Nice to know there's enough margin that it can spare that much, isn't it
Quote from: XNASA on 12/07/2010 09:41 pmQuote from: Kabloona on 12/07/2010 09:26 pmQuote: "The long-awaited first launch, which was delayed a day by cracks in the nozzle of the upper-stage engine of the company's Falcon 9 rocket, was set after engineers decided that they could get rid of the cracks by trimming a few feet off the nozzle extension without significantly impacting the performance of the rocket, according to company sources."A few feet? LOL. Try "inches."Nope, a few feet is correct. That isn't a typo.As in, a few feet of length? Holy moly...please elaborate.
Quote from: Kabloona on 12/07/2010 09:26 pmQuote: "The long-awaited first launch, which was delayed a day by cracks in the nozzle of the upper-stage engine of the company's Falcon 9 rocket, was set after engineers decided that they could get rid of the cracks by trimming a few feet off the nozzle extension without significantly impacting the performance of the rocket, according to company sources."A few feet? LOL. Try "inches."Nope, a few feet is correct. That isn't a typo.
Quote: "The long-awaited first launch, which was delayed a day by cracks in the nozzle of the upper-stage engine of the company's Falcon 9 rocket, was set after engineers decided that they could get rid of the cracks by trimming a few feet off the nozzle extension without significantly impacting the performance of the rocket, according to company sources."A few feet? LOL. Try "inches."
Quote from: docmordrid on 12/07/2010 09:47 pmNice to know there's enough margin that it can spare that much, isn't it I guess they used more than a Dremel...sounds like this was a job for the SawzAll!
Quote from: Kabloona on 12/07/2010 09:43 pmQuote from: XNASA on 12/07/2010 09:41 pmQuote from: Kabloona on 12/07/2010 09:26 pmQuote: "The long-awaited first launch, which was delayed a day by cracks in the nozzle of the upper-stage engine of the company's Falcon 9 rocket, was set after engineers decided that they could get rid of the cracks by trimming a few feet off the nozzle extension without significantly impacting the performance of the rocket, according to company sources."A few feet? LOL. Try "inches."Nope, a few feet is correct. That isn't a typo.As in, a few feet of length? Holy moly...please elaborate.To save bandwidth, from the picture on this post:http://forum.nasaspaceflight.com/index.php?topic=22041.msg667323#msg667323they must be lopping the bell off at the lowest weld joint (probably just below it). Perfect line to follow I was shocked too at the 'few feet' comment, but at 9 feet tall, taking maybe 3 feet off probably isn't at any critical point on the curve. Closer to throat, absolutely, but out near the nozzle's end, probably a 5% hit (guesstimate).
That had to be put out as we've no idea why NASA would say we're already a go. We're close to it, but not yet.
Well, and it's also a thermal issue because now you have a plume expanding "feet" closer than to the aft end of the stage than designed...hope they have plenty of insulation there! And there was that thermal issue last time on S2...
Quote from: Kabloona on 12/07/2010 10:01 pmWell, and it's also a thermal issue because now you have a plume expanding "feet" closer than to the aft end of the stage than designed...hope they have plenty of insulation there! And there was that thermal issue last time on S2...Yes, even the smallest change can come back and bite you when it comes to rockets. I hope they thought this over well, they already have experience with "small" changes. Apparently it's a 4-foot section of the nozzle.
For example, is the vehicle and (most importantly) FSW ready to deal with a few percent underperformance of the second stage?
Quote from: Kabloona on 12/07/2010 10:01 pmWell, and it's also a thermal issue because now you have a plume expanding "feet" closer than to the aft end of the stage than designed...hope they have plenty of insulation there! And there was that thermal issue last time on S2...Very true. Although the radiant heat from the nozzle is also always there.There will probably be some charring. But it is a 'test flight' after all, and very short.Rough sketch attached.