Starship all weather launch capability

[steveleach]

If SpaceX are "aiming for three flights a day for a Starship" then they are presumably going to have to be able to launch in pretty much any weather.

I can imagine them having "weather pathfinder" launches where they deliberately launch tankers in slightly worse weather than their previous record in order to gather data, for example.

Nathan's article at https://www.nasaspaceflight.com/2020/05/why-weather-rules-exist/ is a good read on the reasons for current weather restrictions, but in the future world of Starship they are going to have to work around most of these things. The fact that a launch of some vehicle somewhere once failed due to a particular weather-related problem is no longer going to be allowed to get in the way.

What are the key challenges going to be, and what options are available to deal with them? What weather problems will Starship have to face that commercial airliners don't routinely deal with?

[Alberto-Girardi]

If SpaceX are "aiming for three flights a day for a Starship" then they are presumably going to have to be able to launch in pretty much any weather.

I can imagine them having "weather pathfinder" launches where they deliberately launch tankers in slightly worse weather than their previous record in order to gather data, for example.

I think nobody has done this because why to risk a rocket anfìd a payload, and nobody wants to use a an expensive  only to test. Spacex could do this with starship

Nathan's article at https://www.nasaspaceflight.com/2020/05/why-weather-rules-exist/ is a good read on the reasons for current weather restrictions, but in the future world of Starship they are going to have to work around most of these things. The fact that a launch of some vehicle somewhere once failed due to a particular weather-related problem is no longer going to be allowed to get in the way.

What are the key challenges going to be, and what options are available to deal with them? What weather problems will Starship have to face that commercial airliners don't routinely deal with?

airliner can avoid the core of the storm, rockets can't.

[Gooden]

If SpaceX are "aiming for three flights a day for a Starship" then they are presumably going to have to be able to launch in pretty much any weather.

I can imagine them having "weather pathfinder" launches where they deliberately launch tankers in slightly worse weather than their previous record in order to gather data, for example.

I think nobody has done this because why to risk a rocket anfìd a payload, and nobody wants to use a an expensive  only to test. Spacex could do this with starship

Nathan's article at https://www.nasaspaceflight.com/2020/05/why-weather-rules-exist/ is a good read on the reasons for current weather restrictions, but in the future world of Starship they are going to have to work around most of these things. The fact that a launch of some vehicle somewhere once failed due to a particular weather-related problem is no longer going to be allowed to get in the way.

What are the key challenges going to be, and what options are available to deal with them? What weather problems will Starship have to face that commercial airliners don't routinely deal with?

airliner can avoid the core of the storm, rockets can't.

Storm Ahead! Turn right!...
Yeep that would be a little dificult! xD maybe Elon will find a way to control weather and then problem solve!

[Alberto-Girardi]

If SpaceX are "aiming for three flights a day for a Starship" then they are presumably going to have to be able to launch in pretty much any weather.

I can imagine them having "weather pathfinder" launches where they deliberately launch tankers in slightly worse weather than their previous record in order to gather data, for example.

I think nobody has done this because why to risk a rocket anfìd a payload, and nobody wants to use a an expensive  only to test. Spacex could do this with starship

I think this is son of the extreme reliability launch policy by companies. You don't want to lose a rocket, expecially when after a single failure nobody will  want to launch with you (or you will need to lower the cost), or at least will look you suspicius. Apollo 12 was launched in the middle of a storm, and survived. But it is always better to not risk. Scrubs are better than failures. (expecially if NASA is involved, if a f9 fails NASA will imediatly look if there is risk for future crew flights.

[steveleach]

But it is always better to not risk.

That was the old way, and SpaceX are going to have to find a new way if they are going to meet
their goals.

We have to bear in mind that the majority of Starship flights are going to be tankers, so the risk appetite is going to be very different to anything we've seen previously.

Scrubs are better than failures.

Yes, but how many scrubs are better than one failure? To argue in extremis, if you scrub every launch then you'll never have a failure. Clearly there has to be some level of risk acceptance.

[steveleach]

airliner can avoid the core of the storm, rockets can't.

Good point there, though presumably there are multiple trajectories that could reach orbit, if you allow for a bit of payload reduction.

Something like launching tankers only 80% full so they can stay vertical longer and fly most of the trajectory at a greater altitude than normal to stay above the weather.

Also, I suspect that commercial launch Starships will rarely launch with anything close to their maximum payload. Schedule delays will often cost more than payload efficiency.

[Dave G]

If SpaceX are "aiming for three flights a day for a Starship" then they are presumably going to have to be able to launch in pretty much any weather...

Excellent point, and interesting thread.

I'm starting to think about this from a different angle.  For example, what limits them to 3 flights a day?  Could they squeeze in 4 on a good day? The following quote from SpaceX could be interpreted that way, maybe...

The design goal for Starship is 3 flights per day on average, which equates to roughly 1000 flights per year, at greater than 100 tons per flight. This means every 10 ships would yield 1 megaton per year to orbit.

But I suspect a better way to look at this quote is "roughly 1000 flights per year".
Running with that, 3 * 365 = 1095 possible flight opportunities per year,
so maybe around 10% of the time they plan not to launch due to poor weather or other issues.

Obviously, since we're talking about SpaceX goals here, they may be somewhat optimistic,
but we're hearing these sorts of numbers from multiple people within SpaceX,
so it's also obvious they've given this some thought, and I'm interested in their thinking.

So let's say they're willing to risk launching some payloads in "bad weather" but not "very bad weather",
where "very bad weather" only occurs 10% of the time.

For example, it seems like Mars missions will require 5 tanker launches for every crew or cargo launch.
In other words, 83% of launches for Mars missions will just be launching propellant, no payload.
Now couple that with SpaceX's goal of ramping up production to manufacture a Starship every 72 hours (link here).
In this light, maybe launching in bad weather isn't that much of a risk...

[Jim]

The fact that a launch of some vehicle somewhere once failed due to a particular weather-related problem is no longer going to be allowed to get in the way.

Not true.  They will always be susceptible to lightning, winds aloft and ground winds.

[Jim]

We have to bear in mind that the majority of Starship flights are going to be tankers, so the risk appetite is going to be very different to anything we've seen previously.

Not really.  This isn't a war, where there are acceptable losses.  There isn't going to be a readily available production replacements.  Also, delays are still cheaper than replacing hardware.  Tankers falling out of the sky or blowing up on the pad will still be frowned upon.

Risk "appetite" increases with tankers only when you use expendable vehicles. With reusable, the vehicle costs more than the cargo and the risk "appetite" decreases

[JamesH65]

Although SX may aim for an average of 3 per day, I cannot see that meaning they will launch in unfavourable conditions. There seems not point at all in risking anything just to reach some arbitrary launch rate.

Of course, they may design such that they can launch in more difficult conditions than now, but as Jim says there are always going to be circumstances where you simply don't launch as the risk is not worth it. And I cannot see them wanting to change design too much just to allow them more launch opportunities. It would almost certainly involve a drop in payload.

[schuttle89]

I would think that initially they will stay very conservative with launch parameters so they have as close to an impeccable record as possible and get as much data as possible. Eventually you might see some sightly risky launches then maybe after thousands of launches you'll see some that would scrub any other rocket but where they understand the parameters so well that it is actually very low risk. But they'll never launch during a hurricane or something very crazy as why risk your hardware.

[Barnalby]

The Russians have no problem launching Soyuz in all manner of awful weather and it has a near-flawless safety record to show for it.  Surely it can't be impossible if they're doing it.

[chopsticks]

It seems like landing actually might be more of a concern than launch, another factor that other launch providers don't have to worry about. It seems like Starship could be rather susceptible to wind on the way down, however, this is already known given that Elon has mentioned hot gas thrusters to compensate for high winds. I guess we'll see what happens.

[RonM]

The Russians have no problem launching Soyuz in all manner of awful weather and it has a near-flawless safety record to show for it.  Surely it can't be impossible if they're doing it.

They don't have the thunderstorm and lightning issues that the Florida and Texas coasts have.

[rakaydos]

The fact that a launch of some vehicle somewhere once failed due to a particular weather-related problem is no longer going to be allowed to get in the way.

Not true.  They will always be susceptible to lightning, winds aloft and ground winds.

I would think the stainless hull would provide some faraday protection from lightning strikes, at least for important systems.

[Barnalby]

They launch in those conditions as well.  It mostly has to do with the fact that the Soyuz family of boosters has its origins in the R-7 ICBM and it's, uhhh, "not really acceptable" to have an ICBM system that can be scrubbed because of bad weather.  Real "screen door on a submarine" energy.

Lack of all-weather launches in the west is mostly a function of the pathological risk-aversiveness that permeates NASA and western spaceflight in general and it's that pathological risk-aversiveness that has so hindered our expansion into the cosmos that SpaceX is trying so hard to move away from.

Soyuz can night launch astronauts to the ISS in whiteout blizzard conditions while NASA scrubs due to high altitude wind shear on otherwise clear days.  If SpaceX wants to hit their launch cadence targets for Starship, it's going to need to be able to safely launch during snowfall and tropical storms, etc.

[butters]

The capability to launch multiple times a day will make the tanker campaigns more resilient to weather constraints because they'll be able to squeeze more launches in to the acceptable weather windows.

[Lars-J]

Why do people transform "aiming for three flights a day for a Starship" into "aiming for three flights a day for a Starship WEATHER BE DAMNED!"? It makes no sense.

It doesn't make sense. Envelopes will be expanded eventually, but bad weather can still ground commercial aircraft, even though they are designed to spend the majority of the time in the air.

Nobody (including SpaceX) will risk a reusable craft in this way just because someone way back said that we should be able to fly three flights per day.

[Jim]

1.  They launch in those conditions as well.  It mostly has to do with the fact that the Soyuz family of boosters has its origins in the R-7 ICBM and it's, uhhh, "not really acceptable" to have an ICBM system that can be scrubbed because of bad weather.  Real "screen door on a submarine" energy.

2.  Lack of all-weather launches in the west is mostly a function of the pathological risk-aversiveness that permeates NASA and western spaceflight in general and it's that pathological risk-aversiveness that has so hindered our expansion into the cosmos that SpaceX is trying so hard to move away from.

Soyuz can night launch astronauts to the ISS in whiteout blizzard conditions while NASA scrubs due to high altitude wind shear on otherwise clear days.  If SpaceX wants to hit their launch cadence targets for Starship, it's going to need to be able to safely launch during snowfall and tropical storms, etc.

not true

1.  Atlas and Titan were ICBMs and still had those constraints.   Soyuz doesn't not launch in the thunder storms like in Florida.  Soyuz in Kourou doesn't launch in them.

2. just an inane comment.  The constraints haven't changed in decades.  It has nothing to do with " pathological risk-aversiveness".  Nor has it hindered "our expansion into the cosmos "

3.   High altitude wind shear is only happens on clear days.  It is the reason for clear days.   

Launch probability (wind shear) and launch vehicle performance is a trade.  It is one or the other.


 Airliners don't fly in tropical storms.   Airliners aren't serviced in lightning storms.  Airliners can't even taxi to gates in lightning storms since ground crews are not allowed outside.

[Zardar]

In the future, when "Mission Success" involves launching a Deep Space Transport (starship) into LEO, followed by ~10 tankers (plus a few spares) in rapid succession into the same plane, expecting the weather (and GSE!) to cooperate for a dozen opportunities (possibly over a week or two in real-time), is probably an excessive amount of mission risk.

Perhaps instead of overengineering the Rockets and Launch Infrastructure to rapidly return, restack and refly a small number of craft from the same pad, a better option to assure success might be to set up a "Rocket Row", with shared cranes/service towers, and launch them all over a couple of successive launch windows once the weather is favourable.

On this scale of things, concrete and rebar (for SpaceX style launch pads) is cheap, and their in-house GSE tankage is cheap too. At least compared to deep space missions repeatably scrubbed or aborted due to weather or GSE delays.

Although I do acknowledge that getting control and permission of multiple miles of coastline to setup and use such a Rocket Row might be an issue, one that would require Government support to overcome.

[Jim]

In the future, when "Mission Success" involves launching a Deep Space Transport (starship) into LEO, followed by ~10 tankers (plus a few spares) in rapid succession into the same plane, expecting the weather (and GSE!) to cooperate for a dozen opportunities (possibly over a week or two in real-time), is probably an excessive amount of mission risk.

No, it isn't.  If some tankers get delayed, just send up more to make up for the on orbit boil off.

[docmordrid]

In the future, when "Mission Success" involves launching a Deep Space Transport (starship) into LEO, followed by ~10 tankers (plus a few spares) in rapid succession into the same plane, expecting the weather (and GSE!) to cooperate for a dozen opportunities (possibly over a week or two in real-time), is probably an excessive amount of mission risk.
>

According to the below NASA graphic, Starship HLS leverages a "storage" (read: depot) Starship, presumably  filled well before the mission SS launches. Let's assume this depot is capable of low boil-off and (as Musk has mentioned, SS could get) they choose to add a cryocooler. How long could it store the LOX and LCH4?

A mission Starship basically stops at a gas station before leaving for wherever.

[steveleach]

Why do people transform "aiming for three flights a day for a Starship" into "aiming for three flights a day for a Starship WEATHER BE DAMNED!"? It makes no sense.

It doesn't make sense. Envelopes will be expanded eventually, but bad weather can still ground commercial aircraft, even though they are designed to spend the majority of the time in the air.

Nobody (including SpaceX) will risk a reusable craft in this way just because someone way back said that we should be able to fly three flights per day.

Stop arguing against your own strawman, it doesn't achieve anything.

SpaceX are going to want to ensure that weather impacts an ever smaller proportion of their launches as they work towards their target launch cadence. This is just the same evolution as every other form of transport goes through.

[Rich_Zap]

Assuming that the primary launch sites would end up as the two converted oil rigs (or any further ones developed). Would there be better locations that are statistically less likely to see adverse weather yet maintain similar benefits? Assuming you could set them up pretty much anywhere.

Taking the long view it might even be best if you traded some payload for much better launch reliability. You may get more total mass to orbit that way which is more important for something like refuelling ships.

[Barnalby]

Assuming that the primary launch sites would end up as the two converted oil rigs (or any further ones developed). Would there be better locations that are statistically less likely to see adverse weather yet maintain similar benefits? Assuming you could set them up pretty much anywhere.

No memeing but if we're talking "pretty much anywhere" then it'd probably be somewhere like Madagascar or Mauritius or the east coast of Africa that's arid with minimal inclement weather and close to the equator for maximum payload, but still has thousands of miles of ocean downrange.

Maybe if $TSLA hits $3000 a share Elon can just buy Somalia and rename it to "SpaceXia".

[Kit344]

3 flights per day could be achievable from multiple launch sites, but very unlikely to get 3 per week from Florida in the summer thunderstorm season.

Boca Chica seems to get, fog, wind and high summer temperatures, but is it a better or worse overall site than Kennedy Space Center ?

The offshore platforms could probably be moved according to the time of year to a more favourable location, but they won't move as quickly as a drone ship.

[Barnalby]

Realistically ITAR considerations mean the other locations will likely have to be in the US which means either Wallops or somewhere completely new like the Carolinas or even the Maine Coast.

[JaimeZX]

Realistically ITAR considerations mean the other locations will likely have to be in the US which means either Wallops or somewhere completely new like the Carolinas or even the Maine Coast.

Or, you know, Phobos and Deimos.  And probably other platforms.  Concur with ITAR concerns, at least in the beginning, but I think that'll eventually be sorted as some other countries develop Raptor analogues.

For other terrestrial launch sites... I wouldn't be surprised if we saw a few more, but locations will be constrained by inclination/latitude... Maine seems less likely than say... southwestern New Mexico.

[Alberto-Girardi]

Assuming that the primary launch sites would end up as the two converted oil rigs (or any further ones developed). Would there be better locations that are statistically less likely to see adverse weather yet maintain similar benefits? Assuming you could set them up pretty much anywhere.

No memeing but if we're talking "pretty much anywhere" then it'd probably be somewhere like Madagascar or Mauritius or the east coast of Africa that's arid with minimal inclement weather and close to the equator for maximum payload, but still has thousands of miles of ocean downrange.

Maybe if $TSLA hits $3000 a share Elon can just buy Somalia and rename it to "SpaceXia".

Interstingly Italy in the 60s used a modified oil rig platform to launch the San Marco (obviusly nothing to do wih the MARCO cubesats that flew with Insight)satellites. The oilrig was in the ocean next to Somalia and Kenya.

[Rich_Zap]

Yes ITAR probably would be a concern. I guess there are places like Guam which would be overseas territories where that wouldn't be an issue though? Of course there may be other factors that likewise constrain it such as supply chain issues which make such a move impractical. No point getting lots of nice weather for launching rockets if its a pain to get the rockets built/shipped there.

[schuttle89]

This later part of the thread has me thinking of coming up with a route that Phobos and Deimos and future platforms can take throughout a year to stay in the best weather areas possible. Every time a starship or booster gets rolled off the assembly line do the pressure tests and static fires in BC then fly it over to whatever launch platform it's going to be used on, preferably suborbital transfer. Those ones can wait on weather in Texas to be preferable then, once they get to Launch Platform 69420 sitting off the coast of Virginia where the weather is calculated to be good for a couple weeks, it can land and be integrated with a booster to be sent up to orbit.

[oiorionsbelt]

Ocean platforms on the equator will help with weather and payload.

[RedLineTrain]

Note that SpaceX recently has been hiring engineers for dealing with lightening.  Some examples currently listed...

LIGHTNING DIRECT AND INDIRECT EFFECTS ENGINEER, SENIOR
ELECTROMAGNETIC ENVIRONMENTAL EFFECTS ENGINEER
ELECTROMAGNETIC ENVIRONMENTAL EFFECTS ENGINEER, SENIOR
ELECTROMAGNETIC ENVIRONMENTAL EFFECTS TEST TECHNICIAN

[Jim]

Or, you know, Phobos and Deimos.  And probably other platforms.  Concur with ITAR concerns, at least in the beginning, but I think that'll eventually be sorted as some other countries develop Raptor analogues.

No, there is no consideration for what other countries have.  ITAR is independent of that and always will be in effect.

[Jim]

This later part of the thread has me thinking of coming up with a route that Phobos and Deimos and future platforms can take throughout a year to stay in the best weather areas possible. Every time a starship or booster gets rolled off the assembly line do the pressure tests and static fires in BC then fly it over to whatever launch platform it's going to be used on, preferably suborbital transfer. Those ones can wait on weather in Texas to be preferable then, once they get to Launch Platform 69420 sitting off the coast of Virginia where the weather is calculated to be good for a couple weeks, it can land and be integrated with a booster to be sent up to orbit.

What if there is no payload in Virginia?

[Scintillant]

This later part of the thread has me thinking of coming up with a route that Phobos and Deimos and future platforms can take throughout a year to stay in the best weather areas possible. Every time a starship or booster gets rolled off the assembly line do the pressure tests and static fires in BC then fly it over to whatever launch platform it's going to be used on, preferably suborbital transfer. Those ones can wait on weather in Texas to be preferable then, once they get to Launch Platform 69420 sitting off the coast of Virginia where the weather is calculated to be good for a couple weeks, it can land and be integrated with a booster to be sent up to orbit.

What if there is no payload in Virginia?

No payload in Virginia, but there will be methalox. Tanker flights will be frequently needed, and tankers could launch from any platform. Satellite payloads will be more constrained of course.

[Asteroza]

1.  They launch in those conditions as well.  It mostly has to do with the fact that the Soyuz family of boosters has its origins in the R-7 ICBM and it's, uhhh, "not really acceptable" to have an ICBM system that can be scrubbed because of bad weather.  Real "screen door on a submarine" energy.

2.  Lack of all-weather launches in the west is mostly a function of the pathological risk-aversiveness that permeates NASA and western spaceflight in general and it's that pathological risk-aversiveness that has so hindered our expansion into the cosmos that SpaceX is trying so hard to move away from.

Soyuz can night launch astronauts to the ISS in whiteout blizzard conditions while NASA scrubs due to high altitude wind shear on otherwise clear days.  If SpaceX wants to hit their launch cadence targets for Starship, it's going to need to be able to safely launch during snowfall and tropical storms, etc.

not true

1.  Atlas and Titan were ICBMs and still had those constraints.   Soyuz doesn't not launch in the thunder storms like in Florida.  Soyuz in Kourou doesn't launch in them.

2. just an inane comment.  The constraints haven't changed in decades.  It has nothing to do with " pathological risk-aversiveness".  Nor has it hindered "our expansion into the cosmos "

3.   High altitude wind shear is only happens on clear days.  It is the reason for clear days.   

Launch probability (wind shear) and launch vehicle performance is a trade.  It is one or the other.


 Airliners don't fly in tropical storms.   Airliners aren't serviced in lightning storms.  Airliners can't even taxi to gates in lightning storms since ground crews are not allowed outside.

To sound out your expert knowledge, do you believe Soyuz to have the lowest constraints for a liquid fueled launcher currently operated however? What would you feel is the origin of those lower constraints? Or as you imply, it's merely luck that Baikonur has low weather violation probability and as such Soyuz is just lucky in that regard and it doesn't actually have a substantial poor weather capability margin over other launcher/spaceport combos?

[steveleach]

I really didn't start this thread to watch people chat about how SpaceX could avoid bad weather.

I'd love to understand more about, for example, high-level wind shear, what could be done to better cope with (not avoid) it, and what the penalties of those mitigations would be.

[DigitalMan]

I really didn't start this thread to watch people chat about how SpaceX could avoid bad weather.

I'd love to understand more about, for example, high-level wind shear, what could be done to better cope with (not avoid) it, and what the penalties of those mitigations would be.

Right now Starship is in development. Once it is operational we should expect SpaceX to expand the envelope, no? I don't think it is a good idea to be more aggressive with constraints at this point, don't you think?

For all we know Starship may be able to greatly expand the envelope.

[steveleach]

I really didn't start this thread to watch people chat about how SpaceX could avoid bad weather.

I'd love to understand more about, for example, high-level wind shear, what could be done to better cope with (not avoid) it, and what the penalties of those mitigations would be.

Right now Starship is in development. Once it is operational we should expect SpaceX to expand the envelope, no? I don't think it is a good idea to be more aggressive with constraints at this point, don't you think?

For all we know Starship may be able to greatly expand the envelope.

Yep, fully agree. This is why my original post talked about small expansions of the weather envelope in order to help achieve the "3 flights a day" target cadence.

[Vettedrmr]

The Russians have no problem launching Soyuz in all manner of awful weather and it has a near-flawless safety record to show for it.  Surely it can't be impossible if they're doing it.

Not really.  They launch in rain and snow, but they still don't launch in electrical storm conditions (which don't happen much at those latitudes).  Florida, OTOH, is the thunderstorm capital of the world.

[Jim]

To sound out your expert knowledge, do you believe Soyuz to have the lowest constraints for a liquid fueled launcher currently operated however? What would you feel is the origin of those lower constraints? Or as you imply, it's merely luck that Baikonur has low weather violation probability and as such Soyuz is just lucky in that regard and it doesn't actually have a substantial poor weather capability margin over other launcher/spaceport combos?

It can handle cold weather because it was designed for cold weather. 

Baikonur is in a desert (annual precipitation 5 in) so it doesn't get the rain and storms like Florida. 

The vehicle is fairly robust structurally, but I have no idea about winds aloft in Baikonur.

[Jim]

I'd love to understand more about, for example, high-level wind shear, what could be done to better cope with (not avoid) it, and what the penalties of those mitigations would be.

reduce structural margins - increases risk of structural failure

increase vehicle structural strength -  reduces payload

decrease length/diameter ratio

[edzieba]

Wind shear tolerance: lower fineness ratio, stronger structure.

Lightning: Lightning hardening of electronics (Starship is already even better shielded than your average aluminium-skinned aircraft due to its thicker skin with a higher melting point, and those are struck on average once per year) and ensuring skin heating from an estimated maximum energy lightning strike is not sufficient to cause a tank to fail.
There is also the Soyuz stuck by lightning during a GLONASS launch to no ill effect:

Ground level winds: As long as the wind direction is not pushing the vehicle into the support tower, and the supper surface of the launch platform is free from protrusions, then avionics programming to allow the vehicle to stably 'crab' sideways during the initial ascent determines the tolerance to ground wind speed and gusts.

Freezing rain and ice: A tough one. Full enclosure of the vehicle is likely not feasible (not without your enclosure being unintentionally single use), but similar insulation mats to those seen on Soyuz and Proton during transport, that can be removed remotely immediately before launch, could keep ice buildup on the vehicle itself to a minimum - at least for the first launch attempt of the day. This in particular is going to be the hardest problem for Starship, as it has the double-whammie of externally exposed mechanisms (flap actuation) and exposed hygroscopic TPS, both of which could be rendered inoperable by ice buildup. Superheavy has the gridfins, which would also be exposed to the same issue.

For the offshore platforms, sea-state is going to be the bigger problem. Not just for platform stability during launch, but for all the other operations prior to them (hooking up to propellant supply tankers, transferring personnel on and off, hoisting payload onto the platform for integration, etc).

[Jim]

Ground level winds: As long as the wind direction is not pushing the vehicle into the support tower, and the supper surface of the launch platform is free from protrusions, then avionics programming to allow the vehicle to stably 'crab' sideways during the initial ascent determines the tolerance to ground wind speed and gusts.

There are also exhaust impingement issues that have to be taken into account.

[cuddihy]

Does a wider Superheavy with same Starship help in this regard? In another thread there was speculation that going to an 18m superheavy reduces the volume required height of the superheavy to (pi/4)  ratio of original superheavy height, although increased wall & end bulkhead thickness/ SH->SS transition adaptor/increased structural mass probably cuts it to ~1/4 reduction -- so reduction from 70 m ~ 50m for superheavy, making Starship & Superheavy about the same height & the stack 20m shorter.

fineness ratio goes from 120/9 = 13.3 currently to 100/18 = 5.6  (help me out engineers, did I calculate that right?)

That's got to help on windshear resistance, right?

*edit* not saying this is going to happen for obvious tooling, process, and material reasons, just asking if it would help for all-weather, particularly windshear resistance.

[Barnalby]

SpaceX loves its pencil boosters though.  Sometimes I wonder if they poached someone from the Zenit design team back in the 2000s.

[steveleach]

Freezing rain and ice: A tough one. Full enclosure of the vehicle is likely not feasible (not without your enclosure being unintentionally single use), but similar insulation mats to those seen on Soyuz and Proton during transport, that can be removed remotely immediately before launch, could keep ice buildup on the vehicle itself to a minimum - at least for the first launch attempt of the day. This in particular is going to be the hardest problem for Starship, as it has the double-whammie of externally exposed mechanisms (flap actuation) and exposed hygroscopic TPS, both of which could be rendered inoperable by ice buildup. Superheavy has the gridfins, which would also be exposed to the same issue.

Would the kind of de-icing spray that we see used on commercial passenger jets be of any use for this sort of thing?

And even discounting freezing, how would the felt backing (or whatever it is) behind the TPS cope with getting wet? Presumably that's something they are already dealing with.

[Jim]

Would the kind of de-icing spray that we see used on commercial passenger jets be of any use for this sort of thing?

No.  Too cold, it would add to the ice

[steveleach]

Would the kind of de-icing spray that we see used on commercial passenger jets be of any use for this sort of thing?

No.  Too cold, it would add to the ice

You mean because of the combination of the subcooled propellant and the ambient temperature?

I'm still trying to get my head around the problems of 250k vs 300k air temperature in the immediate vicinity of 100k LOX tanks.

[edzieba]

Would the kind of de-icing spray that we see used on commercial passenger jets be of any use for this sort of thing?

No.  Too cold, it would add to the ice

You mean because of the combination of the subcooled propellant and the ambient temperature?

I'm still trying to get my head around the problems of 250k vs 300k air temperature in the immediate vicinity of 100k LOX tanks.

Add external insulation, shorten time the cryogens are in the uninsulated tanks (load late, load fast), or flood the local atmosphere with dry Nitrogen (not feasible for non-silo launches).

[Jim]

Would the kind of de-icing spray that we see used on commercial passenger jets be of any use for this sort of thing?

No.  Too cold, it would add to the ice

You mean because of the combination of the subcooled propellant and the ambient temperature?

I'm still trying to get my head around the problems of 250k vs 300k air temperature in the immediate vicinity of 100k LOX tanks.

Methane is just as cold. 

Deicing fluid lowest freezing point is -60C.  That is 100 degrees warmer than the propellants.

[Jim]

Add external insulation,

with increased maintenance and turnaround time

[steveleach]

Would the kind of de-icing spray that we see used on commercial passenger jets be of any use for this sort of thing?

No.  Too cold, it would add to the ice

You mean because of the combination of the subcooled propellant and the ambient temperature?

I'm still trying to get my head around the problems of 250k vs 300k air temperature in the immediate vicinity of 100k LOX tanks.

Methane is just as cold. 

Deicing fluid lowest freezing point is -60C.  That is 100 degrees warmer than the propellants.

That makes sense, but just leaves me wondering why cold weather would be a problem at all. They already have to deal with temperatures much colder than anything the weather might throw at them.

[Jim]

That makes sense, but just leaves me wondering why cold weather would be a problem at all. They already have to deal with temperatures much colder than anything the weather might throw at them.

Because the rest of the hardware doesn't like it. The payload, avionics, cabling, GSE and other system. 

Engine compartments, interstages, avionics compartments are purged with warm gas during launch.  But not during all ops and there is risk of water condensation. 

Russians use sealed pressurized containers for their electronics

[cuddihy]

Russians use sealed pressurized containers for their electronics

Given the mass budget would expect SpaceX to do the same with Starship. Also although I can't find it now I remember a detailed interview with the SpaceX avionics team about F1/F9 from 8-10 years ago. They were pressure sealing avionics at the time. Did that change during F9 development?

Do we have any evidence the avionics are not in pressurized containers?

[Jim]

Russians use sealed pressurized containers for their electronics

Given the mass budget would expect SpaceX to do the same with Starship. Also although I can't find it now I remember a detailed interview with the SpaceX avionics team about F1/F9 from 8-10 years ago. They were pressure sealing avionics at the time. Did that change during F9 development?

Do we have any evidence the avionics are not in pressurized containers?

https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=37476.0;attach=1036642;image

[Jim]

Given the mass budget would expect SpaceX to do the same with Starship.

No, not the same. 

This is what is meant by sealed pressurized containers.

https://www.esa.int/var/esa/storage/images/esa_multimedia/images/2003/04/fregat_upper_stage_diagram/9791890-3-eng-GB/Fregat_upper_stage_diagram_pillars.jpg

[cuddihy]

Russians use sealed pressurized containers for their electronics

Given the mass budget would expect SpaceX to do the same with Starship. Also although I can't find it now I remember a detailed interview with the SpaceX avionics team about F1/F9 from 8-10 years ago. They were pressure sealing avionics at the time. Did that change during F9 development?

Do we have any evidence the avionics are not in pressurized containers?

https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=37476.0;attach=1036642;image

You must have access to a photo with resolution sufficient to tell detail that I can't see there...I definitely take your word for it that F9 avionics are not currently in pressurized containers. (Wow, not even boxes for the computers?)

Surely that will be corrected with Starship.

[Jim]

Surely that will be corrected with Starship.

why?  How are you going to cool them?

[cuddihy]

Do you really need to worry about that on short test flights?

For orbital flights, a coolant circulation system with radiators, on the dorsal side of the body like Dragon crew or on the inside of the payload door like shuttle.

[Jim]

Do you really need to worry about that on short test flights?

For orbital flights, a coolant circulation system with radiators, on the dorsal side of the body like Dragon crew or on the inside of the payload door like shuttle.

Yes, for the booster

[Barnalby]

Surely that will be corrected with Starship.

why?  How are you going to cool them?

"Tovarisch remember you will not be of needings to cool the avionics computers if your avionics are not of using computers to be of beginnings with, da?"

I keed I keed I know Roscosmos found a pile of old black market ColecoVisions in one of the open-air waste dumps at Baikonur and cobbled them together so that now Soyuz 2.0 can guide itself along more axes than just pitch and they don't have to do the old "aim the launch pad along the desired orbital inclination" thing anymore.

[Keldor]

Surely that will be corrected with Starship.

why?  How are you going to cool them?

"Tovarisch remember you will not be of needings to cool the avionics computers if your avionics are not of using computers to be of beginnings with, da?"

I keed I keed I know Roscosmos found a pile of old black market ColecoVisions in one of the open-air waste dumps at Baikonur and cobbled them together so that now Soyuz 2.0 can guide itself along more axes than just pitch and they don't have to do the old "aim the launch pad along the desired orbital inclination" thing anymore.

They're in a rocket with tanks holding cryogenic fuel for landing.  I'm sure they can figure out *some* way of cooling the computers.   And of course, computers are far, far faster and more power effecient than they were in the days of Saturn V.  Saturn V's computers were best compared with the computing power of a cell phone.  From 20 years ago.  Yet they were enough to fly a rocket.  Yes, Starship has a much more complicated flight profile than Saturn V, but you can do quite a bit with the roughly 1 *billion* fold increase in computing power per watt we've had since then.

[alastairmayer]

Surely that will be corrected with Starship.

why?  How are you going to cool them?

There's an entire industry devoted to after-market cooling systems for over-clocked PCs.  It shouldn't be too difficult.

[Jim]

There's an entire industry devoted to after-market cooling systems for over-clocked PCs.  It shouldn't be too difficult.

Not the same thing.  There are transmitters, recievers, INS, and many other devices involved. 

The cooling comment was about electronics in a sealed box.  fans don't work in a box.  Spacex wouldn't want liquid cooling 

[xvel]

You can transport heat with some sort of heat pipe https://en.wikipedia.org/wiki/Heat_pipe from what needs to be cooled to external radiators (when you put something in space and it is shaded from the sun it will radiatively lose thermal energy until it reaches around 3K https://en.wikipedia.org/wiki/Radiative_cooling)

[steveleach]

So as we've swung from "electronics would get too cold" to "electronics would get too hot", I'm going to assume that SpaceX can manage to find a way to keep the electronics at a reasonable temperature even in a blizzard.

For GSE, is there something special about spaceflight that means the techniques used on, for example, arctic oil exploration rigs won't work?

I have to admit, a lot of the objections I'm seeing feel more like "it's not trivial" than "it can't be done".

[Redclaws]

So as we've swung from "electronics would get too cold" to "electronics would get too hot", I'm going to assume that SpaceX can manage to find a way to keep the electronics at a reasonable temperature even in a blizzard.

For GSE, is there something special about spaceflight that means the techniques used on, for example, arctic oil exploration rigs won't work?

I have to admit, a lot of the objections I'm seeing feel more like "it's not trivial" than "it can't be done".

That is of course the rub - there’s a huge number of things which are possible, with sufficient effort.  But they all add cost (including ongoing maintenance of specialized systems) and potentially complexity.  And complexity means failure modes.  Again, that can be engineered to reach reliability, but $$$.

The option of launching in truly nasty weather - if we’re talking about arctic grade GSE, then that’s really nasty - is going to add potential failure modes.  Nothing about it is impossible...  but, eeek.  I would think weather envelope expansion, assuming it happens, would be extremely careful and slow.

[Jim]

So as we've swung from "electronics would get too cold" to "electronics would get too hot",

The swing was due to somebody suggesting a sealed container.

[Jim]

For GSE, is there something special about spaceflight that means the techniques used on, for example, arctic oil exploration rigs won't work?

mass and stiffness

[steveleach]

So as we've swung from "electronics would get too cold" to "electronics would get too hot", I'm going to assume that SpaceX can manage to find a way to keep the electronics at a reasonable temperature even in a blizzard.

For GSE, is there something special about spaceflight that means the techniques used on, for example, arctic oil exploration rigs won't work?

I have to admit, a lot of the objections I'm seeing feel more like "it's not trivial" than "it can't be done".

That is of course the rub - there’s a huge number of things which are possible, with sufficient effort.  But they all add cost (including ongoing maintenance of specialized systems) and potentially complexity.  And complexity means failure modes.  Again, that can be engineered to reach reliability, but $$$.

The option of launching in truly nasty weather - if we’re talking about arctic grade GSE, then that’s really nasty - is going to add potential failure modes.  Nothing about it is impossible...  but, eeek.  I would think weather envelope expansion, assuming it happens, would be extremely careful and slow.

Be careful not to combine two things I've said and assume I intended that combination.

I think SpaceX will want to work to minimise the amount of time that weather prevents launches.
I think that there are examples of equipment working reliably in very extreme weather conditions.

That doesn't mean I think SpaceX will insist on launching in arctic blizzard conditions.

In my original post I talked about how they might "launch tankers in slightly worse weather than their previous record".

As for cost and reliability, having their fleet sat around doing nothing because the weather isn't perfect is going to cost a lot, and if they are pushing the boundaries regarding weather with their tankers then that could actually improve reliability for crewed flights (or expensive payloads).

[Jim]

I have to admit, a lot of the objections I'm seeing feel more like "it's not trivial" .

and that is usually why it is not done

[Jim]

As for cost and reliability, having their fleet sat around doing nothing because the weather isn't perfect is going to cost a lot, and if they are pushing the boundaries regarding weather with their tankers then that could actually improve reliability for crewed flights (or expensive payloads).

Sea conditions have been causing most of the delays lately

[edzieba]

Add external insulation,

with increased maintenance and turnaround time

Dry mass too. Of RLVs built or in development thus far:
STS: did not re-use the cryogen tanks
Falcon 9: cryogen tanks not insulated
New Glenn: cryogen tanks not insulated
Rocketlab Electron: cryogen tanks not insulated
Vulcan: will not reuse the cryogen tanks
Starship/Super Heavy: cryogen tanks not insulated

[steveleach]

Add external insulation,

with increased maintenance and turnaround time

Dry mass too. Of RLVs built or in development thus far:
STS: did not re-use the cryogen tanks
Falcon 9: cryogen tanks not insulated
New Glenn: cryogen tanks not insulated
Rocketlab Electron: cryogen tanks not insulated
Vulcan: will not reuse the cryogen tanks
Starship/Super Heavy: cryogen tanks not insulated

I'm still trying to understand the need to insulate cryogenic tanks to cope with cold weather. They are already incredibly cold, why do we need to stop them getting cold?

Feels like I'm missing something obvious.

[Jim]

Add external insulation,

with increased maintenance and turnaround time

Dry mass too. Of RLVs built or in development thus far:
STS: did not re-use the cryogen tanks
Falcon 9: cryogen tanks not insulated
New Glenn: cryogen tanks not insulated
Rocketlab Electron: cryogen tanks not insulated
Vulcan: will not reuse the cryogen tanks
Starship/Super Heavy: cryogen tanks not insulated

I'm still trying to understand the need to insulate cryogenic tanks to cope with cold weather. They are already incredibly cold, why do we need to stop them getting cold?

Feels like I'm missing something obvious.

To keep the vehicle from icing up in rain

[steveleach]

Add external insulation,

with increased maintenance and turnaround time

Dry mass too. Of RLVs built or in development thus far:
STS: did not re-use the cryogen tanks
Falcon 9: cryogen tanks not insulated
New Glenn: cryogen tanks not insulated
Rocketlab Electron: cryogen tanks not insulated
Vulcan: will not reuse the cryogen tanks
Starship/Super Heavy: cryogen tanks not insulated

I'm still trying to understand the need to insulate cryogenic tanks to cope with cold weather. They are already incredibly cold, why do we need to stop them getting cold?

Feels like I'm missing something obvious.

To keep the vehicle from icing up in rain

Ah, with you now. This is about rain in general, not just the "freezing rain and ice" that the "add external insulation" comment was about.

So does this mean that vehicles with cryogenic propellants can't launch in the rain in general?

[alastairmayer]

There's an entire industry devoted to after-market cooling systems for over-clocked PCs.  It shouldn't be too difficult.

Not the same thing.  There are transmitters, recievers, INS, and many other devices involved. 

The cooling comment was about electronics in a sealed box.  fans don't work in a box.  Spacex wouldn't want liquid cooling

They have, what, 50 tons of heat sink surrounding how many tons of cryogenic liquid?  You don't need fans.

[Jim]

So does this mean that vehicles with cryogenic propellants can't launch in the rain in general?

Just another issue to deal with

[Jim]

They have, what, 50 tons of heat sink surrounding how many tons of cryogenic liquid?  You don't need fans.

Doesn't work that way.  Structure either gets too hot or too cold and propellants go away.  Avionics are typically isolated from the structure.  Do you think idiots have building launch vehicles for the last 1/2 century?
Reuse adds more cases to deal with (not just prelaunch and launch, but coast, orbit, entry, and post landing). 

[Dave G]

Starship/Super Heavy: cryogen tanks not insulated

Starship tanks will be partially insulated (as shown) before installing the heatshield tiles.

[steveleach]

So as I wasn't really getting the answers I wanted here, I've been looking into discussions on other forums.

As was pointed out here, the Russians have to cope with more severe weather at their launch sites so they seem to just design for it.

Apollo 12 launched in the rain; it didn't use subcooled methane, obviously, but it did use LOX.

Impact of raindrops on the vehicle at supersonic speeds was mentioned, particularly with respect to more delicate elements such as heat shield tiles. Presumably a reusable vehicle has to be designed to be a bit more robust anyway, so maybe this is less of an issue.

Visibility to allow the range safety officer to activate FTS was one weather factor mentioned, and presumably that doesn't apply to SpaceX vehicles that use autonomous FTS.

Lightning strikes are best avoided, but can be handled. Rockets have survived lightning strikes during launch, and aircraft do it regularly. I couldn't find any comparison of the risks to electronics from lightning compared to cosmic rays.

Wind shear is going to be a problem for control, but then again we're talking about SpaceX vehicles that have enough control authority to do things like landing flips and pinpoint booster landings.

But from what I can tell, it's mainly just a matter of avoiding weather scenarios you haven't tested. For historic vehicles this is a lot of area to cover, but for Starship it could rapidly narrow down to the more extreme conditions.

[Jim]

1.  As was pointed out here, the Russians have to cope with more severe weather at their launch sites so they seem to just design for it.

2.  Apollo 12 launched in the rain; it didn't use subcooled methane, obviously, but it did use LOX.

3.  Impact of raindrops on the vehicle at supersonic speeds was mentioned, particularly with respect to more delicate elements such as heat shield tiles. Presumably a reusable vehicle has to be designed to be a bit more robust anyway, so maybe this is less of an issue.

4.  Lightning strikes are best avoided, but can be handled. Rockets have survived lightning strikes during launch, and aircraft do it regularly. I couldn't find any comparison of the risks to electronics from lightning compared to cosmic rays.

5.  Wind shear is going to be a problem for control, but then again we're talking about SpaceX vehicles that have enough control authority to do things like landing flips and pinpoint booster landings.

1.  And they have different storage methods for their avionics.

2. Extra ice isn't good in any case

3.  Maybe is not going to cut it. 

4.  Most haven't, especially cloud to ground.  And it is not just the rocket but the payload too.  EMP from lightning is much worse than cosmic rays.

5.  Unrelated.  The flip is outside the atmosphere.  Booster landing is not a mated vehicle or one with a lot of propellant.

[rakaydos]

5.  Unrelated.  The flip is outside the atmosphere.  Booster landing is not a mated vehicle or one with a lot of propellant.

Wrong flip. Unless you're saying Starbase is a low pressure work enviroment...

[Jim]

5.  Unrelated.  The flip is outside the atmosphere.  Booster landing is not a mated vehicle or one with a lot of propellant.

Wrong flip

 Unless you're saying Starbase is a low pressure work enviroment...

Doesn't matter, it is happens at too low of attitude to be concerned with winds aloft.

[_MECO]

I bet there's gonna be some food for thought in this thread now...

[steveleach]

I bet there's gonna be some food for thought in this thread now...

You mean because we didn't all get to watch due to the fog, or is there a suggestion that the weather contributed to the SN11 failure?

[Hog]

I bet there's gonna be some food for thought in this thread now...

You mean because we didn't all get to watch due to the fog, or is there a suggestion that the weather contributed to the SN11 failure?

I've already read comments comparing Space Xs "decision to launch in zero visibility reminds me of NASA launching Challenger when it was too cold."

I so want to open my veins! (j/k)

[rakaydos]

I bet there's gonna be some food for thought in this thread now...

You mean because we didn't all get to watch due to the fog, or is there a suggestion that the weather contributed to the SN11 failure?

I've already read comments comparing Space Xs "decision to launch in zero visibility reminds me of NASA launching Challenger when it was too cold."

I so want to open my veins! (j/k)

"I wasnt IN the cherry tree."
https://www.reddit.com/r/Jokes/comments/gae067/george_washingtons_cherry_tree/

Manned flights have different considerations.

[_MECO]

I bet there's gonna be some food for thought in this thread now...

You mean because we didn't all get to watch due to the fog, or is there a suggestion that the weather contributed to the SN11 failure?

It's the worst we've ever seen video cut out on a Stsrship test. Can fog really not screw with GHz range radio links?

[steveleach]

I bet there's gonna be some food for thought in this thread now...

You mean because we didn't all get to watch due to the fog, or is there a suggestion that the weather contributed to the SN11 failure?

It's the worst we've ever seen video cut out on a Stsrship test. Can fog really not screw with GHz range radio links?

Maybe it does, but then again, maybe that was part of the decision.

"Let's wait for the fog to clear" say the team.
"Actually no, let's launch now, we might learn something interesting" says Elon.
"Well, as you've got autonomous FTS anyway... why the hell not?" says the FAA guy.

Food for thought indeed :-)

[sferrin]

I bet there's gonna be some food for thought in this thread now...

You mean because we didn't all get to watch due to the fog, or is there a suggestion that the weather contributed to the SN11 failure?

It's the worst we've ever seen video cut out on a Stsrship test. Can fog really not screw with GHz range radio links?

I think this killed a few brain cells.