tag:blogger.com,1999:blog-8062571400334852082.post6553873479854397429..comments2015-03-06T12:15:29.825-08:00Comments on Armchair engineering: Random Thought: Should we avoid SLS Block 2, or go straight for it? Marijn Molemanhttp://www.blogger.com/profile/10374646748718489690noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-8062571400334852082.post-59991537731046164142013-12-30T06:45:44.829-08:002013-12-30T06:45:44.829-08:00I don't think it would be that simple. The cur...I don't think it would be that simple. The current Ariane 5 core can barely support its own weight as it is "hanging" in between the boosters, which transfer their loads through the top of the core. If it was upgraded structurally, it might work. But it's also much skinnier than the rest of the core, meaning you'll need a big fairing structure around it to carry the loads of the payload; a structure which would be very heavy.<br /><br />Vulcain also isn't air-startable, never mind re-startable, and very inefficient compared to J-2X and RL-10, which will definitely be a problem for an Earth Departure Stage. The amount of upgrades required to make it suitable as an SLS upper stage would be comparable to developing a new upper stage based on a shortened SLS core.Marijn Molemanhttps://www.blogger.com/profile/10374646748718489690noreply@blogger.comtag:blogger.com,1999:blog-8062571400334852082.post-17368437865591620902013-12-28T17:31:36.992-08:002013-12-28T17:31:36.992-08:00 In fact if we made the upper stage be the Ariane ... In fact if we made the upper stage be the Ariane 5 core then it could be ready by the 2017 ffirst launch of the SLS.<br /><br /> Bob ClarkRobert Clarkhttps://www.blogger.com/profile/16114043697010364282noreply@blogger.com