H.I.L.L.S. SPACE PLANE

R

RGClark

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Just saw this mentioned on Hobbyspace.com:

H.I.L.L.S. SPACE PLANE.
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http://www.kickstarter.com/projects/hillsspace/hills-space-plane

Bob Clark
 
It's a continuation of the LEAP (Launcher Evolution Advanced Prototype) project:
http://exospace.wordpress.com/2011/06/15/hello-world/

TSTO concept at any rate. He's planning on stepping up in power as he test flies. Sounding "rocket," Drone, UAV, sub-orbital, etc. Most of the "design" really isn't fixed yet as he's still working the kinks out.

Good project and nice guy. Interesting how he's been around the "new-space" community pitching the idea and getting suggestions and help along the way.

Randy
 
Pretty cool... I have one of this genre design of my own too..I mean a reusable booster with shuttle on it.

How are goin to keep it stable at high mach numbers..the other is pushing the other right ?
 
Have they set at what speed would the two stages separate? The wing sweep would limit the first stage to about M2, while the intakes seem subsonic.
 
Remember; this is a Kickstarter model airplane...compromises included. Prototypes must change as scale increases. Expectations are subsonic climb in lower altitudes with 1st stage rocket boosted in thinner atmosphere. Atmosphere is limited above 5-10 miles and reaching orbit near 200 miles leaves a lot of time for rockets to work most of the delta vee. Air breathing engines are for easy climb and landing the first stage. I welcome the extensive visits to our web page from our Canadian neighbors too. I love the Algonquin Park!
 
Aesthetically pleasant, aerodinamically FUBAR
 
"Aesthetically pleasant, aerodinamically FUBAR..."
Is that anything like aerodynamically or is that a United Kingdom spelling? From Free Fact Finder dot com http://freefactfinder.com/definition/Aerodinamic.html You arrived at this page by searching for Aerodinamic; The correct Spelling of this word is: Aerodynamic

And yes, it is Functional Under Basically All Requirements. We have flown models already, and have fun doing it.
 
diluther said:
Wow someone should tell the X-47 designer their inlets are upside down too!
Are you making low observable TSTO? Because X-47 inlet have such design for a reason.
 
flateric said:
diluther said:
Wow someone should tell the X-47 designer their inlets are upside down too!
Are you making low observable TSTO? Because X-47 inlet have such design for a reason.

Many well tought out RCS designs are actually also better in aerodynamics...and inlets at upper side may increase lift ( undeside gets all WIG forces ) and inhale less depris from the runway.
 
Quote from flateric:
"Are you making low observable TSTO? Because X-47 inlet have such design for a reason."
Thanks for at least asking, not just shooting an opinion off. Some thermal issues may expose turbines if reentry is from high suborbital flight. There may even be a need to include a movable closure. We don't need too much detail for this early model anyway.
 

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Is the second stage of the model going to be powered?
 
[quote author=diluther]Some thermal issues may expose turbines if reentry is from high suborbital flight.
[/quote]
At what speed/altitude you are going to separate stack, I wonder, if you are talking of thermal issues for first stage?
 
How high did you David actually figure the first stage would take it. SS1 and SS2 are accompanied only to 15 000 meters.
 
diluther said:
Quote from flateric:
"Are you making low observable TSTO? Because X-47 inlet have such design for a reason."
Thanks for at least asking, not just shooting an opinion off.

Sometimes opinions are based on education and experience. What AoA is your craft going to take off at? What will the flow field be way in the back of that complex configuration at that speed and AoA?


Some thermal issues may expose turbines if reentry is from high suborbital flight. There may even be a need to include a movable closure.

Complexities easily dealt with by eliminating airbreathing. Except for special cases such as using existing aircraft as first stages (fighters, bombers, cargo craft) as a cost savings or operational simplicity measure, airbreathign first stages almost never pass through the trade studies when stacked up against simple rocket powered first stages. Liquid oxygen is dirt cheap, very dense, and the aerodynamic and trajectory improvements you get by going straight up rather than using an inefficient and difficult-on-the-structure horizontal trajectory.
 
per flateric:

"At what speed/altitude you are going to separate stack, I wonder, if you are talking of thermal issues for first stage?"

I anticipated some issues a little early on, hoping to put as much into the first stage as possible. I expect this design to stage well under 400 feet because it is a model airplane. We are posting a theoretical system for you experts to evaluate. We will evaluate basic flight only for now. But part of the effort is marketing. The Boeing Dreamliner art featured a graceful vertical tail which dissapeared in production. Aesthetics did accomplish some sales before the first flight.

I design and present opportunities to the engineers to evaluate. They change everything and then marketing changes the design requirements. As long as everyone is challenged we all get paid?
 
From AdamF:
"Is the second stage of the model going to be powered?"
We did a drop test of this basic airfoil successfuly in spite of being over weight. The carrier aircraft committed suicide with our craft strapped on before we could try an Estes rocket flight. That is a little "iffy" for AMA rules, so we may favor ducted fans to a powered landing. Proper light model construction is available with our new builder. We should be able to bring it home with light power this way. There are video links on our Kickstarter site which prove that we are not the most professional, but we have fun building stuff that flys.
 
Being new here I see unfamiliar phenomenon in the page behavior. When I reply, I see other questions and my earlier replies that have not yet posted to the site. There must be a delay for admin approval or moderation?
 
Apologies about my confusion:
As a new user I totally missed the “page 2” button at the bottom. Now I can follow up with less confusion. I was gone for a day so let me catch up will all in one now.

per flateric:
"At what speed/altitude you are going to separate stack, I wonder, if you are talking of thermal issues for first stage?"

I anticipated some issues a little early on, hoping to put as much into the first stage as possible. I expect this design to stage well under 400 feet because it is a model airplane. We are posting a theoretical system for you experts to evaluate. We will evaluate basic flight only for now. But part of the effort is marketing. The Boeing Dreamliner art featured a graceful vertical tail which disappeared in production. Aesthetics did accomplish some sales before the first flight.

I design and present opportunities to the engineers to evaluate. They change everything and then marketing changes the design requirements. As long as everyone is challenged we all get paid?

I hope to provoke a little more evaluation before anyone nails down exact numbers. I hope that horizontal launch may remain in consideration, and offered one possible way to shave off some of the drag and mass. I expect to see more propulsion technologies coming on line, and welcome proposals that may use an in-line configuration. This initial representation suggests using rockets to pass the altitude limitations of air breathing systems alone. The upper stage may have a less demanding mission if we can optimize both propulsion methods in the booster. I hope our model will establish basic handling of the configuration so it may be reasonable to consider for future use.

Orionblamblam:
"Sometimes opinions are based on education and experience. What AoA is your craft going to take off at? What will the flow field be way in the back of that complex configuration at that speed and AoA?"

Absolutely, and that education is capable of presenting specific constructive evaluation beyond "FUBAR". My education discourages me from attempting to disgrace others in public.

I would like to see the aircraft use a rail launch partly to avoid the issues Concorde suffered from rubber tires. Rails control the craft in cross winds and may lighten the pilot workload. Vehicles full of rocket fuel may need more control than present aircraft, and rails may provide a good way to brake in case of an abort decision. Perhaps they won’t need maglev or elaborate boost energy if they only offer some additional control and abort potential.

We are going to fly a model that may contribute more to understanding the combined BWB issues. I hope we will employ engineers to use computer modeling and wind tunnels one day, but I am willing to take one small step that I am able to do today. In other words, I don’t know…yet. Let’s find out!

"Complexities easily dealt with by eliminating airbreathing. Except for special cases such as using existing aircraft as first stages (fighters, bombers, cargo craft) as a cost savings or operational simplicity measure, airbreathign first stages almost never pass through the trade studies when stacked up against simple rocket powered first stages. Liquid oxygen is dirt cheap, very dense, and the aerodynamic and trajectory improvements you get by going straight up rather than using an inefficient and difficult-on-the-structure horizontal trajectory."

Stratolaunch and Xcor both indicate conventional aircraft as a first stage, and I expect they have good reason for doing so. I would never propose using an airbreathign first stage. Air breathing stages also “almost never” pass trade studies. It sounds like they might have passed some trade studies in the past though. So I hope they remain an option for future studies, as new ideas may make them worthy in the future.

Vertical launch is indeed a great way to get to orbit. At least you can deliver the upper stages to orbit, and even recover them. The booster is not often recovered since the shuttle was retired. Elon Musk and Buzz Aldrin have suggested that we need to bring these boosters back to use again. Our economy may be making the same suggestion now. Vertical landing is possible, but restarting 27 engines may be a statistical reliability challenge over many flights. Armadillo Aerospace reported a power loss as an “Interesting data point”. I don’t want to be data on a seismograph. If I lose propulsion I like having a wing and a prayer available. It worked for the shuttle and still does for the X-37.

“Is that anything like "flies" or is that a United Kingdom spelling? “ perhaps, much like “airbreathign”

Flys: plural of fly (Noun) A flying insect (order Diptera)

Actually I was speaking of flys as a verb

Flys: As a project that “flys” as a fly in a jar that is brought to the classroom by a well meaning lad, which draws attention from the class bully. He produces tweezers and pulls off one wing. Another pulls another wing off, and now you are pulling my leg!
 
diluther said:
"Sometimes opinions are based on education and experience. What AoA is your craft going to take off at? What will the flow field be way in the back of that complex configuration at that speed and AoA?"

Absolutely, and that education is capable of presenting specific constructive evaluation beyond "FUBAR". My education discourages me from attempting to disgrace others in public.


Misdirection noted.

What AoA is your craft going to take off at? What will the flow field be way in the back of that complex configuration at that speed and AoA?



I would like to see the aircraft use a rail launch partly to avoid the issues Concorde suffered from rubber tires.

Wow. Just getting more and more complex. While SpaceX simply bolts some rockets to some cans of propellant and actually attains orbit.



Stratolaunch and Xcor both indicate conventional aircraft as a first stage,


Stratolaunch proposes a very *unconventional* aircraft as a first stage, an aircraft that flies very, very slow compared to normal boosters. Xcor proposes a single-stage pure rocket series of spaceplanes.

I would never propose using an airbreathign first stage.

Wow. Continuing to play the spelling lamer?

Couple that with the vague "I'm super-awesomely educated" bit, and you don't come off so well.

If I lose propulsion I like having a wing and a prayer available. It worked for the shuttle and still does for the X-37.

Neither the shuttle nor the X-37 are boosters. They, especially the X-37, are little more than extremely complex reusable payload shrouds.

The development of the Shuttle was littered with the carcasses of thousands of fully reusable boosters.
 
Orionblamblam:"Xcor proposes a single-stage pure rocket series of spaceplanes."

Current information about Xcor orbital vehicle design plans: "Orbital system would use an existing aircraft (not custom-built); both rocket-powered stages would be reusable." http://www.parabolicarc.com/2013/04/23/jeff-greason-updates-lynx-status/
 
diluther said:
Orionblamblam:"Xcor proposes a single-stage pure rocket series of spaceplanes."

Current information about Xcor orbital vehicle design plans: "Orbital system would use an existing aircraft (not custom-built); both rocket-powered stages would be reusable." http://www.parabolicarc.com/2013/04/23/jeff-greason-updates-lynx-status/

OK. Note that in using a conventional aircraft, the Xcor system would not be relying upon it for much in the way or either altitude or delta v; carrier aircraft are mostly a way to avoid ground launch infrastructure and to allow you to select launch latitude.
 
Orionblamblam said:
diluther said:
Some thermal issues may expose turbines if reentry is from high suborbital flight. There may even be a need to include a movable closure.

Complexities easily dealt with by eliminating airbreathing. Except for special cases such as using existing aircraft as first stages (fighters, bombers, cargo craft) as a cost savings or operational simplicity measure, airbreathign first stages almost never pass through the trade studies when stacked up against simple rocket powered first stages. Liquid oxygen is dirt cheap, very dense, and the aerodynamic and trajectory improvements you get by going straight up rather than using an inefficient and difficult-on-the-structure horizontal trajectory.

Keep in mind that "airbreathing" in no way precludes taking off "straight-up" and following a modified trajectory. I should also point out that though "LOx" is dirt cheap, rocket engines themselve have short "lifespans" between maintenance while jet engines have thousands of hours or operation lifetimes.

Horizontal take off is not "hard-on-the-structure" as long as the structure is designed to handle the loads involved. The "key" here is as you noted that airbreathing first stages "almost" never make it through the trade studies for Launch Assist. An awful lot depends on the various assumptions and goals of the study.

Randy
 
diluther said:
I hope to provoke a little more evaluation before anyone nails down exact numbers. I hope that horizontal launch may remain in consideration, and offered one possible way to shave off some of the drag and mass. I expect to see more propulsion technologies coming on line, and welcome proposals that may use an in-line configuration. This initial representation suggests using rockets to pass the altitude limitations of air breathing systems alone. The upper stage may have a less demanding mission if we can optimize both propulsion methods in the booster. I hope our model will establish basic handling of the configuration so it may be reasonable to consider for future use.
I think that's one of the biggest missunderstandings here is that the project is very early in flight testing and you don't have the entire system/concept completely fleshed out and ready to roll yet :)
I would like to see the aircraft use a rail launch partly to avoid the issues Concorde suffered from rubber tires. Rails control the craft in cross winds and may lighten the pilot workload. Vehicles full of rocket fuel may need more control than present aircraft, and rails may provide a good way to brake in case of an abort decision. Perhaps they won’t need maglev or elaborate boost energy if they only offer some additional control and abort potential.
I'd suggest NOT having any "launch-assist" ground system if you can help it. They add complexity and cost which detracts for the operations-ability of the system. Vehicles "half-full" of rocket fuel* do thousands of take-offs and landings every day, I don't see "control" as an issue :)

*= Kerosene is "technically" the "fuel" half of a number of rocket launch vehicles today and thousands of aircraft take off and land with similar amounts of aviation kerosene on-board all the time :)
Stratolaunch and Xcor both indicate conventional aircraft as a first stage, and I expect they have good reason for doing so. I would never propose using an airbreathing first stage. Air breathing stages also “almost never” pass trade studies. It sounds like they might have passed some trade studies in the past though. So I hope they remain an option for future studies, as new ideas may make them worthy in the future.
(You missed a couple as both Virgin Galactic and Boeing have both "suggested" air-breathing carrier vehicles for rocket orbital stages as well :) )

May I suggest some research?

A LOT depends on what the assumptions and requirements are for any one design "trade" study. I'd suggest taking in as many various previous works as possible so you can evaluate the varius pros and cons along with the assumptions and requirements of those studies.
Unfortunatly a LOT of them, and most of the really good ones, were/are on the NASA Technical Report Server which is currently off-line for an unknown duration.
(This includes one of the "best," which if you can't find any other way let me know and I'll try and post my copy from NRTS here, is the "CROSSBOW Air Launch Trade Space" study. It is mentioned in passing in this article:
http://www.nasaspaceflight.com/2012/07/commercial-shows-reignited-interest-air-launch-system/ )

I can point to some sites for your information though,
A good basic referrence paper is this one; "A Study of Air Launch Methods for RLVs"
http://mae.ucdavis.edu/faculty/sarigul/aiaa2001-4619.pdf

AirLaunch LLc though they used a rather "normal" rocket dropped from the back of a C17 has some good papers on Air Launch and their studies here:
http://airlaunchllc.com/TechPapers.html

Searching the "Responsive Space" website for past conference papers is also helpful:
http://www.responsivespace.com/

I'd also suggest extensive web-searches for various "keyword" combinations, (such as "Air Launch Launch Vehicle Studies") for information, website, and reports.
Vertical launch is indeed a great way to get to orbit. At least you can deliver the upper stages to orbit, and even recover them. The booster is not often recovered since the shuttle was retired. Elon Musk and Buzz Aldrin have suggested that we need to bring these boosters back to use again. Our economy may be making the same suggestion now. Vertical landing is possible, but restarting 27 engines may be a statistical reliability challenge over many flights. Armadillo Aerospace reported a power loss as an “Interesting data point”. I don’t want to be data on a seismograph. If I lose propulsion I like having a wing and a prayer available. It worked for the shuttle and still does for the X-37.

To get several things "straight" from the above section, let me start with making sure we all understand that booster recovery, or non-recovery is more an economics issue than technical. With the current flight rate of launch vehicles the lower performance penalty has not favored booster recovery. It is cheaper to "expend" the rocket stage and build a new one than it is to recover and refurbish them. You also need to know that at no point has anyone suggested a "need" to restart more than one or two engines for a vertical landing rocket vehicle. What requires "27-engines" to lift off the pad comes back light enough to only need a single engine (per booster) for a fully propulsive landing.

As for an engine-out crash of a VTVL lander being "an interesting data point" and wanting "wings" to avoid this I'd point out that no rocket vertical landing vehicle was required to bring into general the use the terms "controlled-flight-into-terrain," "ditching" or "failure-to-achieve-adequate-flying-conditions" :)

Wings in fact are not needed as exampled by the HL-10, X-24, and X-24B among others :)
(My own "prefered" LV design is based on a Lenticular, or "saucer" shaped vehicle in fact :) )

Something to keep in mind anyway :)
Orionblamblam said:
diluther said:
Orionblamblam:"Xcor proposes a single-stage pure rocket series of spaceplanes."

Current information about Xcor orbital vehicle design plans: "Orbital system would use an existing aircraft (not custom-built); both rocket-powered stages would be reusable." http://www.parabolicarc.com/2013/04/23/jeff-greason-updates-lynx-status/

OK. Note that in using a conventional aircraft, the Xcor system would not be relying upon it for much in the way or either altitude or delta v; carrier aircraft are mostly a way to avoid ground launch infrastructure and to allow you to select launch latitude.
Actually the CROSSBOW study goes into more detail about what "advantages" you can gain from Air Launch. Technically there are three (3) types of "gain" that you can achieve from Air Launch though typically most systems only get a large percentage on one (1) of them.

Note these are NOT in "order" as far as I know,

1) Speed. You can gain speed with some air-launch concepts that directly relates to the LV total delta-V requirement to get into orbit. In most concepts where this is applicalbe the booster/carrier has to be capable of high-supersonic (Mach-4+) or hypersonic (Mach-5+) speeds in order for there to be appricable gain involved. Typically a 'booster' that is staging an orbital vehicle would be used to reach speeds between Mach-6 to Mach-10 or better. This is normally VERY expensive and requires a specifically designed and built airframe, along with a high speed propulsion system.

2) Altitude. Rocket engines can gain efficiency when they are "optimized" for specific altitudes. A nozzle used at sea-level is different than one that operates at high altitude and it saves complexity if a rocket motor does not have to operates at large differences in pressure. At around 35,000ft altitude a rocket nozzle designed to operate in vacuum has a lot more efficent operations than at sea-level. Typically "air-breathing engines depending on the type and how they operate can be utlized to a maxium altitude between 35,000ft and 70,000ft. Going higher requires extensive modifications and operating parameters which again leads to this being expensive. Also typically at very high altitude a rocket will supposedly be able to put more power into accellerating "side-ways" (building up delta-V velocity towards orbital speed) than in holding itself aloft.

3) Angle-Above-The-Horizon. The "typical" Air Launch carrier vehicle isn't fast enough nor does it fly high enough to really take advantage of those factors. In most cases as Orionblamblam mentiones, air launch is simply used to overcome other factors. So typically as in the case of Pegasus, StatoLaunch, or SpaceShip-2 the rocket vehices themselves are technically more "rocket-plane" than launch vehicle. This in that they have to "drop" from the carrier vehicle and then combine propulsive thrust and aerodynamic lift to achieve "flight" and then aerodynamically turn to begin the actual flight trajectory. This wastes a great deal of "energy" and detracts from the LV final delta-V total.
Typically an LV will waste less energy the closer to "vertical" (actual "optimum" is around 70 degrees) it is to the local "horizon" when it is launched. This is why T-Space and AirLaunch LLC developed such systems and the "T-LAD" harness and the "gravity-drop" method to align their launch vehicles. However since these methods pretty much preclude fireing the rocket engines until the LV has left the carrier aircraft and dropped some distance, the LV has to make up that alittude during its propulsive phase.

A "better" method would involve the LV being brought to the optimum angle while still attached to the carrier and/or being able to fire the LV engine prior to leaving the carrier aircraft. In many studies this would be achieved by adding rocket engines to the carrier aircraft to allow a high thrust-to-weight ratio to allow this pitch up. As you might imagine, the modifications and structural bracing involved in mounting a powerful rocket motor system to a "standard" airframe, (an AF study looked into installing a Space Shuttle Main Engine in the tail of a Boeing 747 and all the needed propellant tankage and equipment for example) would be expensive both in the conversion work and operations.
In some cases (the CROSSBOW concept itself for example) the LV rocket engine would be used to provide propulsive power to do the pitch up. Avoiding the need to install rockets on the carrier as well as allowing a check-out and testing of the LV rocket motor before launch. This again though falls back on needing either extensive modifications to an existing airframe or a custom airframe for the carrier aircraft, both of which can be highly expensive.

These are things that have to be considered in the design, and balanced with the various "trade-offs" involved with any systems approach. The biggest "downside" to air-launch is the payload is going to be restricted. StratoLaunch has built the worlds largest aircraft because they are "aiming" for around 10,000lbs to orbit with their system. XCOR will run into scaling issues with their system somewhat, though I'll point out that TSpace/AirLaunch LLC DID put forth a system with a similar payload that was compatable with a modified 747 air-freighter, (http://www.airlaunchllc.com/AIAA-2008-7835-176.pdf) what will determine the amount of "actual" payload possible for the XCOR system is the "mass" penalty of the reusable first and second rocket stages.

I will add one more thing while I'm at it. As I noted in my earlier post "air-breathing" boosters do not HAVE to be horizontal take off and can in fact be vertical take off and/or landing. An early study by Dani Edar of Boeing showed some significant economic advantages to using Jet Engines to boost an LH2/LOX powered vehicle during the initial launch from start to around 50,000ft. (http://yarchive.net/space/launchers/jet_first_stage.html)

Recently NASA-Dryden has put forth a variation where jet-engines are used for the first stage boost and then a ramjet for the second stage with an LH2/LOX stage to put the final payload into orbit.
(http://www.nasa.gov/offices/ipp/centers/dfrc/technology/DRC-010-039-Ram-Booster.html)

Note that while the fist two "booster" stages are recovered it appears that the final stage is not.

Current jet engine technology means that the "choice" of VTVL (OR) HTHL isn't so cut and dried as one might think :)
Operations, flight rate capability, and other factors may mean different things and take on different priorities when different assumptions are made and requirements directed :)

Randy
 
Well now I see some good reference material and constructive input flowing. That will keep me reading for quite a while. These past efforts generated a lot of good data and I expect there will be more interesting ones to come. We may produce only small results initially as our Kickstarter is ending short of the goals. Thanks to all for the comments and suggestions. We may find good ideas that produce new trade studies if combined in new ways. I hope we will find contributors who enter with their eyes open and having the confidence to offer their own opportunities. B)
 
RanulfC: "I'd suggest NOT having any "launch-assist" ground system if you can help it. They add complexity and cost which detracts for the operations-ability of the system. Vehicles "half-full" of rocket fuel* do thousands of take-offs and landings every day, I don't see "control" as an issue."

I should elaborate because two aircraft joined have a different CG than each separately. Landing gear like to be near the CG to allow rotation, and they would be in a different condition as the aircraft are landing independantly. The booster could become tail-heavy without it's payload. Rail launch allows the gear to be for empty landing only, and reduces the mass of those structures. It would require separation for an abort landing, but passengers may like being away from the booster fuel load then anyway. I have also proposed a third stage as an abort only life boat vehicle at times. Another alternative could be a wheeled dolly, and either system may offer more propulsion (and braking or retro capacity) for the launch phase.
 
RanulfC:
"To get several things "straight" from the above section, let me start with making sure we all understand that booster recovery, or non-recovery is more an economics issue than technical. With the current flight rate of launch vehicles the lower performance penalty has not favored booster recovery. It is cheaper to "expend" the rocket stage and build a new one than it is to recover and refurbish them. You also need to know that at no point has anyone suggested a "need" to restart more than one or two engines for a vertical landing rocket vehicle. What requires "27-engines" to lift off the pad comes back light enough to only need a single engine (per booster) for a fully propulsive landing.

As for an engine-out crash of a VTVL lander being "an interesting data point" and wanting "wings" to avoid this I'd point out that no rocket vertical landing vehicle was required to bring into general the use the terms "controlled-flight-into-terrain," "ditching" or "failure-to-achieve-adequate-flying-conditions"

Wings in fact are not needed as exampled by the HL-10, X-24, and X-24B among others
(My own "prefered" LV design is based on a Lenticular, or "saucer" shaped vehicle in fact )"


Good points. I do remember that when Honda determined to conquer the lawnmower market they didn't hseitate to pay up front for an overhead valve design with compression release starting. The flathead Briggs and Stratton was doomed. If we wait for traffic to provide lower cost service we may miss the opportunity.

We did see a Saturn launch with one engine out, so landing should be a done deal with less risk. It will still challenge the engineers to do all the control and mechanical functions needed. I do expect to see it happen, yet I like having a "plan B" available.

Oh yes, we have destroyed all of our test models in flight now. At least it was our carrier aircraft that took our "passenger" along, and not our own design that committed suicide. If we had more altitude we may have achieved separation of the stages before impact. My models are a bit overbilt, so it is not too badly damaged for display use now.

Our "orbiter is inspired by HL-10 in part, blending a little more wing than a lifting body only to extend cross range hopes a bit if needed. It may tolerate another mass penalty for small turbines just to maintain minimal air speed as well. These ideas seem more optimal for passenger operations than heavy lift. I expect to see a lot of new technologies finding a niche in the new space market. Fixed wing and rotary wing aircraft are suited to widely different uses, but both generate revenue. Let's keep looking for ways to shave a few ounces off of the systems that didn't pass trade studies in the past. There may still be one good way to invent a light bulb!
 
RanulfC said:
Technically there are three (3) types of "gain" that you can achieve from Air Launch though typically most systems only get a large percentage on one (1) of them.

There is a fourth advantage in increased flexibility. You can launch closer to equator and get a small extra boost from Earth's rotation. Weather is also a much smaller issue. The carrier aircraft can take-off in a fairly ugly storm, which clears up by the time you reach the launch altitude at 40,000 ft.

RE: Horizontal Stacking

I am also curious on how the separation will be done. The second stage obviously cannot light its engine close to the first stage. I think that the plane could enter a shallow dive with the first stage deploying an air-brake to force separation.
 
AdamF:
"I am also curious on how the separation will be done. The second stage obviously cannot light its engine close to the first stage. I think that the plane could enter a shallow dive with the first stage deploying an air-brake to force separation."

Everyone asks this. Spacex uses compressed air, some use springs, others just let the stages drift apart I believe. At the altitude that is leaving atmosphere behind we may find it easier to do. In-line staging is the standard method with vertical launch, and these will be in a similar flight path by this event.

Our model builder is only concerned with low level, so even air brakes could work. Small Estes rockets could be positioned away from the first stage surfaces too.
 
ARROW DYNAMICS

I find that new ideas are often greeted by slings and arrows. Engineers can always see the dumb ideas from a distance. But they often can’t see the good solutions until they are getting a paycheck. As a designer I worked on a lot of dumb ideas and a few good ones over the years. I try to follow good ideas and consider how they might be applied to other missions. Thus I see potential for wing bodies in horizontal launch applications. We have seen good engineers like Burnelli, Horten, and Northrop producing novel solutions. Boeing and NASA are enthusiastic about wing bodies. While they may not yet fit well in airline terminals they could be great booster stages for horizontal launch.

My notions of staging these craft in-line will face challenges, but may offer more drag reduction. Perhaps they will allow a smaller booster stage. Trade studies by qualified professionals may reveal solutions that make this possible. I seem to have a problem communicating with aerospace professionals though. I do not produce scholarly documents for the AIAA so I may not be speaking the language.

Perhaps my ideas seem arrogant or silly to the real experts in these fields. Still we have seen a lot of experimental programs come and go at NASA and in industry. Some of those might have been dumb ideas and perhaps a few still linger in the works. Still they pay the bills for a while so the work goes on. So my offering may only be one more dumb idea, and it might employ a few engineers if it had funding. If I am poor I am crazy, but if I am wealthy I am only eccentric!

If a poor guy proposes another crazy idea he really fits in at the patent office. I hear that doing something the same way as before while expecting different results is considered crazy. That sounds like congress telling NASA to resurrect Saturn type vehicles and expecting affordable results. I guess you don’t have to be poor to be crazy. But then a lot of patents are crazy enough to leave their authors poor too.

So I want to use this end of my career to suggest possible solutions without being dismissed as a nut case. Most of the basics of horizontal launch keep resurfacing over many decades. Some recent ones are not widely different from my own. I retain hope for a two stage to orbit space plane. I hope to deliver s slight aerodynamic advantage that will also reduce mass slightly. I am warned about structural challenges. Those are targets for more innovative solutions.

This is where my patents are limited. I own a basic concept which the whole world can view on line. The art is already obsolete, and was always generally vague. Hard solutions have to remain in-house for secrecy. In effect I bought the land at the narrow point in the canyon. The blueprints for a dam remain company property though. I think we know that water goes downhill, so this will be the property to build a dam on. I can keep folks off the land, but dam building is more technical so I keep that in-house.

I see direction for space access moving to safe winged systems for human flight. I bought a solution to improve efficiency a bit. I am making test models to demonstrate and illustrate more solutions to qualified investors. I can afford to build the small projects and they cover some of the concerns for space launch. Other design issues require skilled analysis. If we sell a few small projects along the way we may be ready to bring those experts in.

As discussions with others grow I have to try to focus on the best available solutions. Some good new ideas are available, and some still need more development. I have to focus on airframes while considering the best propulsion solutions. Communication between propulsion and aerodynamic expertise has to be open and free. I also have to watch the dynamics of the business development. Good teams can be changed by the needs of the investors.

We need to have a team with a common goal that will not deviate with every new wind of doctrine. There is no advantage to cutting corners that cut the legs off the table. More than one venture has been commandeered by investors in the past. Steve Jobs was redeemed by Apple, but that was a rare case. I want to give this proposal a fair evaluation before it is vectored off on a different technology path.

We cannot be cast in stone early in concept design, so some change is needed for a good final design. We should try to identify the core values we want to evaluate, refine, and take to market. Those should be preserved through the evolution of a good orbital launch technology. For me the in-line staging is my contribution that I hold to be a valuable contribution.

I invested deeply in the patent, and I hope to see more great solutions go to patent later. Others may make these contributions and they will hold those valuable properties themselves. I can’t suggest that they give up all rights for their work for an “open source” philosophy. At some point workers need to own some rewards for their family and retirement.

Open source developments may appeal to some, but eventually highly skilled personnel may have to pay off a student loan. I have been told by one individual that he would feel free to use any of my ideas that he sees for his later ventures. That’s why you see only the obsolete art in the patent applications.

I have known of workers who brought boxes of information from former employers to their new jobs. Loyalty is an issue today, especially where so many firms want to use temporary help. One firm wondered why they had no fresh ideas when 90% of their work force was ineligible for the suggestion plan rewards. Duh! At least one new space venture is getting a reputation for quickly using and losing their young engineers. They also depend heavily on proprietary information protection instead of patents. Will it work?

So space industry faces moral issues on both sides. I want to be able to stand by employees with a rewarding career path. We need to expect a little loyalty in return; especially around expensive research discoveries. I think employees need to share the rewards of patents to motivate better protection of those contributions. Whatever we do as a company should reflect relationships for life as well as for making a living. Enterprise is more than a starship; it’s a fellowship.

I may be a little old to follow this dream to a full scale manufacturing and marketing venture. I expect some young blood to pick up the scent of a good opportunity here. I will have fun with the smallest development projects because I enjoy putting a dream together. But I will have to build the dream for someone else. That is what my whole career has been; putting someone else’s dream together. Some of those ideas are rusting away in junk yards near you today!

There is room for many skills and dreams in this venture. Students in business, law, engineering, science, and marketing should be watching for open doors like this. A few of us older professionals might be able to point out an opportunity but this will be a long term development. My patent is good for seventeen years; are you?

Older professionals are needed to guide this effort now. I am sure there are a few unemployed engineers out there. You have surely worked for at least one nut in your previous employment. Perhaps you can help me to graduate to “eccentric” as we move this towards real customers. We especially need to begin early evaluation of orbital mechanics, propulsion, aerodynamics, and structures.

By the way, I’m not too proud to accept contribution from my critics too. Some of you are good at shooting us down; can you get us back in the air too? Dad was an engineer, and when he saw my proposal he suggested that I need professional help. I think he meant engineering professionals, but I will take all the help I can get.

A FEW SMALL STEPS TODAY: A fast build plywood model
 

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diluther said:
I find that new ideas are often greeted by slings and arrows.
As they should be. Only the crackpots complain when their notions are greeted with skepticism.

By the way, I’m not too proud to accept contribution from my critics too. Some of you are good at shooting us down; can you get us back in the air too?
Simplicate and add lightness.
In short: if you want a functional and economic space launch system, move away from complexity and "coolness."
 
Good points;

This system has been looking at a less economical path in hope of keeping some redundant safety options only for manned operations. It is a hard path which Spacex easily beats for cargo. So we still have a big job to keep the proposal slightly affordable if justified by some safety advantages. Horizontal launch is messy unless we can keep re-usability and still keep it simple.
 
diluther said:
So we still have a big job to keep the proposal slightly affordable if justified by some safety advantages.

Winged launch vehicles will probably always be less safe than non-winged. Not only do they add extra dead mass and complexity, they also require additional control ability (which can in principle fail), and if they use the wings for launch, fly a longer, most costly and harsher launch trajectory than a non-winged rocket that just goes straight up for a few miles.

Horizontal launch is messy unless we can keep re-usability and still keep it simple.

"Horizontal launch" and "simple" are basically mutually exclusive concept. Especially so when you design a multi-stage vehicle where each stage is an all-new vehicle that much fly successfully on its own *and* as a composite vehicle. As a consequence, you have not one, but *multiple* development programs, each as complex and expensive as an individual high-performance aircraft development program (or worse). And if your vehicle is a highly integrated system, your individual winged stages can't be used for anything else. All must work, and all must work together, or the whole thing is a giant failure.
 
Orionblamblam said:
Winged launch vehicles will probably always be less safe than non-winged. Not only do they add extra dead mass and complexity, they also require additional control ability (which can in principle fail), and if they use the wings for launch, fly a longer, most costly and harsher launch trajectory than a non-winged rocket that just goes straight up for a few miles.

Beware of absolute statements like that. What is the successful "launch" rates of B-52s and L.1011s, compared to any rocket booster you care to name? Yet both the Buff and the Tristar make very good first stages.

But as OBB pointed out later, both these first stages had their development programs mostly paid for by somebody other than the launching agency. Still, that doesn't mean you can't develop a new winged first stage. Just be prepared for costs. Maybe using a SpaceX development model rather than a government model will help offset that.
 
Bill Walker said:
What is the successful "launch" rates of B-52s and L.1011s, compared to any rocket booster you care to name?
Non sequitur, unless you select a first stage rocket booster that stages at substantially less than Mach 1.
Yet both the Buff and the Tristar make very good first stages.
Not particularly. They make kinda "meh" first stages, in that they loft the boosters only a fairly low altitude, and extremely low speed. What they are good as is mobile launch *platforms,* to select launch points for inclination and such.

Optimized launch vehicles would stage the second stage off the first at somewhere north of Mach 3. Good luck designing a specialized aircraft for *that* on any kind of non-governmental budget.
 
RanulfC said:
...

A LOT depends on what the assumptions and requirements are for any one design "trade" study. I'd suggest taking in as many various previous works as possible so you can evaluate the varius pros and cons along with the assumptions and requirements of those studies.
Unfortunatly a LOT of them, and most of the really good ones, were/are on the NASA Technical Report Server which is currently off-line for an unknown duration.
(This includes one of the "best," which if you can't find any other way let me know and I'll try and post my copy from NRTS here, is the "CROSSBOW Air Launch Trade Space" study. It is mentioned in passing in this article:
http://www.nasaspaceflight.com/2012/07/commercial-shows-reignited-interest-air-launch-system/ )

I can point to some sites for your information though,
A good basic referrence paper is this one; "A Study of Air Launch Methods for RLVs"
http://mae.ucdavis.edu/faculty/sarigul/aiaa2001-4619.pdf

AirLaunch LLc though they used a rather "normal" rocket dropped from the back of a C17 has some good papers on Air Launch and their studies here:
http://airlaunchllc.com/TechPapers.html

Searching the "Responsive Space" website for past conference papers is also helpful:
http://www.responsivespace.com/

...

Thanks for the very informative post on air launch. This study found by using a supersonic carrier aircraft you could double the payload of the Falcon 1:

Conceptual Design of a Supersonic Air-launch System.
43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit
8 - 11 July 2007, Cincinnati, OH
http://www.ae.illinois.edu/m-selig/pubs/ClarkeEtal-2007-AIAA-2007-5841-AirLaunch.pdf

Bob Clark
 
I posted another link to the ALTO Crossbow in that discussion area. This new pdf offers more points on staging and unique horizontal launch ideas. I suspect that a modular launcher may be a reach to justify development costs though. But there may be ways to offer different upper stage variants for multiple missions.
http://www.secretprojects.co.uk/forum/index.php/topic,14194.0.
 

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