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

[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.