Stratolaunch: General Company and Development Updates and Discussions

[go4mars]

Does the stratolauncher only need a really long runway assuming the rocket is fueled on the ground?  Phrased differently, could a lighter load use more common, shorter runways? 

What i'm thinking: Mid-air refueling of stratolauncher or F5 could impact runway requirements.
Even if no mid-air refueling, loaded stratolauncher would need the long runway.  After it shoots its rocket, it could land somewhere with a more typical runway, re-fuel, and fly to somewhere else (potentially to a more common (shorter) runway. 

[Jim]

Yep. Pretty nifty. Lots of countries could eventually gain routine access to LEO. Stratolaunch could turn out to be better than ice cream on apple pie!


Cheers!

Edited.

No, there still is ITAR

Eventually Jim, eventually...

Cheers!

Nope, not in your lifetime, ITAR will always be around.  The issues now days is components and satellites.  This is an integrated system that does have military applications.  It is not going to be sold to anyone.

Jim, you seem to be assuming that I think it would be sold. I do not. Most small and medium sized countries would most likely prefer the cheaper option of renting the launch service from Stratolaunch when they need it. Non ITAR spacecraft are available. Most countries wouldn't have enough space traffic to justify owning such a Stratolaunch aircraft. 

And the spacecraft would come to the US to be launched vs Stratolaunch going to another country's airport.  That is how to work around ITAR.

[as58]

Does the stratolauncher only need a really long runway assuming the rocket is fueled on the ground?  Phrased differently, could a lighter load use more common, shorter runways? 

Probably, but I'd think the huge wingspan would be a more serious limitation than the length of the runway required.

[Jim]

Does the stratolauncher only need a really long runway assuming the rocket is fueled on the ground?  Phrased differently, could a lighter load use more common, shorter runways? 

Probably, but I'd think the huge wingspan would be a more serious limitation than the length of the runway required.

Bingo

[as58]

Also - can anyone guess at what the velocity of the aircraft would be, when releasing the rocket? What initial velocity would that rocket have, as it ignites its engines? (Sorry if the answer was already posted, because I didn't see it anywhere.)

A guess, (an only a guess ) @30,000ft to around 40,000ft and around Mach-0.87 or so (645)

Like you, I'm just guessing, but I doubt it would be that fast. The wing seems to be completely straight (no wing sweep), so it doesn't seem to be built for fast flight.

[mrmandias]

Launch flexibility is a big one, bigger than the performance improvement you get with airlaunch. They're looking to target orbital human spaceflight at relatively high launch rates. At high launch rates, it really starts making sense to try to do first-orbit rendezvous. There are considerably more opportunities for that if you have the flexibility of airlaunch.

As far as the advantages of first-orbit rendezvous with a space station, imagine if Soyuz didn't have to have the orbital module, didn't need solar arrays, and didn't need consumables for several days waiting for orbital phasing. It'd be considerably less massive (probably around 30% less mass, maybe even more).

Or, more pertinently, imagine what first-orbit rendezvous would do for Dragon... Dragon could get by without needing the trunk (just relying on Dragon's thermal mass or maybe some phase-change material for thermal control) except for structure. Also, it could well be that fitting 7 people for 2 or 3 days in a Dragon may be too crowded (and so could only do 4 or 5 or so), but if you have first-orbit rendezvous, they can withstand a few hours cramped in the Dragon capsule. Plus fewer consumables, no significant food provisions, etc, etc. And happier customers, since they get to the roomier space station with the big windows and the full toilets a lot sooner.

This all adds up to a significant reduction in mass for the spacecraft (and perhaps even along with an increase in viable crew size from 4 to 7) and better responsiveness and more reusability for the Dragon spacecraft itself (don't need to build new solar arrays or radiators each trip). That will probably end up being much more valuable than a small reduction in cost per kg to orbit compared to a Falcon 9. Remember, people are their big target market and spacecraft are generally more expensive than launch vehicles, so improving that side of the equation may well have more opportunity for improving the economics of the whole thing than just the cost-per-kg-to-LEO part.

If you can get almost twice as many people into space with the same IMLEO and a lot faster, that's a pretty big difference. Launch On Need would be an easier capability, as well, with the launch flexibility that airlaunch provides.

So . . . Stratalaunch is designed to ferry to Bigelow?  Because right now the destination space station you describe isn't there.

[Robotbeat]

Launch flexibility is a big one, bigger than the performance improvement you get with airlaunch. They're looking to target orbital human spaceflight at relatively high launch rates. At high launch rates, it really starts making sense to try to do first-orbit rendezvous. There are considerably more opportunities for that if you have the flexibility of airlaunch.

As far as the advantages of first-orbit rendezvous with a space station, imagine if Soyuz didn't have to have the orbital module, didn't need solar arrays, and didn't need consumables for several days waiting for orbital phasing. It'd be considerably less massive (probably around 30% less mass, maybe even more).

Or, more pertinently, imagine what first-orbit rendezvous would do for Dragon... Dragon could get by without needing the trunk (just relying on Dragon's thermal mass or maybe some phase-change material for thermal control) except for structure. Also, it could well be that fitting 7 people for 2 or 3 days in a Dragon may be too crowded (and so could only do 4 or 5 or so), but if you have first-orbit rendezvous, they can withstand a few hours cramped in the Dragon capsule. Plus fewer consumables, no significant food provisions, etc, etc. And happier customers, since they get to the roomier space station with the big windows and the full toilets a lot sooner.

This all adds up to a significant reduction in mass for the spacecraft (and perhaps even along with an increase in viable crew size from 4 to 7) and better responsiveness and more reusability for the Dragon spacecraft itself (don't need to build new solar arrays or radiators each trip). That will probably end up being much more valuable than a small reduction in cost per kg to orbit compared to a Falcon 9. Remember, people are their big target market and spacecraft are generally more expensive than launch vehicles, so improving that side of the equation may well have more opportunity for improving the economics of the whole thing than just the cost-per-kg-to-LEO part.

If you can get almost twice as many people into space with the same IMLEO and a lot faster, that's a pretty big difference. Launch On Need would be an easier capability, as well, with the launch flexibility that airlaunch provides.

So . . . Stratalaunch is designed to ferry to Bigelow?  Because right now the destination space station you describe isn't there.

Bigelow or something else. There have been between 8 and 11 space stations in orbit so far (depending on how you count); ISS is only one of them, and is not likely to be the last. None have used Bigelow modules so far, and not all in the future will, either.

Also, the launch market they intend to serve that would warrant a new launch vehicle like this isn't really there, either. They want to launch humans (and a lot of them).

[gin455res]

If the stratolaunch carrier plane carried a scaled up version of spaceshiptwo, that was powered by merlin engines, any idea how much payload it would be able to lift into an equivalent suborbit?

And if this suborbital payload was a third stage, what the final payload this might give to orbit?

[Comga]

If the stratolaunch carrier plane carried a scaled up version of spaceshiptwo, that was powered by merlin engines, any idea how much payload it would be able to lift into an equivalent suborbit?

And if this suborbital payload was a third stage, what the final payload this might give to orbit?

Stratolaunch is in essence and appearance a scaled-up White Knight 2, the carrier for SpaceShip 2.

The rocket is probably using derivatives of the Merlin 1D engine with air start capability and engine bells optimized for high altitude.

The low Earth orbit capacity has been stated as 13,500 lb (6125 kg) IIRC. 

edited because I misread the question.  I doubt that any manned payload would be a much like SpaceShip 2, with the feather reentry, but that is certainly not my field.

[gin455res]

What I'm asking is, if the falcon is a placeholder, then removing the placeholder and reverting to the original spaceship1, spaceship2 concept, what a 3rd stage launched from a merlin powered spaceship3 (sized to the stratolaunch carrier), might be able to get to orbit?

Not sure why that is illogical, just a trade in payload for reusability.

[go4mars]

Do you mean a giant suborbital tourist "spacecraft" like a big spaceship 2?  Seating 100 instead of 6?  Or something like that?

[Zed_Noir]

Wonder if Stratolaunch might attempt to improve the carrier aircraft's high altitude performance with either turbojets (e.g. J57) or low bypass turbofans (e.g. F414) mounted on over the wing pods.

[simonbp]

What I'm asking is, if the falcon is a placeholder, then removing the placeholder and reverting to the original spaceship1, spaceship2 concept, what a 3rd stage launched from a merlin powered spaceship3 (sized to the stratolaunch carrier), might be able to get to orbit?

The Falcon-based rocket isn't a placeholder (though the particular design of the wing may be), but rather the first and simplest of several potential vehicles which could be launched from the carrier aircraft. These other vehicles would only likely happen after the winged Falcon has successfully flown.

Since any first stage launched from the aircraft has to have wings, it's a logical assumption to have a runway-landing recoverable first stage. However, it's not a simple conversion, and the result first stage would be an almost completely new design. At that point, it would make sense to move to LH2, which would provide much more performance per take-off mass. Plus, you could leverage Scaled's SS2 experience to build it primarily from composites.

Thus, IMHO, a flyback first stage with one or two SSMEs would be an appropriate future upgrade. But there's long way to go before they'd even consider that.

[Jason1701]

Why use SSMEs? That would throw away a flyback stage's advantage of rapid reuse. And there's the issue of airstarting SSMEs.

[go4mars]

Will the stratolaunch falcon 5 also fly from F9 pads? 

That is: will F5 be in competition with stratolaunch as well?

[go4mars]

Would a throttled-down middle engine be useful/helpful during takeoff?   
If they eventually do boost-back reusability (ala F9 & Grasshopper), the middle engine on F5 would probably be a sea-level optimized engine anyways for stratolauncher architecture. 

[deltaV]

Will the stratolaunch falcon 5 also fly from F9 pads? 

That is: will F5 be in competition with stratolaunch as well?

Once you've paid for the launch aircraft using it one more time should be quite inexpensive. Ground launching the rocket sounds like a great way to add additional development costs and reduce payload to orbit for no obvious compensating benefit. Why on earth would SpaceX want to do that when they can either air-launch the Falcon 5 as it's designed or launch payloads using Falcon 9?

Would a throttled-down middle engine be useful/helpful during takeoff?   
If they eventually do boost-back reusability (ala F9 & Grasshopper), the middle engine on F5 would probably be a sea-level optimized engine anyways for stratolauncher architecture. 

Throttling down reduces rocket engine chamber pressure but atmospheric pressure doesn't throttle down to match. Consequently throttling increases the relative importance of back-pressure losses so sea level is not a good place to throttle unless you like poor specific impulse and possible flow separation. It would probably be better to just light a single Merlin at full throttle for a shorter period of time. The thrust of the aircraft/rocket combo would increase by a manageable 50% or so.

Starting one of the rocket engines on the ground sounds like a serious operational inconvenience and a non-trivial safety hazard. What's the benefit?

[gin455res]

Do you mean a giant suborbital tourist "spacecraft" like a big spaceship 2?  Seating 100 instead of 6?  Or something like that?

sort of, just the passengers are replaced by a 3rd stage, which goes to orbit.

[93143]

Starting one of the rocket engines on the ground sounds like a serious operational inconvenience and a non-trivial safety hazard. What's the benefit?

JATO.

Of course, the runway requirements are not seriously unreasonable as matters stand, so it might be superfluous.

[HappyMartian]

Yep. Pretty nifty. Lots of countries could eventually gain routine access to LEO. Stratolaunch could turn out to be better than ice cream on apple pie!


Cheers!

Edited.

No, there still is ITAR

Eventually Jim, eventually...

Cheers!

Nope, not in your lifetime, ITAR will always be around.  The issues now days is components and satellites.  This is an integrated system that does have military applications.  It is not going to be sold to anyone.

Jim, you seem to be assuming that I think it would be sold. I do not. Most small and medium sized countries would most likely prefer the cheaper option of renting the launch service from Stratolaunch when they need it. Non ITAR spacecraft are available. Most countries wouldn't have enough space traffic to justify owning such a Stratolaunch aircraft. 

And the spacecraft would come to the US to be launched vs Stratolaunch going to another country's airport.  That is how to work around ITAR.

Whatever is proper sounds good. There may be various ways to satisfy the ITAR folks.

"For practical purposes, ITAR regulations dictate that information and material pertaining to defense and military related technologies (for items listed on the U.S. Munitions List) may only be shared with U.S. Persons unless authorization from the Department of State is received or a special exemption is used."

And, "Concerns over connections between the Boeing 787 and the B-2 Spirit stealth bomber prompted Boeing to take elaborate steps cleansing the commercial jet of any military technology. The issue arose when Boeing engineers, fearing indictment and penalties, refused to sign forms declaring that the 787 was 'ITAR-free.' As a result Boeing conducted extensive research on the source of technology implemented on the 787. They removed all military technology and either found a commercial source for the same technology or replaced it with technology derived from a commercial source."
From: http://en.wikipedia.org/wiki/International_Traffic_in_Arms_Regulations


Cheers!