Author Topic: Impact of Stratolaunch on F9 demand 5-10 years from now  (Read 28643 times)

Offline go4mars

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First off, F1e seems even more unlikely now imo.

This thread may be too preliminary since F9 may itself be a lot different in another 5 years, but...

It seems to me that if stratolauncher can get a loaded dragon to orbit, it could probably eat some of F9's lunch.  It has the potential to make F9 prices increase (assuming the market stays the same size) since now people and places need to be devoted to supporting each separate system.  Especially if an additional commercial pad is added beyond what they already have. 

When Elon talks about pricing, he usually says something along the lines of "Assuming a minimum flight rate of X".  Well?  Does the minimum flight rate now drop to where the near/mid-term cost for each system disadvantages F9/FH (or its successor)?  Or are the markets separate enough? 

It isn't as bad as it could be; common assembly lines and common components/component overlap will surely help on the production and testing side for SpaceX, but capital costs for pads plus maintenance and related staff will go up. 

I imagine Paul Allen covers the costs on the stratolaunch "pad" side, and he can handle F9 eating some of the stratolaunch business for a while, but how much impact do you think lower flight rates will have on F9+FH pricing? 

Also, up for discussion: 
Will F9 flights cost less than a stratolaunch?   

And:
If a pad-based rocket needs to grow larger to become reusable, it can grow larger.  It needs bigger pad infrastructure and more expensive transportation methods. 

If a stratolaunch rocket needs to grow larger to become reusable, it needs a bigger carrier aircraft (perhaps a bigger hurdle?). 
 
Also:
Market factors for F9 vs stratolaunch related to tourism:
If I wanted a week in orbit with my wife, a low orbit would suffice.  A dragon launched by stratolauncher should be sufficient for that.  Beginning orbital tourism that way puts less money at risk for the financiers vs. paying to design and build a station/hotel in a higher orbit that is more expensive to get to and return from (in terms of energy and complexity).  So is stratolauncher intended to minimally impact F9 by creating its own market?  Would the increased use of dragon for tourism offset the increased costs associated with F9 infrequency?
« Last Edit: 12/15/2011 03:01 pm by go4mars »
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Offline Zed_Noir

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #1 on: 12/15/2011 03:29 pm »
Something like a beef-up F1e could be hang on a multiple ejector rack to launch several light weight LEO comsat in different orbital planes on a single Stratolaunch sortie with several F1plus.

However if Paul Allen wants something like this, he will have to funded it. Don't see SpaceX developing a F1e follow-on with their current plans.

Offline kevin-rf

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #2 on: 12/15/2011 03:51 pm »
In 5 years the plane will have just started flight testing and 10 years it may have finished testing with the rocket we have now labeled a Falcon 5.

So really, the time scale is to short to impact the Falcon 9, though it may steal engineering resources from the Falcon 9 during the period.
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Offline beb

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #3 on: 12/15/2011 03:54 pm »
Frankly I don't see Stratolauncher working. The White Knight seems too flimsy to handle a real rocket, payload intergration looks like it would be a nightmare and I don't see much advantage to launching from 30,000 versus launching a slightly larger rocket from the ground. Fuel, as jim has pointed out many times, is cheap.

Online Robotbeat

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #4 on: 12/15/2011 04:02 pm »
...
So really, the time scale is to short to impact the Falcon 9, though it may steal engineering resources from the Falcon 9 during the period.
Not stealing anything. SpaceX is a subcontractor, not a partner. Thus, SpaceX can hire more engineers for this project than they otherwise could because they are being paid for by this revenue stream (i.e. not an internal SpaceX project with internal funding like Falcon Heavy is).
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Offline Garrett

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #5 on: 12/15/2011 04:21 pm »
...
So really, the time scale is to short to impact the Falcon 9, though it may steal engineering resources from the Falcon 9 during the period.
Not stealing anything. SpaceX is a subcontractor, not a partner. Thus, SpaceX can hire more engineers for this project than they otherwise could because they are being paid for by this revenue stream (i.e. not an internal SpaceX project with internal funding like Falcon Heavy is).
agree with Robotbeat here. I've seen several people make the comment that Stratolaunch will put a strain on SpaceX resources. I can't see how people come up with that opinion. You might as well be saying that companies in general should refuse extra customers. Where's the logic in that?
Also, I doubt SpaceX will be deeply involved in this until the initial studies and tests have been done on the carrier aircraft, which probably won't be anywhere near completion for another 4 years. If I were to speculate further, that'll probably transition nicely with engineering resources being freed up at the end of the Falcon Heavy development cycle.
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Offline catiare

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #6 on: 12/16/2011 09:34 pm »
A few years ago I saw a concept similar to this one by tSpace. One of the benefits compared to taking off from the ground was that the capsule did not required escape rockets as it was already airborne which reduces mass requirements and does not require any launch pad with associated infrastructure.

I guess SpaceX could work on the rocket that goes under the Stratolaunch as well as all the logistics after that.

Offline Rocket Science

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #7 on: 12/16/2011 09:46 pm »
...
So really, the time scale is to short to impact the Falcon 9, though it may steal engineering resources from the Falcon 9 during the period.
Not stealing anything. SpaceX is a subcontractor, not a partner. Thus, SpaceX can hire more engineers for this project than they otherwise could because they are being paid for by this revenue stream (i.e. not an internal SpaceX project with internal funding like Falcon Heavy is).
agree with Robotbeat here. I've seen several people make the comment that Stratolaunch will put a strain on SpaceX resources. I can't see how people come up with that opinion. You might as well be saying that companies in general should refuse extra customers. Where's the logic in that?
Also, I doubt SpaceX will be deeply involved in this until the initial studies and tests have been done on the carrier aircraft, which probably won't be anywhere near completion for another 4 years. If I were to speculate further, that'll probably transition nicely with engineering resources being freed up at the end of the Falcon Heavy development cycle.
Put me down as agreeing as well. I think SpaceX will focus on their resources on their main core business. Though they are wise as to not miss any opportunity that comes up such as Stratolaunch. This is going to be a huge aircraft project for Rutan  and Allen, no pun intended…
« Last Edit: 12/17/2011 11:49 am by Rocket Science »
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Offline RocketmanUS

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #8 on: 12/16/2011 09:50 pm »
A few years ago I saw a concept similar to this one by tSpace. One of the benefits compared to taking off from the ground was that the capsule did not required escape rockets as it was already airborne which reduces mass requirements and does not require any launch pad with associated infrastructure.

I guess SpaceX could work on the rocket that goes under the Stratolaunch as well as all the logistics after that.
The CXV capsule engines were to do an escape burn if needed. I never found out though what the expected thrust was of thoughs engines.

Online HMXHMX

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #9 on: 12/17/2011 12:24 am »
A few years ago I saw a concept similar to this one by tSpace. One of the benefits compared to taking off from the ground was that the capsule did not required escape rockets as it was already airborne which reduces mass requirements and does not require any launch pad with associated infrastructure.

I guess SpaceX could work on the rocket that goes under the Stratolaunch as well as all the logistics after that.
The CXV capsule engines were to do an escape burn if needed. I never found out though what the expected thrust was of thoughs engines.

The "original" CXV of 2004/5 time frame did use six abort engines, and as I recall, I sized them for about 3Gs.  That would make them about 5K lbf each.  Frankly, the principal reason for using a LAS at all was to dump the RCS/OMS propellant as quickly as possible in order to land light and without flammables on-board. 

As we developed the proposal for COTS 1.0, we concluded that it wasn't necessary to have a rocket-powered LAS.  There were essentially no credible combination of failures that would result in detonation (vs. deflagration) when in flight, so there was no overpressure threat, only a thermal one, which was mitigated by the spacecraft TPS.  We ended up proposing separating the spacecraft (which was much smaller than the "original" CXV) using pneumatic pushers.  Then we simply jettisoned the service module that contained the propellant tanks.

Offline Kaputnik

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #10 on: 12/17/2011 10:06 am »
So... if air-launch negates the need for a LAS, that makes Dragon presumably non-optimal, as it is dragging along a LAS for soft-landing (eventually).
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Offline ChefPat

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #11 on: 12/17/2011 11:38 am »
So... if air-launch negates the need for a LAS, that makes Dragon presumably non-optimal, as it is dragging along a LAS for soft-landing (eventually).
Why would you not need the landing capability if you were air launched?
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Offline Rocket Science

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #12 on: 12/17/2011 12:28 pm »
So... if air-launch negates the need for a LAS, that makes Dragon presumably non-optimal, as it is dragging along a LAS for soft-landing (eventually).
In a crewed air launch we would still need an EDS and an escape system. If you are really going to have "a bad day", then we will need it for the carrier aircraft crew as well. This is another one of the complexities with this system, LOV and possible LOC for two systems. Those are a couple of reasons that I don't think this is the "best" approach. Heck, for once I agree with Griffin... Scary :o
« Last Edit: 12/17/2011 12:36 pm by Rocket Science »
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Offline krytek

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #13 on: 12/17/2011 02:18 pm »
So... if air-launch negates the need for a LAS, that makes Dragon presumably non-optimal, as it is dragging along a LAS for soft-landing (eventually).
In a crewed air launch we would still need an EDS and an escape system. If you are really going to have "a bad day", then we will need it for the carrier aircraft crew as well. This is another one of the complexities with this system, LOV and possible LOC for two systems. Those are a couple of reasons that I don't think this is the "best" approach. Heck, for once I agree with Griffin... Scary :o

Any guess as to  how far away from the mothership the rocket is supposed to ignite? I'm thinking if it's far enough there shouldn't be a problem.

Offline Rocket Science

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #14 on: 12/17/2011 02:27 pm »
So... if air-launch negates the need for a LAS, that makes Dragon presumably non-optimal, as it is dragging along a LAS for soft-landing (eventually).
In a crewed air launch we would still need an EDS and an escape system. If you are really going to have "a bad day", then we will need it for the carrier aircraft crew as well. This is another one of the complexities with this system, LOV and possible LOC for two systems. Those are a couple of reasons that I don't think this is the "best" approach. Heck, for once I agree with Griffin... Scary :o

Any guess as to  how far away from the mothership the rocket is supposed to ignite? I'm thinking if it's far enough there shouldn't be a problem.
If you look at the video, it is almost within seconds of launch. My worst case senarion is while still mated, now that would be a bad day...
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Offline Lee Jay

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #15 on: 12/17/2011 03:06 pm »
Just as a reminder, here is a Pegasus XL launch.


Offline go4mars

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #16 on: 12/17/2011 04:16 pm »
As we developed the proposal for COTS 1.0, we concluded that it wasn't necessary to have a rocket-powered LAS.  There were essentially no credible combination of failures that would result in detonation (vs. deflagration) when in flight, so there was no overpressure threat, only a thermal one, which was mitigated by the spacecraft TPS.  We ended up proposing separating the spacecraft (which was much smaller than the "original" CXV) using pneumatic pushers.  Then we simply jettisoned the service module that contained the propellant tanks.
Fascinating!  So the main reason that non-propulsive landing guys use rocket-powered LAS is to empty RCS tanks quickly?   

Just making sure I read that right.  I have long held a different assumption based on the solid-fuel tractor-towers of yesteryear.

Frankly, the principal reason for using a LAS at all was to dump the RCS/OMS propellant as quickly as possible in order to land light and without flammables on-board. 
« Last Edit: 12/17/2011 04:21 pm by go4mars »
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Offline go4mars

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #17 on: 12/17/2011 04:24 pm »
If you are really going to have "a bad day", then we will need it for the carrier aircraft crew as well. This is another one of the complexities with this system, LOV and possible LOC for two systems.
So do think stratolaunch aircraft will have a thermally protective crew ejection system?   Might it be flown as a drone instead? 
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Offline Rocket Science

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #18 on: 12/17/2011 04:35 pm »
If you are really going to have "a bad day", then we will need it for the carrier aircraft crew as well. This is another one of the complexities with this system, LOV and possible LOC for two systems.
So do think stratolaunch aircraft will have a thermally protective crew ejection system?   Might it be flown as a drone instead? 
We can only comment on what was presented which shows a crewed carrier aircraft.  If is to be then ethically they need to be protected with means of escape in some form. Airborne carrier sled concepts from years ago were unmanned. It could be remote piloted or programmed with waypoints as a drone as well. We need to minimize risk to crew as much as possible and eliminated when not needed at all. Do we risk a crew to launch a satellite or cargo? With Shuttle the goal was to separate crew and cargo/payload.
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« Last Edit: 12/17/2011 04:53 pm by Rocket Science »
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Online edkyle99

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #19 on: 12/17/2011 04:41 pm »
It seems to me that if stratolauncher can get a loaded dragon to orbit, it could probably eat some of F9's lunch. 

I don't see the "lunch" that would be eaten.  SpaceX has talked, for the better part of  a decade now, about its big backlog, but it has only successfully launched two missions with paying customer payloads in all that time.  It has launched nothing at all for more than a year.  Meanwhile, many of the payloads listed on its early backlogs have disappeared or been launched by others. 

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Offline go4mars

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #20 on: 12/17/2011 04:58 pm »
Might it be flown as a drone instead? 
We can only comment on what was presented which shows a crewed carrier aircraft.  If is to be then ethically they need to be protected with means of escape in some form... It could be remote piloted or programmed with waypoints as a drone as well. We need to minimize risk to crew as much as possible and eliminated when not needed at all.
  Maybe it would only be crewed at certain phases: use 2 crews to eliminate the risk.  Get airborne, hit the remote control button, then crew 1 parachutes out of there.  If in-flight re-fuelling is possible, then perhaps so is mid-flight re-crewing. 

After launch, a couple guys essentially wearing space-suits drop down along a wire from a different craft into a hatch on stratolauncher.  Sounds a bit too James Bond, but it might be less expensive than developing unmanned systems for takeoff and landing.  Also, it's arguable whether this would decrease risk to crew or increase it. 

If it must be manned, it would be a nifty gig for the pilots!   
« Last Edit: 12/17/2011 04:59 pm by go4mars »
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Offline Rocket Science

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #21 on: 12/17/2011 05:06 pm »
Might it be flown as a drone instead? 
We can only comment on what was presented which shows a crewed carrier aircraft.  If is to be then ethically they need to be protected with means of escape in some form... It could be remote piloted or programmed with waypoints as a drone as well. We need to minimize risk to crew as much as possible and eliminated when not needed at all.
  Maybe it would only be crewed at certain phases: use 2 crews to eliminate the risk.  Get airborne, hit the remote control button, then crew 1 parachutes out of there.  If in-flight re-fuelling is possible, then perhaps so is mid-flight re-crewing. 

After launch, a couple guys essentially wearing space-suits drop down along a wire from a different craft into a hatch on stratolauncher.  Sounds a bit too James Bond, but it might be less expensive than developing unmanned systems for takeoff and landing.  Also, it's arguable whether this would decrease risk to crew or increase it. 

If it must be manned, it would be a nifty gig for the pilots!   
Being a pilot I would like to fly anything I could get my hands on. But bailing out of a perfectly good airplane? I would not consider that normal ops. Some pilots need to get over the fact that they are not needed all the time for all operations with modern computer and robotic technology… The Shuttle was hand flown around the HAC and even then it was designed to land itself going back to the 1970’s.
« Last Edit: 12/17/2011 05:07 pm by Rocket Science »
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Offline Zed_Noir

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #22 on: 12/17/2011 05:15 pm »
If you are really going to have "a bad day", then we will need it for the carrier aircraft crew as well. This is another one of the complexities with this system, LOV and possible LOC for two systems.
So do think stratolaunch aircraft will have a thermally protective crew ejection system?   Might it be flown as a drone instead? 

You could have encapsulated ejection seat like on the B58 Hustler or a crew ejection capule like on the F111/FB111 Aardvark. Think you can fly the Stratolaunch Carrier with 2 persons.

Offline Rocket Science

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #23 on: 12/17/2011 05:32 pm »
If you are really going to have "a bad day", then we will need it for the carrier aircraft crew as well. This is another one of the complexities with this system, LOV and possible LOC for two systems.
So do think stratolaunch aircraft will have a thermally protective crew ejection system?   Might it be flown as a drone instead? 

You could have encapsulated ejection seat like on the B58 Hustler or a crew ejection capule like on the F111/FB111 Aardvark. Think you can fly the Stratolaunch Carrier with 2 persons.
Sure you can, but that again adds weight and complexity and the capsule is like having to design another plane within a plane. Anything can be made to work with enough time and money, just look at the ISS.
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Offline Patchouli

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #24 on: 12/17/2011 05:37 pm »

If you look at the video, it is almost within seconds of launch. My worst case senarion is while still mated, now that would be a bad day...

Since it is air launched crashing on the launch pad which is one of the the primary causes of a an LV exploding is eliminated.

The other instances are usually the range safety system destructing the vehicle and this could be dealt with by having a delay in arming it which I believe most LV's already have to make sure it clears the pad before being blown up.
Since it's air launched the range safety system could possibly even be eliminated and the vehicle just make use of thrust termination like Russian rockets do.
« Last Edit: 12/17/2011 05:40 pm by Patchouli »

Offline Rocket Science

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #25 on: 12/17/2011 05:45 pm »

If you look at the video, it is almost within seconds of launch. My worst case senarion is while still mated, now that would be a bad day...

Since it is air launched crashing on the launch pad which is one of the the primary causes of a an LV exploding is eliminated.

The other instances are usually the range safety system destructing the vehicle and this could be dealt with by having a delay in arming it which I believe most LV's already have to make sure it clears the pad before being blown up.
Since it's air launched the range safety system could possibly even be eliminated and the vehicle just make use of thrust termination like Russian rockets do.
I tend to look at this operation more along the lines of the X-1, X-2 and X-15. If your look back at their problems during their flight history you can see my concerns. From in-flight fires and explosions and this will be at a much larger scale.  Just things to consider while still mated…
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Offline Patchouli

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #26 on: 12/17/2011 05:51 pm »

If you look at the video, it is almost within seconds of launch. My worst case senarion is while still mated, now that would be a bad day...

Since it is air launched crashing on the launch pad which is one of the the primary causes of a an LV exploding is eliminated.

The other instances are usually the range safety system destructing the vehicle and this could be dealt with by having a delay in arming it which I believe most LV's already have to make sure it clears the pad before being blown up.
Since it's air launched the range safety system could possibly even be eliminated and the vehicle just make use of thrust termination like Russian rockets do.
I tend to look at this operation more along the lines of the X-1, X-2 and X-15. If your look back at their problems during their flight history you can see my concerns. From in-flight fires and explosions and this will be at a much larger scale.  Just things to consider while still mated…

I figure the most dangerous time would be during take off as the carrier is heavy.

I don't know the specs of this system such as is the rocket fueled on ground or in flight from tanks inside the plane.

It still should be much safer then the first 5 seconds of a conventional rocket's flight.

Offline Rocket Science

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #27 on: 12/17/2011 06:00 pm »

If you look at the video, it is almost within seconds of launch. My worst case senarion is while still mated, now that would be a bad day...

Since it is air launched crashing on the launch pad which is one of the the primary causes of a an LV exploding is eliminated.

The other instances are usually the range safety system destructing the vehicle and this could be dealt with by having a delay in arming it which I believe most LV's already have to make sure it clears the pad before being blown up.
Since it's air launched the range safety system could possibly even be eliminated and the vehicle just make use of thrust termination like Russian rockets do.
I tend to look at this operation more along the lines of the X-1, X-2 and X-15. If your look back at their problems during their flight history you can see my concerns. From in-flight fires and explosions and this will be at a much larger scale.  Just things to consider while still mated…

I figure the most dangerous time would be during take off as the carrier is heavy.

I don't know the specs of this system such as is the rocket fueled on ground or in flight from tanks inside the plane.

It still should be much safer then the first 5 seconds of a conventional rocket's flight.
As I wrote in a prior post it could happened while still on the ground on the ramp or during take-off roll. Remember the Apollo 1 fire and how a safe and simple plugs-out test turned tragic… Never take anything for granted. Like I tell my students “the laws of physics are unforgiving”…
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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #28 on: 12/17/2011 09:42 pm »
Sidestepping the technical and safety aspects of Stratolaunch for a moment, I want to comment on the demand for the system.

Rather than looking at the impact of Stratolaunch on F9 demand, I want to look at the impact of competition on Stratolaunch demand. If the Stratolaunch payload is in the Delta II class, then two of its competitors would be Antares and Soyuz.

Stratolaunch's advantage is claimed to be in its flexibility to reach "any orbit, any time." This is especially useful in rendezvous missions to ISS where the carrier aircraft can alter its launch point at short notice to extend the launch window available. But for the launch of most commercial payloads this flexibility seems less necessary.

Stratolaunch's flexibility may give it an advantage over a launch vehicle like Antares (even if Antares gets a West Coast launch site), but it's less obvious that it has much advantage over Soyuz. A Soyuz launched from Kourou can reach any inclination from almost equatorial to sun-synchronous.

As far as cost of Stratolaunch compared with the competition is concerned, that's a black area. It's difficult to imagine it being spectacularly cheaper.
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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #29 on: 12/17/2011 10:10 pm »
Falcon 9 would also be a competitor. As would Indian and Chinese launchers.
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Offline Jim

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #30 on: 12/17/2011 10:16 pm »

Stratolaunch's advantage is claimed to be in its flexibility to reach "any orbit, any time." This is especially useful in rendezvous missions to ISS where the carrier aircraft can alter its launch point at short notice to extend the launch window available. But for the launch of most commercial payloads this flexibility seems less necessary.


There are 3 competitors (F9). 

The extended launch window is not really necessary, see STS and Delta launch on times.

Offline JohnFornaro

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #31 on: 12/18/2011 01:51 pm »
Meanwhile, many of the payloads listed on its early backlogs have disappeared or been launched by others.

I did not know that.  Do you have some examples?

Also, wouldn't that sucker require a helluva long runway?
Sometimes I just flat out don't get it.

Offline sammie

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #32 on: 12/18/2011 02:56 pm »
HYLAS 2 was on the F9 manifest, but will be launched by Arianespace now
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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #33 on: 12/18/2011 04:16 pm »
@Jim & Robotbeat:

Agree.
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Offline ArbitraryConstant

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #34 on: 12/19/2011 03:27 am »
Stratolaunch's advantage is claimed to be in its flexibility to reach "any orbit, any time." This is especially useful in rendezvous missions to ISS where the carrier aircraft can alter its launch point at short notice to extend the launch window available. But for the launch of most commercial payloads this flexibility seems less necessary.
Would there be any demand from the DoD for a just-in-time launch service?

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #35 on: 12/19/2011 04:05 am »
Stratolaunch's advantage is claimed to be in its flexibility to reach "any orbit, any time." This is especially useful in rendezvous missions to ISS where the carrier aircraft can alter its launch point at short notice to extend the launch window available. But for the launch of most commercial payloads this flexibility seems less necessary.
Would there be any demand from the DoD for a just-in-time launch service?
Yes, I would imagine there would be. Another previous air launch concept (called QuickReach by Airlaunch LLC) received funding from DARPA's FALCON program which had a requirement to launch within 24 hours of notice. The larger (manned) variant (QuickReach II) of this also proposed using something remarkably similar to the Stratolaunch carrier aircraft. It was supposed to be about as big and also built by Scaled Composites. There's lots of inbreeding in the aerospace sector.
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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #36 on: 12/19/2011 07:40 am »
Stratolaunch's advantage is claimed to be in its flexibility to reach "any orbit, any time." This is especially useful in rendezvous missions to ISS where the carrier aircraft can alter its launch point at short notice to extend the launch window available. But for the launch of most commercial payloads this flexibility seems less necessary.
Would there be any demand from the DoD for a just-in-time launch service?
Yes, I would imagine there would be. Another previous air launch concept (called QuickReach by Airlaunch LLC) received funding from DARPA's FALCON program which had a requirement to launch within 24 hours of notice. The larger (manned) variant (QuickReach II) of this also proposed using something remarkably similar to the Stratolaunch carrier aircraft. It was supposed to be about as big and also built by Scaled Composites. There's lots of inbreeding in the aerospace sector.

What DARPA does doesn't always mean the rest of the DOD wants it or is ready for it.

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #37 on: 12/19/2011 12:21 pm »
Stratolaunch's advantage is claimed to be in its flexibility to reach "any orbit, any time." This is especially useful in rendezvous missions to ISS where the carrier aircraft can alter its launch point at short notice to extend the launch window available. But for the launch of most commercial payloads this flexibility seems less necessary.
Would there be any demand from the DoD for a just-in-time launch service?
Yes, I would imagine there would be. Another previous air launch concept (called QuickReach by Airlaunch LLC) received funding from DARPA's FALCON program which had a requirement to launch within 24 hours of notice. The larger (manned) variant (QuickReach II) of this also proposed using something remarkably similar to the Stratolaunch carrier aircraft. It was supposed to be about as big and also built by Scaled Composites. There's lots of inbreeding in the aerospace sector.

What DARPA does doesn't always mean the rest of the DOD wants it or is ready for it.
True. But there's a potential desire for such a capability.
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Offline ArbitraryConstant

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #38 on: 12/19/2011 02:20 pm »
What DARPA does doesn't always mean the rest of the DOD wants it or is ready for it.
Not guaranteed, but I think it's safe to assume they've considered this as part of their business plan and put out feelers.

Offline baldusi

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #39 on: 12/19/2011 02:45 pm »
What DARPA does doesn't always mean the rest of the DOD wants it or is ready for it.
True. But there's a potential desire for such a capability.
Does DoD have payloads for launch on 24hs notice? Are they developing them? I'm truly intrigued (though I would be highly surprised if any of the answers was yes).

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #40 on: 12/19/2011 03:11 pm »
What DARPA does doesn't always mean the rest of the DOD wants it or is ready for it.
True. But there's a potential desire for such a capability.
Does DoD have payloads for launch on 24hs notice? Are they developing them? I'm truly intrigued (though I would be highly surprised if any of the answers was yes).
Not yet. More of a "want" than a present capability.
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Offline baldusi

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #41 on: 12/19/2011 03:53 pm »
What DARPA does doesn't always mean the rest of the DOD wants it or is ready for it.
True. But there's a potential desire for such a capability.
Does DoD have payloads for launch on 24hs notice? Are they developing them? I'm truly intrigued (though I would be highly surprised if any of the answers was yes).
Not yet. More of a "want" than a present capability.
Want or desire? Want means that they are constantly keeping an eye on the capability. Desire means that they would accept it, and would even pay a premium for it, but it's completely out of their efforts.

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #42 on: 12/19/2011 04:11 pm »
Would-like-to-have, at least right now. Not a must-have.
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Offline RanulfC

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #43 on: 12/19/2011 04:20 pm »
We can only comment on what was presented which shows a crewed carrier aircraft.  If is to be then ethically they need to be protected with means of escape in some form.

While I can in general "agree" with your point, reality tends to negate "ethical" considerations :)

When was the last time you were handed a parachute and instructions on a cross-country commercial airliner? Has anyone ever informed you that the airline companies have knowingly put you in danger of serious injury on every flight simply because they refuse to turn the seats 180-degrees as the DoD pointed out 60 years ago?

It's possible they might set up the carrier aircraft to be optionally manned but the flight testing will be manned. Some risks you take and live with.

I tend to look at this operation more along the lines of the X-1, X-2 and X-15. If your look back at their problems during their flight history you can see my concerns. From in-flight fires and explosions and this will be at a much larger scale.  Just things to consider while still mated…
Actually your not "helping" your case that much :)

How many carrier aircraft did we lose during the test programs? Any issues while still attached and it is "safe" to do so you just jettision the LV. The way they are discussing abort options it's likely they will be working with both manned and unmanned intact abort even if they have to jettision the LV. And it would seriously have to be a "bad-day" to get to that point.

Given Space-Xs work on isolating and shielding the engines (and the 5-X config has a LOT more room to work with for shielding) even an engine explosion would probably not result in the loss of the LV as long as it was still attached to the Carrier Aircraft.

Randy
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Offline Rocket Science

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #44 on: 12/19/2011 04:29 pm »
We can only comment on what was presented which shows a crewed carrier aircraft.  If is to be then ethically they need to be protected with means of escape in some form.
While I can in general "agree" with your point, reality tends to negate "ethical" considerations :)

When was the last time you were handed a parachute and instructions on a cross-country commercial airliner? Has anyone ever informed you that the airline companies have knowingly put you in danger of serious injury on every flight simply because they refuse to turn the seats 180-degrees as the DoD pointed out 60 years ago?

It's possible they might set up the carrier aircraft to be optionally manned but the flight testing will be manned. Some risks you take and live with.

I tend to look at this operation more along the lines of the X-1, X-2 and X-15. If your look back at their problems during their flight history you can see my concerns. From in-flight fires and explosions and this will be at a much larger scale.  Just things to consider while still mated…
Actually your not "helping" your case that much :)

How many carrier aircraft did we lose during the test programs? Any issues while still attached and it is "safe" to do so you just jettision the LV. The way they are discussing abort options it's likely they will be working with both manned and unmanned intact abort even if they have to jettision the LV. And it would seriously have to be a "bad-day" to get to that point.

Given Space-Xs work on isolating and shielding the engines (and the 5-X config has a LOT more room to work with for shielding) even an engine explosion would probably not result in the loss of the LV as long as it was still attached to the Carrier Aircraft.

Randy
Randy,
All I am saying is that this system should be considered an experimental  and not to rush to deem it operational right off the bat. This was one of the many lessons learned fron Shuttle.

Regards
Robert
« Last Edit: 12/19/2011 04:30 pm by Rocket Science »
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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #45 on: 12/20/2011 02:05 am »
Stratolaunch's advantage is claimed to be in its flexibility to reach "any orbit, any time." This is especially useful in rendezvous missions to ISS where the carrier aircraft can alter its launch point at short notice to extend the launch window available. But for the launch of most commercial payloads this flexibility seems less necessary.
Would there be any demand from the DoD for a just-in-time launch service?
Yes, I would imagine there would be. Another previous air launch concept (called QuickReach by Airlaunch LLC) received funding from DARPA's FALCON program which had a requirement to launch within 24 hours of notice. The larger (manned) variant (QuickReach II) of this also proposed using something remarkably similar to the Stratolaunch carrier aircraft. It was supposed to be about as big and also built by Scaled Composites. There's lots of inbreeding in the aerospace sector.

What DARPA does doesn't always mean the rest of the DOD wants it or is ready for it.

Don't I know it.  I still have the tread marks across my back from that one.  Even with their signatures on an Agreement with DARPA, USAF managed to weasel out of it.
« Last Edit: 12/20/2011 02:07 am by HMXHMX »

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #46 on: 12/20/2011 03:59 am »
Stratolaunch's advantage is claimed to be in its flexibility to reach "any orbit, any time." This is especially useful in rendezvous missions to ISS where the carrier aircraft can alter its launch point at short notice to extend the launch window available. But for the launch of most commercial payloads this flexibility seems less necessary.
Would there be any demand from the DoD for a just-in-time launch service?
Yes, I would imagine there would be. Another previous air launch concept (called QuickReach by Airlaunch LLC) received funding from DARPA's FALCON program which had a requirement to launch within 24 hours of notice. The larger (manned) variant (QuickReach II) of this also proposed using something remarkably similar to the Stratolaunch carrier aircraft. It was supposed to be about as big and also built by Scaled Composites. There's lots of inbreeding in the aerospace sector.

What DARPA does doesn't always mean the rest of the DOD wants it or is ready for it.

Don't I know it.  I still have the tread marks across my back from that one.  Even with their signatures on an Agreement with DARPA, USAF managed to weasel out of it.
Yeah, I was very disappointed that your approach wasn't allowed to continue.
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Offline alexterrell

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #47 on: 12/24/2011 12:49 pm »

Stratolaunch's advantage is claimed to be in its flexibility to reach "any orbit, any time." This is especially useful in rendezvous missions to ISS where the carrier aircraft can alter its launch point at short notice to extend the launch window available. But for the launch of most commercial payloads this flexibility seems less necessary.

Stratolaunch's flexibility may give it an advantage over a launch vehicle like Antares (even if Antares gets a West Coast launch site), but it's less obvious that it has much advantage over Soyuz. A Soyuz launched from Kourou can reach any inclination from almost equatorial to sun-synchronous.

As far as cost of Stratolaunch compared with the competition is concerned, that's a black area. It's difficult to imagine it being spectacularly cheaper.
Would it save money if the strato launcher / F5 could fly to where the payload is, take on the payload and fuel, and then launch from there?

I'm thinking of something like flying to an airport near Astrium assembly facilities in the UK.

It would need a special runway and I doubt Heathrow would accept disruptions to schedule but something like Boscombe Down (would need another 1,500 feet on the runway).

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #48 on: 12/24/2011 01:55 pm »

Stratolaunch's advantage is claimed to be in its flexibility to reach "any orbit, any time." This is especially useful in rendezvous missions to ISS where the carrier aircraft can alter its launch point at short notice to extend the launch window available. But for the launch of most commercial payloads this flexibility seems less necessary.

Stratolaunch's flexibility may give it an advantage over a launch vehicle like Antares (even if Antares gets a West Coast launch site), but it's less obvious that it has much advantage over Soyuz. A Soyuz launched from Kourou can reach any inclination from almost equatorial to sun-synchronous.

As far as cost of Stratolaunch compared with the competition is concerned, that's a black area. It's difficult to imagine it being spectacularly cheaper.
Would it save money if the strato launcher / F5 could fly to where the payload is, take on the payload and fuel, and then launch from there?

I'm thinking of something like flying to an airport near Astrium assembly facilities in the UK.

It would need a special runway and I doubt Heathrow would accept disruptions to schedule but something like Boscombe Down (would need another 1,500 feet on the runway).
No, that wouldn't make sense. The more optimum is to have a central, single location for payload integration at some place with a long runway and do all payload integration there. I believe that's what Pegasus does (at Vandenberg).
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Offline jimoutofthebox

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #49 on: 01/04/2012 04:32 pm »
There is a significant cost savings to be had from launching a booster from an aircraft.  For example Saturn V used almost 1/3rd of its launch weight in RP and LOX just to get to Mach 1.  I think air launch has the potential to dramatically reduce the cost of putting people in orbit.  Instead of the modified 747s proposed I would use a modified C5 aircraft with the floor removed so that the booster could be carried internally.  With a good redesign the C5 could probably carry 350,000 lbs.   
I would then create a booster based on a scaled up X-37.  The booster would consist of two parts the orbiter section would consist of an airframe with a LOX tank, crew compartment, and a pair of J2 engines as well as a pair of small engines for orbital insertion and reentry.  The orbiter would return for reuse.  The other section would be mounted to the nose of the main assembly and would consist of the LH fuel tank.  The LH fuel tank would also have solid rocket motors that would pull the tank away from the orbiter once the fuel was exhausted.  The tank would then burn up.  The small engines would place the orbiter in orbit just as was done with the shuttle.
There are several advantages to this proposal.  The passengers would not have to enter the orbiter until the aircraft got to altitude so in an emergency the booster could be jettisoned from the aircraft without endangering the passengers.  A lot of money could be saved because all the expensive stuff could be reused.
I estimate that the system outlined above would weigh 350,000 lbs when fully fuelled with a 90% fuel fraction.  It could carry 7 people to orbit or a robot version could carry a payload of 5,000lbs to orbit.

Offline go4mars

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #50 on: 01/04/2012 04:46 pm »
The booster would consist of two parts the orbiter section would consist of an airframe with a LOX tank, crew compartment, and a pair of J2 engines as well as a pair of small engines for orbital insertion and reentry.  The orbiter would return for reuse.  The other section would be mounted to the nose of the main assembly and would consist of the LH fuel tank.  The LH fuel tank would also have solid rocket motors that would pull the tank away from the orbiter once the fuel was exhausted.  The tank would then burn up.  The small engines would place the orbiter in orbit just as was done with the shuttle.
Neat idea. 

There are several advantages to this proposal.  The passengers would not have to enter the orbiter until the aircraft got to altitude so in an emergency the booster could be jettisoned from the aircraft without endangering the passengers. 
I think the LAS system with people in dragon would be lower risk to passengers.  If something goes wrong, you don't have to wait for actuators to open the bottom of the aircraft with dragon LAS.

A lot of money could be saved because all the expensive stuff could be reused.
How much would throwing away hydrogen tanks and SRM cost per flight?  Still seems more like a partial re-use solution that can't ever get as cheap as something that throws away only reaction agents.  But I'm no expert. 

I estimate that the system outlined above would weigh 350,000 lbs when fully fuelled with a 90% fuel fraction.  It could carry 7 people to orbit or a robot version could carry a payload of 5,000lbs to orbit.
7 passengers in a winged re-entry vehicle including its rocket engines and oxygen tanks for only 5000 pounds?  Did I read that right?
« Last Edit: 01/04/2012 04:47 pm by go4mars »
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Offline jimoutofthebox

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #51 on: 01/05/2012 12:09 am »
There are several advantages to this proposal.  The passengers would not have to enter the orbiter until the aircraft got to altitude so in an emergency the booster could be jettisoned from the aircraft without endangering the passengers. 
I think the LAS system with people in dragon would be lower risk to passengers.  If something goes wrong, you don't have to wait for actuators to open the bottom of the aircraft with dragon LAS.

The Dragon would be risky because the passengers would have to be sealed in before take off and I suspect that the aircraft will need a minimum altitude for the escape system to work.

A lot of money could be saved because all the expensive stuff could be reused.
How much would throwing away hydrogen tanks and SRM cost per flight?  Still seems more like a partial re-use solution that can't ever get as cheap as something that throws away only reaction agents.  But I'm no expert.

 A single pressure stabilized tank could be built cheap and small solid rocket motors are also cheap.  I think a completely reusable system would have too high a weight penalty to be cost effective

I estimate that the system outlined above would weigh 350,000 lbs when fully fuelled with a 90% fuel fraction.  It could carry 7 people to orbit or a robot version could carry a payload of 5,000lbs to orbit.
7 passengers in a winged re-entry vehicle including its rocket engines and oxygen tanks for only 5000 pounds?  Did I read that right?
[/quote]

I propose the vehical in orbit would weigh 30,000 lbs including the payload

Offline go4mars

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #52 on: 01/05/2012 02:26 am »
I suspect that the aircraft will need a minimum altitude for the escape system to work.
why would it need minimum altitude to work?  Seems to me it could work while taxiing around the airport. Couldn't do that with yours until it is airborn.
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Offline Zed_Noir

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #53 on: 01/05/2012 03:46 am »
I suspect that the aircraft will need a minimum altitude for the escape system to work.
why would it need minimum altitude to work?  Seems to me it could work while taxiing around the airport. Couldn't do that with yours until it is airborn.

IIRC both the F/FB111 & the B1A bombers have crew escape capsules capable of zerp-zero (zero altitude & zero speed) egress. So, don't think a Dragon capsule with throttle-able LAS should have any problems getting away from the carrier aircraft at any altitude.

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #54 on: 01/05/2012 05:00 am »
The stratolaunch idea, in combination with cross feed for F9H, makes me wonder about an alternate idea for Stratolaunch to turn the Lifter from a "0.5" stage to a "0.75" stage -- what about using a boost from one of the F5 engines as a JATO to allow smaller wings, and then additionally to boost speed and altitude for pitchup and release-- meanwhile  crossfeeding from the A/C-- either just Fuel or both-- to increase payload?

This would allow some 'envelope expansion' for the lifter over time as well.

Any thoughts?

Offline jimoutofthebox

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #55 on: 01/06/2012 04:37 pm »
I suspect that the aircraft will need a minimum altitude for the escape system to work.
why would it need minimum altitude to work?  Seems to me it could work while taxiing around the airport. Couldn't do that with yours until it is airborn.

IIRC both the F/FB111 & the B1A bombers have crew escape capsules capable of zerp-zero (zero altitude & zero speed) egress. So, don't think a Dragon capsule with throttle-able LAS should have any problems getting away from the carrier aircraft at any altitude.

Both of the aircraft systems you refer to fire straight up.  When the air launched dragon is on the ground it is pointed forward.  In order to escape on the ground the LAS system would have to double the size of the system compared to the vertical LAS system since you can only use the thrusters pointed down.  Also you wont have a lot of time from when the explosive bolts fire and the Dragon falls to runway.  I don't believe safety was well thought out for this system.  Thats why I proposed a system that would leave the passengers in the mother aircraft until a safe altitude was reached.

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #56 on: 01/10/2012 03:31 pm »
The stratolaunch idea, in combination with cross feed for F9H, makes me wonder about an alternate idea for Stratolaunch to turn the Lifter from a "0.5" stage to a "0.75" stage -- what about using a boost from one of the F5 engines as a JATO to allow smaller wings, and then additionally to boost speed and altitude for pitchup and release-- meanwhile  crossfeeding from the A/C-- either just Fuel or both-- to increase payload?

This would allow some 'envelope expansion' for the lifter over time as well.

Any thoughts?
I suspect that's the only way they are going to reach the AoA shown for the carrier aircraft in the first place so IMHO that's already a "given" feature.

As a JATO you're going to have issues with runway impingement of the exhaust plume which COULD be an issue unless a special surface is used. On wing size, the wings are sized for maximum altitude so reducing the wing-span means the carrier aircraft won't reach as high an altitude with the given payload mass.

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline RanulfC

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #57 on: 01/10/2012 03:44 pm »
Both of the aircraft systems you refer to fire straight up.  When the air launched dragon is on the ground it is pointed forward.  In order to escape on the ground the LAS system would have to double the size of the system compared to the vertical LAS system since you can only use the thrusters pointed down.  Also you wont have a lot of time from when the explosive bolts fire and the Dragon falls to runway.  I don't believe safety was well thought out for this system.  Thats why I proposed a system that would leave the passengers in the mother aircraft until a safe altitude was reached.
Just as an FYI, "zero-zero" escape systems are specifically designed to get the crew to a minimum altitude where a parachute can function to slow their ground impact. This means (in the cited cases of the F-111, and B-1B) that they have control systems which function to ensure that the crew is headed UP and AWAY from the ground even if the aircraft in question is upside down and only a few feet from the runway.

In the case of a Dragon-ish LAS on an Air-Launched rocket the Dragon on-board flight computer would use ALL the rockets with those towards the bottom at a higher thrust pushing the vehicle FORWARD and UP to clear the scene. The rockets would fire at the same TIME as the explosive bolts, (though I think on Dragon it is a spring system rather than explosives??) so the drop would be minimul.

Something I need to ask: You state that you would "modify" a C-5 by removing the floor, and later mention a mechanism to "open" the bottom. First I need to point out that while the main "frame" of the C-5 is hung from the wing unlike most commercial aircraft the "floor" is an integral part of the airframe as well having the ties that support the wheel assemblies included within the structure. (Note also that maximum payload mass is determined by the wing-carry structure not the cargo flooring)

How exactly are you planning on releasing the Launch Vehicle in flight in the first place?

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline jimoutofthebox

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #58 on: 01/10/2012 05:00 pm »
I don't believe safety was well thought out for this system.  Thats why I proposed a system that would leave the passengers in the mother aircraft until a safe altitude was reached.
Just as an FYI, "zero-zero" escape systems are specifically designed to get the crew to a minimum altitude where a parachute can function to slow their ground impact. This means (in the cited cases of the F-111, and B-1B) that they have control systems which function to ensure that the crew is headed UP and AWAY from the ground even if the aircraft in question is upside down and only a few feet from the runway.

In the case of a Dragon-ish LAS on an Air-Launched rocket the Dragon on-board flight computer would use ALL the rockets with those towards the bottom at a higher thrust pushing the vehicle FORWARD and UP to clear the scene. The rockets would fire at the same TIME as the explosive bolts, (though I think on Dragon it is a spring system rather than explosives??) so the drop would be minimul.

Something I need to ask: You state that you would "modify" a C-5 by removing the floor, and later mention a mechanism to "open" the bottom. First I need to point out that while the main "frame" of the C-5 is hung from the wing unlike most commercial aircraft the "floor" is an integral part of the airframe as well having the ties that support the wheel assemblies included within the structure. (Note also that maximum payload mass is determined by the wing-carry structure not the cargo flooring)

How exactly are you planning on releasing the Launch Vehicle in flight in the first place?

Randy

Let’s do the math.  You have 12,000 lb object 15 ft from the runway.  It has to generate 12,000 lbs of thrust directed at the ground just to hover.  You need to do more than hover so let’s say you need 24,000 lbs of thrust to accelerate away at a reasonable speed. The thrusters are fixed at 30 deg to the runway so the resultant vertical thrust vector is ½ of the available thrust so now you’re up to a total of 48,000 lbs of thrust.  This results in a need big fuel gulping engine.
 
You can’t argue with basic physics

As far as the question on the C5.  If you remove weight from an airframe you increase the useful load because you don’t have to lift the missing structure.  I suspect there is a lot of weight in the vehicle deck and ramp that doesn’t add the strength of the airframe especially if the load is suspended from the center section of the wing.  The load from the wings to the landing gear is carried by the sides of the fuselage not the deck.  I would not change structure on the sides. If aerodynamics required doors on the bottom of the aircraft they would weigh a fraction of the original structure because they wouldn’t  carry any load.

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #59 on: 01/10/2012 05:52 pm »
The load from the wings to the landing gear is carried by the sides of the fuselage not the deck. 


Load from the wing is meaningless WRT removal of the floor.  The landing gear puts loads into the floor.  The load bearing capability of the fuselage is from is shape of its structure. That is why during ground crashes vehicle breaks apart at fuselage joints.

Offline RanulfC

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #60 on: 01/10/2012 07:11 pm »
Let’s do the math.

Not to be a smart-a**, but it might be a BIG help if you actually DID the math...

Quote
You have 12,000 lb object 15 ft from the runway.  It has to generate 12,000 lbs of thrust directed at the ground just to hover.  You need to do more than hover so let’s say you need 24,000 lbs of thrust to accelerate away at a reasonable speed. The thrusters are fixed at 30 deg to the runway so the resultant vertical thrust vector is ½ of the available thrust so now you’re up to a total of 48,000 lbs of thrust.  This results in a need big fuel gulping engine.
 
You can’t argue with basic physics
"Escape" systems routinely avoid "arguing" with basic physics by means of "brute-force" ignoring them :)

More to the point; any USEFUL Launch Abort System is going to generate at a MINIMUM around 3X the force of gravity so your initial "assumption" of 12,000lbs is far to small. (A more "accurate" guess would be around 5X or closer to 60,000lbs available from the LAS for thrust) You also make a very basic mistake in "assuming" that the force is "fixed" in regards to the runway. This is in no way true as the vehicle has the capability to rotate in relation with the horizon allowing ALL the "thrust" to be directed to both lift AND speed as needed during an abort.

I suspect the capsule would be closer to only 10 or so feet off the ground at the begining of an abort sequence which is more than enough room to rotate to a near vertical orientation under thruster power.

During this the main "thrust" will be to put distance between what very well might be a speeding "plane-wreck" and the capsule while simultaniously rotating to bring the thrusters for the LAS into vertical opposition to gravity, at which point the vehicle would accelerate upwards to a distance where a parachute can be deployed to lower it to the ground.
It is also possible for the Dragon to make a ballistic descent and powered vertical landing since that is what it is being designed to do currently.

This is simply a change in the abort-navigation software and would not require any changes to the overall LAS capability itself since the LAS is specifically designed to "escape" from a standing start or avoid an on-rushing malfunctioning booster rocket suddenly relieved of the Dragon's mass.

This is what I wanted to clear up regarding such systems.

Quote
As far as the question on the C5.  If you remove weight from an airframe you increase the useful load because you don’t have to lift the missing structure.
True to a point, but this only applies to structure not required by design for airframe integrity. The C-5 and pretty much all strictly "cargo" aircraft are not so cut and dryed though.

Quote
I suspect there is a lot of weight in the vehicle deck and ramp that doesn’t add the strength of the airframe especially if the load is suspended from the center section of the wing.  The load from the wings to the landing gear is carried by the sides of the fuselage not the deck.  I would not change structure on the sides. If aerodynamics required doors on the bottom of the aircraft they would weigh a fraction of the original structure because they wouldn’t  carry any load.
In this case Jim is quite correct:
Quote from: author Jim
Load from the wing is meaningless WRT removal of the floor.  The landing gear puts loads into the floor.  The load bearing capability of the fuselage is from is shape of its structure. That is why during ground crashes vehicle breaks apart at fuselage joints.

The deck of the airframe helps tie the load into the wing box structure AND carriers the majority of the overall loading to the landing gear so "removal" is not really and option. Adding "doors" to the bottom would compromise the entire structure and would in no way be "lighter" than the current decking itself.

As I noted in another thread your basic "concept" of the LV seems to be similar to the SwiftLaunch concept:
http://mae.ucdavis.edu/faculty/sarigul/aiaa2001-4619.pdf

With the main engine(s) and thrust structure carried in a lifting fuselage and the propellants attached forward of the vehicle in a set of expendable "drop-tanks" only without the attendent "sled" and carry structure.

I've read of the advantages subscibed to with this set up, but I suspect this is another point where you need to "do-the-math" because the required amount of LH2 tankage for a "near-SSTO" Air Launched vehicle is significant enough to exceed the capability of the C-5 to carry internally. So you would be back to needing a specially constructed carrier aircraft anyway.
I'd suggest you refer to these articles on the Air Launched Sortie Vehicle studies done by the USAF:
http://www.thespacereview.com/article/1569/1
http://www.thespacereview.com/article/1580/1
http://www.thespacereview.com/article/1591/1
http://www.thespacereview.com/article/1608/1

You MAY have a point on crew safety in that loading the crew later in flight rather than before hand on the ground, but I think it's arguable at this point.

MY personal take is that perhaps the entire flight should be "flown" from the Launch Vehicle command module with the carrier vehicle flown unmanned and operated as a UAV for return to the launch-point. I'm sure folks here can have fun with THAT idea :)

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline jimoutofthebox

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #61 on: 01/12/2012 04:25 pm »
Let’s do the math.

Not to be a smart-a**, but it might be a BIG help if you actually DID the math...

Quote from: author Jim

The deck of the airframe helps tie the load into the wing box structure AND carriers the majority of the overall loading to the landing gear so "removal" is not really and option. Adding "doors" to the bottom would compromise the entire structure and would in no way be "lighter" than the current decking itself.

As I noted in another thread your basic "concept" of the LV seems to be similar to the SwiftLaunch concept:
http://mae.ucdavis.edu/faculty/sarigul/aiaa2001-4619.pdf
[quote}

I'm familar with these already With the main engine(s) and thrust structure carried in a lifting fuselage and the propellants attached forward of the vehicle in a set of expendable "drop-tanks" only without the attendent "sled" and carry structure.

I've read of the advantages subscibed to with this set up, but I suspect this is another point where you need to "do-the-math" because the required amount of LH2 tankage for a "near-SSTO" Air Launched vehicle is significant enough to exceed the capability of the C-5 to carry internally. So you would be back to needing a specially constructed carrier aircraft anyway.
I'd suggest you refer to these articles on the Air Launched Sortie Vehicle studies done by the USAF:
http://www.thespacereview.com/article/1569/1
http://www.thespacereview.com/article/1580/1
http://www.thespacereview.com/article/1591/1
http://www.thespacereview.com/article/1608/1

You MAY have a point on crew safety in that loading the crew later in flight rather than before hand on the ground, but I think it's arguable at this point.

MY personal take is that perhaps the entire flight should be "flown" from the Launch Vehicle command module with the carrier vehicle flown unmanned and operated as a UAV for return to the launch-point. I'm sure folks here can have fun with THAT idea :)

Randy

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #62 on: 01/12/2012 04:28 pm »
edit yr quotes. :)
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #63 on: 01/12/2012 09:59 pm »
edit yr quotes. :)

Sorry about that.  I hit post instead of preview.

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #64 on: 01/13/2012 06:07 pm »
edit yr quotes. :)

Sorry about that.  I hit post instead of preview.
Ouch, I hope you didn't loose TOO much post :)

As folks here can attest, I have a bad habit of writing "novel" length responses and I HATE when I do something like that!

Hope to "hear" from you again on this soon though :)

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #65 on: 01/15/2012 03:42 am »
Someone mentioned competing vehicles.  The last time I heard anything about the single An-225, it had been withdrawn from service to be modified for the same purpose as the Stratolauncher.  Supposedly, the air launched rocket was to be mounted atop the aircraft.  The Russian shuttle was test glided from atop this same plane, just as Enterprise was from NASA's STS carrier 747, but it seems very problematic to me as to how you would safely launch a big rocket from that position.

One thing that seems particularly troublesome about the Stratolauncher is a scrubbed mission. Landing with the rocket still attached and fully fueled would require the landing to be very smooth. I wonder how much clearance the rocket tail has if landing with a high angle of attack. Hitting the ground too hard, having to decelerate quickly, crabbing into a stiff crosswind then jerking the fuselage into runway alignment at touchdown, all these things could put a fair amount of leveraged stress on the attachment points.  If a fueled rocket dislodged at touchdown........   

Even if the thing is launched fueled, having the ability to offload the fuel to the mother ship may be prudent.  You'd have to make sure you could transfer all of it though, because landing with half filled tanks of sloshing fuel is even more dangerous. F-16s and F/A-18s land with attached ordinance under far greater stresses every day, but the purpose of this rocket is defeated if you add the mass equivalent to the attachment points of those carrier based bombs. Just to support the weight of the fuel prior to takeoff, the fuselage of the rocket would have to be stronger and heavier than a vertically launched version of the same size because all that fuel weight is being leveraged/vectored on the point of suspension. The mass of the attachment points needs to be kept reasonably low and the vectored stresses due to the size of this thing seem scary.

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #66 on: 01/15/2012 07:15 am »
....just as Enterprise was from NASA's STS carrier 747, but it seems very problematic to me as to how you would safely launch a big rocket from that position.

Images of the air launch fiasco during Superman Returns  :o
« Last Edit: 01/15/2012 07:16 am by docmordrid »
DM

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #67 on: 01/15/2012 12:30 pm »
The Russian shuttle was test glided from atop this same plane, just as Enterprise was from NASA's STS carrier 747,

No, it wasn't.  Buran used jet engines for glide tests.  AN-225 was only used for transport.

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #68 on: 01/15/2012 12:32 pm »

One thing that seems particularly troublesome about the Stratolauncher is a scrubbed mission. Landing with the rocket still attached and fully fueled would require the landing to be very smooth. I wonder how much clearance the rocket tail has if landing with a high angle of attack. Hitting the ground too hard, having to decelerate quickly, crabbing into a stiff crosswind then jerking the fuselage into runway alignment at touchdown, all these things could put a fair amount of leveraged stress on the attachment points.  If a fueled rocket dislodged at touchdown........   


Not really, no different than landing with an orbiter on top as long as they are in the same weight range.

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #69 on: 01/15/2012 04:53 pm »
They'd likely need some sort of fuel dump (or drain-back) capability.
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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #70 on: 01/15/2012 05:08 pm »
The Russian shuttle was test glided from atop this same plane, just as Enterprise was from NASA's STS carrier 747,

No, it wasn't.  Buran used jet engines for glide tests.  AN-225 was only used for transport.

Thanks.

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #71 on: 01/15/2012 05:24 pm »

One thing that seems particularly troublesome about the Stratolauncher is a scrubbed mission. Landing with the rocket still attached and fully fueled would require the landing to be very smooth. I wonder how much clearance the rocket tail has if landing with a high angle of attack. Hitting the ground too hard, having to decelerate quickly, crabbing into a stiff crosswind then jerking the fuselage into runway alignment at touchdown, all these things could put a fair amount of leveraged stress on the attachment points.  If a fueled rocket dislodged at touchdown........   


Not really, no different than landing with an orbiter on top as long as they are in the same weight range.

Statistically, would you say that landing after a mission scrub is the most dangerous point in the flight?

The orbiter was secured front and rear, while the Stratolaunch rocket is only secured in the center, though I realize at the balance point.  Also, the orbiter was not loaded with all that fuel/oxidizer. Those factors would seem to increase the danger to at least some degree??

Perhaps I am mentally comparing too much to commercial aircraft takeoff and landing conditions or even combat conditions. SpaceX likely would not take off unless the forecast was for optimal landing conditions, including the possibility of a mission scrub. If the conditions existed for wind shear to occur within the next two hours, they likely just wouldn't take off to begin with.

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #72 on: 01/15/2012 05:36 pm »
There probably will be a propellant dump capability

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #73 on: 01/18/2012 05:37 pm »
The orbiter was secured front and rear, while the Stratolaunch rocket is only secured in the center, though I realize at the balance point.
If you look closely the current pictures (I know, I know "artists-rendition" and all that but...  :) ) the Carrier Aircraft strongback would seem to encompass both stages so I suspet that it is suspended over a bit wider area than your assuming :)

Probably it will have carry points built into the thrust structure of the second stage and a "strong-back" running the length of the first and second stage itself.

Quote
Also, the orbiter was not loaded with all that fuel/oxidizer. Those factors would seem to increase the danger to at least some degree??
Well to be honest the Orbiter was never designed to carry much "liquid" payload at all so the comparision isn't really there. In the case of the Falcon-4 (at this point) it is going to have to be engineered for "Air-Launch" which means taking into account the various loading and stress' that entails.

It's also exactly the reason you can't simply take an "off-the-shelf" rocket and strap it to a carrier aircraft for launch. It doesn't work like that. While the very "basic" structure of the F-4 is going to be made from F-9 parts it's NOT going to be a simple transition. (Though thinking about it this is going to work well for Space-X because they can now charge a lot of the work on the "Boosters" for the F-9H to StratoLaunch, since the work for the StratoLaunch F-4 strong-back and the F-9H booster strong back are going to be similar if not the same engineering wise :) )

What you're going to end up with is going to be similar to, but built to stand different stress' and loading than the "original" F-9 structure.

Quote
Perhaps I am mentally comparing too much to commercial aircraft takeoff and landing conditions or even combat conditions. SpaceX likely would not take off unless the forecast was for optimal landing conditions, including the possibility of a mission scrub. If the conditions existed for wind shear to occur within the next two hours, they likely just wouldn't take off to begin with.
No you're actually correct overall but you're falling into the assumption that the rocket will be for all intents and purposes a "standard" F-9 but with only 4 engines :)

For this design of Air Launch the rocket itself is going to be different than a "normal" vertically launched rocket and will have to take into account those different "needs" when being designed.

HMXHMX might have a different take on this though...

Randy
From The Amazing Catstronaut on the Black Arrow LV:
British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #74 on: 01/18/2012 06:59 pm »
(Though thinking about it this is going to work well for Space-X because they can now charge a lot of the work on the "Boosters" for the F-9H to StratoLaunch, since the work for the StratoLaunch F-4 strong-back and the F-9H booster strong back are going to be similar if not the same engineering wise :) )


Huh?  They are nowhere the same.  If Spacex follows convention, the loads will be transmitted from booster thrust section to core thruster section just as Titan III, Titan IV, Delta IV Heavy, Atlas V heavy, SRM's for Delta II, Atlas V and Delta IV do.  The upper attachments are only sway braces.  How is this similar to a fueled vehicle being suspended from the mid section on an aircraft

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #75 on: 01/18/2012 07:18 pm »
RanulfC:
Another company (Dynetics) is doing the engineering for the Stratolaunch "strong-back" (as you call it). SpaceX is just another subcontractor, it's not a SpaceX project.
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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #76 on: 01/18/2012 09:08 pm »
(Though thinking about it this is going to work well for Space-X because they can now charge a lot of the work on the "Boosters" for the F-9H to StratoLaunch, since the work for the StratoLaunch F-4 strong-back and the F-9H booster strong back are going to be similar if not the same engineering wise :) )


Huh?  They are nowhere the same.  If Spacex follows convention, the loads will be transmitted from booster thrust section to core thruster section just as Titan III, Titan IV, Delta IV Heavy, Atlas V heavy, SRM's for Delta II, Atlas V and Delta IV do.  The upper attachments are only sway braces.  How is this similar to a fueled vehicle being suspended from the mid section on an aircraft
Uhm, as similar as they want it to be? :)

Ok I did NOT know that about the upper attachments. I was under the impression they were attached to the interstage bracing. I thought the Delta-IV boosters and core had a set of bracing down the side of the vehicle.

RanulfC:
Another company (Dynetics) is doing the engineering for the Stratolaunch "strong-back" (as you call it). SpaceX is just another subcontractor, it's not a SpaceX project.
Ya, I missed that I used that convention twice. The "strong-back" for the Carrier Aircraft is being built by Dynetics and they will have to coordinate closly with Space-X on the "stong-back" for the F-4 since it the one will require load sharing between the two for flight and other loads.

I'm coming from this from an aircraft-carried-stores background both munitions and other stores like travel pods and drop tanks. I'd THOUGHT that booster and core rockets were similar but it appears that I'm incorrect.

SRMs as far as I know have far different load paths than do liquid boosters so I'd assumed that liquids were going to have to have further bracing along the tank sides to even out the loads but Jim says this is not so. In aircraft/stores (such as a drop tank) the tank is designed to route all the loads along a path to the attachment points and is reinforced along that side to achieve this. Similarly the "rail/pylon" on the aircraft is designed to support and cushion the loads from and to the store to avoid stressing any one section too much.

Since there is no way to pass the loads through the thrust structure on a horizontally carried rocket I guess this IS going to be new territory for Space-X.

Randy
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British physics, old chap. It's undignified to belch flames and effluvia all over the pad, what. A true gentlemen's orbital conveyance lifts itself into the air unostentatiously, with the minimum of spectacle and a modicum of grace. Not like our American cousins' launch vehicles, eh?

Offline baldusi

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #77 on: 01/19/2012 03:02 pm »
I can only remember the Ariane 5 as attaching the boosters on the interstage. The Shuttle did it in the intertank section, of course. So it seems that segmented solids like having the thrust structure up.

Offline Jim

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #78 on: 01/19/2012 03:06 pm »
I can only remember the Ariane 5 as attaching the boosters on the interstage. The Shuttle did it in the intertank section, of course. So it seems that segmented solids like having the thrust structure up.

Titan lifted from the aft.

Offline go4mars

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #79 on: 02/08/2012 01:32 pm »
http://www.popularmechanics.com/science/space/rockets/elon-musk-on-spacexs-reusable-rocket-plans-6653023?src=rss

If this succeeds, will stratolauncher be cancelled?  Or will its "any orbit any time" feature ensure demand for stratolaunch as well? 
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Offline kevin-rf

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Re: Impact of Stratolaunch on F9 demand 5-10 years from now
« Reply #80 on: 02/08/2012 02:15 pm »
Why is this article linked in several threads?

Anyway, I love this bit of spin
Quote
So what does that mean for ticket prices in the future? Musk tells us that with daily flights, the cost will run about $100 per pound. For the average male, that means about 20,000 bucks. Start saving your money.

Only if you are just paying for the fuel to launch yourself, not including the weight of the spacecraft, depreciation, no return on investment, no profit taking, no crew and no maintenance costs, ect.

$100 per pound has been the rule of thumb fuel costs per pound to orbit since the early days of usenet. It is not a realistic goal. It only includes the fuel costs. Though I am sure several SpaceX fans will take this as gospel.
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