Talk:3093: Drafting

Site issues

Anyone else getting lots of "site is experiencing difficulties" errors Barmar (talk) 15:28, 23 May 2025 (UTC)

Yes. It must be drafting behind another, more powerful rocket-themed web page and was experiencing some of that "99% inefficiency." 172.68.26.136 15:56, 23 May 2025 (UTC)

" getting lots of "site is experiencing difficulties" errors " Yes. --PRR (talk) 16:22, 23 May 2025 (UTC)

Yes. From the experience of another forum I'm in, it's probably a sudden uptick on (possibly AI-feeding?) site-scraping. On that site, the number of viewers suddenly increased from a few hundred people online, maximum, at any given time, to tens of thousands. The owner of the site put an additional "are you human" check in the way (after about a week of it), and it fell back to less than a hundred simultaneous connections (not that far off the actual observable user-traffic, with a couple of handfuls of Guest lurkers at any given time, rather than the pre-slowdown peaks of three or four times the provably genuine users).

That site didn't have Cloudflare, unlike here, and didn't use that as a solution. I would have hoped that this would have mitigated it here, though. Possibly, however, things could have already been hundreds of times worse without it as it is, hard to know for sure.

And though my reasoning of the cause is just a guess, I'm sure others have noticed that the amount of 503/Connection Issue responses we're getting has substantially reduced the spam-level numbers of "goes nowhere, does nothing" new accounts that this site tends to get (its other anti-spam protections having long since prevented most of those from doing anything, while still seemingly allowing genuine users to interact). Hard to fully qualify that as a positive, but I suspect that genuinely driven 'honest editors' are more likely to persevere and get past the current bottlenecks, so it might (in certain, rather limited, terms) improve the editing experience. (The other site started to be really hammered (to then prompt calls for its subsequent changes) on 11/May, which seems to me to coincide very closely with the drop in new spam-style account names on here, which seems to corroborate it being the same global issue causing both sites problems.)

Not that I wouldn't appreciate less of the 503s/etc. It definitely is a direct annoyance. Which I can't see being solved any time soon (if Cloudflare doesn't blanket add to its proxying protections, itself). 172.68.229.49 16:34, 23 May 2025 (UTC)

Also here. Had to reload the page three times before I could begin writing. And will likely have to reload or try again several times before this is posted --Kynde (talk) 19:06, 23 May 2025 (UTC)

Suggestion to move the comments regarding the site difficulties down to the bottom of the page under the topic "Temporary Site Difficulties Coincidental to This Page". Once they are over there is Zero reason for them to remain, and should be removed to avoid confusion. These Are Not The Comments You Are Looking For (talk) 16:35, 25 May 2025 (UTC)

Really, there are better places even right now. Like where the more abbreviated mention is under Community Portal.

But, while I'm here, might as well say that it's not like anything practical can be done about it. Even if we had a more active sysadmin, the job of regulating what is effectively (if not intended to be) a mild-DDoS attack is best handled between the server and the connections.. That's a job that the proxy-host needs to deal with, and I don't think CF is completely up to speed with something that's not just our problem.

Though it's only slightly annoying, IMO. Should you get a connection error, my advice is to take two or three deep breaths before hitting the Refresh/Retry/whatever. It doesn't help to mash the reload button to add to the number of pokes and prods the server is getting. And responsiveness still seems to work well enough to give any initially refused pages up on the second or maybe third attempt. I sometimes got far worse performance when in a low mobile-Wifi reception area. ;) 172.69.79.164 20:01, 25 May 2025 (UTC)

---

The efficiency loss is presuamably because the exhaust from the lead rocket is pushing back on the following rocket. It's also really hot, so the follower may be destroyed. Barmar (talk) 15:27, 23 May 2025 (UTC)

Added notes on difference between friction and expellant propulsion 172.69.212.151 16:14, 23 May 2025 (UTC)

Just a comment about drafting and cycle-sport. It might be used in peletons and certain velodrome events (i.e. not "pursuit" ones). But in my own part of the sport, time-trialling, it is actually not allowed (excepting in team time-trials), as competitors that have just been passed by a faster rider are not supposed to hang on (figuratively, of course) to their wheel. Nor should you try to catch your minute-man just so that you can stick behind them. Also, the rules on the amount of traffic allowed on the roads during an event, as well as being a direct safety aspect on the busiest of roads, are meant to remove any excessive advantage from passing traffic (especially lorries) pushing/pulling the competitors along. This doesn't mean that the occasional ride won't get some assistance. A fast tractor may be too slow for a fast rider to stay behind, who would really need to pass it when safe to do so, but could be going just fast enough for a slower one to benefit (but at the risk of being spotted doing so and the issue addressed appropriately). But competitor-on-competitor co-pacing (or accompanied riding of any other unofficial kind) is definitely a no-no. 172.68.229.49 16:34, 23 May 2025 (UTC)

This comic made me think of this video: https://www.youtube.com/shorts/yuMcAS_wRRQ 172.69.212.145 17:45, 23 May 2025 (UTC)

The exhaust of the lead rocket might increase the density of the gas around the following rocket, thus affecting the efficiency of the following rocket's engine. (Giving the effect of being at a lower altitude if in atmospheric flight.) Rockets generally are less efficient in higher density atmosphere, and are designed for a particular density. If the following rocket was close enough, it might alter the efficiency of the lead rocket by increasing density near the lead rockets engine, or by providing something similar to ground effect for the lead rocket. (The extent of such effects would also depend on any atmosphere.) 108.162.245.19 19:12, 23 May 2025 (UTC)

Since rockets often travel at supersonic speeds, it seems like the costs and benefits of drafting might be altered, compared to land vehicles drafting at subsonic speeds. (Would both rockets have shock waves in front, would the shockwave from the trailing rocket interact with the first rocket, ...) Seems like it would be worth mentioning, but I couldn't find much about supersonic slipstreaming. Since I am not a rocket scientist, I wouldn't hazard a guess what might happen. 162.158.41.115 19:35, 23 May 2025 (UTC)

I am aware that bicycle races exist and except for occasional articles about cheating (the most interesting method was extracting one's red blood cells, storing up quite a lot, and putting them back in right before the race) don't care. Geese. Drafting is why I see a vee of geese where the leader peels back and becomes a follower accompanied by a bunch of geese that are just a flock. I think that fighter planes can use drafting. I've noticed the effect when a semi blows past me.172.71.222.202 06:26, 24 May 2025 (UTC)

That's not even close to the most interesting method of cheating in cycling - cork between the teeth, anyone?172.71.178.157 13:57, 27 May 2025 (UTC)

Ironically, Elon Musk has just announced that when the Starship hot-stages from the Super Heavy (meaning one rocket closely following another, both with engines firing, much like the picture), some of the vent ports at the top of the Super Heavy will be blocked so that the thrust from Starship will come out directionally and push the Super Heavy in a predictable direction... thus increasing its efficiency! Cphoenix (talk) 06:43, 24 May 2025 (UTC)

Also people seem to be ignoring a comically enormous flaw with this method (no matter how well the exhaust of the leading rocket would provide a slipstream -- or obstacle -- for the trailing rocket): it requires TWO rockets. For example, let's assume drafting works perfectly with cars and such, to the point that the trailing car uses no fuel at all, which would be an incredible efficiency increase. It is not a reasonable idea to suggest improving your car efficiency like that by buying a second (bigger) car and having it somehow drive in front of yours, since it would cost you the second car and the fuel for the second car. With cars, it isn't unreasonable to expect maybe a second vehicle will be going the same path and create that slipstream for you, but rockets aren't as widespread, so at most this would only be applicable (with dubious results as the other commenters point out) if mission planners grouped various launches together at the same time so the launch of one mission would benefit from the launch of another mission (with the starting launch always having to pay the full price for their launch). 162.158.122.196 (talk) 07:07, 24 May 2025 (please sign your comments with ~~~~)

If 'rocket drafting' worked like vehicle drafting, but the Rocket Equation also applied, then conceivably (especially if you get towards 100% efficiency for the dragged vehicle) you'd be able to deliver a whole lot more mass (either unspent fuel or extra cargo with less fuel) to the point at which the guide-rocket has to peel off. It might be considered similar to adding extra disposable lower-stages to the rearwards rocket, instead of giving it a forwards one, but without the need for those stages to effectively have the payload capacity to carry a (significantly) passive assisted rocket on their nose.

(In fact, because a drafting vehicle can smooth the turbulent drag behind the lead vehicle, improving both their effective efficiencies, if tucked in just right behind the right kind of vehicle, sending two rockets up in tandem would (with such mythical 'drafting' in operation) potentially get both loads up further (and/or with more liftable mass) than either alone. So be sending a rocket up to LEO and trailing it with one that you want to go to GEO, the conceipt would be that you can do the both better. Or just get two up to LEO/GEO/wherever but with less fuel than two missions. And, indeed, we see that the front rocket is probably a 2+2b configuration, and the rear one is probably just a 2-stage (give or take any 'orbital bus' stage, within each faring), so the expectations may be that a normally insufficient unboosted lower rocket is achieving an orbit (or even eventually escape from Earth to lunar/inter-planatery transfer) that normally it would absolutely require its own additional boosters/third-stages+ for.)

Of course, rocket drafting as paridied here is bunkum (not helpful, and probably counterproductive). At best, the following rocket could be used to nudge (physically, or by bringing in its supersonic shockwave in close enough behind the lead to lend impetous to the front rocket's rearward thrust) and act as an additional 'loose booster' to add to the initial rocket's eventual travel. But the engineering, and coordination, behind that is very much less ...useful... than just designing the first rocket configuration to have extra extra boosters (like the Energia base stage, rather than the reduced Energia-M version, say), or creating extra stages for the stack (effectively like converting a Saturn-IB into a Saturn-V, though that did involve far more change than pushing a new Stage-1 onto the bottom of the original two). 141.101.98.226 09:53, 24 May 2025 (UTC)

When cyclists start having afterburner set up, the same problem will occur on TourDeFrance. --172.71.122.252 15:32, 24 May 2025 (UTC)

When geese get afterburners, will hunters bring home pre-cooked birds? Obligatory note to hunters: Some geese are legally protected in some countries. 172.71.167.88 18:43, 24 May 2025 (UTC)

Biggest advantage: You can toast marshmallows on the way up as well as down. Lordpishky (talk) 17:19, 24 May 2025 (UTC)

Only cycling and geese have been mentioned in regards to real-world drafting, but it is immensely important to most forms of auto racing. Drafting is the reason you see packs of 20 or so cars driving nose to tail during NASCAR oval track races. For more: Drag & Drafting | NASCAR Science of Speed (National Science Foundation News) These Are Not The Comments You Are Looking For (talk) 16:35, 25 May 2025 (UTC)

Rocket Scientist here. Believe it or not, self drafting is employed in the form if aerospikes. https://en.wikipedia.org/wiki/Drag-reducing_aerospike Also, drafting and self collision is a major concern during first stage separation. 01:27, 26 May 2025

I think the key inefficiency here is that the lead rocket doesn't have a slipstream per se as it's blasting hot gas out behind it. So whereas on a highway the air behind a truck is moving slower compared to the air around the truck (relative to velocity of following vehicle), with a rocket the gas behind the rocket is being propelled backwards by the combustion inside the rocket. So while you don't have as much atmospheric resistance (5% gain), you are competing with exhaust fumes resistance (99% loss). The stuff about it being dangerous or whatever is interesting but beside the point imho. Randall doesn't care about the fact that it's impractical, this is the guy who once proposed a jet pack using machine guns, after all. I would recommend focusing the explanation on the drag forces involved. 172.70.214.66 22:17, 26 May 2025 (UTC)

Yes and no. To my mind, the joke is that normally it's unadvised because of the danger of collision (and sometimes counter-productive aerodynamic effects), but in this case it's because the stream of hot gas means (a) it's not going to work, and (b) it will likely destroy your rocket.172.68.229.40 09:43, 27 May 2025 (UTC)