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Russia uses the R-7 ICBM-derived Soyuz launch vehicle for most of its space launches. The advantage of it is that there's no concern on what the weather is like on launch day and Soyuz launches almost never get postponed due to weather. The only ICBMs the USA used for crewed flights were the Atlas for several Mercury missions and the Titan II for the Gemini program. The Saturn V must have been quite strong too obviously, they even launched Apollo 12 during very bad weather.

Many present-day rockets of NASA are quite weak and launches get postponed due to not very strong winds. Why don't the USA use ICBMs for crewed and other more important flights? They aimed to launch the planned Dream Chaser on the Atlas V but the plans for the crewed Dream Chaser went on hold for some reason.

GdD
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    Atlas V was never an ICBM (it's a completely different rocket from the original Atlas), and it's dubious of ICBM-versus-non-ICBM has bearing on the weather issue. – Russell Borogove Apr 30 '20 at 05:16
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    Making an all-weather launch vehicle is pretty expensive, so why the rush? There are hardly any instances that your launch window is so short that you can not wait it out, except the actual ICBM missions? Most important missions are important in a sense that failures are expensive, not delays. – user3528438 Apr 30 '20 at 05:18
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    The climate in the continental desert is fundamentally different from the coast of the Atlantic Ocean near the tropics. – A. Rumlin Apr 30 '20 at 05:40
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    @RussellBorogove ICBMs are built so that they can launch at quite any weather. In wartime you must not refuse to launch one because of 'bad weather conditions'. –  Apr 30 '20 at 06:31
  • @A.Rumlin The R-7 Soyuz also launches from Kourou, Vostochny and Plesetsk. –  Apr 30 '20 at 06:32
  • https://www.arianespace.com/press-release/flight-vs20-soyuz-with-cso-1-24-hour-delay-due-to-weather-conditions/ – Tom Goodfellow Apr 30 '20 at 07:06
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    There's never a need to launch a single ICBM in any weather. If a launch order comes, that means at least a couple dozen missiles are going to launch, and you can afford losing/not launching some due to bad weather. – TooTea Apr 30 '20 at 07:09
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    Increasing structural strength for bad weather increases the rocket weight and decreases payload weight. You get nothing for free. – Uwe Apr 30 '20 at 10:19
  • @Uwe I doubt that. And since Russians use an ICBM for their crewed and most of their uncrewed flights, Americans surely can too. –  Apr 30 '20 at 10:40
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    "they even launched Apollo 12 during very bad weather". And never did so again, because having lightning strike your rocket turns out to be not good. – Polygnome Apr 30 '20 at 10:57
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    The shuttle was never postponed for months due to wind. That's a ridiculous statement. – Organic Marble Apr 30 '20 at 11:11
  • @OrganicMarble I wrote Shuttle and Falcon. In 2011 there was no Falcon Dragon launch because they postponed it until 2012 despite being so successful. You're right, that's ridiculous. –  Apr 30 '20 at 11:33
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    I know nothing about Falcon but your comment states that Shuttle launches were postponed for months due to wind and that's utterly wrong. I worked on DOLILU which was all about Shuttle launches and wind. – Organic Marble Apr 30 '20 at 11:37
  • @OrganicMarble No, it states "Shuttle and Falcon". There must be a SE bug if the entire comment is invisible to you. The reason ISS launches sometimes get postponed so long is that the ISS must be at a certain position for a launch window, otherwise you have to wait long until the ISS is at another good position. –  Apr 30 '20 at 12:03
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    @use30007 surely you understand that if you state "A and B" is true, then both A and B must be true? – Organic Marble Apr 30 '20 at 12:05
  • @OrganicMarble There stands "up to several months" so it states a record. If you postpone a launch due to weather too often, the ISS gets out of the launch window. Simply understand my question as why America has not as strong rockets as Russia which hardly ever postpones its launches due to weather. –  Apr 30 '20 at 12:08
  • Comments are not for extended discussion; this conversation has been moved to chat. – called2voyage Apr 30 '20 at 15:39
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    Someone should perhaps ask the reverse question: "why hasn't Russia built more-special-purpose rockets to launch into space, instead of using the equivalent of ICBM?" – CGCampbell May 01 '20 at 00:16
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    @user30007, you changed the question to say "this has been answered", deleting the original question. Please don't do this, leave the question as it was so the answers make sense. – GdD May 01 '20 at 11:34
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    @user30007 Just wanted to second what GdD said. Don't do that. – called2voyage May 01 '20 at 14:18

3 Answers3

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I think you got it wrong: R-7 launches sometimes are also postponed due to weather. Just to name few examples: 18 December 2018, 9 March 2018, 22 April 2016 - Kouru; March 22, 2016 - Baikonur, 2 october 2011 - Plesetsk. These are just few examples of Soyuz launches delayed to weather conditions. R-7 is actually not especially structurally strong, it's a bad ICBM in nearly every aspect, including this one. Besides the raw strength is not the only one concern; Apollo-12 was nearly lost when it was struck by a lighting during liftoff.

Going back to your question, it all boils down to economic reasoning. Making a rocket that can ride harsh weather costs significant amount of additional money and in exchange you get essentially no practical gain. Nearly every launch (except for some deep space missions) can be postponed by few days without losing pretty much anything and there are many more possible reasons for delays that are not related to weather.

Sergei Ozerov
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  • I changed my statement to "almost never". –  Apr 30 '20 at 12:23
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    Yes, they are postponed there due to bad weather. https://www.spacedaily.com/reports/First_Launch_Of_Soyuz_2_1A_Postponed_Again_999.html – Organic Marble Apr 30 '20 at 12:24
  • @OrganicMarble Ah yes, it's the source from your answer. –  Apr 30 '20 at 12:24
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    @user30007 "less frequently" - maybe. "Almost never" - a gross overstatement, especially when you look at spaceports located in comparable climate (Kouru vs Florida). – Sergei Ozerov Apr 30 '20 at 12:51
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    @user30007 Judging by the number of argumentative responses you have made to every answer and commenter, simply becuae they have "challenged the frame" and have not told you what you want to hear, it appears that nothing less than saying "why yes, you are right, America has always done it wrong," will suffice. America has done it different, not wrong. – CGCampbell May 01 '20 at 00:08
  • @CGCampbell No, it's a question out of curiosity. I love America and its space programs and rocket technology. –  May 01 '20 at 04:15
  • "Nearly every launch (except for some deep space missions) can be postponed by few days" - I thought that gravity assists were pretty tight. What kind of window is there for those (let's say, the type of path that the Voyagers took)? – John Dvorak May 02 '20 at 20:22
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    You can always trade few days to some delta-v loss. In Voyager case the window opened on August 20 and closed on September 20. Two spacecraft were launched during that window, with Voyager-2 on the very first date possible and Voyager-1 close to the optimal date 16 days later. Thanks to the launch on a better date, Voyager-1 quickly overtook Voyager-2, but both fit the window of opportunity. This seems typical for planetary missions, but I guess that visiting some comets and asteroids might require tighter launch windows. – Sergei Ozerov May 02 '20 at 21:53
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This question is based on several serious misconceptions.

  • R-7 launches never get postponed due to weather.

Actually, they do. "The launch of the Soyuz 2-1A modernized carrier rocket, scheduled for Wednesday evening, has been put off again, this time due to bad weather conditions at an altitude of more than 11 kilometers," the source said.

  • The only ICBMs the USA used for crewed flights were the Atlas for several Mercury missions and the Titan II for the Gemini program.

Actually, there was one other. The Redstone was an ICBM (well, an IRBM).

  • The only ICBM-derived rocket NASA is currently using for (uncrewed) spaceflight is the Atlas V, afaik.

Actually, the Atlas V is not an ICBM but a purpose-built space launcher.

  • To address "Why don't (sic) the USA use ICBMs for crewed and other more important flights?":

The US stopped using liquid-fueled ICBMs in 1987. All current US ICBMs are solid-fueled. Attempts have been made to use derivatives of these ICBMs as space launchers but they were not notably successful.

A general statement on winds and launching is

You choose the wind conditions to design your system for based on a statistical study of the wind conditions at the launch site, your tolerance for scrubbing based on winds, and your budget. Then on the day of launch you measure the winds of the day to ensure that the design criteria are not exceeded.

Source

No economical system could be designed to launch in all weather conditions.

Organic Marble
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    You could add that "structural strength" is insufficient to guarantee safe launch in windy conditions. You'd probably need massive "side-thrusters" to offset wind shear – Carl Witthoft Apr 30 '20 at 12:16
  • Structural strength is part of "You choose the wind conditions to design your system for" All launch vehicles can tolerate some amount of wind shear. – Organic Marble Apr 30 '20 at 12:17
  • The Atlas V is from the Atlas rocket family. Thererfore I wrote ICBM-derived, not ICBM (I actually edited my question due to Russell Borogrove's statement). What does the fuel have to do with the question? –  Apr 30 '20 at 12:18
  • I changed the statement to "almost never". –  Apr 30 '20 at 12:20
  • @OrganicMarble I was thinking more of a rocket being rotated about its center of percussion (angular center of momentum) by the wind, which involves the shape more than the strength of the rocket – Carl Witthoft Apr 30 '20 at 12:22
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    @OrganicMarble: wind shear appears to be a control issue rather than one of vehicle strength. At least in the case of Atlas V and it seems likely for other vehicles to be similar. https://www.nasa.gov/pdf/605813main_Atlas-V_MSL_Weather_Criteria.pdf – Christopher James Huff Apr 30 '20 at 23:48
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    @ChristopherJamesHuff you could be right, not familiar with those. I worked on shuttle and it was an issue there for the wings and vertical tail, so not applicable to most vehicles. "Structural dynamic/flexible body effect is included as an increment based on a flat-top discrete gust with wind shear that is added (RSS with other dispersions) to the deterministic load" - personal notes – Organic Marble Apr 30 '20 at 23:58
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    @OrganicMarble: That might be relevant to the crewed Dream Chaser variant as well (which can't be enclosed in a fairing, to allow for escape if things go wrong). – Christopher James Huff May 01 '20 at 02:10
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    @user30007 I think solid-fueled rockets are "not good for a crew" because they rattle quite a bit and are also hard to scale up to human+support system (see: Shuttle). Once your ICBMs have gone solid fuel, you won't be even thinking about "Use ICBM to get astronaut aloft" anymore. – David Tonhofer May 01 '20 at 09:07
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Structural strength is not the only factor in rockets dealing with weather, they are already designed to withstand many Gs of acceleration carrying tons of explosive fuel. Flying through a cloud isn't going to hurt them. Although there delays due to winds launches are postponed because of weather for several other reasons, including:

  • Wind: High winds could potentially blow a spacecraft into its launch tower
  • Sea State: an abort of a manned spacecraft from Florida shortly after liftoff means a spacecraft splashdown, heavy seas will complicate rescue and endanger lives
  • Visibility: Most launch authorities want to be able to visually track their spacecraft using cameras, clouds prevent that kind of tracking
  • Lightning potential: lightning can disrupt spacecraft electronics and potentially cause an abort. This almost happened on Apollo 12, it was only the quick thinking of one controller who saved the mission

Increasing structural strength will solve none of these.

GdD
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  • A heavier rocket wouldn't be blown that easy into its launch tower and as for the 3rd point Visibility there are onboard cameras on many rockets (and even their separate stages) today. –  Apr 30 '20 at 18:13
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    How much extra weight are you envisioning @user30007? An Atlas V is 730,000lbs typical launch weight with a maximum of 40,000lbs payload to LEO. You can't just add weight to it, the maximum it can be is 730k lbs. Make it twice as heavy and 10 times as expensive so it can be launched on a windy day? Why in the world would you do that when you can just wait? – GdD Apr 30 '20 at 19:19
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    Also, your premise that a heavier rocket wouldn't get blown into the tower as easily isn't correct @user30007. A denser object would have more inertia and move less in the wind, but a heavier rocket would have pretty much the same density as a lighter one, and would get moved similarly. – GdD Apr 30 '20 at 20:19
  • @GdD A heavier rocket is denser if it remains of the same size as the lighter one. –  May 01 '20 at 04:18
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    How will you achieve said denser rocket @user30007? Heavier materials? You do that and you reduce the payload to orbit, which defeats the purpose. They are already a compact mass of fuel, oxidizer, pumps and structure to hold it together, it's hard to see how you could make them more dense. – GdD May 01 '20 at 07:20
  • @user30007 a heavier coat would also protect me from bullets, but rather than wear something weighing 25kg just in case, I avoid being hit by bullets. – Tim May 01 '20 at 11:11
  • @Tim A rocket can't avoid it. When it gets hit by wind the launch may be postponed. –  May 01 '20 at 11:27
  • @user30007 that’s avoiding it. Just like when there’s bullets flying around outside, I postpone shopping. – Tim May 01 '20 at 11:34
  • @user30007: google nasa light weight - you're proposing that all that effort spent to save launch mass was the wrong idea and we should have been looking for ways to make our rockets denser. Step back and look at the big picture of how much it costs to get an extra gram of payload into orbit, then think about your arguments for denser rockets. (Although since you accepted an answer already, you probably realized this already.) The rocket equation is brutal; with the energy density of current propellants, we couldn't get to orbit in the first place with much denser rockets. – Peter Cordes May 02 '20 at 02:37
  • @PeterCordes There's no such proposal on Google search. I was asking for as strong rockets as Russia has (ICBM-derived ones) whose launches are hardly ever postponed. –  May 02 '20 at 04:28
  • @user30007: I just meant look at all the hits about people trying to make things lighter to get to space more efficiently, to remind yourself that light-weight stuff is a huge deal in the big picture of space flight. Your "proposal" that I was referring to was this comment - A heavier rocket is denser if it remains of the same size as the lighter one. You want to make rockets out of steel instead of aluminum because wind? – Peter Cordes May 02 '20 at 04:32
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    @user30007: your initial proposal for strong rockets isn't obviously insane. (Although making something stronger usually costs mass). But then people pointed out that getting blown off course is a different problem from strength, and I think you lost sight of the all-important https://en.wikipedia.org/wiki/Propellant_mass_fraction being in the 80 to 90% range when you proposed making rockets denser to avoid this problem, too. Rockets don't have much empty space to compact. To be fair, a larger rocket of the same density would have less area to volume ratio and be somewhat less affected by wind – Peter Cordes May 02 '20 at 04:39
  • @PeterCordes It wasn't really a proposal but an answer to GdD's statement. My question is concerning the fact that Russia uses ICBM-derived rockets which therefore can fly at more weather conditions than some lighter American ones and the Space Shuttle. That's no criticism of US spacecraft, I love NASA's and the private companies' space programs (except for the fact that NASA halted flying to the Moon). –  May 02 '20 at 06:01