>