Stratolaunch: General Company and Development Updates and Discussions

[Lars-J]

Presumably it is the piece that holds and releases the launch vehicle.

[john smith 19]

I wonder what it means by 'Pylon' and if more need to be constructed.

That's the part that hangs off the wing of the Stratolaunch plane that the rocket hangs off.  IIRC Stratolaunch sub contracted this to a third party, working with Orbital for Pegasus.

This suggests they are starting the process to develop some kind of in house "launch vehicle." Note that phrase. Could be a rocket on its side, could be (basically) a version of Pegasus (but bigger?) could be something more radical.....

This is a key high level position and the equivalent role for Pegasus was a PhD in engineering, but I think the crucial thing is experience of having done the role (or something quite a bit like it) before.

That also suggests they are probably 5 years from an in house LV. OTOH hooking up with Orbital ATK (soon to be NG/OA, or NOGA ?)  should get them some launches, and hence revenue in the meantime.

[Gliderflyer]

I wonder what it means by 'Pylon' and if more need to be constructed.

Not sure if this was meant as a joke, but this is how I interpreted it:
http://knowyourmeme.com/memes/you-must-construct-additional-pylons

[spacenut]

Is the cost of Stratolaunch  worth it for the payload to LEO capability?  SpaceX can get a 10 ton payload to LEO for a minimum of $62 million plus processing.  Can Stratolaunch do this and at what cost?

[nacnud]

Is the cost of Stratolaunch  worth it for the payload to LEO capability?  SpaceX can get a 10 ton payload to LEO for a minimum of $62 million plus processing.  Can Stratolaunch do this and at what cost?

I think the USP of Stratolaunch is the near constant access to any inclination LEO. It remains to be seen how much of a premium this commands.

[russianhalo117]

That's the part that hangs off the wing of the Stratolaunch plane that the rocket hangs off.  IIRC Stratolaunch sub contracted this to a third party, working with Orbital for Pegasus.

This suggests they are starting the process to develop some kind of in house "launch vehicle." Note that phrase. Could be a rocket on its side, could be (basically) a version of Pegasus (but bigger?) could be something more radical.....

This is a key high level position and the equivalent role for Pegasus was a PhD in engineering, but I think the crucial thing is experience of having done the role (or something quite a bit like it) before.

That also suggests they are probably 5 years from an in house LV. OTOH hooking up with Orbital ATK (soon to be NG/OA, or NOGA ?)  should get them some launches, and hence revenue in the meantime.

No just called NG. OATK name may be out the door as it will become a new business division within NG. It is a purchase NOT a merger.

[Lars-J]

Is the cost of Stratolaunch  worth it for the payload to LEO capability?  SpaceX can get a 10 ton payload to LEO for a minimum of $62 million plus processing.  Can Stratolaunch do this and at what cost?

At the moment they don’t have any launch vehicle, so they have zero capability to LEO.

The closest thing to ‘real’ they have is just OrbitalATK’s Pegasus, and that can only put ~0.5 ton to LEO.

[docmordrid]

Presumably it is the piece that holds and releases the launch vehicle.

Wonder if this is a pylon for their proposed Black Ice shuttle?

Washington Post....

>
The Black Ice space plane — should it be built — would be about as big as the former space shuttle developed by NASA and capable of staying up for at least three days. It could be launched from virtually anywhere in the world, as long as the runway could accommodate Stratolaunch’s size. And it would be capable of flying to the International Space Station, taking satellites and experiments to orbit, and maybe one day even people — though there are no plans for that in the near-term.

Then it would land back on the runway, ready to fly again.
>

[john smith 19]

Is the cost of Stratolaunch  worth it for the payload to LEO capability?  SpaceX can get a 10 ton payload to LEO for a minimum of $62 million plus processing.  Can Stratolaunch do this and at what cost?

At the moment they don’t have any launch vehicle, so they have zero capability to LEO.

The closest thing to ‘real’ they have is just OrbitalATK’s Pegasus, and that can only put ~0.5 ton to LEO.

That is a LV. It's not a very big LV, but it is flight proven.

[Rocket Surgeon]

I wonder what it means by 'Pylon' and if more need to be constructed.

Not sure if this was meant as a joke, but this is how I interpreted it:
http://knowyourmeme.com/memes/you-must-construct-additional-pylons

Was I too subtle?

[FutureSpaceTourist]

Stratolaunch planning first aircraft flight this summer
by Jeff Foust — April 16, 2018

COLORADO SPRINGS — Stratolaunch expects to conduct the first flight of its giant aircraft this summer as it develops a broad spectrum of launch services that will make use of it, the company said April 16.

http://spacenews.com/stratolaunch-planning-first-aircraft-flight-this-summer/

[yg1968]

In the recent book The Space Barons, Stratolaunch founder Paul Allen, the billionaire co-founder of Microsoft, said the company was studying a concept called Black Ice: a reusable spaceplane that would launch from the aircraft and with the option to be human-rated. Company officials at the conference confirmed that the Black Ice concept is still under study but offered few details about it.

For more on Black Ice, see this article:

The Black Ice space plane — should it be built — would be about as big as the former space shuttle developed by NASA and capable of staying up for at least three days. It could be launched from virtually anywhere in the world, as long as the runway could accommodate Stratolaunch’s size. And it would be capable of flying to the International Space Station, taking satellites and experiments to orbit, and maybe one day even people — though there are no plans for that in the near-term.

https://www.washingtonpost.com/news/the-switch/wp/2018/03/06/why-is-paul-allen-building-the-worlds-largest-airplane-perhaps-to-launch-a-space-shuttle-called-black-ice/?noredirect=on&utm_term=.dce82d5647e3

[Asteroza]

Hrm, regarding Black Ice, I wonder if the Roc can get near transonic, close enough to do a subsonic start of a ramjet equipped LV...

[Lars-J]

I'll believe "Black Ice" when I see it. But good luck with that.

[hkultala]

Hrm, regarding Black Ice, I wonder if the Roc can get near transonic, close enough to do a subsonic start of a ramjet equipped LV...

Should work even at 0.5 mach, though the thrust will be less than 30% of maximum thrust.

Found this from somewhre:

[john smith 19]

Hrm, regarding Black Ice, I wonder if the Roc can get near transonic, close enough to do a subsonic start of a ramjet equipped LV...

The USAF were looking at a subsonic ramjet to power target drones. Fixed geometry, mostly rolled and welded steel. IIRC its Mach range was limited to M0.7-M0.9. Definitely capable of being launched from a modern passenger jet, FWIW.

I'm guessing you can build subsonic (but not too efficient) ramjets fairly easily (the Germans did in WWII. There's an AGARD conference proceedings on the work, along with a load of other stuff). Likewise M2+ seems pretty doable, as BOMARC demonstrated.

But Subsonic launch and accelerate through M1 up as high as possible? That sounds kind of tough. 

[Asteroza]

Hrm, regarding Black Ice, I wonder if the Roc can get near transonic, close enough to do a subsonic start of a ramjet equipped LV...

The USAF were looking at a subsonic ramjet to power target drones. Fixed geometry, mostly rolled and welded steel. IIRC its Mach range was limited to M0.7-M0.9. Definitely capable of being launched from a modern passenger jet, FWIW.

I'm guessing you can build subsonic (but not too efficient) ramjets fairly easily (the Germans did in WWII. There's an AGARD conference proceedings on the work, along with a load of other stuff). Likewise M2+ seems pretty doable, as BOMARC demonstrated.

But Subsonic launch and accelerate through M1 up as high as possible? That sounds kind of tough. 

I was thinking in the context of something like http://astronautix.com/g/gnom.html, which featured an air augmented solid booster. If it's a first stage booster for Black Ice, you will be likely dropping it around when you no longer have usable air anyways. Even fixed inlet solid ramjet would be serviceable, though with more recent work on variable duct ramjets for missiles, you might gain something from having a variable 2D inlet.

[RanulfC]

Asteroza wrote:

Hrm, regarding Black Ice, I wonder if the Roc can get near transonic, close enough to do a subsonic start of a ramjet equipped LV...

A ramjet can be started at speeds as low as 10mph given the proper design More 'common' for the type you're thinking of is around 300mph or so with a variable inlet and exhaust.

JS19 wrote:

But Subsonic launch and accelerate through M1 up as high as possible? That sounds kind of tough.

Not really. The now defunct "alt.accel.com" pages had a couple of different design concepts for subsonic start up through about Mach-4-ish but the kicker as noted above is you have to use "active" inlets and exhausts. A 'fixed' inlet/exhaust is normally good for about +/- 2 Mach levels, (ie: design to start around Mach-1 can maybe get up to Mach-3) but it's not a 'hard' rule. (For example the ALSAM which had a fixed inlet designed to run efficiently at around Mach-4 was approaching Mach-6 with no seeming issues when it ran away due a stuck throttle. See: http://www.designation-systems.net/dusrm/app4/asalm.html Data suggests it would have kept going past that at which point the inlet would have been 'efficient' again around Mach-8 had the airframe been able to survive it )

The X7 ramjet test vehicle and engine were designed to operate to at 'least' Mach-3 but was getting up to around Mach-4.5 on a fixed inlet. The Bomarc missile which essentially used the same engine was designed to operate at Mach-3 but one test got away from them and it was destroyed pushing Mach-5 IIRC. (The person behind alt.accel actually intensively interviewed ex-ramjet engineers including the ones that built the Bomarc and all agreed that given the proper design getting a subsonic combustion, {standard rather than supersonic or Scramjet} fixed inlet ramjet up to Mach-10 was quite possible. They figured the Bomarc engines could do it but the airframe would fall apart a few seconds after hitting Mach-6)

Of course moving inlets and exhausts are heavy and expensive so there's a downside, on the other hand there was research in the late 50s which showed that by the use of 'injections of fluid' into the intake system a 'fixed' intake could take on the aspects of a 'variable' intake but the research was dropped due to technological advances. In the last few decades intake work has been focused on using the "thermal" aspects of the incoming air to create a 'virtual' inlet with various means of thermal choking of the inlet air. Unfortunately since most of the research effort has been directed towards Scramjets no one has looked seriously at applying the same process to standard ramjets.

So...

1) Use a Ejector-ramjet, (one with a rocket inside to 'pump' air through the ramjet) which helps to 'fool' the ramjet into thinking it's going faster

2) Add 'mass-injection' into the inlet to simulate a variable inlet nozzle, (water or nitrogen probably though you can use liquid methane for 'deep-cooling' I suspect LH2 would be too bulky) so you don't need a variable inlet system or can use a simpler one

3) Can use similar injection on the exhaust but as simple back-and-forth spike may be more cost effective and easier to do

4) Drop the vehicle at 'cruise' speed or around Mach-0.6 (460mph) at 35,000ft

5) Trajectory uses air-breathing till around Mach-5 or Mach-6, (no real point in going longer due to aerodynamic heating) and pure rocket from there to orbit.

(Bonus) You can use a 'super-charging' fan run by the rocket (turbine) which nets you a smaller rocket, (classify it as a 'gas-generator' ) which you can then use once you come back as propulsion for a powered landing. If you're only going up to Mach-5/6 the fan can 'freewheel' in the airstream without too much issue. Which again they found out during testing in the late 60s. It also gives you massive more airflow than just the ejector effect itself which will make your ramjet more efficient)

Significantly more important is that you can if you need to make this a multi-stage vehicle with a ramjet "second" stage and pure rocket third and all of it fully recoverable due to the increased efficiency. You also avoid the whole "trying to make a rocket strong enough to carry horizontally" which is why people keep 'defaulting' back to solids since liquid tankage is vastly more fragile. Fully support the "rocket" stage on a solid ramjet airframe

Randy

[RanulfC]

And keep in mind that Dan DeLong, (ex-XCOR) specifically conceptualized an "assisted" SSTO vehicle powered by 1 SSME and 6 RL10 capable of delivering about 14Klbs to a 400km LEO orbit.
http://selenianboondocks.com/2008/01/orbital-access-methodologies-part-i-air-launched-ssto/

So "Black Ice" isn't so far fetched as one might think

Randy

[Kabloona]

And keep in mind that Dan DeLong, (ex-XCOR) specifically conceptualized an "assisted" SSTO vehicle powered by 1 SSME and 6 RL10 capable of delivering about 14Klbs to a 400km LEO orbit.
http://selenianboondocks.com/2008/01/orbital-access-methodologies-part-i-air-launched-ssto/

So "Black Ice" isn't so far fetched as one might think

Randy

Thanks for that link, Randy. i wondered what the weight of the Dan DeLong concept vehicle was, and it wasn't readily findable in the long essay, but I assume this is the relevant part:

There have also been several rumors (from all sorts of sources) about the possibility of a White Knight 3 down the road. T/Space showed such a vehicle in their original presentations. That would likely be capable of carrying a booster in the 300-500klb range, which is about the weight of Dan’s original “Space Plane” proposal.

So, apparently that "Space Plane" concept was in the 300-500klb range, if I'm reading this correctly. And the Stratolaunch page on Wikipedia says the external payload capacity is 550klb. Conveniently comparable.