Why are launches so sensitive to weather?

[Phronesis]

Hi all -- Why are rocket launches so sensitive to weather conditions, such that they're often canceled because of weather? Airplanes fly in all kinds of weather, and rockets are much more powerful. I'd expect rockets to be more resilient to weather than airplanes, but that doesn't appear to be the case...

[ejb749]

1) Lighting.  Rockets are full of explody stuff and sensitive electronics (see apollo 12 for what happens)
2) Upper levels winds have a much greater effect.
3) Freezing conditions can be bad (challenger)
4) Sometimes good launch video is required/desired.  Clouds can get in the way. 
(Especially during the late shuttle days when they needed to monitor dabris. )

[erioladastra]

1) Lighting.  Rockets are full of explody stuff and sensitive electronics (see apollo 12 for what happens)
2) Upper levels winds have a much greater effect.
3) Freezing conditions can be bad (challenger)
4) Sometimes good launch video is required/desired.  Clouds can get in the way. 
(Especially during the late shuttle days when they needed to monitor dabris. )

Depending on the cargo - for example, humans -  you may also need to protect for an abort landing.

[MattMason]

As learned from Apollo 12 (which had to launch through a rainstorm that day or, else, postpone the launch to another month because of launch windows), rockets can cause triggered lightning. It's the counterpart to static electricity you can generate on your own body that causes a shock when you touch something conductive.

As Apollo 12 illustrated, you didn't need a thunderstorm to make lightning--there were none around at that launch. Certain atmospheric conditions can increase the chances of triggered lightning that can zap the rocket or the pad.

Florida tanks more lightning than any other US state. About 35% of all launches from the Cape are postponed because of it. And it's why launch pads have those large lightning towers around them.

You might be interested on a document on the Lightning Launch Commit Criteria for both the Cape and VAFB.

https://ams.confex.com/ams/Annual2006/techprogram/paper_103803.htm

[Phronesis]

Interesting video of an F/A-18C getting struck by lightning: https://theaviationist.com/2018/12/28/watch-lightning-bolt-strikes-an-f-a-18c-hornet-flying-through-the-clouds/

[hop]

Hi all -- Why are rocket launches so sensitive to weather conditions, such that they're often canceled because of weather? Airplanes fly in all kinds of weather, and rockets are much more powerful.

Aircraft also frequently adjust their flight plans to avoid severe weather. Unlike space launch vehicles, they have the flexibility to significantly vary their course while still flying the planned flight.

I'd expect rockets to be more resilient to weather than airplanes, but that doesn't appear to be the case...

Definitely not. Space launch vehicles tend to be built with lower safety factors, because the performance requirements are so much higher. Given the relatively low number and extremely high cost, occasional weather delays are an acceptable trade for performance.

[Jim]

Hi all -- Why are rocket launches so sensitive to weather conditions, such that they're often canceled because of weather? Airplanes fly in all kinds of weather, and rockets are much more powerful. I'd expect rockets to be more resilient to weather than airplanes, but that doesn't appear to be the case...

Rockets are not more resilient than planes.

[John-H]

Large rockets lift off slowly and can be hard to control in the wind until they pick up speed.

On the other hand, they don't usually have to land. 

John

[Jim]

Large rockets lift off slowly and can be hard to control in the wind until they pick up speed.

That doesn't apply to high altitude winds

[Brovane]

Are some rockets more sensitive to the weather than other rockets? 

[Jim]

Are some rockets more sensitive to the weather than other rockets? 

See fineness ratio or tank thickness

[leovinus]

In the light of the current Florida weather related struggles to launch, I was wondering whether there is a historical table or graph or analysis somewhere that analyzes the relation between "x % favorable weather conditions for launch forecast" vs. "launch actually proceeded" ? There should be 50+ years worth of Cape and Florida data somewhere?

[Starlab90]

In the light of the current Florida weather related struggles to launch, I was wondering whether there is a historical table or graph or analysis somewhere that analyzes the relation between "x % favorable weather conditions for launch forecast" vs. "launch actually proceeded" ? There should be 50+ years worth of Cape and Florida data somewhere?

There is data available, and it has been used by SLS, for example. I can't put my virtual hands on it at the moment and don't even know if it's publicly available.

[IanO]

Were there notable early launch disasters that first made us aware of the dangers of high altitude wind shear?

[Proponent]

It would have to have been very early -- even the launch of Explorer 1 was delayed from 29 to 31 January 1958, because of wind shear.

[spacenut]

SpaceX not only has to deal with launch, but they land their rockets, especially downrange on a boat.  Then they are trying to recover their fairings.  Weather at landing location as well as fairing location has to be good. 

I've noticed that SpaceX is using as many pre-flown rockets as well as fairing on their in house Starlink launches.  So they are trying to get Starlink up with as many recovered rockets and fairings as possible.  They won't make money on Starlink until it is complete and up and running.  So yeah, weather is a serious consideration not only for launching, but landing and recovery of fairings. 

I was hoping they could get Boca Chica set up for F9/FH launches to be able to complement the Cape and be able to launch from both, especially in bad weather which is and has affected recent launch attempts from the Cape for both ULA and SpaceX. 

[mulp]

Planes have been flying on schedules for almost a century, jets for about a half century. Add in military flights in hot war and  cold War. Lots of flights to learn risks, and develop mitigation.

And lots of planes crash due to weather, just not that many scheduled commercial craft.

Crash reported yesterday on TV as it happens in Massachusetts.

If SpaceX gets Starship where planned, it will probably fly in "bad" weather on a schedule similar to Concorde, but faster and further. Hundreds of flights per week initially with a hundred passengers will require it. Big sellers would be NYC, London, Paris to Singapore, Beijing, Sydney (off shore spaceports to limit impact of sonic booms, etc). Time to/from spaceport would be longer than flight.

[nimab]

No precipitation, ground wind speed is less than 8 meters per second, horizontal visibility is greater than 20 kilometers
weather

[dondar]

beside some factors already mentioned I would like to do a simple observation.

The question is misspelled.

If to look at the statistics of delays due to the weather Florida is a local champion with 1.2% delayed flights.
It's a lot. Especially considering that the time periods when the  delays happen  coincide generally with the luls in flights (because of the higher probability of the delays. Inner airlines fly quite happily at night too). These gaps in aircraft traffic are the preferable time periods for the rocket  flights (which happen because of the luls in aircraft flights exactly. ).
Generally coast cities (Miami, New York) are effected greatly by the weather events (one can be stranded in New York for days due to the weather). The season periods when the flight delays happen not accidentally coincide with the seasons of
the time periods when the weather can be specifically bad for the rocket launches.
As I like to point out Soyuz when launched from Kourou experiences no less delays than Falcon 9 when launched from Florida.