SpaceX, rapid reuse, and vertical rocket stacking (integration)

[meekGee]

To start off, this is based on engineering reasoning, not on any inside information or anything that SpaceX has made public.

I think that with rapid reuse, SpaceX will move to vertical rocket stacking.

The usual mantra is that "SpaceX does horizontal integration since it's cheaper".   The word that comes to mind for me, however, when I see horizontal integration is "agility" rather than "low cost".

There's no argument of course that a strong back, a railway, and a couple of ladders (to over-simplify things) is cheaper than a mobile service tower.

However, in any industrial process, there's the trend that as the tempo of operations increases, you invest in more expensive, more dedicated infrastructure that reduced the per-operation costs.  Of course you MUST have enough volume to amortize the cost of the infrastructure over.  Many companies failed because they invested too quickly in such infrastructure, and were then stuck with the debt of the capital costs, while sales volume didn't increase as fast as they thought it would.  A mobile service tower, when you're only launching once a month, is probably an overkill from a cost perspective.

Elon's a smart guy.  I reckon the one thing he doesn't want to do is repeat other people's mistakes.  If he has to make any, he wants to make his own.

So back to the infrastructure.  The best example I have in mind is the standard diamond jack in your car.  It's cheap, agile (can be used with pretty much any car) and does the job.   But if you go to a NASCAR race, you'll see a different type of jack:  Dedicated, expensive, lifts the entire car at once, and does so in 2 seconds.  (Further, it gets the operator away from the path of the wheel-changers and refueling guy, so operations can happen even faster)   In NASCAR, time is money, and this jack is worth every penny.

So back to rockets.

The strongback arrangement is agile.  SpaceX flew the F9 1.0 only what, 5 times over 2 years?  and I bet there were changes to it all the time, and then ta-da! F9 1.1 is some 20% longer.  So now what - add stories to the mobile service tower?  Clearly horizontal integration is the correct choice for their current mode of operation.

However, when you want to turn around a rocket in a matter of days, it's a completely different story.  The rocket is not changing any more.  You can build dedicated support structures for it, with safe gantries at all necessary levels.

A vertical rocket gives you access to everything at once.  All 9 engines, in vertical position, the bells can be centered and unloaded, all vertical walls are accessible at eye level simply by walking to them, all fluid tanks and plumbing only ever see one orientation, so draining and such is easier (trap-wise), etc.

A horizontal rocket only gives you sort-of-good access to the lower engine, and you have to rotate it.  So if you're servicing engine #3 and need to escalate something for deeper inspection, all the other teams (e.g working on the RCS thrusters) have to wait since the rocket can't roll.  (not to mention that access to the center engine is awkward)

A vertical first stage can be rolled, as-is, on its legs, into a fixed service tower, doors can close around it, and the rocket can processed by as many people as you wish.  It can then be rolled to the pad for attachment to the launch holds, and fueling.  Faster, and per operation, cheaper.

Stacking of the US and payload can occur at the service tower (need somewhat stronger legs), or at the pad. In my mind, for a rapidly reusable rocket, the connection between the first and second stage is basically only mechanical.  Each is an independent flying vehicle, and so basically they just need to be latched together. If they need to communicate, it's low bandwidth digital stuff, and a two piece opto-coupler will do the trick just fine.

Finally, there's no tilting.  In an expendable rocket, since it's transported horizontally, there will always be a tilt-up. Either before integration, or before launch.   But a reusable rocket lands vertically.  At this point horizontal integration becomes ADDED complexity.

How soon?  How would I know... Development wise, SpaceX is moving incredibly fast.  Will this happen with F9 1.2? (or whatever the naming scheme will be) - maybe.  It depends whether the current F9 was designed with this option in mind. I have no inside information, so am just waiting to see.

So, again, this is basically only my personal opinion.  What SpaceX plans to or will do is, well, obviously up to them.

[guckyfan]

The idea of a full service tower may well be good, if a fast launch rate justifies the expense.

However regarding speed of operation. The landing pad will be a few km away from the launchpad. Getting the stage horizontal and transporting it that way will be a LOT faster and safer than moving it vertically. Once you have it horizontal you can mate first stage and pre-loaded second stage very easily. The second stage with integrated payload waits in the hangar. The first stage enters through the back door, they are mated and move out the frontdoor to the pad. Like on a roll on roll of ferry. Service that can be done better horizontal in the hangar will be done there. Service that can be done better vertical in a launch tower will be done there.

The need for a complex launch structure at the pad seems to me way in the future. Servicing the engines does not need it as they demonstrated with the SES-8 scrubs and engine service.

Edit: purely my opinion of course.

[Jim]

  Each is an independent flying vehicle, and so basically they just need to be latched together. If they need to communicate, it's low bandwidth digital stuff, and a two piece opto-coupler will do the trick just fine.

Not they are not independent. There is high bandwidth requirements and many connections.   The upperstage provides guidance for the stack.  There are range safety harnesses.  There are telemetry lines v

[Jim]

1.  A vertical rocket gives you access to everything at once.  All 9 engines, in vertical position, the bells can be centered and unloaded, all vertical walls are accessible at eye level simply by walking to them, a

2.  A horizontal rocket only gives you sort-of-good access to the lower engine, and you have to rotate it.  So if you're servicing engine #3 and need to escalate something for deeper inspection, all the other teams (e.g working on the RCS thrusters) have to wait since the rocket can't roll.  (not to mention that access to the center engine is awkward)

No, there is a hole under the engines and there are vehicle holddowns and umbilicals in the way.  There is nothing around the aft section of the vehicle in the hangar.

And because the design of the vehicle is so great and the manpower so low, there is no need or capability for simultaneous access, the engines can get worked on and then the RCS.

[meekGee]

  Each is an independent flying vehicle, and so basically they just need to be latched together. If they need to communicate, it's low bandwidth digital stuff, and a two piece opto-coupler will do the trick just fine.

Not they are not independent. There is high bandwidth requirements and many connections.   The upperstage provides guidance for the stack.  There are range safety harnesses.  There are telemetry lines v

I think that's one of the things that will change.  There is absolutely no reason why the first stage can't control the ascent till separation.  It has all the necessary avionics and sensors, and they are redundant.

What you describe is the logical way to do it in an expendable rocket.

That's part of re-thinking the design when you build a reusable rocket.

The first stage is an independent "carrier plane" for the upper stage.  So you don't need the avionics at the U/S to sense and control the engines on the first stage.  It's just that the two avionics suites need to communicate at a high level, the the US can shadow the flight.

The first stage will have its own independent range safety system anyway, and its own downlink anyway, since it needs to talk to the ground when if comes back to land.

So again, no connections necessary.

[guckyfan]

1.  A vertical rocket gives you access to everything at once.  All 9 engines, in vertical position, the bells can be centered and unloaded, all vertical walls are accessible at eye level simply by walking to them, a

2.  A horizontal rocket only gives you sort-of-good access to the lower engine, and you have to rotate it.  So if you're servicing engine #3 and need to escalate something for deeper inspection, all the other teams (e.g working on the RCS thrusters) have to wait since the rocket can't roll.  (not to mention that access to the center engine is awkward)

No, there is a hole under the engines and there are vehicle holddowns and umbilicals in the way.  There is nothing around the aft section of the vehicle in the hangar.

And because the design of the vehicle is so great and the manpower so low, there is no need or capability for simultaneous access, the engines can get worked on and then the RCS.

Where do these quotes come from? They are not from me and I don't see them in this thread.

Edit: Fixed quotes

Second Edit: I see the quotes, they are in meekGees opening post, but not mine.

[Jim]

Stacking of the US and payload can occur at the service tower (need somewhat stronger legs), or at the pad.

Nip this one in bud.  That is two separate lifts.  There is no positives and only negatives.  Lifting a fueled spacecraft is a facility/complex clear.  Lifting the spacecraft integrated with the second stage on the first stage means there had to be an early lift of the spacecraft on to the second stage, which would be another hazardous lift with clears.  The mantra of keeping spacecraft and launch vehicles apart as long as possible fits into Spacex's matra.  Assemble the launch vehicle and test it and then put the spacecraft on as close to launch as possible.  This keep the two product lines independent and from interfering with each other until late as possible.

[meekGee]

1.  A vertical rocket gives you access to everything at once.  All 9 engines, in vertical position, the bells can be centered and unloaded, all vertical walls are accessible at eye level simply by walking to them, a

2.  A horizontal rocket only gives you sort-of-good access to the lower engine, and you have to rotate it.  So if you're servicing engine #3 and need to escalate something for deeper inspection, all the other teams (e.g working on the RCS thrusters) have to wait since the rocket can't roll.  (not to mention that access to the center engine is awkward)

No, there is a hole under the engines and there are vehicle holddowns and umbilicals in the way.  There is nothing around the aft section of the vehicle in the hangar.

What hole?  Why would the fixed service tower have a hole under the engines?  If anything, it has a nice jack there, so you the engines are easy to pull.

[rcoppola]

  Each is an independent flying vehicle, and so basically they just need to be latched together. If they need to communicate, it's low bandwidth digital stuff, and a two piece opto-coupler will do the trick just fine.

Not they are not independent. There is high bandwidth requirements and many connections.   The upperstage provides guidance for the stack.  There are range safety harnesses.  There are telemetry lines v

I think that's one of the things that will change.  There is absolutely no reason why the first stage can't control the ascent till separation.  It has all the necessary avionics and sensors, and they are redundant.

What you describe is the logical way to do it in an expendable rocket.

That's part of re-thinking the design when you build a reusable rocket.

The first stage is an independent "carrier plane" for the upper stage.  So you don't need the avionics at the U/S to sense and control the engines on the first stage.  It's just that the two avionics suites need to communicate at a high level, the the US can shadow the flight.

The first stage will have its own independent range safety system anyway, and its own downlink anyway, since it needs to talk to the ground when if comes back to land.

So again, no connections necessary.

There will need to be connections from 1st to 2nd to Dragon when it's crewed for abort sequences.

Also, I think Payload integration will have more to do with how they introduce future vertical integration then reusability will.

[meekGee]

Stacking of the US and payload can occur at the service tower (need somewhat stronger legs), or at the pad.

Nip this one in bud.  That is two separate lifts.  There is no positives and only negatives.  Lifting a fueled spacecraft is a facility/complex clear.  Lifting the spacecraft integrated with the second stage on the first stage means there had to be an early lift of the spacecraft on to the second stage, which would be another hazardous lift with clears.  The mantra of keeping spacecraft and launch vehicles apart as long as possible fits into Spacex's matra.  Assemble the launch vehicle and test it and then put the spacecraft on as close to launch as possible.  This keep the two product lines independent and from interfering with each other until late as possible.

Maybe, but it's not an absolute.

I'd say the mantra (I hate mantras.  Every rule of thumb, every one-time statement becomes a mantra) preference would be to fuel the spacecraft at the pad - if the spacecraft allows it.

The reason I'm thinking about a combined lift (and yes, you're right, there would be a lift of the spacecraft onto the second stage first) is that Elon was talking about the first stage flying back within a day (or a few days), but the second stage will probably have a longer turn around time (longer time in space, maybe have to service the landing engines - we don't know much about those yet, and heat shield, etc)

So for steady state, you need more upper stages than you do first stages.   This doesn't directly mean you do the combined stack, but it means you can save time on your critical path by pre-integrating the US and the Spacecraft when possible.

The two options are not mutually exclusive btw.  If the Spacecraft absolutely has to be fueled in the service tower, then fine - do separate lifts, and slow everyone down - for a price of course.   (or fuel it after it's lifted, but still in the service tower)

Another thing you need to consider for rapid reuse is that payloads by definition have to be highly standardized. (As GS so eloquently put it - no "Giving birth")

So under this scenario, SpaceX will dictate the interface that the spacecraft must adhere to, and this will include on-pad refueling - so that the process can be streamlined.

[Jim]

I think that's one of the things that will change.  There is absolutely no reason why the first stage can't control the ascent till separation.  It has all the necessary avionics and sensors, and they are redundant.

What you describe is the logical way to do it in an expendable rocket.

That's part of re-thinking the design when you build a reusable rocket.

The first stage is an independent "carrier plane" for the upper stage.  So you don't need the avionics at the U/S to sense and control the engines on the first stage.  It's just that the two avionics suites need to communicate at a high level, the the US can shadow the flight.

The first stage will have its own independent range safety system anyway, and its own downlink anyway, since it needs to talk to the ground when if comes back to land.

So again, no connections necessary.

No, it is the wrong thinking based on the lack of knowledge in the field and using the excuse of "reusable" to make up for it.

The first stage is not "carrier plane".  It does not have excess fuel to loiter and reschedule the drop like carrier plane nor does it have to follow a precise trajectory.   

The upperstage needs to control the whole flight so that it can integrate the trajectory and make decisions on staging based on what is will be able to make up for first stage shortfalls or tell the first stage to keep burning and give up on recovery.

All launch vehicles have independent FTS systems on each stage but they are still tied together by data and sensing lines.  This is to ensure that received signal gets to all destruct packages and to shut down the engines and to sense inadvertent separation. 

[Jim]

this will include on-pad refueling - so that the process can be streamlined.

That will do the opposite and add many days to the flow.  Loading and servicing spacecraft on the pad is the exact opposite of what everybody and specifically Spacex want to do.   This really shows that you don't know what you are talking about. 

[meekGee]

The idea of a full service tower may well be good, if a fast launch rate justifies the expense.

However regarding speed of operation. The landing pad will be a few km away from the launchpad. Getting the stage horizontal and transporting it that way will be a LOT faster and safer than moving it vertically. Once you have it horizontal you can mate first stage and pre-loaded second stage very easily. The second stage with integrated payload waits in the hangar. The first stage enters through the back door, they are mated and move out the frontdoor to the pad. Like on a roll on roll of ferry. Service that can be done better horizontal in the hangar will be done there. Service that can be done better vertical in a launch tower will be done there.

The need for a complex launch structure at the pad seems to me way in the future. Servicing the engines does not need it as they demonstrated with the SES-8 scrubs and engine service.

Edit: purely my opinion of course.

Maybe.  It would be an interesting race.   

1)  Grab/Cradle, tilt, drive-like-the-wind, untilt.
2)  Tow slowly.

How many km to you envision between launch and landing pad?

If there's a dirt mount between them, it can be a very short distance, just enough to guarantee separation under the divert maneuver strategy.

[guckyfan]

Engine service for SES-8 was done vertical and Elon Musk stated they left the Falcon on the pad because it is easier to access the engines there.

I hope I don't have to dig out that quote.

[guckyfan]

Maybe.  It would be an interesting race.   

1)  Grab/Cradle, tilt, drive-like-the-wind, untilt.
2)  Tow slowly.

How many km to you envision between launch and landing pad?

If there's a dirt mount between them, it can be a very short distance, just enough to guarantee separation under the divert maneuver strategy.

I was thinking of distances on Cape Canaveral which would be several km. But even if they are closer they would have to drive around the dirt mound which adds distance. I really don't think they will ever like to land within less than a km from the launch pad.

[Jim]

No, it is the wrong thinking based on the lack of knowledge in the field and using the excuse of "reusable" to make up for it.

You were doing good till this.   Not responding otherwise.

Its your standard mantra, "processes for ELV's don't apply for reusable vehicles" without understanding what the process is

[meekGee]

There will need to be connections from 1st to 2nd to Dragon when it's crewed for abort sequences.

Also, I think Payload integration will have more to do with how they introduce future vertical integration then reusability will.

True, but that's high-level, low-bandwidth - the opto-coupler or similar will suffice.

And payload integration is really a side discussion.  The logic in the OP holds even if you eventually load a pre-fueled spacecraft to the top of the stack.  I mean, that's how it'd done today with vertical integration, and I was proposing a move to vertical integration, so no conflict really.

[meekGee]

Maybe.  It would be an interesting race.   

1)  Grab/Cradle, tilt, drive-like-the-wind, untilt.
2)  Tow slowly.

How many km to you envision between launch and landing pad?

If there's a dirt mount between them, it can be a very short distance, just enough to guarantee separation under the divert maneuver strategy.

I was thinking of distances on Cape Canaveral which would be several km. But even if they are closer they would have to drive around the dirt mound which adds distance. I really don't think they will ever like to land within less than a km from the launch pad.

how long does it take to cradle, tilt, and untilt IYO?

[guckyfan]

how long does it take to cradle, tilt, and untilt IYO?

They have to cradle it somehow for moving, no matter moving horizontal or vertical.

Their declared aim is to go from hangar to launch in one hour. But that seems hard as it includes tanking and the whole launch sequence. But tilting horizontal and back should be less than that. I don't see them moving the vertical stage in that time by even only a few hundred meters.

[meekGee]

how long does it take to cradle, tilt, and untilt IYO?

They have to cradle it somehow for moving, no matter moving horizontal or vertical.

Their declared aim is to go from hangar to launch in one hour. But that seems hard as it includes tanking and the whole launch sequence. But tilting horizontal and back should be less than that. I don't see them moving the vertical stage in that time by even only a few hundred meters.

I think if it can land on its legs, it can be towed on its legs.  You need to attach a dolly to each one, just like they do to skidded helicopters, but that's much simpler than attaching a cradle to an empty unpressurized tank.

It's not a fragile process, there's no alignment necessary etc.   Just one dolly at a time, it can be done pretty much manually by the tow-tractor driver.

The tractor can then move at least as fast as the one pushing your plane back at the airport, which is a good walking speed, and so 3-5 km/h.   If you're 1 km away, you're done in 10-20 minutes.  (and honestly I think you can drive faster...)

If you want to get fancier, you can invest in motorized, individually controlled dollies, and no tractor.

[Elmar Moelzer]

We have seen SpaceX do the lowering and raising of the LV pretty quickly in the past. Once horizontal it can be rotated for easy access. Integrating the current F9 vertically would require some very complex and tall structures and from what I understand, this problem is not going to get smaller with their future vehicles.
Complex and tall buildings are expensive.
I can see vertical integration only to make sense if the VTOL LV has a much larger diameter to length ratio, like say a DC-X or a Phoenix and is not quite as tall, or if the LV launches pretty much from where it landed and is a VTOL SSTO (which probably would have a large diameter to length ratio anyway). Then going horizontal becomes a lot less useful and much more complicated.
Current SpaceX vehicles both active and planned (that I know of anyway), are not like that. So the only justification seems to be customer request.

[Nomadd]

how long does it take to cradle, tilt, and untilt IYO?

They have to cradle it somehow for moving, no matter moving horizontal or vertical.

Their declared aim is to go from hangar to launch in one hour. But that seems hard as it includes tanking and the whole launch sequence. But tilting horizontal and back should be less than that. I don't see them moving the vertical stage in that time by even only a few hundred meters.

I think if it can land on its legs, it can be towed on its legs.  You need to attach a dolly to each one, just like they do to skidded helicopters, but that's much simpler than attaching a cradle to an empty unpressurized tank.

It's not a fragile process, there's no alignment necessary etc.   Just one dolly at a time, it can be done pretty much manually by the tow-tractor driver.

The tractor can then move at least as fast as the one pushing your plane back at the airport, which is a good walking speed, and so 3-5 km/h.   If you're 1 km away, you're done in 10-20 minutes.  (and honestly I think you can drive faster...)

If you want to get fancier, you can invest in motorized, individually controlled dollies, and no tractor.

I have to quit reading this now. I promised myself I'd get blind drunk if I ever felt sympathy for Jim.

[pathfinder_01]

Moving something as tall as a rocket in a vertical position will probably present more problems than it is worth. The height of the rocket would make moving it under things like bridges or anything else in the way difficult. The height could elevate the center of gravity making it tippy. The height could be acted on by high winds attempting to push it down.  Fluids that need to be drained before moving could be drained while the rocket is vertical and other fluid systems could be designed to stay in the tank when tilted over.

The rocket isn’t going to need to be turned around in minutes or hours like a car, race car, or airplane and working on it in an horizontal position gives lots of advantages ( safety for personal since they don’t need to climb on something or be in danger of dropping tools as much—i.e. most of the work being done on the ground.) and the rocket is already built to be worked on in an horizontal fashion.  The second stage is likewise currently built and matted on the ground.

About the only reason why rockets in the past used vertical integration was for performance reasons (i.e. design the thing to take loads in one direction only saving weight…even if adding processing costs).

[meekGee]

Moving something as tall as a rocket in a vertical position will probably present more problems than it is worth. The height of the rocket would make moving it under things like bridges or anything else in the way difficult. The height could elevate the center of gravity making it tippy. The height could be acted on by high winds attempting to push it down.  Fluids that need to be drained before moving could be drained while the rocket is vertical and other fluid systems could be designed to stay in the tank when tilted over.

The rocket isn’t going to need to be turned around in minutes or hours like a car, race car, or airplane and working on it in an horizontal position gives lots of advantages ( safety for personal since they don’t need to climb on something or be in danger of dropping tools as much—i.e. most of the work being done on the ground.) and the rocket is already built to be worked on in an horizontal fashion.  The second stage is likewise currently built and matted on the ground.

About the only reason why rockets in the past used vertical integration was for performance reasons (i.e. design the thing to take loads in one direction only saving weight…even if adding processing costs).

The premise was rapid reuse.  1-day turn-around or thereabouts.

I agree there's no point making any changes when you're only launching once a month.

The tail of a 747 is 65 feet, and you don't worry about it striking power lines or bridges between the terminal and the runway, right?  We're talking about a recurring operation here, not a one time exercise.

Center of gravity of an empty first stage - how high do you think that is?  I don't see why you'd have any problem with it, though I'd like to see the F9R with legs deployed first.

[Jim]

The premise was rapid reuse.  1-day turn-around or thereabouts.

Hence this thread should be in the Advance topics, because that isn't near term or on the horizon.

[meekGee]

We have seen SpaceX do the lowering and raising of the LV pretty quickly in the past. Once horizontal it can be rotated for easy access. Integrating the current F9 vertically would require some very complex and tall structures and from what I understand, this problem is not going to get smaller with their future vehicles.
Complex and tall buildings are expensive.
I can see vertical integration only to make sense if the VTOL LV has a much larger diameter to length ratio, like say a DC-X or a Phoenix and is not quite as tall, or if the LV launches pretty much from where it landed and is a VTOL SSTO (which probably would have a large diameter to length ratio anyway). Then going horizontal becomes a lot less useful and much more complicated.
Current SpaceX vehicles both active and planned (that I know of anyway), are not like that. So the only justification seems to be customer request.

Which vehicle are you referring to?

I know of F9 and F9H, and all we know of them is that SpaceX intends to reuse cores with them - eventually.  Very far from rapid reuse.

There isn't a current market for rapid reuse, and as I said, Elon is too smart to jump into expensive infrastructure for a market that does not exist. 

The current mode of operations is perfectly suitable for the current and the near-term projected launch rate.

[Elmar Moelzer]

Which vehicle are you referring to?

I know of F9 and F9H, and all we know of them is that SpaceX intends to reuse cores with them - eventually.  Very far from rapid reuse.

There isn't a current market for rapid reuse, and as I said, Elon is too smart to jump into expensive infrastructure for a market that does not exist. 

The current mode of operations is perfectly suitable for the current and the near-term projected launch rate.

Ok, either you did not understand my post, or I don't understand what you are trying to say.

[meekGee]

Which vehicle are you referring to?

I know of F9 and F9H, and all we know of them is that SpaceX intends to reuse cores with them - eventually.  Very far from rapid reuse.

There isn't a current market for rapid reuse, and as I said, Elon is too smart to jump into expensive infrastructure for a market that does not exist. 

The current mode of operations is perfectly suitable for the current and the near-term projected launch rate.

Ok, either you did not understand my post, or I don't understand what you are trying to say.

I picked up mostly on

Current SpaceX vehicles both active and planned (that I know of anyway), are not like that. So the only justification seems to be customer request.

But I guess you meant "like that" as in "like a wide diameter SSTO".

I agree that vertical processing is more appetizing in a vehicle as you describe - but I think a legged VTOL first stage is already past the threshold where it makes sense to keep it vertical.

I actually see almost no difference in processing between a VTOL SSTO and a VTOL first stage - up until the payload - but like I said before, payload integration is really a separate issue.

[pathfinder_01]

The premise was rapid reuse.  1-day turn-around or thereabouts.

I agree there's no point making any changes when you're only launching once a month.

The tail of a 747 is 65 feet, and you don't worry about it striking power lines or bridges between the terminal and the runway, right?  We're talking about a recurring operation here, not a one time exercise.

Center of gravity of an empty first stage - how high do you think that is?  I don't see why you'd have any problem with it, though I'd like to see the F9R with legs deployed first.

Not quite. In the case of the 747 there are airports it can not land at due to short runways, lack of equipement or places to store and so on.  As for 1 day turn arounds I would love to see that one day but at the moment the entire world only launches maybe about 100 or a little over 100 times a year not 365 times from a single space port and to enable this you would need to have nothing in the way from the landing pad to the processing facility.

The reason you could have problems with the center of gravity is becuase the stage is empty(Propellant eqauals weight). The stage is also lacking the wieght of the other stages on top of it and to add icing to the cake, I suspect the stage is likely bolted down on the pad or has an hold down system to keep it from moving before launch all of which would be missing at landing.

Also to move it the ground between the landing pad and the processing place is going to have to be flat becuase any bump, incline or decline could damage or tip it or cause unexpected loads in the structure. The shuttle moves in a vertical fashion from or to it's pad and it ain't quick.
 
You could also have problems with wind. There maybe a day when rockets only need to be refueled to fly again like cars, busses, trains, and planes but that is not soon.

[pathfinder_01]

I actually see almost no difference in processing between a VTOL SSTO and a VTOL first stage - up until the payload - but like I said before, payload integration is really a separate issue.

There is a difference. A VTOL SSTO might not need to have an 2nd stage hoisted over it an VTOL first stage(unless it works in parrell, will) as well as the payload and fairings.

[Elmar Moelzer]

I actually see almost no difference in processing between a VTOL SSTO and a VTOL first stage - up until the payload - but like I said before, payload integration is really a separate issue.

There is a difference. A VTOL SSTO might not need to have an 2nd stage hoisted over it an VTOL first stage(unless it works in parrell, will) as well as the payload and fairings.

Indeed, one of the differences.

[Elmar Moelzer]

I mean, I know that looks can be deceiving, but to me the SpaceX way looks cheaper and more efficient than the Atlas way:
http://www.spacex.com/sites/spacex/files/styles/media_gallery_large/public/img_2181_0.jpg?itok=G5EMKxrM
versus:
http://www.americaspace.com/wp-content/uploads/2013/11/MAVEN-Atlas-2.jpg

[Elmar Moelzer]

But I guess you meant "like that" as in "like a wide diameter SSTO".

Yes, that is what I was referring to. I am sorry, if this was not clear enough.

[Jim]

I mean, I know that looks can be deceiving, but to me the SpaceX way looks cheaper and more efficient than the Atlas way:
http://www.spacex.com/sites/spacex/files/styles/media_gallery_large/public/img_2181_0.jpg?itok=G5EMKxrM
versus:
http://www.americaspace.com/wp-content/uploads/2013/11/MAVEN-Atlas-2.jpg

Spacex can't fly many types of payloads with its method.  The Atlas method was driven by USAF requirements.   Also, Spacex can't adapt their launch vehicle to increasing spacecraft performance requirements.

[Elmar Moelzer]

Spacex can't fly many types of payloads with its method.  The Atlas method was driven by USAF requirements.   Also, Spacex can't adapt their launch vehicle to increasing spacecraft performance requirements.

Which is why I mentioned customer requirements as a justification for vertical integration earlier.
I cant think of anything else though.

[meekGee]

I mean, I know that looks can be deceiving, but to me the SpaceX way looks cheaper and more efficient than the Atlas way:
http://www.spacex.com/sites/spacex/files/styles/media_gallery_large/public/img_2181_0.jpg?itok=G5EMKxrM
versus:
http://www.americaspace.com/wp-content/uploads/2013/11/MAVEN-Atlas-2.jpg

For sure - but read the OP - it starts out with that exact same observation.

[meekGee]

I actually see almost no difference in processing between a VTOL SSTO and a VTOL first stage - up until the payload - but like I said before, payload integration is really a separate issue.

There is a difference. A VTOL SSTO might not need to have an 2nd stage hoisted over it an VTOL first stage(unless it works in parrell, will) as well as the payload and fairings.

That's why I said "almost"....

Like the VTOL SSTO, IMO most of the turn-around work will revolve around propulsion and fueling.
Stage integration can be made very simple, as I described above.

[meekGee]

I mean, I know that looks can be deceiving, but to me the SpaceX way looks cheaper and more efficient than the Atlas way:
http://www.spacex.com/sites/spacex/files/styles/media_gallery_large/public/img_2181_0.jpg?itok=G5EMKxrM
versus:
http://www.americaspace.com/wp-content/uploads/2013/11/MAVEN-Atlas-2.jpg

Actually, I really liked these two pictures since they illustrate the point well.  Obviously the service tower looks "more expensive".

But compare these two pictures.

Obviously the first picture looks "more expensive".  But we know that with enough volume, the investment in that infrastructure pays off, and the actual per-unit costs are lower.

Rockets are not sold by the millions, but the comparison is still valid.  When you want to turn around rockets in a day, you need something much more like the Atlas facility then like the SpaceX facility.   

I think the vertical facility is the "industrialized" way of doing things, and the SpaceX way, right now, is more like the second picture.

[Jim]

I mean, I know that looks can be deceiving, but to me the SpaceX way looks cheaper and more efficient than the Atlas way:
http://www.spacex.com/sites/spacex/files/styles/media_gallery_large/public/img_2181_0.jpg?itok=G5EMKxrM
versus:
http://www.americaspace.com/wp-content/uploads/2013/11/MAVEN-Atlas-2.jpg

Actually, I really liked these two pictures since they illustrate the point well.  Obviously the service tower looks "more expensive".

But compare these two pictures.

Obviously the first picture looks "more expensive".  But we know that with enough volume, the investment in that infrastructure pays off, and the actual per-unit costs are lower.

Rockets are not sold by the millions, but the comparison is still valid.  When you want to turn around rockets in a day, you need something much more like the Atlas facility then like the SpaceX facility.   

I think the vertical facility is the "industrialized" way of doing things, and the SpaceX way, right now, is more like the second picture.

quite the opposite.

The top photo is rockets coming off the line (from trailers coming from the factory or landing site) and being erected at the end of the line and launched.  Much like the current system.

The Atlas facility uses a lot of cranes and takes multiple lifts.  Vertical is required because of the balloon Centaur. 

Delta does a hybrid and uses no cranes except for the payload at the pad.  The GSE that the vehicle is built on in the factory is used to deliver the vehicle to the launch site, used for mating stages and boosters and then used to go the pad, where it is removed after erection.
 

[Jim]

A vertical rocket gives you access to everything at once.  All 9 engines, in vertical position, the bells can be centered and unloaded, all vertical walls are accessible at eye level simply by walking to them, all fluid tanks and plumbing only ever see one orientation, so draining and such is easier (trap-wise), etc.

A horizontal rocket only gives you sort-of-good access to the lower engine, and you have to rotate it.  So if you're servicing engine #3 and need to escalate something for deeper inspection, all the other teams (e.g working on the RCS thrusters) have to wait since the rocket can't roll.  (not to mention that access to the center engine is awkward)

False logic.  If this is far in the future, there is no 9 engines but only one large Raptor replace the 9.  Engine access become a moot point and a minor consideration at best.

[meekGee]

Maybe.

I am not advocating a copy of the Atlas facility, but am saying that the current system is tuned for roughly one-per-month (maybe twice) operations, which is appropriate.

There'd be no point in investing in more infrastructure until flight rates increase by a lot - which as people pointed out won't happen overnight.

But with larger volumes (1/day), I see a vertical facility (not built like the Atlas facility) being able to work faster and cheaper per-unit than a horizontal line.

As you say, rockets coming in from one side, processed, and out the other.   But if you have to potentially pull engines, or dwell on any of the other systems, there's nothing like concurrent access to everything to streamline the process. 

Horizontal, to me, means that there's always conflict in the access, and thus bottlenecks in the processing.


EDIT:  Yes, far to the future, but I don't think 1 Raptor will replace 9 Merlins - it is too small.  And they won't build a rocket with a few engines.  It's 1-or-many, from a reliability standpoint, and having many engines really helps with the landing and reuse.

[Jim]

Maybe.

As you say, rockets coming in from one side, processed, and out the other.   But if you have to potentially pull engines, or dwell on any of the other systems, there's nothing like concurrent access to everything to streamline the process. 

Which all exist in the horizontal method.  The same access used to build the vehicle is available.  Also no cranes needed

Pulling engine is another false argument.  GSE and task easier to horizontal. 

[meekGee]

Maybe.

As you say, rockets coming in from one side, processed, and out the other.   But if you have to potentially pull engines, or dwell on any of the other systems, there's nothing like concurrent access to everything to streamline the process. 

Which all exist in the horizontal method.  The same access used to build the vehicle is available.  Also no cranes needed

Pulling engine is another false argument.  GSE and task easier to horizontal.

Not all.

Concurrent access exists in horizontal flow?  I thought you argued that they'll turn the vehicle to access one engine at a time.  That's not concurrent.

Pulling engines - You were quite adamant that cycle time will be dominated by engine service time, which will be significant.  So pulling/inspecting/servicing.

So if engine operations are time consuming, and you can only access 1/9 of them at a time, you've got a serious bottleneck.  If engine operation dictate your access to the rest of the rocket (since it all rotates together) then it gets worse.

It's ok if you have time to do everything sequentially, but then your processing rate is limited.

---

As an aside, I've worked on a lot of projects involving precision assembly of large and heavy sub-components (e.g. multi-meter optics).  I like vertical mating a lot more when possible. 

[Jcc]

Maybe.

As you say, rockets coming in from one side, processed, and out the other.   But if you have to potentially pull engines, or dwell on any of the other systems, there's nothing like concurrent access to everything to streamline the process. 

Which all exist in the horizontal method.  The same access used to build the vehicle is available.  Also no cranes needed

Pulling engine is another false argument.  GSE and task easier to horizontal.

Not all.

Concurrent access exists in horizontal flow?  I thought you argued that they'll turn the vehicle to access one engine at a time.  That's not concurrent.

Pulling engines - You were quite adamant that cycle time will be dominated by engine service time, which will be significant.  So pulling/inspecting/servicing.

So if engine operations are time consuming, and you can only access 1/9 of them at a time, you've got a serious bottleneck.  If engine operation dictate your access to the rest of the rocket (since it all rotates together) then it gets worse.

It's ok if you have time to do everything sequentially, but then your processing rate is limited.

---

As an aside, I've worked on a lot of projects involving precision assembly of large and heavy sub-components (e.g. multi-meter optics).  I like vertical mating a lot more when possible.

I have a hard time imagining them actually working on all engines simultaneously in a vertical configuration either.

[meekGee]

I have a hard time imagining them actually working on all engines simultaneously in a vertical configuration either.

You don't have to work on all 9 simultaneously.

Imagine even 1 guy, starting to inspect engines.  On engine #2, he has to perform a deeper inspection since he saw something.  On engine #4, he actually has to call someone to escalate it.

If you have simultaneous access to all, then all these things can occur without special scheduling.  If you need to rotate the rocket per each engine, then the guy who has to perform the escalated inspection, when he gets there, of course the rocket is rotated wrong, and so either he has to wait, or everyone else has to stop and re-rotate the rocket.   Your odds of being efficient on each step are really low - only 1-in-8.

And as I said - the other people - taking care of RCS for example - they're all slaved to this problem too.  If the rocket is rotated wrong, they can't work.

The only way to have a managed maintenance cycle is to give up and do everything in sequence.  Start with engine #1, and if you have an issue, then then everything stops until that issue is resolved.   Inefficient, but at least more predictable.

All of this goes away if you can approach any part of the rocket, anytime.

Now, if you have two teams inspecting the engines, you also double your speed right off the bat.

Just like with the NASCAR jack, in rapid reuse time is money, and so you invest in infrastructure.   Rotating the rocket is just a really clever way to save on infrastructure costs when you're only launching once a month.

[Jcc]

I have a hard time imagining them actually working on all engines simultaneously in a vertical configuration either.

You don't have to work on all 9 simultaneously.

Imagine even 1 guy, starting to inspect engines.  On engine #2, he has to perform a deeper inspection since he saw something.  On engine #4, he actually has to call someone to escalate it.

If you have simultaneous access to all, then all these things can occur without special scheduling.  If you need to rotate the rocket per each engine, then the guy who has to perform the escalated inspection, when he gets there, of course the rocket is rotated wrong, and so either he has to wait, or everyone else has to stop and re-rotate the rocket.   Your odds of being efficient are really low - only 1-in-8.

And as I said - the other people - taking care of RCS for example - they're all slaved to this problem too.

The only way to have a managed maintenance cycle is to give up and do everything in sequence.  Start with engine #1, and if you have an issue, then then everything stops until that issue is resolved.   Inefficient, but at least more predictable.

All of this goes away if you can approach any part of the rocket, anytime.

Now, if you have two teams inspecting the engines, you also double your speed right off the bat.

Just like with the NASCAR jack, in rapid reuse time is money, and so you invest in infrastructure.   Rotating the rocket is just a really clever way to save on infrastructure costs when you're only launching once a month.

Ok, but to an extent you could use a scissor lift, scaffolding, ladder, etc., to accesss 2 or 3 engines at once, and likewise the upper portions of the rocket if horizontal.

[meekGee]

Ok, but to an extent you could use a scissor lift, scaffolding, ladder, etc., to accesss 2 or 3 engines at once, and likewise the upper portions of the rocket if horizontal.

Yeah, but you can see where that's going.  Scissor lifts and ladders instead of robust fixturing - not a recipe for incident-free operations. 

In my mind, when the rocket is sitting in the vertical position inside the service area, everything is fixtured so that initial inspection is almost entirely hands-off.    Again - costs more to build, but less to run, and is more reliable.

[Jason1701]

If this helps at all, almost all operations with engine installation and checkouts occurs in a vertical orientation (either with the octaweb at the factory in in McGregor).

[meekGee]

If this helps at all, almost all operations with engine installation and checkouts occurs in a vertical orientation (either with the octaweb at the factory in in McGregor).

Thanks

[Jim]

If this helps at all, almost all operations with engine installation and checkouts occurs in a vertical orientation (either with the octaweb at the factory in in McGregor).

And then

If this helps at all, almost all operations with engine installation and checkouts occurs in a vertical orientation (either with the octaweb at the factory in in McGregor).

Thanks

not applicable to launch site ops. The factory isn't a launch pad with a flame duct with hold downs and umbilicals in the way.

[Jim]

As an aside, I've worked on a lot of projects involving precision assembly of large and heavy sub-components (e.g. multi-meter optics).  I like vertical mating a lot more when possible. 

When the EELVs were designed, all studies pointed to horizontal ops as more efficient, cheaper, safer and quicker.  Atlas only went vertical because of requirements in handling the Centaur. 

That make 3 different organizations launch vehicle organization that prefer horizontal ops.

Edit.  Forgot something.  Soyuz, Proton, N-1, and Energia all are horizontal. 

A later edit for an important omission:   the latest new rocket Antares uses horizontal.

But this all doesn't matter, meekGee thinks he knows better.

[Nilof]

What about using something like this for quick inspection of the vehicle? You'd likely still need some visual inspection, but it certainly looks like something that would be helpful for fast inspection of a recovered stage.

[meekGee]

If this helps at all, almost all operations with engine installation and checkouts occurs in a vertical orientation (either with the octaweb at the factory in in McGregor).

And then

If this helps at all, almost all operations with engine installation and checkouts occurs in a vertical orientation (either with the octaweb at the factory in in McGregor).

Thanks

not applicable to launch site ops. The factory isn't a launch pad with a flame duct with hold downs and umbilicals in the way.

Jim - what flame duct, hold downs, and umbilicals?   We're talking about the fixed re-processing facility, not the launch pad.


As for Jason's comment, it corroborates that it is easier to deal with an engine cluster when the engines are vertical.

You said over and over again that rapid reusability is impossible since even just the work re-processing the engines will take too long.  So this is a significant considerations.

[meekGee]

As an aside, I've worked on a lot of projects involving precision assembly of large and heavy sub-components (e.g. multi-meter optics).  I like vertical mating a lot more when possible. 

When the EELVs were designed, all studies pointed to horizontal ops as more efficient, cheaper, safer and quicker.  Atlas only went vertical because of requirements in handling the Centaur. 

That make 3 different organizations launch vehicle organization that prefer horizontal ops.

Edit.  Forgot something.  Soyuz, Proton, N-1, and Energia all are horizontal. 

A later edit for an important omission:   the latest new rocket Antares uses horizontal.

But this all doesn't matter, meekGee thinks he knows better.

Like I said, horizontal processing makes sense for once-a-month launches, especially of expendable rockets. Since SpaceX doesn't carry legacy baggage, it could go with the system the best fit its needs - which it did.

But once we're talking about near-daily operations, (or anything more than 1/week IMO) then things change.  Time is money, and the investment in infrastructure is warranted.

Therefore those studies, which I agree with, are irrelevant.  It's different answers to too vastly different sets of circumstances.

That's the whole premise of this thread.  I didn't say horizontal processing is more expensive.  I said that for rapid reusability, I think vertical processing will be faster, and less expensive per-launch. (emphasis on faster, since it translates to money)

[Jim]

Therefore those studies, which I agree with, are irrelevant.  It's different answers to too vastly different sets of circumstances.

And how do you know they are wrong?  Have you read them?   It is not too vastly different sets of circumstances.   It is one basic thing: throughput.   And the way to increase it, reduce risks, and increase safety is to eliminate crane lifts, especially at height.  Crane lifts stop all near by work.  Also moving people, parts and tools between levels increase time (stairs and elevators). 

And it is not for once a month launches.  Get that out your head.  It was for around once a week.
Soyuz could do days between launches.

[Jim]

I think vertical processing will be faster, and less expensive

you have nothing relevant to back up that "think"

[meekGee]

Therefore those studies, which I agree with, are irrelevant.  It's different answers to too vastly different sets of circumstances.

And how do you know they are wrong?

... ahem...

.....
And it is not for once a month launches.  Get that out your head.  It was for around once a week.
Soyuz could do days between launches.

We were talking about a vertical hangar for a reusable rocket.  The Soyuz is horizontal, and expendable.

I said before, an expendable arrives horizontally anyway, and does not require the kind of engine processing that a reusable does after a flight.

[Lobo]

how long does it take to cradle, tilt, and untilt IYO?

They have to cradle it somehow for moving, no matter moving horizontal or vertical.

Their declared aim is to go from hangar to launch in one hour. But that seems hard as it includes tanking and the whole launch sequence. But tilting horizontal and back should be less than that. I don't see them moving the vertical stage in that time by even only a few hundred meters.

I think if it can land on its legs, it can be towed on its legs.  You need to attach a dolly to each one, just like they do to skidded helicopters, but that's much simpler than attaching a cradle to an empty unpressurized tank.

It's not a fragile process, there's no alignment necessary etc.   Just one dolly at a time, it can be done pretty much manually by the tow-tractor driver.

The tractor can then move at least as fast as the one pushing your plane back at the airport, which is a good walking speed, and so 3-5 km/h.   If you're 1 km away, you're done in 10-20 minutes.  (and honestly I think you can drive faster...)

If you want to get fancier, you can invest in motorized, individually controlled dollies, and no tractor.

What's the dry mass do the 1st stage?  Can it be helicoptered from where it lands to where it needs to go.  And then just set back down on its legs?

[Jim]

Jim - what flame duct, hold downs, and umbilicals?   We're talking about the fixed re-processing facility, not the launch pad.

That is what the rocket is sitting on.  It is sitting on mobile launch platform in the processing facility.  Don't tell me you are take it to the pad, then lift it on to the launch mount and then hook up all the services.

Also, there are ways to make Spacex ops more effient and eliminate major lift. 
The strongback is on the wrong side.    The vehicle should be sitting on dollies all integrated and then the TEL rolls in with the strongback over top of the vehicle.  The TEL grabs the vehicle off the dollies and rolls to the pad.

[Lobo]

Maybe.

As you say, rockets coming in from one side, processed, and out the other.   But if you have to potentially pull engines, or dwell on any of the other systems, there's nothing like concurrent access to everything to streamline the process. 

Which all exist in the horizontal method.  The same access used to build the vehicle is available.  Also no cranes needed

Pulling engine is another false argument.  GSE and task easier to horizontal.

So they can already access what they need to.  And I think the only vertical consideration if for some payloads that require vertical integration?  And that can be accomplished by encapsulating it vertically in the PLF at a payload integration clean room, and the lifting it on the vertical LV already on the pad and all tested and ready for launch with a crane or gantry or hoist or something...right at the pad?

If I understand previous posts correctly anyway.  So only a crane or perhaps movable gantry would be needed to be added to LC-40 or SLC-4...and everything else would process as is?

[Jim]

I said before, an expendable arrives horizontally anyway, and does not require the kind of engine processing that a reusable does after a flight.

And you are still thinking it will be nine engines and the current vehicle.  Since you are fantasizing about a one launch per day, that is so far in the future that these will also happen and they will support my conop.

a.  It will be 1-4 engines.
b.  Deep throttling is not problem
c.  Methane or similar will be use eliminating coking and other issues.
d.  The engines will be more like jet engines and don't need inspection/removal after each flight.  Just like an airliner, if there is a need for maintenance, then it taken offline facility for work (airline: ramp vs hangar; rocket:  launch prep/assemble facility vs maintenance facility)
e.  Since we are fantasizing about high flight rates, it isn't going to be just one vehicle.  Over the course of the years starting from now, the need for more launches will be met more vehicles flying and support by more pads.    The point is before we get to one vehicle flying every day, there will be some ramping up of flight rate over the years, like the equivalent of 7 vehicles flying once a week .
My point with all this?  There can multiple launch prep/assemble facilities will minimalistic like the original Spacex hangar and equivalent to an airport ramp.  And there can be a maintenance facility for those vehicles that have an issue and are taken out of rotation and worked on.

If you are going to employ willing suspension of disbelief to support your once per day vehicle flight rate, then don't apply it to the current vehicle.

Then again take it further and , there is no second stage and the vehicle is fueled and launched from the landing pad and is an SSTO RLV.

But as long as it is going to be multistage with a separate payload in fairing, then horizontal wins out. 

[meekGee]

I said before, an expendable arrives horizontally anyway, and does not require the kind of engine processing that a reusable does after a flight.

And you are still thinking it will be nine engines and the current vehicle.  Since you are fantasizing about a one launch per day, that is so far in the future that these will also happen and they will support my conop.

a.  It will be 1-4 engines.
b.  Deep throttling is not problem
c.  Methane or similar will be use eliminating coking and other issues.
d.  The engines will be more like jet engines and don't need inspection/removal after each flight.  Just like an airliner, if there is a need for maintenance, then it taken offline facility for work (airline: ramp vs hangar; rocket:  launch prep/assemble facility vs maintenance facility)
e.  Since we are fantasizing about high flight rates, it isn't going to be just one vehicle.  Over the course of the years starting from now, the need for more launches will be met more vehicles flying and support by more pads.    The point is before we get to one vehicle flying every day, there will be some ramping up of flight rate over the years, like the equivalent of 7 vehicles flying once a week .
My point with all this?  There can multiple launch prep/assemble facilities will minimalistic like the original Spacex hangar and equivalent to an airport ramp.  And there can be a maintenance facility for those vehicles that have an issue and are taken out of rotation and worked on.

If you are going to employ willing suspension of disbelief to support your once per day vehicle flight rate, then don't apply it to the current vehicle.

Then again take it further and , there is no second stage and the vehicle is fueled and launched from the landing pad and is an SSTO RLV.

But as long as it is going to be multistage with a separate payload in fairing, then horizontal wins out.

Again, maybe.   

I think the line where things change is over 1/wk, since that makes individual stages of the operation be roughly 1 day.

1-4 engines - I think the rule is either 1 or many.  not 2, not 3, not 4.    Simple math shows that if failures are independent, then a large cluster is the best option, followed by a single large engine.  But not a small cluster.

How large?  Not large enough that the options of 2 independent bad engines is statistically possible, and most importantly - large enough so that the lost thrust of 1-out-of-N still gives you engine-out capability at lift-off.

9 is working great for SpaceX.  You are the one that always complains that they're lying about engine-out at T+0.
But the more engines you have, the easier it is to achieve that.  So I don't get the drive to 4 engines.


Deep throttling - sure - if it comes without a cost.   1-out-of-9 gives you insta-11% without any performance cost, and then you can add throttling on top of that.

Methane - hey, I'm all for it.   But I still think the engines will have to be inspected.  This is NOT a jetliner, there's no graceful return-to-base.  You have a single engine-out capability (or none at all if you're using a single engine) and so you'd better take a good look at them before you go.  Methane or not.


I agree about having more than one vehicle.  You can take the numbers I gave as per vehicle, not per the entirety of SpaceX.

[meekGee]

I think vertical processing will be faster, and less expensive

you have nothing relevant to back up that "think"

Jim - I presented this as an opinion, based on my engineering analysis and my common sense. Of course it could be wrong.  I don't have inside info from SpaceX. But even though you disagree, it's not like I stated it without anything to back it up.  There are lots of posts upthread that back it up.  You just happen to think they're wrong.

What I don't understand is how you're so absolutely certain.

We had a similar argument about whether F9 1.1 will have reusability features designed into it.  You were equally ferocious.  But it turned out that it did.   We had a similar one about whether SpaceX is developing a Methane engine.   We don't have the inside info - all we can do is make best guesses based on what we see, and they're always going to be uncertain.  This would be a better foundation for such conversations.  I state upfront that this is simply my prediction, it can be wrong, and I care more about what the final outcome is than whether I was right about it or not.

[Jim]

We had a similar one about whether SpaceX is developing a Methane engine. 

That is still too early to call.
But you did get me on the re-usability.  I was looking at old data. 

[Jim]

What I don't understand is how you're so absolutely certain.

Because I know what is takes to process a vehicle (ELV or reusable) and everything points to horizontal.   

[Jim]

1-4 engines - I think the rule is either 1 or many.  not 2, not 3, not 4.    Simple math shows that if failures are independent, then a large cluster is the best option, followed by a single large engine.  But not a small cluster.

 nine engines were not selected based on reliability.  It was an easy way to get to EELV class with an existing engine.  There was going to be a Falcon 5.  And Spacex matra was one engine per stage.  They just went to engine out because of back pedaling 

[meekGee]

1-4 engines - I think the rule is either 1 or many.  not 2, not 3, not 4.    Simple math shows that if failures are independent, then a large cluster is the best option, followed by a single large engine.  But not a small cluster.

 nine engines were not selected based on reliability.  It was an easy way to get to EELV class with an existing engine.  There was going to be a Falcon 5.  And Spacex matra was one engine per stage.  They just went to engine out because of back pedaling

I remember the F5, but I think the F9 was planned even then.

I don't think SpaceX knew for sure where they are headed, though Elon thinks pretty far ahead.  So maybe the reason for the engine sizing was that a) it's what they could comfortably do, b) it took them from F1 to larger rockets, and c) it gave them the most flexibility in deciding how big a rocket to build next.

But irrespective of the rationale, 9 engines is working out well.  It makes it easy to get engine-out from as early as possible in the flight (obviously T+0 engine-out depends on how much payload is on top), it makes it easier to land, etc.

So even if the initial rationale no longer applies, my money is that they'll stay with 5/7/9 engines when they move to Raptor and a heavy lifter.  With extra money of 7/9.  (5 is just weaseling out...)

[guckyfan]

7 sounds perfect if it gives the desired thrust. Equal spacing of the engines allows for maximum space for the engine bells and for gimballing. The throttling range needs to allow for landing but that should be achievable.

[Jim]

I remember the F5, but I think the F9 was planned even then.

Nope, F5 was first, they were going after Delta II and F9 came later

[meekGee]

I remember the F5, but I think the F9 was planned even then.

Nope, F5 was first, they were going after Delta II and F9 came later

I seem to recall the F5 as the "next rocket we'll build" and the F9 as the "far off next-next rocket we'll build".  Then everything shifted up.

But the point was - nevermind the initial rationale.  We don't know what Elon was thinking of.   What matters is that the 9-engine cluster is working out well today, whether it's due to premonition or blind dumb luck. 

Today, 9-engine works well for the 11% down throttle, whether they intended this from the beginning or not.  It works well for 88% of remaining thrust on engine-out.

So given what we know today, I don't think they'll go to a small cluster or single engine with Raptor.

[meekGee]

We had a similar one about whether SpaceX is developing a Methane engine. 

That is still too early to call.
But you did get me on the re-usability.  I was looking at old data.

And Jim - I appreciate the first-hand knowledge that you bring in.  I picked up a lot from these arguments, though usually I have to back you into a corner before you cough up the "why" that I'm looking for...

It's just that knowing the details of how things work doesn't immediately translate into seeing what SpaceX is planning.  They have some surprises left in them, I'm pretty sure, and almost nothing is cast in stone.

If it ends up that they remain with Horizontal processing, so be it...   But if one day we'll see the rocket pulled on its legs back to a vertical hanger, I'll have a drink to this thread....

[Jim]

I will use a never here.  They will never integrate the upperstage and payload and then attach them to the booster.  That is too disruptive to the flow.

[meekGee]

I will use a never here.  They will never integrate the upperstage and payload and then attach them to the booster.  That is too disruptive to the flow.

I hear you about the payloads.

The thread was mostly about first stage processing and stacking of the second stage - payload is a more specialized operation, and it differs from payload to payload.  So that's secondary.

So the main things I'm saying:
1. I think it will be advantageous, in terms of speed and probably per-unit cost as well, to process the first stage while vertical, and never lay it down.
2. I think loading the second stage onto the first stage is also best done while both are vertical.
3. I think the connection between the two can be simplifies to the point where it is practically only mechanical.
4. I think the first stage will be an independent flyer.

1 and 2 - they only become relevant with high flight volume.  My completely WAG is somewhere between 1/week and 1/day.

3 and 4 - I can't see why they wouldn't be doing it even now.  (I don't think they are, because we'd have heard about it, but we do know the capabilities to do so are already in the first stage)

[mgfitter]

How far downrange does the first stage land (or splashdown or crash) on these flights without the boost-back profile?

And (maybe this question should go in the Q&A thread, but I'll put it here for now), is there an easy way to calculate an approximate landing point for the first stage, assuming you know the vertical and horizontal velocities at separation?

Thanks!

-MG

[meekGee]

How far downrange does the first stage land (or splashdown or crash) on these flights without the boost-back profile?

And (maybe this question should go in the Q&A thread, but I'll put it here for now), is there an easy way to calculate an approximate landing point for the first stage, assuming you know the vertical and horizontal velocities at separation?

Thanks!

-MG

yeah, this belongs in the general thread - please re-post there.

[RocketmanUS]

I hear you about the payloads.

The thread was mostly about first stage processing and stacking of the second stage - payload is a more specialized operation, and it differs from payload to payload.  So that's secondary.

So the main things I'm saying:
1. I think it will be advantageous, in terms of speed and probably per-unit cost as well, to process the first stage while vertical, and never lay it down.
2. I think loading the second stage onto the first stage is also best done while both are vertical.
3. I think the connection between the two can be simplifies to the point where it is practically only mechanical.
4. I think the first stage will be an independent flyer.

1 and 2 - they only become relevant with high flight volume.  My completely WAG is somewhere between 1/week and 1/day.

3 and 4 - I can't see why they wouldn't be doing it even now.  (I don't think they are, because we'd have heard about it, but we do know the capabilities to do so are already in the first stage)

Payload could possibly use a payload canister similar to the one planned for the Venture Star. Fairing and 2nd stage could be one making the fairing reusable too. Would require the larger Raptor based vehicle for usable payload mass.

1. Why would it be a problem laying it down?
     Use a mobile transport to bring it back to the hanger horizontally.
     Go up to it's landing area and grab on to it ( multiple arms on a strong back ), then lower it to horizontal
     position.

2. If they are on horizontal rolling racks would the stages aline easy compared to 2nd stage hanging from
    a crane?

3/4. K-1 stages were to be independent flyer's. So with the 1st stage flying back it should have it's own
       systems already.

They will need several 1st and 2nd stages for rapid reuse.
Inspections stations.
integration stations.

The same 1st stage would not always launch with the same 2nd stage.

[meekGee]

I hear you about the payloads.

The thread was mostly about first stage processing and stacking of the second stage - payload is a more specialized operation, and it differs from payload to payload.  So that's secondary.

So the main things I'm saying:
1. I think it will be advantageous, in terms of speed and probably per-unit cost as well, to process the first stage while vertical, and never lay it down.
2. I think loading the second stage onto the first stage is also best done while both are vertical.
3. I think the connection between the two can be simplifies to the point where it is practically only mechanical.
4. I think the first stage will be an independent flyer.

1 and 2 - they only become relevant with high flight volume.  My completely WAG is somewhere between 1/week and 1/day.

3 and 4 - I can't see why they wouldn't be doing it even now.  (I don't think they are, because we'd have heard about it, but we do know the capabilities to do so are already in the first stage)

Payload could possibly use a payload canister similar to the one planned for the Venture Star. Fairing and 2nd stage could be one making the fairing reusable too. Would require the larger Raptor based vehicle for usable payload mass.

1. Why would it be a problem laying it down?
     Use a mobile transport to bring it back to the hanger horizontally.
     Go up to it's landing area and grab on to it ( multiple arms on a strong back ), then lower it to horizontal
     position.

2. If they are on horizontal rolling racks would the stages aline easy compared to 2nd stage hanging from
    a crane?

3/4. K-1 stages were to be independent flyer's. So with the 1st stage flying back it should have it's own
       systems already.

They will need several 1st and 2nd stages for rapid reuse.
Inspections stations.
integration stations.

The same 1st stage would not always launch with the same 2nd stage.

Read upthread, but the short version is that I think processing a 9-engine stage is a lot faster (and more "natural" when it is vertical.
The actual laying down is not the main problem.

If the stage connection is simple, then doing it vertically should be (ready for it?) a snap. 

[Nomadd]

 Not sure why processing vertical is faster or more natural. The things were assembled horizontally and that's how they're used to working on it. Removing and replacing a component would be a more complicated movement if it was vertical. You'd need an entirely different procedure as opposed to mainly using the same one you did for assembly at the plant. Same for putting the 2nd stage on. Why would they do it differently than they do for the first flight?

[meekGee]

The premise was rapid reuse.  1-day turn-around or thereabouts.

I agree there's no point making any changes when you're only launching once a month.

The tail of a 747 is 65 feet, and you don't worry about it striking power lines or bridges between the terminal and the runway, right?  We're talking about a recurring operation here, not a one time exercise.

Center of gravity of an empty first stage - how high do you think that is?  I don't see why you'd have any problem with it, though I'd like to see the F9R with legs deployed first.

Not quite. In the case of the 747 there are airports it can not land at due to short runways, lack of equipement or places to store and so on.  As for 1 day turn arounds I would love to see that one day but at the moment the entire world only launches maybe about 100 or a little over 100 times a year not 365 times from a single space port and to enable this you would need to have nothing in the way from the landing pad to the processing facility.

The reason you could have problems with the center of gravity is becuase the stage is empty(Propellant eqauals weight). The stage is also lacking the wieght of the other stages on top of it and to add icing to the cake, I suspect the stage is likely bolted down on the pad or has an hold down system to keep it from moving before launch all of which would be missing at landing.

Also to move it the ground between the landing pad and the processing place is going to have to be flat becuase any bump, incline or decline could damage or tip it or cause unexpected loads in the structure. The shuttle moves in a vertical fashion from or to it's pad and it ain't quick.
 
You could also have problems with wind. There maybe a day when rockets only need to be refueled to fly again like cars, busses, trains, and planes but that is not soon.

Sorry missed this one earlier.

A reusable launch facility, if considering rapid reuse, is very similar to an airport.

You must have several landing pads (at least 3 for first stages and 1 for upperstage - but you probably want spares.

You then must have taxiways from them to the processing facility.   They will be level and clean enough for the stages to move on.

(Quoting GS again - "We don't want each flight to be like giving birth")

So just like in an airport where a 747 is operating out of, the taxiways are compatible with the airplane's dimension.

--

c.g. wise, lack of second stage and payload drops the center of gravity.
Lack of fuel in the tank does the same, since you have a heavy engine cluster at the bottom, and empty tank on top.
Look at a side-view of GH and try to paint where the c.g. is.  (granted, the legs are wider and it is a tad shorter, but still - it's not anywhere near in danger of tipping)

[meekGee]

Not sure why processing vertical is faster or more natural. The things were assembled horizontally and that's how they're used to working on it. Removing and replacing a component would be a more complicated movement if it was vertical. You'd need an entirely different procedure as opposed to mainly using the same one you did for assembly at the plant. Same for putting the 2nd stage on. Why would they do it differently than they do for the first flight?

It's all upthread.

For example here:  http://forum.nasaspaceflight.com/index.php?topic=33430.msg1129579#msg1129579

and then Jason's comment about how in the plant they do it in the vertical orientation.


From my experience - it's easier to slowly drop or raise a heavy (and delicate) components to place then to slide it sideways. 

[guckyfan]

From my experience - it's easier to slowly drop or raise a heavy (and delicate) components to place then to slide it sideways.

Elon Musk made the statement during the SES-8 launch campaign. They left Falcon vertical at the pad after the second scrub for easier engine maintenance.

Yet I am still convinced that transport and mating with a second stage is a lot easier done horizontal. They would probably do engine maintenance vertical at the landing pad after securing the stage in a strongback, then go horizontal for transport and mating with the second stage, then on to the launch pad. That's my opinion on optimized operations.


Edit: Or rather they take it horizontal, move it to a dedicated engine maintenance facility, going vertical there. Then go horizontal, move it to a hangar for mating with the second stage and payload. Then on to the launch pad. Changing between horizontal and vertical is just no issue of time and cost once the stage is secured in a strongback.

[Jim]

From my experience - it's easier to slowly drop or raise a heavy (and delicate) components to place then to slide it sideways. 

[llanitedave]

Not sure why processing vertical is faster or more natural. The things were assembled horizontally and that's how they're used to working on it. Removing and replacing a component would be a more complicated movement if it was vertical. You'd need an entirely different procedure as opposed to mainly using the same one you did for assembly at the plant. Same for putting the 2nd stage on. Why would they do it differently than they do for the first flight?

It's all upthread.

For example here:  http://forum.nasaspaceflight.com/index.php?topic=33430.msg1129579#msg1129579

and then Jason's comment about how in the plant they do it in the vertical orientation.


From my experience - it's easier to slowly drop or raise a heavy (and delicate) components to place then to slide it sideways.

I would think that all depends on the jig you're using.  Tooling is everything.

[meekGee]

Not sure why processing vertical is faster or more natural. The things were assembled horizontally and that's how they're used to working on it. Removing and replacing a component would be a more complicated movement if it was vertical. You'd need an entirely different procedure as opposed to mainly using the same one you did for assembly at the plant. Same for putting the 2nd stage on. Why would they do it differently than they do for the first flight?

It's all upthread.

For example here:  http://forum.nasaspaceflight.com/index.php?topic=33430.msg1129579#msg1129579

and then Jason's comment about how in the plant they do it in the vertical orientation.


From my experience - it's easier to slowly drop or raise a heavy (and delicate) components to place then to slide it sideways.

I would think that all depends on the jig you're using.  Tooling is everything.

... I didn't say impossible.   I said easier.

The problem with horizontal integration is that you typically have to "float" one of the components.  Also, adjustments perpendicular to the axis of the connection (motion and rotations) are more difficult to accomplish.

With vertical, gravity (which is now aligned with the axis of connection) has become your friend.   The load is supported against gravity, and can freely float in X-Y-theta.

Easier to void jamming, wedging, etc, and easier to avoid damage to the interface.

[Avron]

With vertical, gravity (which is now aligned with the axis of connection) has become your friend.   The load is supported against gravity, and can freely float in X-Y-theta.

Easier to void jamming, wedging, etc, and easier to avoid damage to the interface.

Was thinking vertical may be easier for some components but increase the level of danger by a few orders of magnitude.

Jim, did you not post during SES-8, that you observed the LV was horizontal

[meekGee]

With vertical, gravity (which is now aligned with the axis of connection) has become your friend.   The load is supported against gravity, and can freely float in X-Y-theta.

Easier to void jamming, wedging, etc, and easier to avoid damage to the interface.

Was thinking vertical may be easier for some components but increase the level of danger by a few orders of magnitude.

I suspect you mean "by a whole-number factor"....   "Few orders of magnitude" is anywhere between say 1000 and 1,000,000....

But even under the first meaning - how many payloads do you know of that were dropped off cranes in the past, say, 10 years?

[Avron]

With vertical, gravity (which is now aligned with the axis of connection) has become your friend.   The load is supported against gravity, and can freely float in X-Y-theta.

Easier to void jamming, wedging, etc, and easier to avoid damage to the interface.

Was thinking vertical may be easier for some components but increase the level of danger by a few orders of magnitude.

I suspect you mean "by a whole-number factor"....   "Few orders of magnitude" is anywhere between say 1000 and 1,000,000....

But even under the first meaning - how many payloads do you know of that were dropped off cranes in the past, say, 10 years?

Thinking humans, falling off a ladder 1000 falling from 30 M 1,000,000

[Garrett]

The problem with horizontal integration is that you typically have to "float" one of the components.  Also, adjustments perpendicular to the axis of the connection (motion and rotations) are more difficult to accomplish.
With vertical, gravity (which is now aligned with the axis of connection) has become your friend.   The load is supported against gravity, and can freely float in X-Y-theta.

Highlighting in red by me to point out the contradiction.No matter what orientation, there is always a need to "float" components.

Also, the "axis of connection" is not necesarily vertical. I imagine there could be many engineering reasons for it to be slightly off-vertical, or even horizontal. SSME's didn't seem to be "connected" along the principal orbiter axis (see photo by Jim above)

Finally, vertical integration requires access to heights of the order of the stage length or entire rocket length. Horizontal integration only requires access to heights on the order of the stage/rocket diameter.

[meekGee]

The problem with horizontal integration is that you typically have to "float" one of the components.  Also, adjustments perpendicular to the axis of the connection (motion and rotations) are more difficult to accomplish.
With vertical, gravity (which is now aligned with the axis of connection) has become your friend.   The load is supported against gravity, and can freely float in X-Y-theta.

Highlighting in red by me to point out the contradiction.No matter what orientation, there is always a need to "float" components.

Also, the "axis of connection" is not necesarily vertical. I imagine there could be many engineering reasons for it to be slightly off-vertical, or even horizontal. SSME's didn't seem to be "connected" along the principal orbiter axis (see photo by Jim above)

Finally, vertical integration requires access to heights of the order of the stage or entire rocket. Horizontal integration only requires access to heights on the order of the stage/rocket diameter.

No contradiction...

When you hang something from above, you naturally get high rigidity in Z, and low rigidity and friction in X-Y-Theta, which is exactly what you want.   This is because gravity is pointing along Z.  Even if you lift from below, it is easier to get to this result.

When you hold something with a lift, or hang it from above, and try to mate horizontally, you now have an issue since you have high stiffness along the Z axis (which is counteracting gravity).  It's solvable, but is a pain.

Doing a combined move where the engine is horizontal, but you mate it vertically is problematic too, since naturally you want it to mate as it moves "into" the rocket, so that X-Y-Theta (in the frame of the rocket) can be positioned accurately. 

...  and Space'X comments make it seem they believe so too.

[meekGee]

BTW - just in case you think horizontal integration is risk free:

[Jim]

BTW - just in case you think horizontal integration is risk free:

Bad example and supports the opposite. 
It was vertical.  That was the issue.  It was unsafe condition in the vertical configuration.  It would have fallen over even if they tried moving the base to another location in the work area.

[meekGee]

BTW - just in case you think horizontal integration is risk free:

Bad example and supports the opposite. 
It was vertical.  That was the issue.  It was unsafe condition in the vertical configuration.  It would have fallen over even if they tried moving the base to another location in the work area.

It shows that handling (as in attaching to fixtures, tilting, etc) has risks no matter what you do.

I wasn't arguing that "you need to go vertical to reduce risk".

I was pointing out that "vertical is risky because cranes" is not a good argument.

[Garrett]

It shows that handling (as in attaching to fixtures, tilting, etc) has risks no matter what you do.

That is a given and not something being argued.

I wasn't arguing that "you need to go vertical to reduce risk".

Seemed like you were. Especially in light of your previous posts in this thread.

[Nomadd]

 Being free to float doesn't make precision insertion easier. Gravity isn't some enemy force to overcome. Random motion is.

[meekGee]

It shows that handling (as in attaching to fixtures, tilting, etc) has risks no matter what you do.

That is a given and not something being argued.

I wasn't arguing that "you need to go vertical to reduce risk".

Seemed like you were. Especially in light of your previous posts in this thread.

The discussion about risk started with a comment that Horizontal integration is many times safer.

I was pointing out that as far as I know, no spacecraft or stage was dropped from a crane, but actually I can show an example where a spacecraft was dropped under the kind of handling you'd expect when tilting stages up and down.

Overall, keeping the rocket vertical reduces the amount of handling.

However, this was not the main argument of the thread, it's just an offshoot. In both cases, the rick of incident can be reduced enough so it's not an overriding concern.

[Jim]

Overall, keeping the rocket vertical reduces the amount of handling.

No, quite the opposite.  That is the main benefit of horizontal.   Delta uses no cranes until the vehicle gets to the pad.  The core is built, shipped and assembled on the same set of GSE. 

[Elmar Moelzer]

I don't know about the US, but in Austria unionized workers get paid higher salaries if they have to work in great heights.

[meekGee]

Overall, keeping the rocket vertical reduces the amount of handling.

No, quite the opposite.  That is the main benefit of horizontal.   Delta uses no cranes until the vehicle gets to the pad.  The core is built, shipped and assembled on the same set of GSE.

Never mind Delta - it's an expendable, the components arrive horizontal anyway, and no engine cluster.


With FH for example, the starting point is 3 cores, each with 9 engines, already standing vertical on their legs.

Your choices are:

A. Move them on their legs, and have access to all part of the rocket at the same time, then re-mate in the same attitude.

B. Cradle them on the pad, rotate to horizontal, then spin 8 times to access only one engine at a time, mate horizontally, then re-rotate to vertical.

A is simpler and faster.
B is more flexible when you're making changes

[Jim]

A. Move them on their legs, and have access to all part of the rocket at the same time, then re-mate in the same attitude.

B. Cradle them on the pad, rotate to horizontal, then spin 8 times to access only one engine at a time, mate horizontally, then re-rotate to vertical.

A is simpler and faster.
B is more flexible when you're making changes

 Unsupported claims. 

a.  No data the legs will not be strong enough for transport loads and attaching some mode of a transporter to each leg is not trivial.    Also logistics of working the legs into facility doesn't interfere with the structure or umbilical tower.

b.  no need to spin that much, Just like now,the vehicle is less than 4m wide.  Simple rollup platforms and manlifts can aid access. 

Never mind engine access, you are grossly overstating it and wrongly fixating on it. 
Spacex does it all the time in the current configuration before going vertical.  It was done at the pad for SES-8 for mostly for the spacecraft (the spacecraft would have to have been disconnected from AC and comm for roll back.  I bet if it was a Dragon, they would have rolled back.

Just grab the vehicle, retract gear, break it over and transport.  Just the opposite of mobile TEL's

Also, the nine engines is not a given for that far into the future nor is the diameter.

Here are an easy and simple, safe, efficient methods for access. 

http://upload.wikimedia.org/wikipedia/commons/3/30/The_First_Stages_of_Saturn_IB_in_Final_Assembly_-_GPN-2000-000043.jpg

http://history.nasa.gov/MHR-5/fig348t.jpg

[meekGee]

A. Move them on their legs, and have access to all part of the rocket at the same time, then re-mate in the same attitude.

B. Cradle them on the pad, rotate to horizontal, then spin 8 times to access only one engine at a time, mate horizontally, then re-rotate to vertical.

A is simpler and faster.
B is more flexible when you're making changes

 Unsupported claims. 

a.  No data the legs will not be strong enough for transport loads and attaching some mode of a transporter to each leg is not trivial.    Also logistics of working the legs into facility doesn't interfere with the structure or umbilical tower.

b.  no need to spin that much, Just like now,the vehicle is less than 4m wide.  Simple rollup platforms and manlifts can aid access. 

Never mind engine access, you are grossly overstating it and wrongly fixating on it. 
Spacex does it all the time in the current configuration before going vertical.  It was done at the pad for SES-8 for mostly for the spacecraft (the spacecraft would have to have been disconnected from AC and comm for roll back.  I bet if it was a Dragon, they would have rolled back.

Just grab the vehicle, retract gear, break it over and transport.  Just the opposite of mobile TEL's

Also, the nine engines is not a given for that far into the future nor is the diameter.

Here are an easy and simple, safe, efficient methods for access. 

http://upload.wikimedia.org/wikipedia/commons/3/30/The_First_Stages_of_Saturn_IB_in_Final_Assembly_-_GPN-2000-000043.jpg

http://history.nasa.gov/MHR-5/fig348t.jpg

Supported by the logic upthread.

If the legs can take the landing+margin, they can take a rollout on a taxiway between the pad and the hangar. 
No data?  SpaceX is the one designing them - if they choose to go that route, they'll design them accordingly.

Nothing easier than attaching gear to a leg with a 1-2" lift.  A simple over-center cam will do it even for something like a first stage.  The stage can take the misalignment as you attach the gear one leg at a time.

Specifically, the lead wheel is aligned with the tow bar, the two side gears are locked parallel the direction of travel, and the back gear is free-rotating (caster).  The stage will follow the tractor, no problem.

Travel at 5-10 km/hr, be back at the facility in 10 minutes.

The legs won'd interfere with anything, since again - SpaceX is designing it, so if they go that route, they won't forget to leave clearance... 

and there's no "just" break it over.  It's easy to tilt a stage once it's on a strongback.  But to pick it up without damaging it, from a concrete pad, outdoors (night, rain, wind) is not so trivial.  Conditions are not controlled as well as in a service hangar, and if you do it rapidly, 4 times per flight, it's a concern.  Towing it "as-is" is a lot safer.


I am not over-stressing engine access.  You're the one that stated (many times) that rapid reuse is impossible because just engine rework will take too long.  So vertical access increases your access to the engines - you can access all 9 in parallel, and in parallel to other components of the stage.


The key emphasis here is on processing of the first stage.  That's the most amount of work in the re-flight cycle, and so needs the most attention.

[llanitedave]

I'm agreeing with Jim here. Vertical integration is not much of an advantage if any, and laying a stage horizontal and picking it up again is dead-easy.  I don't see any downside, pardon the pun.

[aero]

It seems to me that ground handling of the return stage shouldn't be complicated.

1 - Stage lands and is safed with equipment at the landing pad...
2 - Stage is lifted taking weight off the legs. A purpose built fork lift with a vertical stabilizing tower could do this.
3 - Legs are retracted and latched and/or perhaps strapped in a safe position.
4 - Stage is transported upright back to the launch site and deposited on the upright erector.
5 - Stage is secured to the erector, lowered and moved into the hanger.
Or perhaps the erector is skipped all together, the transport carries the stage into the hanger where cranes are used to place it properly.

Or, They could simply lift the safed stage on the landing pad using cranes, retract the legs and lay it down on a horizontal transport truck, then drive it back to the hanger as is normally done.

[Jim]

1.  If the legs can take the landing+margin, they can take a rollout on a taxiway between the pad and the hangar. 
No data?  SpaceX is the one designing them - if they choose to go that route, they'll design them accordingly.


2. and there's no "just" break it over.  It's easy to tilt a stage once it's on a strongback.  But to pick it up without damaging it, from a concrete pad, outdoors (night, rain, wind) is not so trivial.  Conditions are not controlled as well as in a service hangar, and if you do it rapidly, 4 times per flight, it's a concern.  Towing it "as-is" is a lot safer.

1. wrong.  Landing loads are no where the same as tow loads.  Totally different directions.  towing "as-is" is not any more safer.  It adds more risks.

2,  Yes, it would be very easy. .  The stage will be lighter.   A  strongback would be used for retrieval and break over.   It would be similar to the weapons systems TEL's, which handle heavier vehicles loaded with solid propellant.

And because horizontal is quicker, easier, safer, faster and cheaper, here is the key, hence Spacex will design the vehicle accordingly.

Any vehicle design compromise needed for vertical processing can be offset in by ease of doing horizontal which will save time.

[cuddihy]

Since we're talking about pad processing and rapid re-use: I was thinking about that purported 30 day minimum pad processing time between launches. What are the major drivers of that timeframe? OK it's kind of 'inside baseball' stuff, but if you leave out the SC specific stuff like propellant loading, what makes 30 days necessary?
I'm sure a lot can be done in parallel but a lot is sequential.
The list of stuff I can figure out would be:
1. Engine checkouts for flight. (At least one day per engine, so 10 minimum)
2. Pad consumbles replacement (hoses, o-rings, etc), interface checkouts, etc. (7 days?)
3. FTS install and checkout.(1-2 days)
4. Avionics checkouts/battery installs
5. Stage mating& end to end checks (3 days?)

Anyway I'm obviously SWAGging here but do I have the general scheme right?

[meekGee]

2,  Yes, it would be very easy. .  The stage will be lighter.   A  strongback would be used for retrieval and break over.   It would be similar to the weapons systems TEL's, which handle heavier vehicles loaded with solid propellant.

The TEL's I've seen don't pick up a free-standing rocket. They just raise/lower between launch and transport positions.


Anyway - building a pick-up and lay-down "custom forklift" is definitely possible. 

But the logic I'm following is:

First determine which orientation is preferred for first stage processing, since that's the majority of the work, and we're looking for RAPID reusabiilty.  From the reasons stated upthread, I think vertical is it.

Then look at the transport from the pad.  It will be IMO about 1 km, and the vehicle is already vertical. So I think it will travel that way.  Not having to handle tilt/untilit is an extra bonus here.

Lastly, look at 1st/2nd stage stacking.  Since I think inter-stage connections will be minimal-to-none, I don't see the difficulty in lift the 2nd stage on top, and then off to payload integration.

[Jim]

1.  It will be IMO about 1 km,.

2.    Since I think inter-stage connections will be minimal-to-none,

1.  It won't be, it will be miles

2.  Proven otherwise

[Wetmelon]

What's the dry mass do the 1st stage?  Can it be helicoptered from where it lands to where it needs to go.  And then just set back down on its legs?

Apparently about 28 tons.  Too much for any Western helicopter.  Plus rockets aren't designed to be under tension, they're designed for compression forces.

The only way I see SpaceX doing vertical integration outside of USAF requirements is if they are able to hoist the U/S and S/C on stable platforms in a launch tower.  They would wait for the first stage to arrive at the launch pad, then simply push them out over the clamped-down first stage and lower them a few feet and clamp 'em in.  Think a sort of cantilevered crane that can extend out over the rocket.  Fuel on the pad.

[Lars_J]

Plus rockets aren't designed to be under tension, they're designed for compression forces.

There are many counter examples to this one, but here is just one.

[meekGee]

1.  It will be IMO about 1 km,.

2.    Since I think inter-stage connections will be minimal-to-none,

1.  It won't be, it will be miles

2.  Proven otherwise

1.  How do you know?  Can you justify why "miles"?    The entirety of the Boca Chica site is not "miles".

2.  Proven how?  In the EELVs?

Are we back to "it can't be done since it wasn't done?"

[Wetmelon]

Plus rockets aren't designed to be under tension, they're designed for compression forces.

There are many counter examples to this one, but here is just one.

I didn't rule out the possibility!    A quick google would have been prudent though.  Thanks for the pic.

[llanitedave]

Another point to consider is that if SpaceX were planning for vertical integration, they'd be planning a VAB to support it.  I see no sign of that.  Even their proposed facilities at Brownsville show only a horizontal hanger.

[meekGee]

Another point to consider is that if SpaceX were planning for vertical integration, they'd be planning a VAB to support it.  I see no sign of that.  Even their proposed facilities at Brownsville show only a horizontal hanger.

That's definitely true.

But those plans go along with a plan to launch maybe once a month.   There aren't any landing pads, and the permits they are seeking (IIRC) does not mention landings.   

If anything, there's a mismatch between SpaceX's grand aspirations and the site plans as submitted.

So I think those are just "get your foot in the door" plans.

[Jim]

1.  How do you know?  Can you justify why "miles"?    The entirety of the Boca Chica site is not "miles".

2.  Proven how?  In the EELVs?

1.  That is not the only site

2.  In many posts on this topic.  Range safety rules and missions success. 
The upperstage is going to drive the lower stage to ensure making it to orbit.  The upperstage is integrating the whole trajectory and the booster does have that need nor can it effect changes.  The upperstage can override the booster on saving propellant for boost back. 

The carrier aircraft is not a relevant analogy.

Also, using  future designs is no more relevant than using past designs. 

Additionally, the reusable VTVL has yet to be proven. 

[Todd Martin]

Just to be clear, would SpaceX need vertical integration infrastructure at both Vandenburg & Cape Canaveral, or just Vandenburg to launch DOD satellites? 

[Jim]

Just to be clear, would SpaceX need vertical integration infrastructure at both Vandenburg & Cape Canaveral, or just Vandenburg to launch DOD satellites? 

there are east coast DOD missions

[411rocket]

Another point to consider is that if SpaceX were planning for vertical integration, they'd be planning a VAB to support it.  I see no sign of that.  Even their proposed facilities at Brownsville show only a horizontal hanger.

Maybe you forgot, that they are trying to lease one of the shuttle pads. Where the rocket & payload, probably will be vertically installed. That is, unless the transporter platform, is not there. Then the rocket can be rolled to the pad & payload installed vertically, as needed. This pad could also, be used for crewed Dragon.

[meekGee]

1.  How do you know?  Can you justify why "miles"?    The entirety of the Boca Chica site is not "miles".

2.  Proven how?  In the EELVs?

1.  That is not the only site

2.  In many posts on this topic.  Range safety rules and missions success. 
The upperstage is going to drive the lower stage to ensure making it to orbit.  The upperstage is integrating the whole trajectory and the booster does have that need nor can it effect changes.  The upperstage can override the booster on saving propellant for boost back. 

The carrier aircraft is not a relevant analogy.

Also, using  future designs is no more relevant than using past designs. 

Additionally, the reusable VTVL has yet to be proven.

1. So - how many plans of SpaceX rapid reuse spaceports have you seen?  About the same as I have.
2. That's about as far away from proof as can be.  It's a sort-of conjecture based on how EELVs are wired.

EELVs are not reusable.  They don't have a fully capable avionics suit in the first stage, so are irrelevant.


For a reusable:

Why would you pass all the high-bandwidth sense and control of 9 engines across the stage boundary, (complicating integration, adding failure modes) when there's a perfectly capable avionics package right there on the state, that is (wait for it) ALREADY CONNECTED to all 9 engines and can drive them on the way back home?

The first stage avionics are exactly, by definition, as capable of taking care of first stage trajectory.  Upper stage avionics will be alive and aware of what's going on, but it only needs a low-bandwidth channel to the first stage. (For example for range safety, or if you want to tell the first stage it can quit early, as you suggest)

After stage separation, the upper stage can take care of itself just like rockets that are dropped off of a carrier plane.  Perfectly good analogy in this sense.

[Lobo]

Another point to consider is that if SpaceX were planning for vertical integration, they'd be planning a VAB to support it.  I see no sign of that.  Even their proposed facilities at Brownsville show only a horizontal hanger.

Be interesting to see what plan they might have in store for Pad 39A if they go that way. 
It might be hard to do a traditional horizontal integration there, given the existing hardware.  It would be hard to have a HIV on the ramp side.  They could have one on the other side and roll out to the flame trench, and go vertical in the trench...but then the rocket's exhaust would come back out that direction.  So the HIV could be exposed to the flame plume.  Maybe if they made it at a large angle so that thererector/transporter turns a corner to go into the flame trench.

But...alternatively, there is an existing FSS and RSS.  I could see something like a hybrid between Shuttle on pad processind and Delta IV processing at LC-37.   The F9 cores are loaded into the flame trench from the side opposite the ramp.  They could modify the RSS so that it's similar to the MSS one at LC-37, just that it would rotate around to sit around the F9/FH stack.  And there the payload is vertically integrated.
When the RSS/MSS is over the pad, then the F9 cores are loaded in like the D4 cores are at LC-37.  That could be desirable for USAF and NASA commercial crew contracts.
The existing FSS could then be modified with access arms and umbilicals for F9/FH, along with a crew access around about where the beanie cap arm is.

Or they may bulldoze everything there and start over from scratch.  :-)

But I think they are limited on what they can do using the existing flame trench/ramp concrete setup.  THey can't really make a flat pad as they have at LC-40 and SLC-5 because of the layout of 39A.
So I'm interested to see what they might do with that if they get it and go that route.

[Lobo]

Plus rockets aren't designed to be under tension, they're designed for compression forces.

There are many counter examples to this one, but here is just one.

Yea, I think rockets cores aren't design to be in tension...but that's probably more for liftoff (booster with top lift less core thrust than core mass...for example), or for handling fueled. 
I'd think they'd want the option to be able to lift them from the top with a crate or something, for putting them on test stands or whatever, as the picture shows.

But, if there's no US helicopter than can lift it, then that's a moot idea.  More likely...seeing this picture, there'd probably more likely just be a crane at the landing area that will lift it, allow the legs to be retracted or removed, and then laid down onto some sort of horizontal transporter for transportation back to the launch complex.  Obviously at the test stand facility they already pick it up from horizontal to vertical for testing, and vice versa to ship it after testing using cranes.  The simplest answer is usually the right one.  :-)

[Jim]

1. That's about as far away from proof as can be.  It's a sort-of conjecture based on how EELVs are wired.

  EELVs are not reusable.  They don't have a fully capable avionics suit in the first stage, so are irrelevant.


For a reusable:

2.  Why would you pass all the high-bandwidth sense and control of 9 engines across the stage boundary, (complicating integration, adding failure modes) when there's a perfectly capable avionics package right there on the state, that is (wait for it) ALREADY CONNECTED to all 9 engines and can drive them on the way back home?

1.  wrong.  Titan Centaur had two guidance systems.  So did other ELV'

2.  I never said that, I said trajectory control.   Anyways, even in the booster that engine control and info doesn't go the guidance system, that is the job of an engine controller.  It just passes on engine health, thrust and  steering commands to and from the guidance system.

Info that is passed between stages.  engine status, stage status, avionics status, power status, range safety interconnects, stage breakwires, stage breakup indicators.

[Jcc]

I don't see a need to integrate the first and second stages vertically, if only the payload can't be rotated in gravity. Build a tower and swing arm gantry next to the pad, bring up the rocket on the TE and raise it, then integrate the encapsulated payload onto it. The tower is also needed for manned missions.

If you are thinking in terms of gas and go reusability, that will not happen with the current designs.

[meekGee]

1. That's about as far away from proof as can be.  It's a sort-of conjecture based on how EELVs are wired.

  EELVs are not reusable.  They don't have a fully capable avionics suit in the first stage, so are irrelevant.


For a reusable:

2.  Why would you pass all the high-bandwidth sense and control of 9 engines across the stage boundary, (complicating integration, adding failure modes) when there's a perfectly capable avionics package right there on the state, that is (wait for it) ALREADY CONNECTED to all 9 engines and can drive them on the way back home?

1.  wrong.  Titan Centaur had two guidance systems.  So did other ELV'

2.  I never said that, I said trajectory control.   Anyways, even in the booster that engine control and info doesn't go the guidance system, that is the job of an engine controller.  It just passes on engine health, thrust and  steering commands to and from the guidance system.

Info that is passed between stages.  engine status, stage status, avionics status, power status, range safety interconnects, stage breakwires, stage breakup indicators.

Doesn't matter.  You were saying that it's impossible to simplify stage integration because all of the high-bandwidth signals between them.

I'm telling if you have a reusable fly-back booster, you can treat it like a carrier vehicle, and only need very low bandwidth (status) communication between the two stages.

So you tell me about Titan?    In an expendable, the motivation to simplify all of this was secondary, since yeah, it's driven from the top.  It's a single rocket shedding parts.

Not so with a reusable rocket - there's a lot that can modified if you change your point of view, but you keep going back to how it works on Titans and such.

[llanitedave]

Another point to consider is that if SpaceX were planning for vertical integration, they'd be planning a VAB to support it.  I see no sign of that.  Even their proposed facilities at Brownsville show only a horizontal hanger.

Maybe you forgot, that they are trying to lease one of the shuttle pads. Where the rocket & payload, probably will be vertically installed. That is, unless the transporter platform, is not there. Then the rocket can be rolled to the pad & payload installed vertically, as needed. This pad could also, be used for crewed Dragon.

Why would they have different processing modes for different locations?  If they're horizontal at one, what good does it do them to go vertical at another?  They're trying to set up a single, predictable, repeatable system.

[Jcc]

What does it take to send "high bandwidth" data signals. A single fiber optic cable will give all the bandwidth you need, so make it 3 of them for redundancy.

[411rocket]

Why would they have different processing modes for different locations?  If they're horizontal at one, what good does it do them to go vertical at another?  They're trying to set up a single, predictable, repeatable system.

Apparently, some Govt payloads need to be installed vertically & it would also make sense, for crewed Dragon ops. In my view, the former Appolo / Shuttle pad, would be most likely, be their only vertical ops pad. But for now it is wait & see, if they get the 5 year lease, to that pad.

[Lobo]

Another point to consider is that if SpaceX were planning for vertical integration, they'd be planning a VAB to support it.  I see no sign of that.  Even their proposed facilities at Brownsville show only a horizontal hanger.

Maybe you forgot, that they are trying to lease one of the shuttle pads. Where the rocket & payload, probably will be vertically installed. That is, unless the transporter platform, is not there. Then the rocket can be rolled to the pad & payload installed vertically, as needed. This pad could also, be used for crewed Dragon.

Why would they have different processing modes for different locations?  If they're horizontal at one, what good does it do them to go vertical at another?  They're trying to set up a single, predictable, repeatable system.

If they were using pad 39A, they might -not- be able to do it the same as the old Titan pads because the old Titan pads are flat with a flame trench below the deck.  Where 39A has a raised pad with the flame trench on the deck.  So I'm not quite sure they could do it at 39A exactly like they have ad LC-40 and SLC-4.
And the only way I think they could try would be to build a HIV down on the deck, and then have an erector/transporter take the stack around a corner and into the bottom of the flame trench and erect it there.  Since the plume would come back out that side, the HIV couldn't be inline with it.  So there's a few issues there.
And as 411Rocket said, there appears to be DoD payloads that need to be integraded vertically.  That could be done with a crane or some sort of mobile gantry, but there's already hardware at 39A which could be used in the RSS and FSS.  I don't necessarily know if a crew Dragon would be beneficial to integrate vertically or not.  Cargo dragon doesn't need to be.  But, since it would be a -manned- spacecraft, I could see there being a need to access it on the pad for various checkouts and such prior to putting the crew on it.  This is where I could see the RSS being modified to make a LC-37 like MSS out of it.  D4 cores are loaded horizontally into the LC-37 MSS, and then rotated up vertically.  Once the single or 3 cores are vertical and the upper stage stacked on, the payload processing room closes around the top of the upper stage and the payload is integrated vertically.  When done, the doors open up and the MSS rolls back.
But on 39A, there already is a build RSS that does basically the same thing. It'd need to be rebuilt for a rocket instead of an orbiter, but the basical structure that rotates back and forth could be used I would think.
The FSS could be used for crew access.

Now, they could level the FSS, and RSS, and stick more with their conventional HIV, but I don't know if there's room for a HIV on the ramp side of the pad...and there's a flame trench on that side too.  So how do you get the horizontal stack over to the pad form that side?  You can put a flame divider off to that size so no flame actually comes out it and blows up the HIV, but there's still the big hole there you have to get over.  Saturn and Shuttle did it with a really big and side CT and MLP.    How would SpaceX do it?
And if they do do it, how do they integrate vertical payloads for DoD contracts?  They'd still need cranes and/or gantries. 

So it's a little different than the Titan pads they've used thus far.  So maybe they want to try to utilize the existing hardware as much as possible and integrate vertically with a payload integration room on a rebuilt RSS.  If they set the rocket down in the flame trench (as Jim suggested one time), they could then load the cores in through the trench side opposite the ramp.  Then the existing tower will be about the right height to access the upper stage and paylaod. 

[sugmullun]

It would seem to this layman:
  Vastly cheaper launches would be a watershed event, in a lot, if not most of the disciplines of the space industry. What is considered financially or technically necessary at the present time may well not be if the cost or difficulty of mitigating some issue could well be moved to another part of the "integration" of the package...even hardware-to-software or vice verse.
  While in the short term present engineering rules are rock solid. They are based very much on present technology and practicality.
  I think if one had to bet his/her life savings on which system, vertical or horizontal integration, past that watershed point, the best bet would be based purely on the financial considerations of the physical plant.  It almost seems impossible to predict whether it will be cheaper to have two independent entities cooperating in flight, or a master-slave relationship, or even if that consideration will have much effect on the cost. I only presume to have an opinion about this because in all of history, discovery or rapid technical advancement only fails to trump engineering discipline when the laws of nature are encountered.
  So...in my inexpert opinion, for at least the next couple of decades; 12 foot cores will be horizontal and larger ones will be vertical.
  Added: Trump is a poor choice of words, since engineering enables...., but it makes the point.
 

[AJW]

There are a number of crawler-cranes that with a 200' boom and counterweights could travel to a landing site, raise the core while the legs are stowed, and then lower the core onto a transport.  The cranes can't extend too far with significant weight, but many can carry twice the weight of an empty first stage which is a reasonable margin. 

What I don't know is whether a stage could be moved by the crawler while vertical, or if this can only be done with outriggers extended.  This might allow the crane to return the core to the strongback for lowering or reintegration & launching.

Another photo from McGregor and this one appears to show a mobile crane raising the core.

KISS

[Lobo]

There are a number of crawler-cranes that with a 200' boom and counterweights could travel to a landing site, raise the core while the legs are stowed, and then lower the core onto a transport.  The cranes can't extend too far with significant weight, but many can carry twice the weight of an empty first stage which is a reasonable margin. 

What I don't know is whether a stage could be moved by the crawler while vertical, or if this can only be done with outriggers extended.  This might allow the crane to return the core to the strongback for lowering or reintegration & launching.

Another photo from McGregor and this one appears to show a mobile crane raising the core.

KISS

Agreed.

As I worked through it in this thread, trying to helicopter it...even if there was a skycrane chopper that could do it...seems unnecessarily complicated compared to just having a crane pick it up slightly off the ground.  Retract the landing gear to the up postition, and then have some sort of carrier semi trailer to set it in horizontally for a nice slow drive back to LC-40 where it would slide horizontally back into the HIV (or perhaps a new building specifically for cores being reused prior to going into the HIV) and be ready to go again.
Assuming the F9 cores land at another pad not in use at the Cape like LC-36 or LC-46, it's not like they have to drive through any populated areas to get back to LC-40.

[RocketmanUS]

If on a MLP with a service tower could there be an elevator on the side of the service tower with an arm to lift up a fairing with the payload in it up to the top of the 2nd stage to be integrated to it?

[AJW]

There are a number of crawler-cranes that with a 200' boom and counterweights could travel to a landing site, raise the core while the legs are stowed, and then lower the core onto a transport.  The cranes can't extend too far with significant weight, but many can carry twice the weight of an empty first stage which is a reasonable margin. 

What I don't know is whether a stage could be moved by the crawler while vertical, or if this can only be done with outriggers extended.  This might allow the crane to return the core to the strongback for lowering or reintegration & launching.

https://twitter.com/elonmusk/status/413772104786780160/photo/1

Thanks, Elon.  Would you mind answering my question about what altitude the legs will be deployed at and if they are extended in one step or two?

[RanulfC]

2,  Yes, it would be very easy. .  The stage will be lighter.   A  strongback would be used for retrieval and break over.   It would be similar to the weapons systems TEL's, which handle heavier vehicles loaded with solid propellant.

The TEL's I've seen don't pick up a free-standing rocket. They just raise/lower between launch and transport positions.

TEL: Transporter/Erector/Launcher vehicle correct? They operate almost totally in the horizontal positon for several reasons most having to do with ease of access and storage of the weapon. However there are also TE trailers (Transport/Erectors) which are used to place and remove ICBMs from silos. An internal crane pulls the missile into the trailer where it is secured and then lowered to a horizontal position for transportation.

You're towing idea isn't very likely for several (mostly safety related) reasons but I'll give you the biggie right up front: Any "wind" at all (and there is a reason I put that in quotes) is going to cause increased stess' on the "down-wind" legs and through them to the dollies. Take your "example" tow concept, the "front" dolly/leg is going to be subjected to a "lifting" moment by the stage drag while under tow, meanwhile the "aft" (in your scenerio "free-wheeling) is going to be under increased "down-force" loads at the same time. This "assumes" a realtively "mild" tow speed of 15mph, your more likely tow speed of a high object like this is going to be 5mph or less. There is a very good REASON why anyone tries to avoid moving a vertical tall object if they can at all avoid it

And just and FYI you'd want to use a "Y" bar in any case and spread the "tow" load over two landing legs/dollies to increase control authority and distribute the stress in any case but again "towing" a "high" light objet with a low CG is asking for the majority of the "control" authority to be on the rear support wheels and not on the front/tow vehicle where it should be. Towing a booster around in a vertical position is just asking for an accident.

But the logic I'm following is:

First determine which orientation is preferred for first stage processing, since that's the majority of the work, and we're looking for RAPID reusabiilty.  From the reasons stated upthread, I think vertical is it.

I've read the whole thread and I think I "see" your reasoning but it is based on some false assumptions and what seems to me to be a lack of actual maintenance experiance for "rapid-reuse" items.

Vertical is used when you really have no other choice, it is much safer and easier to work on a "tall" object in a horizontal position because all of your work positions are then spead out instead of stacked on top of each other. Similarly "draining" becomes easier as all fluids are gravity fed to "one-side" where simple raising of the TE trailer gravity drains the fluids out the drain lines. Engine access is easy as a rolling "stand" system can give "level" access to each engine without having to "roll" the vehicle. (Your comment on the "RCS-crew" having to wait on the engine crew is an example of why I don't think your looking at this from a "maintenance" viewpoint. In a vertical position if an engine needs to be pulled or replaced or the engine bay opened up THEN the RCS crew along with every one else has to back off and wait on that operation to be finished because the rocket will have to be jacked up far enough to drop the engine and/or work ABOVE the inspection team will have to cease until they clear the area)

That last part is another reason NOT to work vertically "stacked": dropped tools and parts. If the RCS-crew drops a wrench in the vertical processing position everyone BELOW them is in danger as is the rocket itself from the wrench. (Falling further means more momentum and more impact energy at any point along the drop. We lost a Titan-II this way) Meanwhile in the horizontal position the furthest the tool/part can fall is a little over the stage diameter and the wrench dropped hits the floor sooner and not the engine inspection crew 70 some feet below.

Then look at the transport from the pad.  It will be IMO about 1 km, and the vehicle is already vertical. So I think it will travel that way.  Not having to handle tilt/untilit is an extra bonus here.

Travelling vertically calls for much lower speeds EVEN if the rocket is supported and stabilized on and in all axis'. A rocket on a TE trailer on the other hand is already supported in along all axis' and can be moved at much higher speeds from one point to another. The "extra" time for erection to vertical is trivial.

Distance from pads to processing: The main reason for distance is safety. An explosion on the pad can throw debris a long way, exploding in the air is worse and the debris travels farther. In the case of an RTLS reusable vehicle it will be "better" if the returning vehicle does not fly over any vehicle pads with ready or being prepared for launch vehicles. So there will be a seperation of landing and take off pads. (You'd want a pretty much "clear" flat pad to land on anyway) So your processing facility will be located between the two sets of pads. Since "berms" (earthwalls) only protect against debris/pressure from ground explosions the processing facility will also be located out from under any of the normal launch/return flight paths which will probably add some distance as well.

Lastly, look at 1st/2nd stage stacking.  Since I think inter-stage connections will be minimal-to-none, I don't see the difficulty in lift the 2nd stage on top, and then off to payload integration.

When "stacking" stages horizontally you only have to deal with left/right+forward/aft (4 direction but only two axis' of movement) as long as your assembly trailers are capable of fine up/down adjustment. All of these factors are easily done with minimum effort in a controlled environment such as an HIV. In a vertical (lifted) operation you have to worry about N/S/E/W+Up/Down (6 directions and at least 4 axis of direction) all at once during close operations. In addition you have to have a very high building unless you want to have to deal with complications due to wind activity, and high-bays are usually more expensive to build and maintain than low ones.

Even if the interstage connections were nothing but simple mechanical "locks" it is easier and faster to connect them horizontally rather than vertically.

As for picking up the landed stage at the pad, you'd back the TE into close position, raise the strongback and attach stabilizing cables to the booster. Raise the booster with a crane or jacks, fold the legs and then ease the booster into the TE cradle arms. Clamp and then lower to horizontal and off to the "barn" for processing.

I really can't stress the safety and operations factors that favor horizontal over vertical operations for high throughput enough. The main fact that several "crews" can be working at the same time on different parts of the vehicle without interference and in a safer manner than being "stacked" on top of each other is really a "killer" against vertical intergration. As long as rockets are going to be "tall-and-thin" horizontal is much safer and easier in every aspect and the "downside" of having to lower and then erect the vehicle is so small an effort it is simply a non-factor.

Now if we ever go to "shorter/squater" reusable first stages (always a possibility) then vertical servicing begins to make more "sense" in a lot of ways, but that does not seem to be the way SpaceX is going.

Randy

[Jim]

The TEL's I've seen don't pick up a free-standing rocket. They just raise/lower between launch and transport positions.

Free standing or sitting on the pad, no difference.
No different than picking up a rocket from the launch pad and returning it to a hangar for repair after a scrub

[meekGee]

The TEL's I've seen don't pick up a free-standing rocket. They just raise/lower between launch and transport positions.

Free standing or sitting on the pad, no difference.
No different than picking up a rocket from the launch pad and returning it to a hangar for repair after a scrub

That's a very inefficient way to design things.

The launch pad is holding the rocket using precision fiduciary points, and the TEL should register (dock) with them so that there's good alignment between the TEL and the rocket.   If that's not how it's done, that's too bad, but it still should be done that way.   (BTW do you know that there's no registration between the TEL and the pad at SpaceX?)

[Jim]

  (BTW do you know that there's no registration between the TEL and the pad at SpaceX?)

Spacex isn't the only TEL user, there is Antares and Delta IV.  The stage will be empty and light with no upperstage.   Backing up a TEL to the vehicle would be easy.  It would just have to engage one of the hold on points and have a similar gripper at the top like the current launcher.  After it engages the holdon and the gripper is in place, then it just has to take the load while the legs are retracted.  Once that is done, it can break over the vehicle for transport.  One hold down point should be adequate since the loads would be many times less without propellant and upperstage.

[Jim]

The launch pad is holding the rocket using precision fiduciary points,

No, it is not.  It is using the 4 holddown points, simple brackets with holes in it.

[meekGee]

That's what I mean.

There should be another set of mount points, whose relation to the "rocket brackets" is known, and to which the TEL docks.  Once you have that, there are no alignment issues between the TEL and the rocket, so you can haul it between the pad and the hanger quickly.

[llanitedave]

...snip great explanations...
I really can't stress the safety and operations factors that favor horizontal over vertical operations for high throughput enough. The main fact that several "crews" can be working at the same time on different parts of the vehicle without interference and in a safer manner than being "stacked" on top of each other is really a "killer" against vertical intergration. As long as rockets are going to be "tall-and-thin" horizontal is much safer and easier in every aspect and the "downside" of having to lower and then erect the vehicle is so small an effort it is simply a non-factor.

Now if we ever go to "shorter/squater" reusable first stages (always a possibility) then vertical servicing begins to make more "sense" in a lot of ways, but that does not seem to be the way SpaceX is going.

Randy

Best post in this thread so far.  Thanks!

[Jim]

Those were a given and obvious to most in the business

[Robotbeat]

If you could somehow eliminate (via automation) basically all the little tasks that workers need to do while integrating stages, it might make sense to do vertical stacking if you have a gas-and-go first stage (with pre-integrated upper stage and payload... perhaps themselves integrated horizontally).

A big question is when the launch rate will be high enough to support such a decision at all. Certainly not in the next five years and probably not in this decade, either.

[meekGee]

It was already established, actually by people "from the business", that the long pole was processing the first stage itself - 9 engines, several sets of RCS, etc.

So first and foremost, I'm addressing the processing of landed first stages, and so none of the above contradicts anything.

Integrating the stages, (again under the premise of rapid reuse) will be a lot simpler than what you're used to today.  You basically keep imagining "how it's done today, only faster" and that's not the right way to think about it.

Shrug.  We'll find out eventually.

[douglas100]

... You basically keep imagining "how it's done today, only faster" and that's not the right way to think about it.

No, those who have argued against vertical integration have argued in terms of ease and safety of work. That it is safer to work at ground level than on high level platforms is a fundamental fact and has nothing to do with "how it's done today." That is is easier to handle long thin things in a horizontal position rather than in a vertical position is obvious. You might as well assert that people who predict that in the future car wheels will be circular are only "thinking how it's done today."

I don't think you have made the case for vertical integration over other means of handling. I don't believe it makes much difference to how quickly the vehicle can be turned around. The important point about rapid re-usability is not how the vehicle is handled but how much work has to be done on it to get it ready for the next flight.

[Robotbeat]

What if there's simply no work to do, just need to stack the stages, they "click" together? I.e. like docking or berthing?

Work on the first stage engines can be done at ground level before integrating the upper stage and payload. Obviously, this is what SpaceX did with Grasshopper between flights (as far as we can tell, since being put on the legs, the tank has never again been horizontal in 8 little flights, the later ones having about half to a third the burn time of a Falcon 9 first stage), so it's at least somewhat feasible and can't be THAT expensive.

[meekGee]

... You basically keep imagining "how it's done today, only faster" and that's not the right way to think about it.

...

That it is safer to work at ground level than on high level platforms is a fundamental fact and has nothing to do with "how it's done today."

That is is easier to handle long thin things in a horizontal position rather than in a vertical position is obvious.

 

No it isn't....  If the work platform reaches and conforms to the wall of the rocket, then it's safer than handling stuff overhead at ground level.  You walk up to an access cover at eye level, and that's that.

I can't see why handling a 9 engine cluster is easier when it's on its side, and you have to keep rotating the rocket for each specific engine.

The engines are man-sized.  If they're standing in front of you, and you have full-around access, it's a lot simpler than walking under the bottom-most engine and using step ladders to reach in between them.

The only good thing about the step ladders was that it allowed flexibility when the rocket and procedures kept changing from flight to flight.

[douglas100]

What if there's simply no work to do, just need to stack the stages, they "click" together? I.e. like docking or berthing?

Work on the first stage engines can be done at ground level before integrating the upper stage and payload. Obviously, this is what SpaceX did with Grasshopper between flights (as far as we can tell, since being put on the legs, the tank has never again been horizontal in 8 little flights, the later ones having about half to a third the burn time of a Falcon 9 first stage), so it's at least somewhat feasible and can't be THAT expensive.

Even rapid turnaround airliners need some work done on them.  But I agree with your general point that the key to rapid reuse is the amount of work needing done. That is more about the technology of the vehicle itself rather than what position it's processed in.

Grasshopper needs no work done on the top end between flights so there's no need to rotate it to the horizontal. The minute you put a second stage and payload on top we are back to the same choice being discussed. If we were talking about a squat SSTO vehicle like Delta Clipper or Roton then, yes, keeping the vehicle vertical makes sense. But for long thin multistage things, I still think horizontal is better.

@ meekGee: you made these arguments upthread. People who work in the industry disagree. This amateur votes with them. Both methods of processing are currently used. Either would work. You haven't convinced me vertical is better in principle.

You always reply, but I've said all I need to on this subject (unless you come up with a compelling new argument.)

[Jim]

No it isn't....  If the work platform reaches and conforms to the wall of the rocket, then it's safer than handling stuff overhead at ground level.  You walk up to an access cover at eye level, and that's that.

Wrong.  It is 10's of feet in the air and the platforms never really conform.  there is always a drop hazard.   And there is still a need for elevators and stairs.  To move ten feet in either direction on the vehicle, one must leave the area and to an elevator or stairs.

As for the engines, there is interference from the launcher and holddowns that reduces accessibility.

[Jim]

head at ground level.  You walk up to an access cover at eye level, and that's that.

I can't see why handling a 9 engine cluster is easier when it's on its side, and you have to keep rotating the rocket for each specific engine.

The engines are man-sized.  If they're standing in front of you, and you have full-around access, it's a lot simpler than walking under the bottom-most engine and using step ladders to reach in between them.

Several unqualified assumptions.

1.  9 engine cluster.  There is nothing that indicates this future vehicle will use this specific number.  9 was chosen for the F9 for performance and adaptability of an existing engine.  It has nothing to do with reuse.

2.  that there is no free access to the engines.  The vehicle will be sitting on the launcher platform.  There will be interference from holddown points, umbilicals, etc.   The engines will either be at ground level surrounded by support structure or elevated and will need access platforms. 

[guckyfan]

2.  that there is no free access to the engines.  The vehicle will be sitting on the launcher platform.  There will be interference from holddown points, umbilicals, etc.   The engines will either be at ground level surrounded by support structure or elevated and will need access platforms.

I am with you that much of the processing is better done horizontal. But Elon Musk made that statement that the SES-8 launcher was left vertical on the pad for easier access to the engines.

[Jim]

I am with you that much of the processing is better done horizontal. But Elon Musk made that statement that the SES-8 launcher was left vertical on the pad for easier access to the engines.

That is true when it is on the launcher/erector.  They would have had to go horizontal, roll back and demated from the launcher for access to the engines.  We are talking prelaunch. 

[sugmullun]

Not exactly on topic, but related:
On it's Vandenberg erector, can SpaceX actually put 53 mtons under a fairing, above the grapples and hoist it up OK with the present setup?

[RanulfC]

... You basically keep imagining "how it's done today, only faster" and that's not the right way to think about it.

...

That it is safer to work at ground level than on high level platforms is a fundamental fact and has nothing to do with "how it's done today."

That is is easier to handle long thin things in a horizontal position rather than in a vertical position is obvious.

 

No it isn't....  If the work platform reaches and conforms to the wall of the rocket, then it's safer than handling stuff overhead at ground level.  You walk up to an access cover at eye level, and that's that.

Work platforms are NEVER "confromal" they always have a gap though they can usually be "bridged" by some type of "soft" bumper, the bumpers are NOT load-bearing and more often than not they get torn up really quickly in regular use. And I'll point it out again, "ground-level" means maxium fall distance is the diameter of the booster, where as "vertical" means a lot of activity is going to be STACKED above each other with all the safety issues that entails.

Your description of checking an access panel leaves out quite a bit of effort btw: Step one, check out and don your fall protection harness and lanyard (required) Step two, enter and use elevator or stairs to gain access to correct level. Step three, attach fall protection lanyard to over-head rail and test fittings. Step four, move out onto work level platform and work your way around to inspection panel. Step five, carefully remove fastners on panel if they are "loose" you must bag them up along with the panel and secure them to the work platform, if the panel and fasteners are "attached" to the vehicle by a lanyard or other restraining device you have to ensure all the fasteners are secured to the panel and the panel is not going to come loose during the time you are working with it. (Nominally you'll use a piece of "flash-breaker" tape and attach it to the hull) Step six, do the inspection or perform the maintenance action. Step seven ensure all tools and parts are accounted for prior to closing the panel. Step eight, supervisor has to reveiw and inspect the tools and panel to ensure no parts are missing or loose. (Which means he has to don and use a safety harness and fall protection as well) Step nine, reseal the panel. Step ten, inspect surrounding area for tools and lose parts. (In any case where a part or tool falls either outside or inside the rocket all work must be stopped until the part or tool is found and any damage to the rocket hull or assemblies assessed and dealt with. This CAN include haveing to de-panel the entire side of the rocket to ensure that the part did not fall into the engine bay somewhere and get lodged or more) Step eleven, move back to elevator/stairs and detach fall protection system from overhead rail. Step twelve, return down elevator/stairs to ground level. Step thirteen, return fall protection lanyard and harness to storage.

Same "process" in a horizontal position? Step one, climb stairs to platform (12 feet does not require fall protection systems normally) walk down the hull until you reach the panel, unfasten the panel, if any parts or fastners fall off during this operation they can fall no further than 12 feet and since there is no one working below you they are not a danger. Since the rocket will be moved away after processing the parts can be "secured" any time a general clean up of the processing facility floor is done, (Worst case scenerio is a part falls INSIDE the rocket in which case panels along the lower "section" of the rocket may have to be removed to find and remove the loose part/tool.) Perform inspection and or maintenance and replace the panel. Move on to next job or climb down off the platform.

I don't think you're quite getting the amount of "infrastructure" for each process. Horizontally you would "require" at most two "long" platforms each the length of the booster from engine-bay to interstage adapter with a single platform capable of being used to access the engines and engine-bay but would also be usable at the "front" of the interstage adapter as well if need be.

Meanwhile a "vertical" set up would require from two to four "tower" set ups taller than the booster is. (Probably a LOT taller as you'd use the same set up to help with mating the interstage, 2nd stage and payload but at the very least the towers have to be tall enough to have a "top" level for inspection and maintenance of the interstage adapter AND the relevent fall protection system attachments over-head of that platform)

Then the towers would have to have the folding platform levels which for the moment we'll "assume" a platform every 10 feet so that's about 10 "platforms" maximum with a high probably of around three minimum assuming that the majority of the hull inspection can be done with a set of cameras. In addition the towers will have to have associated lights, ladders, stairs, ducting and HVAC systems attached as well as power generation systems and hydralics capable of lifting the booster so that the legs can be folded and in all likely hood the "towers" when closed up around the booster will be used to move the booster as well in place of a TE assembly.

Possible? Yes, I've worked on various equipment both horizontally and vertically, (Radar maintenance on the E3B AWACS which means I've had to lug stuff up to and into that big "saucer" on top as well as work inside the aircraft hull) "Texas-Towers" exist for getting people and equipment into place to do the work but they are specialized equipment and more expensive than the more numerous and easier to access "low" work platforms.

Drop a tool from the top of the aircraft hull (about 20 or so feet) and you MIGHT put dent in a panel, drop the same tool from 40ft and if you're lucky it won't put a hole in a panel. The former will give anyone not wearing a hard-hat a bruise, the latter will give them a concusion if they are lucky.

I can't see why handling a 9 engine cluster is easier when it's on its side, and you have to keep rotating the rocket for each specific engine.

You're assuming that "horizontal" and "ground-level" are litterally the same thing here when they are not. They DO use platforms to handle and interact with the booster when it is horizontal they are not however as tall as those that are required for vertical interaction. Work platforms have only to be as high as the TE and the Booster diameter but usually will only reach half the booster diamter as ladders and additional work stands can be easily brought up to reach all parts of the booster. In the case of the engines rotation is not neccessary as a single work platform with hydralic adjustment can reach all the engines without the need to rotate the booster.

The only specific time you'd have to "rotate" the booster is to reach panels that are normally "covered" by the TE supports, not to inspect or maintenance the engines.

Randy

[meekGee]

Hi Randy.   I appreciate the time you took to write this - I've read it carefully.  You clearly are familiar with the operation of the VIF, and I trust your experience.

I think the key is in how you build the VIF.  All the problems you describe are a result of the VIF being too "general purpose", or just having "heritage" features that get in the way.

You say "work platforms are NEVER conforming".  I have to ask - why not?   I'm discussing a vertical facility as I imagine it should be built, not as it is built today.   (I assume that by "NEVER" you mean you've never seen a conforming one , not that there's a fundamental problem building one).

I can't see a reason why at any level you want access, there'd be a fully conformal floor, that reach up to a few cm from the wall.  If the gap is small, the soft adapter can be strong enough to hold even a full person's load, even if that person could fit their foot in the gap.  At that point, not even a bolt can fall through. This must be a requirement for building the VIF.

If built like that, the maximum fall distance is irrelevant - do you worry about falling through the floor to the basement?  Definitely no lanyards should be necessary when the stage is in place, since the structure is as good as a regular building.

The ten steps you enumerated - they are basically the details of following procedures.  They would be the same on a HIF.  Count all your tools.  Count every piece of removable hardware.  Sure - but all of these steps are easier to perform at eye-level and side access than they are when you're working "upwards" with things over your head.  Don't drop bolts inside the rocket - that's a matter of how the rocket is designed - it's easily preventable.

I'd rather work on a sturdy floor than on a step-ladder, even if only 12' high.  You can't move sideways with a ladder.  It's not a natural body position, and you might still fall, with hardware in your hands.   In my imaginary VIF, there are indeed elevators to access each level, but parts and tools are already at those levels. You don't have to go up and down for every task.

I COMPLETELY agree with the observation about the amount of infrastructure.  A purpose built VIF is easily an order-of-magnitude more complex than an HIF.   That's why it doesn't make sense if you only fly once a month.  But if you want to do single-day turn-around like Musk wants, then time is money, and a dedicated VIF will pay for itself - provided you have the volume.  Musk won't go there before he has flight volume, since that's a classic mistake for start-ups - jump ahead of themselves and invest too much, too quickly, in infrastructure that only makes sense for markets that have yet to materialize. 

---

I attached the famous Maven/Atlas picture.  I think it is gorgeous, but it shows both the good and bad sides of the VIF.

The good:  The large number of connections at the perimeter of the bottom of the payload illustrates the advantage of vertical.  You can access all of them, all the time.  I'd rather access all nine engine bells like this at one level, all actuators and turbopumps (and start cartridges and what not) at a second level, Leg hinges and bottom RCS at third, Leg latches at a fourth, Upper RCS at a fifth, avionics at a sixth...   Each level has 8 access directions, and with an HIF, you can only access one at a time.

The bad: You mentioned lanyards.  This means that not all work platforms are indeed conformal.  The gantry should be built independent of the wind bearing walls, so it never moves.  There's a crane, and I don't like cranes.  If the rocket is of standard height, the payload (or second stage) should arrive on a dolly, be lifted up by an elevator, then rolled with the dolly at just the right height so that it can be set onto the second stage (or first stage) by lowering the dolly a few inches at most.  No risk, and alignment can be done by basically centering the dolly, so the load is pre-aligned when it is lowered.

---

In short - you're listing the real-life deficiencies of working on high gantries.  I think they can be overcome - I don't think they are inherent to a VIF.  The key is that it has to be a dedicated "tight" facility - basically a processing building that's purpose built to get a stage through the steps as quickly (hours) as possible, since it needs to fly again the next day.

If work on it resembles what you describe (lanyards, drop hazards, etc) then you're 100% right.  I just think it is possible to do much better.

[zodiacchris]

That is a great picture, and a setup like this definitely comes in under 'nice to have'. But look at the massive vertical integration bay, and the sheer amount of hardware for the different levels, which also have to partially retract to allow for removal of the integrated vehicle!

This is not KISS, and if a number of rollable horizontal platforms and a cherry picker can do the trick in a low and long hangar, why would a cost conscious mob like SpaceX do anything else??

Cheers,
Chris

[RonM]

That is a great picture, and a setup like this definitely comes in under 'nice to have'. But look at the massive vertical integration bay, and the sheer amount of hardware for the different levels, which also have to partially retract to allow for removal of the integrated vehicle!

This is not KISS, and if a number of rollable horizontal platforms and a cherry picker can do the trick in a low and long hangar, why would a cost conscious mob like SpaceX do anything else??

Cheers,
Chris

With horizontal integration, you can set up shop in what is basically a sheet metal warehouse. Vertical integration requires a complex structure with all the fiddly bits we see in the picture. Horizontal integration will be far cheaper.

Now I don't know which is faster, but turn around time shouldn't be a problem with multiple reusable rockets. You wouldn't want to rush refurbishing a rocket. That would lead to disaster. You're better off with a fleet and taking your time on each rocket.

[meekGee]

The image below does NOT try to equate the process of changing tires with reusable rocket stage re-processing.

What I'm showing is that once the volume of operations is high, "cheaper infrastructure" is no longer a figure of merit, and what becomes important is "Cost as amortized per launch" and "time to process".

Once we agree that for rapid operations (but not before that!) investing in expensive infrastructure does make sense, we can get back to which form of infrastructure (HIF or VIF) we want to invest in - which is a technical rather than financial discussion.

[Jim]

That is a great picture, and a setup like this definitely comes in under 'nice to have'. But look at the massive vertical integration bay, and the sheer amount of hardware for the different levels, which also have to partially retract to allow for removal of the integrated vehicle!

This is not KISS, and if a number of rollable horizontal platforms and a cherry picker can do the trick in a low and long hangar, why would a cost conscious mob like SpaceX do anything else??

Exactly.  And to make things even easier (which equates to cheaper and quicker), you design the vehicle so that the hardware that needs to be accessed is at less than shoulder height.  The Atlas booster is designed that way: all the booster avionics, harness, tubing, etc are in a fairing on the side of the vehicle that can be accessed from standing next to the vehicle.  See the photo, the worker is next to the fairing.  The bulk of the stage avionics is in the wider aft portion of the fairing.

Atlas only uses a VIF for 3 reasons and none of them have to do with ease of access, turn around expediency or cost.  The 3 reasons are:  1. vertical payload integration; 2. Centaur upperstage mate (balloon tank makes horizontal mate difficult if not impossible) and SRB installation. 

[joek]

That is a great picture, and a setup like this definitely comes in under 'nice to have'. But look at the massive vertical integration bay, and the sheer amount of hardware for the different levels, which also have to partially retract to allow for removal of the integrated vehicle!

This is not KISS, and if a number of rollable horizontal platforms and a cherry picker can do the trick in a low and long hangar, why would a cost conscious mob like SpaceX do anything else??

And as a point of reference... 2010 estimate for another Atlas V VIF at CCAFS $350M.  Reported estimates for SpaceX: CCAFS LC-40 (before F9v1.1 work) about $50M; for VAFB site nearly $100M; and for Brownsville Tx site $65-85M.

[meekGee]

That is a great picture, and a setup like this definitely comes in under 'nice to have'. But look at the massive vertical integration bay, and the sheer amount of hardware for the different levels, which also have to partially retract to allow for removal of the integrated vehicle!

This is not KISS, and if a number of rollable horizontal platforms and a cherry picker can do the trick in a low and long hangar, why would a cost conscious mob like SpaceX do anything else??

And as a point of reference... 2010 estimate for another Atlas V VIF at CCAFS $350M.  Reported estimates for SpaceX: CCAFS LC-40 (before F9v1.1 work) about $50M; for VAFB site nearly $100M; and for Brownsville Tx site $65-85M.

I never once said an HIF is cheaper... The starting point was that a VIF is more expensive.

However, there isn't any person on this board that has seen, or can give examples of what a rapid reprocessing facility looks like. The facilities mentioned above are built for assembly.  Stages arrive from the factory in a pristine condition, and are then put together towards a single launch, with a cycle time of several weeks.  This includes Atlas, Delta, and Falcon for the next several years.

They are absolutely not built for the tasks of:
- Accepting a just-flown stages
- Inspecting engines and related subsystems
- Inspecting landing gear, RCS, batteries, etc
- Possibly doing component maintenance (e.g. engine cleaning)
- Possibly doing component replacements

All with the intent of not keeping the stage on the ground for longer than necessary, since it has to fly ASAP.

A stage on the ground is a stage that's not bringing in revenue. If you settle for a slow re-processing cycle and many stages on the ground, then you're just looking at non-flying non-revenue-generating stock.

Perhaps I'm misleading the conversation by calling them VIFs or HIFs.  They are not "integration" facilities.  They are "reprocessing" facilities.

STS had reprocessing facilities, but they (and the vehicle design) were not rapid and were not cheap per flight - so not much we can learn from there.   

This is why extrapolating from the Delta and Atlas facilities as baselines is not the right way to look at things.

[joek]

...

Perhaps I'm misleading the conversation by calling them VIFs or HIFs.  They are not "integration" facilities.  They are "reprocessing" facilities.

STS had reprocessing facilities, but they (and the vehicle design) were not rapid and were not cheap per flight - so not much we can learn from there.   

This is why extrapolating from the Delta and Atlas facilities as baselines is not the right way to look at things.

My point in offering that information was that it provides reasonably concrete costs for two very different approaches.  In any case ...

Assuming some or all of the LV components are reused, there are still three basic capabilities required: (re)processing; integration; and launch.  I think we can say with certainty that launch requires a vertical orientation.  Beyond that, whether capabilities should be combined and their optimal orientation are closely related but different questions--although obviously optimal end-to-end flow depends on the answer to all question, not just one.

Rather than continue to debate whether one answer is better than another, it would be more instructive and constructive to quantitatively articulate the assumptions and model on which those answers are based.

[AJW]

I would think that the most important factor is that the cores are currently designed to be assembled and maintained horizontally, so all of the tools, procedures, and experience are all based on working on these cores in the horizontal position.  Switching to vertical will require new facilities, tools, processes, documentation, and training.  All of these introduce risk and a significant investment in time to develop, and the intent of going vertical should be to reduce time and risk.

The physical act of attaching a crawler-crane to the core and returning it to the PF should take no more than a few hours, but during this effort there will also be hours to offload fuel, purge lines, and safe the core before moving it indoors for inspection and maintenance.  I suspect that once reusability is proven over subsequent flights we will see significant improvements in turn-around, but building a VIF and creating all new procedures to save a few hours will not be the way to do this.

BTW, I should point out with the auto-jack example that at races, manual floor jacks are used on the track because they are significantly faster than raising the entire vehicle. 

[RanulfC]

Hi Randy.   I appreciate the time you took to write this - I've read it carefully.  You clearly are familiar with the operation of the VIF, and I trust your experience.
[/quote}

You're lucky I couldn't figure out any good ways to intergrate some "War Stories" in there

That surely would have crashed the forums

I think the key is in how you build the VIF.  All the problems you describe are a result of the VIF being too "general purpose", or just having "heritage" features that get in the way.

Yes to the first part and both yes-and-no to the second. The only way you get a non "general-purpose" VIF is to size it to a SINGLE system. Otherwise you have to include the ability to deal with varying parameters for future and modified vehicles.

You say "work platforms are NEVER conforming".  I have to ask - why not?   I'm discussing a vertical facility as I imagine it should be built, not as it is built today.   (I assume that by "NEVER" you mean you've never seen a conforming one , not that there's a fundamental problem building one).

The easy answer is because rocket stages are easily damaged by impact and the only way to avoid that is to leave a good amount of space between where your "hard-structure" ends and your rocket hull begins.

I actually HAVE seen "conformal" structures both used vertically and horizontally and the vertical ones tend to have to be "creeped" together in very small increments over a long period of time. Even then they never actually "touch" the structure and either use the "bumpers" I mentioned or in some cases inflated pillows.

The "fundamental" issue in a VIF versus a HIF is that the VIF is less adjustable and able to deal with changes once built. Any changes usually take a major effort (and money) to make in order to handle different hardware.

I can't see a reason why at any level you want access, there'd be a fully conformal floor, that reach up to a few cm from the wall.  If the gap is small, the soft adapter can be strong enough to hold even a full person's load, even if that person could fit their foot in the gap.  At that point, not even a bolt can fall through. This must be a requirement for building the VIF.

It would pretty much HAVE to be the requirements but then you're getting into some major structural work as well. I don't know if you've seen them but the majority of VIF work platforms don't have solid floors. They have gridded floors often covered with matting or something specifically to try and catch tools and parts before they fall. It doesn't work as often as we could wish. If you're 'gap' at the platform edge is ony a few cm you've now locked yourself into ONLY servicing a specific size vehicle and any change in diameter would require the removal and replacement of all the platforms. In a HIF the work-platforms can be adjusted by simply unlocking some wheels and moving it in or out. (Having said that I will note that the HIF facilities used by the AF have had their platforms replaced twice going from the MM-1 to the MM-3 which I think shows poor planning more than anythinig else )

If built like that, the maximum fall distance is irrelevant - do you worry about falling through the floor to the basement?  Definitely no lanyards should be necessary when the stage is in place, since the structure is as good as a regular building.

If you're in a building with no fixed "rails" around a very long fall you still have to have fall protection, the same applies to the VIF as it has at least ONE side which is considered "open"

The problem is safety regulations have to take into account the possibility of a fall no matter how low the odds. And tools and parts can and do "ignore" safety measures. Working with a "conformal" platform with the afore mentioned "bumpers" butted up against the aircraft I still managed to drop a socket-wrench that went right through the "sealed" gap between the bumpers. It missed the airframe and landed in another techs tool box that was working 40 feet below me. The "fix" for that was we were then required to use the inflatable bumpers instead of the normal ones. Even so another tech dropped a screwdriver which bounced off the inflatable and flew off the BACK side of the platform and wound up lodged in the roof of the supervisors van.

The ten steps you enumerated - they are basically the details of following procedures.  They would be the same on a HIF.  Count all your tools.  Count every piece of removable hardware.  Sure - but all of these steps are easier to perform at eye-level and side access than they are when you're working "upwards" with things over your head.  Don't drop bolts inside the rocket - that's a matter of how the rocket is designed - it's easily preventable.

Sorry I thought I'd mentioned those steps in both scenerios, however the difference is that instead of working "above" other people and very far above the floor you are only working somewhere between 6 and 12 feet off the ground. You're not working "upward" nor "over-your-head" but at eye-level just with the booster on its side not vertical. I think this is the main stickinig point in the discussion as you seem to be assuming everythin is on the ground level when it doesn't (and usually isn't) have to be.
For example:

I'd rather work on a sturdy floor than on a step-ladder, even if only 12' high.  You can't move sideways with a ladder.  It's not a natural body position, and you might still fall, with hardware in your hands.   In my imaginary VIF, there are indeed elevators to access each level, but parts and tools are already at those levels. You don't have to go up and down for every task.

The "step-ladder" won't be 12' high, at most it would be six and more likely less than three. You'd have a "steady-floor" or a work platform next to the rocket that is probably no more than 6 feet off the ground putting you at "eye-level" with the middle of the rocket. In most cases you would simply rotate the rocket at set intervals to reach and interact with all the required maintenance and inspection panels without ever having to change "levels" on the platform.

As a former tool-room tech and current parts attendant/equipment room tech I need to point out that having tools and parts on "every-level" of the VIF, (recall there could be anywhere between three and ten levels) is a LOT of stuff that has to be inventoried and accounted for at the begining and end of every shift! With a much increased chance of loosing or misplacing the same due to the high numbers.

Really you'd have each tech issued a tool box he would move to the work site with the "common" tools and a more centerally located large tool bin that they would go to for more specialty tools. And they WOULD have to carry them from job to job I'm afraid.

You would probably have the same in a HIF except you could place the larger tool bin on the platform (one for each side) and only need to move a maximum of around 6 feet (climb) and half way down the platform to reach them at any time.

I COMPLETELY agree with the observation about the amount of infrastructure.  A purpose built VIF is easily an order-of-magnitude more complex than an HIF.   That's why it doesn't make sense if you only fly once a month.  But if you want to do single-day turn-around like Musk wants, then time is money, and a dedicated VIF will pay for itself - provided you have the volume.  Musk won't go there before he has flight volume, since that's a classic mistake for start-ups - jump ahead of themselves and invest too much, too quickly, in infrastructure that only makes sense for markets that have yet to materialize. 

The thing is it would be much easier to expand an HIF as compared to doing the same with a VIF and there still doesn't seem to be a convincing reason to prefer VIF over HIF. Given the very nature of a processing facility that is trying to get down to single day processing the analog of assembly line structure would seem to beat out the idea of a "high-bay" structure.

Though again it really comes down to WHAT you're imagining versus what the rest of us are seeing

The good:  The large number of connections at the perimeter of the bottom of the payload illustrates the advantage of vertical.  You can access all of them, all the time.  I'd rather access all nine engine bells like this at one level, all actuators and turbopumps (and start cartridges and what not) at a second level, Leg hinges and bottom RCS at third, Leg latches at a fourth, Upper RCS at a fifth, avionics at a sixth...   Each level has 8 access directions, and with an HIF, you can only access one at a time.

See that's an "issue" right there, at the LEAST you could access two sides of the vehicle in a HIF. Again you're assuming that everything is accessed at "ground-level" while underneath the rocket and that's not how it's done.

Another thing you miss but address as an "advantage" is the fact that you have "8-access-directions" which would then assume you have 8-crews per level so that you can access any of them at any time
In reality you would in effect have only ONE (1) crew per level and they would have to pick up and move to each new location. Similarly to the way the crew is in the HIF though with more "steps" required to do the same work.

The bad: You mentioned lanyards.  This means that not all work platforms are indeed conformal.  The gantry should be built independent of the wind bearing walls, so it never moves.  There's a crane, and I don't like cranes.  If the rocket is of standard height, the payload (or second stage) should arrive on a dolly, be lifted up by an elevator, then rolled with the dolly at just the right height so that it can be set onto the second stage (or first stage) by lowering the dolly a few inches at most.  No risk, and alignment can be done by basically centering the dolly, so the load is pre-aligned when it is lowered.

Lanyards and safety devices are a fact of life on high projects. Everyone hates them until they save your life, then you usually hate them a little less but still complain about them
(Personal experiance, I fell off the wing during an aircraft wash and was saved by my harness and lanyard. Then again during an ice/snowstorm the same harness and lanyard failed to prevent me from falling off the wing while removing snow/ice and what saved me was the 5 feet of snow on the ground. The main difference being was that in the former case there was an actual fall protection system installed in the wash building, in the latter someone decided that simply having two people holding 40 foot ropes attached to the harness' would suffice. Note the aircraft wing is only about 12 to 15 feet off the ground at its lowest point. Note also that I had a perfectly good set of insulated pants, uniform pants and my keester ripped open by the row of "flow-seperators" along the aft edge of the wing when I yanked the guy who was supposed to be "belaying" me off his feet. 14 stiches and suddenly it wasn't so "important" to clean the snow/ice off the wings anymore. )

The mating sequence you point out is as I understand it pretty much how it is done in the HIF.

In short - you're listing the real-life deficiencies of working on high gantries.  I think they can be overcome - I don't think they are inherent to a VIF.  The key is that it has to be a dedicated "tight" facility - basically a processing building that's purpose built to get a stage through the steps as quickly (hours) as possible, since it needs to fly again the next day.

Above a certain hight off the "ground" some of these ARE going to be inherent simply because of the process and safety needs. Some can be mitigated and avoided by careful design yes, but the same can be said for an HIF and it won't have the inherent issues involved in the VIF. I go back again to the question of what each of us is "seeing" when we say "HIF/VIF"?

If work on it resembles what you describe (lanyards, drop hazards, etc) then you're 100% right.  I just think it is possible to do much better.

Possible? Of course, but the question is WHAT is the "better" you see compared to what I and others are seeing?

How about this, this is what I "see" as the "process" for a "fast" turn around F9R (yes Jim we know this is probagbly NOT going to be the vehicle but we'll work with it for an example at this point )

Ok, F9R lands and is safed by a ground crew. During that time the TE vehicle is moved into place near the landing pad and readied to retrieve the vehicle. Once safed, the TE backs to within a few feet of the F9R and clamps are secured at the top and bottom and either the TE or a dedicated lift vehicle raises the F9R so that the legs can be folded and locked. The TE completes mating with the F9R and then lowers it into a horizontal transport position and proceeds to the processing facility. TE is dropped off at enterance to the HIF processing facility where it is pulled into the "dock" and work-platforms placed on both sides of the vehicle. Processing begins on both sides of the vehicle as well as from underneath, meanwhile the upper "leg" is extended, inspected and maintenance done. If it needs to be replaced this is done so with the overhead crane. (The F9R will be rotated a total of four times but only needs two rotations for full processing) Any engine changes or major maintenance will be performed using the overhead crane and an aft "engine" platform.

Once processing is done the TE is towed "forward" to have an interstage and associated processing done, meanwhile another F9R is already being towed into position to begin the processing stage. ONce the interstage is attached and checked out the TE is towed foward again into position where the second stage and payload have already been intergrated and checked out. Mating of the F9R and second stage takes place and all-up vehicle check out is done. (Second F9R is getting its interstage attached and checked out while a third F9R is begining being processed)

At this point the "all-up" F9R vehicle TE is towed from the facility to a launch pad and erected for pre-launch check out and fueling prior to launch. Meanwhile another F9R has landed and is being safed for pick up by another TE.

Randy

[meekGee]

I would think that the most important factor is that the cores are currently designed to be assembled and maintained horizontally, so all of the tools, procedures, and experience are all based on working on these cores in the horizontal position.  Switching to vertical will require new facilities, tools, processes, documentation, and training.  All of these introduce risk and a significant investment in time to develop, and the intent of going vertical should be to reduce time and risk.

The physical act of attaching a crawler-crane to the core and returning it to the PF should take no more than a few hours, but during this effort there will also be hours to offload fuel, purge lines, and safe the core before moving it indoors for inspection and maintenance.  I suspect that once reusability is proven over subsequent flights we will see significant improvements in turn-around, but building a VIF and creating all new procedures to save a few hours will not be the way to do this.

BTW, I should point out with the auto-jack example that at races, manual floor jacks are used on the track because they are significantly faster than raising the entire vehicle.

On the race track, with Formula One at least, they invested in specialized dedicated jacks that lift the car in about 2 seconds.   Being unique machines, these jacks are obviously very expensive, and they are only good for that one specific car design - which fits what I've been describing.

As for braking the stage at the pad - sure - you can do it in maybe even a couple of hours.   Which is a huge slice of the time you have available if you want to turn it around in a day.  (And you have 3 boosters if it was an FH-like vehicle)

And yes, the F9.1 is designed for horizontal processing (or at least integration), but the F9.1 is not going to be flying daily, not anytime in the next 2-3 years, right?  SpaceX is very happy with horizontal everything for the time being.

[RanulfC]

First and foremost let me make it quite clear that while I THINK Musk's "stated" goals of less than one day turn around is a good GOAL, it is still only a goal and not one that is going to come about "soon"

Because Musk is dealing with a "rocket" there is going to be a certain "bottom-line" processing time to get it read to fly another mission and the ability to reduce THAT to "hours" is going to take a rocket design we have not seen yet and a lot of work/money.

Now onto subject which is why I "prefaced" this

However, there isn't any person on this board that has seen, or can give examples of what a rapid reprocessing facility looks like.

OK, I CAN actually do that for you; It is a flat concrete pad, somtimes with a roof more often than not though it is open to the weather. The vehicle is towed into position, (horizontally) where it is swarmed by technicians who go over every inch using very thorough and complex check-lists and a very sophisticated fault detection system. (The flight guidance system also has a fault detection system but while it consulted the answers are taken with a grain of salt) Meanwhile various general and specialty equipment, workplatforms, tools, and parts will be installed around and in the vehicle along with mating of payloads and fueling and consumables top off procedures. There will be between two and three times the number of technicians working on the vehicle compared to any other vehicle of its "type" and the majority of those technians will also be working with up to 11 other vehicles of this type at the same time, moving back and forth as various tasks are assigned and supplies provided.
The reason for this is that the vehicle WILL be ready to be flown again within two (2) hours unless a major fault is found in which case it will be ready to fly in no MORE than twelve (12) hours including major maintenance. At that time a new flight guidance system is installed and the vehicle launched.

AS most of you probably guessed I'm describing the "processing" facility and methods for "surge" turning a combat aircraft And while one might say that has nothing to do with fast processing of a launch vehicle, you'd be very much correct and THAT was my point above

Till we get vehicles that are designed to be robust enough and fly often enough to be able to do really fast turn arounds I don't see that one way of "processing" them is going to save enough time to justify major costs in doing so. And at that point it won't BE a vehicle we are familiar with nor comparable to what has gone before.

If Musk can get flight rates up to a couple of times a month THAT is significant, up to a couple times a week? Amazing! But overall HOW he process' the vehicles that do even this much is going to be not worth spending major amounts of money on saving a couple of hours here and there. Not yet.

IMO/YMMV

Randy

[meekGee]

People were saying that ("it's a GOAL, it's something to keep in mind for 10 years from now") about reusability too.  Yet F9R will fly this year, and maybe even be recovered.

Fast turn-around is more complex, since you need both technology and demand.  Market demand is an elusive thing.  It hides for 20 years, then one day it pops up and suddenly there's a new reality.  In this case, I think SpaceX itself will be part of making the market happen, since they will become their own customer on the way to Mars.

Irrespective of this though, what I'm describing is "How I think a reprocessing system for rapid reusable rockets should be designed".  Fair?   If it doesn't happen, it doesn't happen.

So what I'm describing is a launch complex that can handle at least a flight per day.  (I spoke before of 1/wk being a "turning point", but that's only if you're planning to get to 1/day.  You can also do 1/wk by stretching today's methodologies to the limit, but it won't get you to 1/dy)

So you have an integrated facilities.  At least 4 landing pads, a taxiway from them to reprocessing facilities, then (IMO) a separate integration facility, and a launch pad.

The rockets IMO are still running large engine clusters.  I think that's imperative.  You need very high reliability, engine-out from T+0, and the 11% thrust penalty of a 9-engine cluster is a good design feature for that.  (Even if at some point in the past they envisioned the F5.  It's moot by now)

I also think the main vehicle will be triple-barreled.  I really like this configuration, even considering the complexity of recovering the center core.

So I am looking at the problem of how to re-process a just-landed 9-engine core as quickly as possible, measured in hours.

I don't think you can avoid inspections.  Rockets don't have graceful abort modes.  There's "fly-forward with engine-out", but since this might result in loss of recovery, and leaves no margin for a second malfunction, you can't rely on it as a "normal" event.   The advantage of a reusable vehicle is that each flight serves as a 100% test for the next flight - but the benefits of the test are lost if you don't inspect the vehicle after it.

So there's some manner of work to be done on each engine, and as I said - if you want to "swarm all over it", you need the stage to be in an attitude where you have equal access to all of its parts.  A horizontal stage only shows you 1/8 of the engines, 1/4 of the RCS units (half of the time), 1/4 of the legs, etc. 

So *in the context I describe above*, I wouldn't lay the stage down at all.

---

Now we can talk again about re-assembling the rocket, but I don't want to repeat the posts from above.  Suffice to say that I don't see it happening with cranes as it is done with today's VIF.  That's just a carry-over from the days that the service tower had a big construction cranes on top of it.  There are much better ways to perform this task.

[Avron]

most spacex tasks make use if cranes. That seems to work for them. I don't see that change

[jpfulton314]

So, a question based on this discussion...

What is the maximum rate that SpaceX can integrate boosters (units/month) given the technique they use now?

And if they move to vertical integration (however unlikely) what rate would they be able to achieve?  I recall some comment earlier that said Soyuz was launching at the rate of around 1/week.

[Jim]

So, a question based on this discussion...

What is the maximum rate that SpaceX can integrate boosters (units/month) given the technique they use now?

And if they move to vertical integration (however unlikely) what rate would they be able to achieve?  I recall some comment earlier that said Soyuz was launching at the rate of around 1/week.

Nobody can answer those on this forum

[joek]

People were saying that ("it's a GOAL, it's something to keep in mind for 10 years from now") about reusability too.  Yet F9R will fly this year, and maybe even be recovered.

Fast turn-around is more complex, since you need both technology and demand.  Market demand is an elusive thing.  It hides for 20 years, then one day it pops up and suddenly there's a new reality.  In this case, I think SpaceX itself will be part of making the market happen, since they will become their own customer on the way to Mars.

Irrespective of this though, what I'm describing is "How I think a reprocessing system for rapid reusable rockets should be designed".  Fair?   If it doesn't happen, it doesn't happen.

...

I think maybe there is too much emphasis (pardon me Mr. Musk) on "rapid resuable reusable"  That is a means to an end, and an expression of a more fundamental goal: cheaper launch.

Launching every X days does not mean you have to turn a given vehicle in X days.  E.g., if you are launching once per week and you have four vehicles in process at any given time, you have four weeks to turn a given vehicle.

Obviously, all other things equal, the longer it takes to process a vehicle, the lower the launch rate, or the greater the cost (deeper pipeline, inventory cost, etc.).  So what is the optimum for a gven inventory of vehicles, processing time, and launch rate?  Hard to tell.

How about laying out some more concrete and prospective numbers that might provide a more fruitful basis for discussion?


edit: That would be reusable, not resuable (thanks QuantumG)

[meekGee]

I don't have Elon's numbers of course, but there's a caveat to what you said. (which is partly correct - it's just not the whole story)

Capital expense (the cost of the rocket) gets amortized over number of flights.   If you look at your rocket as a revenue generator, like a jet liner, then you want it idle as little as possible.  Airliners don't get twice as many airplanes so they can process them more slowly.  Rather, they do everything they can in order to get the maximum air time our of each airframe.

We've seen Elon talk this way about the Mars vehicle.  He wants it back in one launch window, since otherwise he can only use each vehicle every 3rd cycle - and he'd rather take the expense if fuel of rushing the trip than build 3x as many ships.

For first stage processing, you also have to add (in your example) not only 4x as many rockets, but also 4x as much ground infrastructure.

So I do think he's aiming for fast-turn around as a means of reducing cost.  It will take a radical design of both rocket and processing facility to get there.

[joek]

For first stage processing, you also have to add (in your example) not only 4x as many rockets, but also 4x as much ground infrastructure.

Agree with the first;  I do not see how the latter is a given.  Although I have some doubts, there is no reason why some of the infrastructure could not be common.  Again, if you would put some numbers to your hypothetical scenarios, it would help to focus the conversation.

[meekGee]

Would love to if I could...  But this is pretty uncharted.

All I can say is that if you invest 4X amount of money to get your 1 flight per day, then the loans you took in order to build the vehicles are 4x as much, and so your interest is 4X, and it's that much more burden on your cash flow - so it's not as simple as "flight-rate != 1/turn-around-time".

I'm also arguing, however, that it's worth it to invest in a more expensive infrastructure, if it enables faster processing of the rockets - so clearly I'm not thinking it's all black-and-white.

As you say, numbers will matter.  What's a bigger investment - the cost of the fleet, or the cost of the ground infrastructure?   If it's the fleet, then definitely invest more in infrastructure that allows you to get more flights out of the same fleet (or a smaller fleet for the same number of flights)   If the infrastructure costs more than the fleet, however, then maybe it's time to cool it with the checkbook.

How many vehicles do you have per processing facility?  This affects the above balance.  With airplanes, a typical jet liner doesn't need anything between maintenance checks, which are tens of flights apart.  Here, we don't know.  Is the rocket truly gas-and-go?  My intuition says that no, and some level of inspection is necessary after each flight, even if it's only 1 hour's worth.   But who knows.

Elon's not a happy-go-lucky guy.  He's got things planned a lot further than people here give him credit for. We'll find out with the next "reveal cycle".  Over the last couple of years, we were surprised twice - once with the planned scope of full reusability (so soon after getting the first F9 airborne), and then with how quickly SpaceX implemented it (F9.1).  I am pretty sure the next "big reveal" will be no less surprising in its scope, and we already know they're not wasting time going after implementation (e.g. Raptor).

[guckyfan]

It all really depends on the number of flights. Assume 100 flights per year. I would also assume that they want at least 5-7 launch vehicles so they can keep flying high rate even if they lose one and take one out for refurbishment. That gives them at least 2 weeks to work on any one vehicle.

If there are many more flights than that turnaround time becomes an issue. And I would assume that much of the engineering effort to reduce turnaround time would go into the design of the rocket. When they have a flight per day or more they will really go deep into groundside infrastructure to optimize processing flow.

[joek]

@meekGee -- Ok, let us posit some hypothetical numbers for sake of discussion:
1. Launch to fist stage touchdown -- 1.0hr
2. First stage touchdown to safing -- 2.0hr
3. Touchdown/safing to reburb facility -- 4.0hr
4. First stage to refurb/checkout complete -- 24.0hr
5. LV (first+second) stage integration complete -- 24.0hr
6. System (LV+payload) integration complete -- 24.0hr
7. System rollout -- 1.0hr
8. System launch -- 1.0hr
Total time = 81.0hr per cycle.

On what basis would you defend such numbers (again an example, so feel free to pick your own)?  Or alternatively what changes to existing practices would you advocate and justify or require to achieve that, a similiar, or faster cyle rate?

[AJW]

If we look at the types of launches, we may get a sense of the requirement for rapid reuse.  Here are some types of launches and WAGs for cadence.

1-5 years

Supply/Crew to ISS -- Every 2-3 months?
Commercial Satellite -- Every 2-3 weeks?
DOD Launch -- Every 2-3 months?
Science Missions -- Every 6 months?

5-year plus

MCT Assembly -- Weekly?
Fuel to MCT -- Daily during pre-flight?
Crew to MCT -- ?

Space Tourism -- ?

This seems pretty light for four pads. 

[aero]

I have followed this conversation with interest. After reading all the concepts and counter concepts and delays inherent in reuse, I am concerned that fuel depots on orbit will never happen simply because it takes way to much inspection, repair and time delay between docking and fueling.  I mean, why would it work any different on orbit than it works on the ground and why would it work differently on the ground than it (hypothetically)works in orbit?

There will be either a considerable process to launch a recovered stages and never a refueling depot in space, or there will be gas and go for recovered stages, and gas and go on orbit. JMO

[AJW]

I have followed this conversation with interest. After reading all the concepts and counter concepts and delays inherent in reuse, I am concerned that fuel depots on orbit will never happen simply because it takes way to much inspection, repair and time delay between docking and fueling.  I mean, why would it work any different on orbit than it works on the ground and why would it work differently on the ground than it (hypothetically)works in orbit?

There will be either a considerable process to launch a recovered stages and never a refueling depot in space, or there will be gas and go for recovered stages, and gas and go on orbit. JMO

I think that MCT will be powered by a collection of center cores that are attached together in orbit.  Why build fuel depots when you are already sending up a big tank that conveniently also comes with propulsion.  The SpaceX reusable video also shows a moveable nozzle skirt extension which would indicate an engine that can be efficient both at launch and in vacuum.  Launch a bunch of center cores, link them together and attach the crew module.  Send fuel to top off the tanks and then send up the crew/colonists.  This is why I listed fuel to MCT rather than to a depot.  Depots will exist at some point, but I think the short-term goals can be met without them.

Fuel haulers are the scenario where rapid reuse makes the most sense.  No dependency on outside payload, just move the fuel up, off-load it, return and repeat. 

[guckyfan]

I think that MCT will be powered by a collection of center cores that are attached together in orbit.  Why build fuel depots when you are already sending up a big tank that conveniently also comes with propulsion.  The SpaceX reusable video also shows a moveable nozzle skirt extension which would indicate an engine that can be efficient both at launch and in vacuum.  Launch a bunch of center cores, link them together and attach the crew module.  Send fuel to top off the tanks and then send up the crew/colonists.  This is why I listed fuel to MCT rather than to a depot.  Depots will exist at some point, but I think the short-term goals can be met without them.

Topping off the tanks instead of using depots seems the way to go to me also until there would be really many flights to Mars every window. In that case lifting the fuel between windows would make sense.

But I don't see the need for a vehicle with several cores. A single big enough tank would be better IMO.

[meekGee]

Shrug.  I don't have any basis for numbers as I said, and I doubt anyone else does either.

My only sense is that unless you can process the rockets really quickly (a few hours) then you end up with requiring a large set of ground facilities, and more rockets that mostly sit idle.

I will try out some numbers, but I want to do it in context of what we know about the Mars plan, since the only driver for large launch rates right now is a prolonged Mars campaign.  I'll do it on a different thread though.

[imspacy]

With airplanes, a typical jet liner doesn't need anything between maintenance checks, which are tens of flights apart.  Here, we don't know.  Is the rocket truly gas-and-go?  My intuition says that no, and some level of inspection is necessary after each flight, even if it's only 1 hour's worth.   But who knows.

Early airliners were subject to frequent 'inspections' involving disassembly, intrusion... and airlines had component (e.g. radios, instruments, etc) replacements based solely on age.... millions upon millions of man hours were expended in the name of 'safety...
However, subsequent airline and FAA analysis revealed that many/most failures and accidents were caused by the human intervention/inspections... e.g. mistakes in reassembly, contamination, inadvertent damage... and that proven parts were more reliable than new ones subject to installation errors and infantile failure...that the inspections and scheduled replacements were counter-productive..
In modern systems (like jet engines), manual inspections are replaced by automated monitoring/logging of operating temps/pressures/vibrations/g forces... identifying trends, out of bounds conditions, and pending failures..

SpaceX has all this airline/aircraft experience and technology to draw from...

[meekGee]

With airplanes, a typical jet liner doesn't need anything between maintenance checks, which are tens of flights apart.  Here, we don't know.  Is the rocket truly gas-and-go?  My intuition says that no, and some level of inspection is necessary after each flight, even if it's only 1 hour's worth.   But who knows.

Early airliners were subject to frequent 'inspections' involving disassembly, intrusion... and airlines had component (e.g. radios, instruments, etc) replacements based solely on age.... millions upon millions of man hours were expended in the name of 'safety...
However, subsequent airline and FAA analysis revealed that many/most failures and accidents were caused by the human intervention/inspections... e.g. mistakes in reassembly, contamination, inadvertent damage... and that proven parts were more reliable than new ones subject to installation errors and infantile failure...that the inspections and scheduled replacements were counter-productive..
In modern systems (like jet engines), manual inspections are replaced by automated monitoring/logging of operating temps/pressures/vibrations/g forces... identifying trends, out of bounds conditions, and pending failures..

SpaceX has all this airline/aircraft experience and technology to draw from...

Yup - I completely agree.  There's a world of improvement ahead.

It doesn't mean nobody will look inside the engine, but overall they should be able to reduce turn around time to a few hours.

(The analogy is only that - as analogy.   Rocket don't fail as gracefully as airplanes, and operate with lower margins - but still, just the fact the rocket has just flown is a better test of its abilities then most ground tests can provide.)

[rst]

In modern systems (like jet engines), manual inspections are replaced by automated monitoring/logging of operating temps/pressures/vibrations/g forces... identifying trends, out of bounds conditions, and pending failures..

SpaceX has all this airline/aircraft experience and technology to draw from...

But the thresholds are themselves based on experience, and extensive testing of a sort that SpaceX hasn't had the chance to do yet.  A new airliner typically has six months to a year of test flights before going into service, in addition to non-flight testing on static structural test articles.  And those test programs are only as short as they are because of prior experience with previous generations of airliners, which have given people a reasonably good idea of what sorts of problems they need to be looking for.

And while airliners need that much testing in part because they go up in a much greater range of wind and weather conditions, none of them involve anything much like the physical stress involved in a rocket launch.  So, it really isn't clear how experience with airliners is supposed to generalize to reusable launch vehicles.  At best, it'll give SpaceX a good set of tools to evaluate data on rocket wear and expected lifetime once they have it --- but that'll be a while.

The problem is that no one yet has much experience with reusable liquid-fueled orbital rockets.  So, even if SpaceX had been shooting for gas-and-go reusability as much as they could while designing F9R, they'd be crazy to expect it to work.  (Or to tell anyone about it, because they wouldn't expect it to work.)  As with the first recovery try off Vandenberg, it's more likely that they're expecting some unpleasant surprise.  And for the first few at least, if not the first few dozen, they'll likely be disassembling, reassembling, and doing the full round of factory-floor checkouts and qualification tests and then some trying to find it.

[MP99]

I don't have Elon's numbers of course, but there's a caveat to what you said. (which is partly correct - it's just not the whole story)

Capital expense (the cost of the rocket) gets amortized over number of flights.   If you look at your rocket as a revenue generator, like a jet liner, then you want it idle as little as possible.  Airliners don't get twice as many airplanes so they can process them more slowly.  Rather, they do everything they can in order to get the maximum air time our of each airframe.

We've seen Elon talk this way about the Mars vehicle.  He wants it back in one launch window, since otherwise he can only use each vehicle every 3rd cycle - and he'd rather take the expense if fuel of rushing the trip than build 3x as many ships.

By your analogy, airframes could perform more flights per day by running at Mach  2 or 3.

But, like with huge dV for TMI, it would take huge amounts of fuel.

Cheers, Martin

[AncientU]

In modern systems (like jet engines), manual inspections are replaced by automated monitoring/logging of operating temps/pressures/vibrations/g forces... identifying trends, out of bounds conditions, and pending failures..

SpaceX has all this airline/aircraft experience and technology to draw from...

The problem is that no one yet has much experience with reusable liquid-fueled orbital rockets. 

Exactly zero, that is.

[rst]

In modern systems (like jet engines), manual inspections are replaced by automated monitoring/logging of operating temps/pressures/vibrations/g forces... identifying trends, out of bounds conditions, and pending failures..

SpaceX has all this airline/aircraft experience and technology to draw from...

The problem is that no one yet has much experience with reusable liquid-fueled orbital rockets. 

Exactly zero, that is.

Well, there is the Space Shuttle and SSME, but that's a different enough system that again it isn't clear what lessons transfer, if any.

[meekGee]

I don't have Elon's numbers of course, but there's a caveat to what you said. (which is partly correct - it's just not the whole story)

Capital expense (the cost of the rocket) gets amortized over number of flights.   If you look at your rocket as a revenue generator, like a jet liner, then you want it idle as little as possible.  Airliners don't get twice as many airplanes so they can process them more slowly.  Rather, they do everything they can in order to get the maximum air time our of each airframe.

We've seen Elon talk this way about the Mars vehicle.  He wants it back in one launch window, since otherwise he can only use each vehicle every 3rd cycle - and he'd rather take the expense if fuel of rushing the trip than build 3x as many ships.

By your analogy, airframes could perform more flights per day by running at Mach  2 or 3.

But, like with huge dV for TMI, it would take huge amounts of fuel.

Cheers, Martin

Actually, the time-in-air is a serious consideration.  If you were to build a SST that can hop the Atlantic in an hour and thus fly several times a day, this ability would factor heavily into its commercial viability (since it generates revenue maybe 6 times a day).   Of course designing an SST is such a radical departure from subsonic jets that the increase in cost proved (at least in the case of Concorde) to be too much.

However, here we're talking about designing a rocket and infrastructure for faster turn around times, but with the actual performance of the rocket remaining more or less the same.  If you could bring the turn around time from a month to a day, I don't think the vehicle will cost 30x more.  (Assuming reusability in both cases - the comparison to non-reusable rockets is of course much more extreme)

[MP99]

I don't have Elon's numbers of course, but there's a caveat to what you said. (which is partly correct - it's just not the whole story)

Capital expense (the cost of the rocket) gets amortized over number of flights.   If you look at your rocket as a revenue generator, like a jet liner, then you want it idle as little as possible.  Airliners don't get twice as many airplanes so they can process them more slowly.  Rather, they do everything they can in order to get the maximum air time our of each airframe.

We've seen Elon talk this way about the Mars vehicle.  He wants it back in one launch window, since otherwise he can only use each vehicle every 3rd cycle - and he'd rather take the expense if fuel of rushing the trip than build 3x as many ships.

By your analogy, airframes could perform more flights per day by running at Mach  2 or 3.

But, like with huge dV for TMI, it would take huge amounts of fuel.

Cheers, Martin

Actually, the time-in-air is a serious consideration.  If you were to build a SST that can hop the Atlantic in an hour and thus fly several times a day, this ability would factor heavily into its commercial viability (since it generates revenue maybe 6 times a day).   Of course designing an SST is such a radical departure from subsonic jets that the increase in cost proved (at least in the case of Concorde) to be too much.

The large increase in dV for rapid Mars transit seems to depend on very cheap prop delivery to LEO (or an expensive SEP development programme).

However, here we're talking about designing a rocket and infrastructure for faster turn around times, but with the actual performance of the rocket remaining more or less the same. 

Actually, we weren't. We were discussing whether the huge increase in dV to achieve 3 month Mars transit is worth the reduced time in air / increased utilisation of the craft.

If you could bring the turn around time from a month to a day, I don't think the vehicle will cost 30x more.  (Assuming reusability in both cases - the comparison to non-reusable rockets is of course much more extreme)

And then, the question becomes whether there exists 30x the demand.

Or,  more specifically, whether the price is then low enough to trigger 30x the demand through the price elasticity curve.

Cheers, Martin

[meekGee]

I don't have Elon's numbers of course, but there's a caveat to what you said. (which is partly correct - it's just not the whole story)

Capital expense (the cost of the rocket) gets amortized over number of flights.   If you look at your rocket as a revenue generator, like a jet liner, then you want it idle as little as possible.  Airliners don't get twice as many airplanes so they can process them more slowly.  Rather, they do everything they can in order to get the maximum air time our of each airframe.

We've seen Elon talk this way about the Mars vehicle.  He wants it back in one launch window, since otherwise he can only use each vehicle every 3rd cycle - and he'd rather take the expense if fuel of rushing the trip than build 3x as many ships.

By your analogy, airframes could perform more flights per day by running at Mach  2 or 3.

But, like with huge dV for TMI, it would take huge amounts of fuel.

Cheers, Martin

Actually, the time-in-air is a serious consideration.  If you were to build a SST that can hop the Atlantic in an hour and thus fly several times a day, this ability would factor heavily into its commercial viability (since it generates revenue maybe 6 times a day).   Of course designing an SST is such a radical departure from subsonic jets that the increase in cost proved (at least in the case of Concorde) to be too much.

The large increase in dV for rapid Mars transit seems to depend on very cheap prop delivery to LEO (or an expensive SEP development programme).

However, here we're talking about designing a rocket and infrastructure for faster turn around times, but with the actual performance of the rocket remaining more or less the same. 

Actually, we weren't. We were discussing whether the huge increase in dV to achieve 3 month Mars transit is worth the reduced time in air / increased utilisation of the craft.

If you could bring the turn around time from a month to a day, I don't think the vehicle will cost 30x more.  (Assuming reusability in both cases - the comparison to non-reusable rockets is of course much more extreme)

And then, the question becomes whether there exists 30x the demand.

Or,  more specifically, whether the price is then low enough to trigger 30x the demand through the price elasticity curve.

Cheers, Martin

The dV and time-to-mars were in a different thread...

This conversation (vertical processing) was about whether the LEO launcher (which Elon wanted to launch with a same-day turn-around, and now we understand why, as you point out) should be built to turn-around quickly on the ground, or rather be built for longer turn-around times but cheaper as was suggested up-thread.

I still think that fast turn-around is critical, even if it means the equipment/infrastructure costs more.  To a point, of course, but right now everything is weighted very far towards reducing cost of infrastructure (which makes sense for now)

I've been mulling the numbers for the whole system too.  It warrants a different thread.  The high dV requirement has many ramifications, beyond only explaining why Elon wants such a rapid launch rate of such large rockets.

Interestinger and interestinger