The titletext parodies the 'old' single-use boosters. It appears that the predecessors to the 'retractable rockets' were capable of controlled extension only. Once they had lofted the payload to orbit, they were then allowed to fall over, with no intention to use them again.
However it is done, note that the base of the 'first stage' extends/retracts in advance of the bit further up, as can be seen by the panelling position in the standing/extending/extended/retracted frame-sequence. Which might be worth noting if you're wanting to copy the technology. 220.127.116.11 03:09, 28 October 2021 (UTC)
- I think this might be theoretically possible, ignoring the apparently topological outer skin of the "rocket", with some kind of steerable space fountain. Accelerating the astronauts at 10g for about two minutes might be survivable, and could limit the overall length to just over 800 miles. Though the shroud only has to extend to where the atmosphere is "sufficiently" thin. No idea whether this kind of design would tend to fall over when finished or not. -- Ken g6 (talk) 04:24, 28 October 2021 (UTC)
- I believe it is 100% impossible. --Kynde (talk) 07:45, 28 October 2021 (UTC)
- Only things which are 100% impossible are the ones mathematically proven so. All physical laws - including basic stuff like thermodynamic laws - are theories based on statistics and confirmed by statistics, but just because something didn't happened since the beginning of universe doesn't mean it can't happen. For example, even assuming no proton in whole universe ever decayed doesn't mean it's impossible: there are indeed theories that protons decay with half-life about 1031 to 1036 years. -- Hkmaly (talk) 22:37, 28 October 2021 (UTC)
If (as it appears) the Bot created the page with various references to "Retractible" rarher than "Retractable", does this mean Randall made that error initially? (I say this as the guy who failed to notice he'd put "resuable" in his Transcript edit. ;) ) 18.104.22.168 03:54, 28 October 2021 (UTC)
- Looks like yep, Randall originally made that error persistently, as the image here still has "retractible" in the comic, but the image on xkcd.com has been updated. Not sure how this is usually handled, I think it's mentioned in the FAQ.
- Edit: okay, I've uploaded the new image, and added a trivia bit about the original. No idea how to update the page URL, that'll have to be someone else. Esogalt (talk) 04:02, 28 October 2021 (UTC)
In my own opinion I think this is actually a brilliant idea, if you think outside the box. Imagine those floppy noodle blow up baloons they use at car dealerships and the like. Now replace the continuous membrane with a membrane combined with multiple stages of internal baffles that can collapse and move around vertically, and scale the whole thing up. Now think about a straw. What if we engineered a straw that reaches all the way to the target (and then back into the atmosphere), and inflate it? we could have  the ThothX tower but that is a stacked kevlar cell system that only reaches 12 miles in height. The weight is not truly supported by the air, but rather by the tensile strength of the membranes. The question is how much air we'd need to move and how big would it need to be to function. 22.214.171.124 04:45, 28 October 2021 (UTC)
Is there a compelling reason to refer to the countdown as spoken by "Tannoy" rather than "PA" or "Loudspeaker" or something? I had to look up what that was. Esogalt (talk) 05:09, 28 October 2021 (UTC)
- I have correct to a count down voice. We have no idea how it emanates. --Kynde (talk) 07:44, 28 October 2021 (UTC)
I tried to update the page and image URLs to fix the misspelling, and I think it mostly worked. But if you click the "Next" button from the previous comic it doesn't work so smoothly. Anyone know how to fix that?? Orion205 (talk) 05:40, 28 October 2021 (UTC)
Erm, this seems to have broken the main page as well. I've found [], which says to use the "Move" option in the "More" menu at the top of the page. Did you use that? Never mind, I think I was just the victim of cache weirdness. Esogalt (talk) 05:51, 28 October 2021 (UTC)
As a rule, when you’re correcting someone else’s mistake, proofread your correction, or you might make a new mistake that will leave “it is” mark on explainxkcd. 126.96.36.199 09:13, 28 October 2021 (UTC)
When I first read this comic, I thought it was a KSP reference. I feel like half the rockets I build do that if I don’t add struts. I realized in a second it was extending and not just noodling but it made me laugh, and then I laughed again after understanding the real joke. I got two jokes out of one. --BlackBeret (talk) 11:36, 28 October 2021 (UTC)
Can't believe nobody connected this with SpinLaunch, who had a successful slingshot of a "rocket" days earlier. Added it to the explanation. -boB (talk) 22:32, 22 November 2021 (UTC)
0% Penis Joke?
It's hard for me to believe this is in no way a penis joke; particularly with the falling over rather than gracefully retracting, afterward. Is everyone truly certain there's not a penis joke intended, here?
ProphetZarquon (talk) 14:06, 28 October 2021 (UTC)
- I don\'t think so. --GcGYSF(asterisk)P(vertical line)e (talk) 18:29, 28 October 2021 (UTC)
- Me neither. randall hasn't done anything even remotely like that since over a thousand comics ago. kinda sad, really 188.8.131.52 19:58, 28 October 2021 (UTC)Bumpf
- How was the joke ... "Who can tell me which organ of the human body expands to 10 times its usual size when stimulated?" ... ... iris of the human eye. -- Hkmaly (talk) 22:18, 28 October 2021 (UTC)
Of course it's (also) a penis joke! https://www.theguardian.com/uk-news/2021/jun/11/digested-week-should-we-tell-jeff-bezos-his-rocket-looks-like-a-penis