BlackStar TSTO build

[FlyBack]

BlackStar TSTO Description:

This model is loosely based on Lockheed/Martin design studies for a two stage to orbit (TSTO), reusable space transportation system done in the late sixties. It consisted of a Carrier Vehicle and Orbiter stack that sled launched. The Carrier Vehicle had air breathing engines for fly back recovery and horizontal landing. The Orbiter was also recovered to a runway. Something similar was rumored to be operating out of Groom Lake about 16 years ago under the code name BlackStar.

The model will be flyable in three different configurations. Configuration 1 is being built now and will be covered in this thread.

Configuration 1 - R/c Orbiter glider / Rear ejection, parachute recovery Booster.
Power: AeroTech E15-WP in the Obiter. AeroTech F20-3W in the Booster.

Configuration 2 - Free-flight Orbiter glider / R/c Carrier Vehicle glider.
This was my prototype built back in 1986. Flown once but never successfully recovered. The stack failed to separate after a perfect boost... it augured. The attached photos were taken after it was re-built, but never flown again.
Power: To be determined… the original used one 24mm and one 29mm AeroTech SU motor. (for the life of me, I just can’t remember which ones). They did have the characteristic thrust/time curves of “long burn” motors in use today. The Orbiter motor ejected with streamer recovery and I’m not sure I want to do it that way this time around.

Configuration 3 - R/c Orbiter glider / R/c Carrier Vehicle glider.
Power: AeroTech E6-RCT in the Obiter. AeroTech G12-RCT in the Carrier Vehicle


More photos to come… but for now, enjoy these.

Regards,


FlyBack

[FlyBack]

One critical aspect of this design is locating the 3D center of gravity. Mockups help me do that. With an asymmetrical configuration like this one, simply pointing the motor thrust lines through the C.G. isn't enough. You have to use some math. The vector equations for static equilibrium are written around a known C.G. Summation of forces on the Z axis and summation of moments about the C.G. must equal zero. That requires some trig.

[rokitflite]

I am so dying to see this one finished and flown! :D

[FlyBack]

...Not exactly a mockup. A test model built from 6mm depron foam and .010in vacu-formed plastic. Sometimes called a "toss model" or "chuck glider". This one allowed me to confirm the C.G. and elevon deflections for the Orbiter R/c model. Oh, and yes, it flies! Glide ratio is about 8 to 1. Not bad for a low aspect ratio delta wing with a blunt body tail.

[FlyBack]

Rail mods finished. The outriggers fold inward for transport. The rail itself is 96 inches long. Why so long? In order to keep acceleration below about 5 g's I'm using long burn motors (higher accelerations would rip the wings off or induce flutter... a bad thing). Critical velocity when it clears the rail is about 35fps. IF I meet my weight targets, RocSim says it will be going 35fps at the 84 inch mark. I don't trust RocSim.

[FlyBack]

I am so dying to see this one finished and flown! :D
You and me both! I figure I have about six weeks...to make the contest that is. You'd think after twenty-three years I would be a little further along. :chuckle:

Regards,

DJ Miller

[blackshire]

One critical aspect of this design is locating the 3D center of gravity. Mockups help me do that. With an asymmetrical configuration like this one, simply pointing the motor thrust lines through the C.G. isn't enough. You have to use some math. The vector equations for static equilibrium are written around a known C.G. Summation of forces on the Z axis and summation of moments about the C.G. must equal zero. That requires some trig.

A most challenging but equally rewarding project! In either or both (or neither?) of your models, is/was the orbiter's motor ignited in flight so that it flies/flew free as a true second stage, or are/were the booster's motor and the orbiter's motor ignited simultaneously at launch as a cluster?

[FlyBack]

Black Shire

In all three configurations both motors are ignited at the same time (like a cluster). A hold back system is required. The E7-RCT orbiter motor burns slightly longer than the E15-4 booster motor. That makes it a 1 1/2 parallel stage rocket. Separation occurs when the rear ejection parachute deploys from the booster stage. The orbiter motor remains with the orbiter.

The two motors used have different impulses and average thrusts. As a consequence, they have different offsets from the vertical C.G. and also different thrust line angles. Getting that part right is a real B... err, challenge.

Regards,

DJ Miller

[blackshire]

Black Shire

In all three configurations both motors are ignited at the same time (like a cluster). A hold back system is required. The D5-P orbiter motor burns slightly longer than the E9-4 booster motor. I guess that makes it a 1 1/2 stage rocket. Separation occurs when the rear ejection parachute deploys from the booster stage. The orbiter motor remains with the orbiter.

The two motors used have different impulses and average thrusts. However, their thrust/time curves have nearly identical shapes. That characteristic is what allows me to meet the conditions stated above. As a consequence, they have different offsets from the vertical C.G. and also different thrust line angles. Getting that part right is a real B... err, challenge.

Regards,

DJ Miller

Thank you for clarifying this. Having done a bit of preliminary design work (which convinced me that I needed more mathematical design tools than I had at the time) for a flying model of Max Faget's original "DC-3" TSTO Space Shuttle, the last part of your comment feels very familiar... :-)

[FlyBack]

...just a few photos of the booster before final assembly. Tested the rear ejection system on the Fourth of July without any structural failures, scared neighbors, chared chutes or local police showing up. Worked as designed.

Next step will be installing the mating pins on the two wings. Tooling is complete, just need the time.

Regards,

DJ

[blackshire]

...just a few photos of the booster before final assembly. Tested the rear ejection system on the Fourth of July without any structural failures, scared neighbors, chared chutes or local police showing up. Worked as designed.

Next step will be installing the mating pins on the two wings. Tooling is complete, just need the time.

Regards,

DJ

Thank you for keeping us all up to date with your work on this project! Have you considered kitting it once the bugs are all worked out? If you don't wish to kit it yourself, companies such as Sirius Rocketry (I have no financial stake in them--I'm just a very satisfied customer of theirs!) produce licensed kits of other people's rocket designs.

[FlyBack]

... Have you considered kitting it once the bugs are all worked out?

Short answer... YES! That is one reason I've gone to the trouble of building tooling for certain key parts. However, my focus right now is to finish it and fly it (hopefully, before the end of the voting period for the first annual YORF rocket glider contest :chuckle: ).

Regards

DJ

Note: Post #10 has text notes added to booster_1.jpg

[FlyBack]

.. finished the mating pins, getting ready to join the wings. Attached photos should tell the story. These pins take all the thrust loads from the Orbiter to the Carrier/Booster. They have to be precisely aligned in 5 different parallel planes... on two seperate vehicles.


DJ

[FlyBack]

... finished the access hatch for the R/c gear compartment. This is a load bearing structural member. To keep it light I made some 1/8" balsa ply and used nylon screws. Next step, build the servo tray and mount the servos.

DJ

[FlyBack]

... just added text notes to photos in Posts #13 and #14. Enjoy!

DJ

[FlyBack]

.. finally finished mating the wings. The whole design hinges on how the two vehicles interface. Getting that right was a capitol B b*&^#. Final assembly of both models is now underway. Photos below show the actual glider "flight article" going together.

Regards

FlyBack

[FlyBack]

...finished the booster wing saddle. This series of photos show some of the steps. I used a relatively high density foam, cut with a hot wire. What I found most difficult was getting the "kerf" right. It took several attempts.

Regards,

FlyBack

[FlyBack]

... added stringers to the fuselage. It is starting to resemble a typical aerospace structure with ring frames, bulkheads and longerons. All thats missing is the stressed skin to make it a true semi-monoque structure. The next step is building the "servo hut". After that, install the control system and I can close it up. Photo set below.

Regards,

FlyBack

[FlyBack]

... trial fitting the fins and trailing edge flaps. The fins are made from a balsa laminate composed of two 3/32 inch thick sheets. The grain is offset just enough to resist splitting. This also helps to avoid flutter by increasing their torsional stiffness (not alot, but it helps). The trailing edge flaps will be fixed at the same angle as the Orbiter elevons, only down instead of up. Probably about 5-6 degrees.

Regards,

FlyBack

[wilsotr]

When you're ready to take orders for this thing, let us know ......... wow!

[FlyBack]

Thanks wilsotr...

That's at least one successful test flight plus about a year off...

In the mean time, more build photos. This set shows the "servo hut" and associated control runs. Also threw in some pix of the Spektrum AR500 full range receiver (case removed to save weight). The servos are Dymond D47's (probably the best sub 5gram servos made). I still have to put connectors on the Dimension Engineering 4.8v DC/DC converter. That little 1.8 gram device will allow me to use a single LiPo cell to power everything.

Regards,

DJ

[FlyBack]

... getting down to the wire. Some notes on the really dull and boring stuff. Fins were cut from contest grade balsa, tip reinforcements added, then sealed. One coat of MinWax sanding sealer followed by a layer of Silkspan on the booster and Japanese tissue on the glider. Water based polyurethane is used as the binder. The foam wing saddle on the booster/carrier fuselage gets the same treatment.

DJ

[FlyBack]

Final assembly prior to painting.... no more trial fitting. No more test pieces. Design frozen! (I like to take lots of pictures at this point because there are only two things I can do to it from here on out... screw up the paint job or crash it.) Only one critical element remains - the "Mouse Trap" (coming in next photo set). After that, most of what's left to complete is pure drudgery. Sanding, sealing, priming... sanding, priming, taping , painting. You know the drill.

Regards,

DJ

[U812]

NICE!

Steve

[snaquin]

Final assembly prior to painting.... no more trial fitting. No more test pieces. Design frozen! (I like to take lots of pictures at this point because there are only two things I can do to it from here on out... screw up the paint job or crash it.) Only one critical element remains - the "Mouse Trap" (coming in next photo set). After that, most of what's left to complete is pure drudgery. Sanding, sealing, priming... sanding, priming, taping , painting. You know the drill.

Regards,

DJ

DJ

I followed your entire built thread to date. The BlackStar TSTO is spectacular!

.

[jflis]

This is an amazing build! Very kewl concept. I love a design you can really sink your teeth into and this one's got it all!

[FlyBack]

Thanks gents! Considering the body of work you have all contributed to the hobby and this forum... high praise indeed.

Sorry, no new photos this week. I've been a little under the weather and have just not gotten much done. Besides, photos of paint drying don't make for the most exciting presentation. Anyway, here's what remains on the "to do prior to launch" list. (After the primer coat has had time to dry.)

-Finish soldering up connectors for the R/c gear.
-Re-install linkages and hinges that were reimoved for painting.
-Check control throws and mixing.
-Static test fire motors with the hold back fitting in place. This will be done twice to simulate failure of either the upper or lower motor to light.
-One more ejection system test with all the parachute rigging installed and the "Mouse Trap" holding the glider in place.
-Final checks of the the C.G. for both the glider and the combined stack. The glider is balanced with an expended motor, the stack must balance with live motors.



Regards

DJ

[FlyBack]

The part that holds the whole thing together... "The Mouse Trap".

Here's how it works; the parachute piston has a tab on it that butts up against the Orbiter, forcing it onto the mating pins. While both motors are producing thrust, the stack is rigidly held together. When the ejection charge fires, the piston is fired out the back releasing the Orbiter. In the milliseconds before the parachute deploys, the Orbiter is pushed off the mating pins by air loads and inertial loads.

Regards,

DJ

[FlyBack]

...probably the last photos of the R/c gear before gluing on the nose fairing. Items shown include the AR500 receiver, the arming pin/switch on the aft bulkhead and the voltage booster mounted on top of the battery bay.

Regards

DJ

[FlyBack]

.. a few photos of the model in its primer coat. Detailing, decals and matt finish won't be added until after it flies.

Next photo set - the hold back fitting.

Regards

DJ

[U812]

Outstanding!

Steve

[FlyBack]

Thanks Steve, and now for..

The "Hold Back Fitting".... not a lot to it, but it is a crucial component. It's purpose is just what the name describes, to hold the model onto the pad until both motors light. The tricky part was providing clearance for the lower motor when it kicks out the parachute while it's still sitting on the launch rail. Also, the upper support has to hold the Orbiter onto the Booster once the "Mouse Trap" has sprung (if it, the Orbiter, slides down more than about 3/8th of an inch it will fall onto the ground and probably hurt itself, a bad thing).

The burn strings are not shown in these photos. They are so thin you couldn't see them anyway. 10Lb test Spider Wire (looped and pull tested to 20lbs)... they don't photogragh very well. First chance I get I will update these pix with a photoshopped overlay of how they get routed. Probably would help to show where they attach to the underside of the model too.

Regards,

DJ

[U812]

This is just so well done. Can't wait to see more.

Steve

[FlyBack]

It flies!

...had a rare day of clear sky's and calm winds. Despite a few teething problems with motors and the hold back fitting, I did manage to get in one flight. Boost was hands off, straight up, arrow straight to about 300 feet. The Orbiter flies beautifully. Had some friends take a few shots of the actual launch but it may be a few days before I get them (I was a little busy learning how to fly it). Posted photos show before and after.

Regards,

DJ

P.S. My apologies for the poor quality of the pics... didn't notice until I got home I had some of the settings on my camera a bit off.

[U812]

Well done DJ! Congrats on your successful maiden. Bravo Zulu!

Next time try to get some video too.

Can't wait to see the pics!

Steve

[FlyBack]

... Bravo Zulu!...
Next time try to get some video too.

Thanks again Steve!

Oh, BTW, a friend did get some video (http://our.rocketryplanet.com/video/dj-second-attempt-at-flight-of) ... , you're also stuck with a few more before and after shots (by a much better photographer).

Next entry will outline what I learned from the test flight and what needs to be modified or improved before the next flight. Also coming, detailed specs with final weights and dimensions (didn't want to post them before because, frankly, I didn't know what they would come out to be).

Regards,

DJ Miller


photo credit: Jewel Butler -NHRC

[GregGleason]

Very nice, DJ!

Greg

[U812]

Excellent! Looks like all you need is a bit more up elevator. But that's all. Fantastic flight. Congrats!

Steve

[blackshire]

A beautiful flight of a well-planned and well-executed model project!

I can't help thinking that a winged version of the Ares I's new 5-segment Solid Rocket Motor, combined with a proportionally-scaled winged orbiter, could be a scaled-up version of the BlackStar TSTO reusable launch vehicle.

[Leo]

Very nice. Congrats :)

[FlyBack]

Thanks gents, appreciate all the kind words. Now on to...

Lessons learned from first flight.

What worked:

The aerodynamics and structure are sound. Thrust line angles are precisely correct for the motors used (this was my biggest concern). Separation dynamics were very good. The C.G for the stack and the Orbiter model was right on the money. Trim settings and control deflections for the glider worked well, although a little more nose up trim on boost will be used next flight. The parachute seems to be sized correctly for the booster weight and the external risers took the deployment loads just fine (my next biggest concern).

What didn’t work:

The hold back fitting didn’t hold the model back when one motor failed to light. Apparently, the chuff of the igniters alone was enough to burn through the strings. Gonna have to experiment with this a bit. Possibly move the model further up the rail. Fortunately, it hung up on the launch rail and wasn’t damaged too badly. (2 minutes of sanding the tip fins fixed that... I had the clearance a little too tight. :o )

The parachute deployed fully at high speed without failing but the shock cord snagged on the cutouts for the external risers (it has a three point harness on the outside of the body tube). Consequently, the three point harness didn’t do its thing and the booster came down nose first instead of horizontal. This has already been fixed for the next flight. I did some minor re-rigging and that solved the problem.

What’s getting changed:

I’m doubling the motor retention hooks so they can be safety wired. There was some evidence that the booster motor could kick itself out without firing the chute piston out (a very, very bad thing).

Motor selection and delays:

Motors for the first flight were an E15-4W and a D7-RCT. The next test flight will be with an E15-3W and an E7-RCT. This will give me true boost/sustainer 1 ½ staging. The sustainer will finish burning approximately 1.0 to 0.5 seconds before the ejection charge on the booster fires. This should provide separation just before apogee (instead of 2.5 very long seconds after).

Preliminary Specifications:

Body tube dia: 2.6 inches
Length 47 ½ inches
Span 17 ½ inches
Combined Empty Weight : 26.17 oz
Recommended Motors : still testing


Regards,

DJ Miller

(Blackshire - I haven't gotten any calls from Lockheed/Martin about a RLV yet ;) ... I'll let ya know.)

[wilsotr]

Great post-flight analysis!

[blackshire]

(Blackshire - I haven't gotten any calls from Lockheed/Martin about a RLV yet ;) ... I'll let ya know.)

For aesthetic and utility reasons, I have always preferred the early 1970s Phase B Space Shuttle study design proposals (particularly the ones that used Dr. Max Faget's straight-winged, low-crossrange orbiter designs) because those two-stage, fully-reusable winged booster/orbiter vehicles were true spaceships. The BlackStar TSTO design is also a true spaceship.

The new Shuttle-derived, 5-segment Ares I solid propellant first stage motor (and perhaps the "stock" 4-segment Space Shuttle Solid Rocket Booster motor) could be fitted with wings, tail surfaces, avionics, landing gear, and a flyback turbofan propulsion system to convert the large motor into an automated flyback booster, which would be much easier to refurbish and reload than the parachute-lowered, ocean-recovered Solid Rocket Boosters and Ares I first stages. Such flyback boosters could carry both reusable winged orbiters and (for orbiting heavier payloads) expendable upper stages.

[FlyBack]

.... The new Shuttle-derived, 5-segment Ares I solid propellant first stage motor (and perhaps the "stock" 4-segment Space Shuttle Solid Rocket Booster motor) could be fitted with wings, tail surfaces, avionics, landing gear, and a flyback turbofan propulsion system to convert the large motor into an automated flyback booster, which would be much easier to refurbish and reload than the parachute-lowered, ocean-recovered Solid Rocket Boosters and Ares I first stages. ....

It all comes down to mass fraction to orbit, doesn't it?.

Our governments unwillingness to fund projects that require huge financial outlays initially, but manageable funding over time lead to the Space Shuttle. I've seen the early wind tunnel models of alternative designs (like those you mentioned) and in the long run some of them might have been cheaper.

I respectfully disagree on one point. Large payloads (and I mean really large ) will, for the foreseeable future, require an expendable booster. You are dealing with two separate and distinct classes of vehicles here. What I have tried to do with my BlackStar model is merely present a tantalizing hypothetical solution to the two stage to orbit problem .

Now, back to the build log...

Flew it again last Saturday and nearly lost it. Got an early separation (been messing with the delays on an E15), lost orientation on the glider at low altitude and flew it right into the ground. Fortunately she's a rugged little ship and the ground was soft. No damage, its ready to fly again.

However, it needs MORE POWER! In light winds it's manageable, but for the next series of test flights I'm looking at an F20 or even an F32 in the booster . In order to do that I will have to completely redesign the "Mouse Trap". Above 4.5 G's and 90mph it needs a positive locking mechanism to hold the stack together. I can't take the chance of it coming apart during the coast phase due to air loads. In addition to that. I have to build a new motor mount that can support 29mm motors (a contingency I already planned for and have all the parts stockpiled ... not a big deal).

The good news...

Doubling the motor retention hooks and safety wiring them together worked flawlessly. I've also improved my parachute and rigging technique (clean deployment, even at low altitude). Heavy duty burn strings on the hold back fitting and an additional 1 3/4 inch offset from the nozzles looks like it may solve the "chuffing" problem.

Oh, I have attached my RockSim file. Please do not try and build anything from it. Also, make note that the Cd, Cg and reference area have all been overridden to reflect what has been measured or observed from the first two flights (don't mess with them).

Regards,

DJ Miller
Formerly: Captain of Marines / Naval Aviator

Next week: Vacation... taking my father to the Marine Corps Reserve Birthday Banquet. Two generations of Marines in one room on the same day... standby for heavy rolls and high seas. Oooh-Rah. Semper Fi !

[kevinj]

Oh, I have attached my RockSim file. Please do not try and build anything from it. Also, make note that the Cd, Cg and reference area have all been overridden to reflect what has been measured or observed from the first two flights (don't mess with them).


To this post, or some earlier post?

kj

[blackshire]

[I]It all comes down to mass fraction to orbit, doesn't it?.

Our governments unwillingness to fund projects that require huge financial outlays initially, but manageable funding over time lead to the Space Shuttle. I've seen the early wind tunnel models of alternative designs (like those you mentioned) and in the long run some of them might have been cheaper.

I respectfully disagree on one point. Large payloads (and I mean really large ) will, for the foreseeable future, require an expendable booster. You are dealing with two separate and distinct classes of vehicles here. What I have tried to do with my BlackStar model is merely present a tantalizing hypothetical solution to the two stage to orbit problem .

You're disagreeing with a point I never made. I never said that such a vehicle would be a heavy-lift launch vehicle, just that it could orbit more using an expendable upper stage than a reusable winged orbiter. For orbiting truly massive payloads (Saturn V-size and more), a huge expendable vehicle like Aerojet's solid propellant "260 Space Booster" (see the Estes model plan here: http://www.spacemodeling.org/JimZ/eirp_36.htm ) or a liquid propellant equivalent similar to the old Nova designs would be the way to go.

[FlyBack]

To this post, or some earlier post?

kj

OOps, added it to post #44.

DJ

[FlyBack]

You're disagreeing with a point I never made. I never said that such a vehicle would be a heavy-lift launch vehicle, just that it could orbit more using an expendable upper stage than a reusable winged orbiter. ..
BlackShire

I think I misread your post and interpreted "heavier" as "heavy". Actually we are in complete agreement. Sorry for the misunderstanding.

For orbiting truly massive payloads (Saturn V-size and more), a huge expendable vehicle like Aerojet's solid propellant "260 Space Booster" (see the Estes model plan here: http://www.spacemodeling.org/JimZ/eirp_36.htm ) or a liquid propellant equivalent similar to the old Nova designs would be the way to go.
These are the sorts of things that came to my mind when you said "heavier".

Regards,

DJ

[blackshire]

BlackShire

I think I misread your post and interpreted "heavier" as "heavy". Actually we are in complete agreement. Sorry for the misunderstanding.


These are the sorts of things that came to my mind when you said "heavier".

Regards,

DJ

No problem. I think the reusable launch vehicle problem has a psychological element as well as the engineering challenges--it is a seemingly impassable barrier in many engineers' minds. If a sub-scale, suborbital sounding rocket version of the BlackStar vehicle (say, 500 pounds of payload to 400 miles and back) were built and then flown several times in two months, it would break that psychological "block" that "it can't be done."

[FlyBack]

No problem. I think the reusable launch vehicle problem has a psychological element as well as the engineering challenges--it is a seemingly impassable barrier in many engineers' minds. If a sub-scale, suborbital sounding rocket version of the BlackStar vehicle (say, 500 pounds of payload to 400 miles and back) were built and then flown several times in two months, it would break that psychological "block" that "it can't be done."

Give me a grant for 28.3 million dollars and some students (http://www.jf2.com/oldcsaweb/pr010523.html) from Cal Poly (my old school) and I'd be happy to try. It would seem from their work on the StarBooster project (http://www.starbooster.com/AIAA-2001-3960.pdf) that they have what it takes to surmount "a seemingly impassable barrier". :D

Now back to the build... next post, a better "Mouse Trap" and bigger motors.

Regards

FlyBack

[FlyBack]

Progress update-

Static tested the new 29mm motor mount. Worked as designed and will allow me to use an F20-3w motor in the Booster/Carrier. The Orbiter will now carry an E15-P.

The catch/release mechanism now stays with the booster. I got the idea from looking at the upper half of a clothes pin. The torque on the hinge is provided by small magnets instead of a spring. A forward set attracting and an aft set repelling. Attached to the parachute piston/motor mount is a small clip that holds it all together during boost and coast. In the catch position, drag loads on the Orbiter are transferred to the mouse trap hinge pin and not the motor mount. Hopefully the photos below will help explain.

An additional 6" was added to the booster to get the C.G and C.P. to fall into the "stable" range (without adding a ton of nose ballast). Overall length is now 53 1/2 inches.

Next launch window will be March 20th. Hope for light winds.

Regards,

FlyBack

[FlyBack]

Larger motors... a good thing.

Finally got the photos for the March 20th shot. The Booster/Carrier model flew with an F20-4W and the Orbiter had an E15-WP. Booster delay was cut down to 3 seconds. The stack flew as designed with a nice stable boost. Altitude was estimated to be between 450 to 600 feet (based on observer polling). Separation was flawless with the improved "mouse trap" mechanism and parachute deployment was 90 percent flawless. The glider was brought in for a controlled, wings level landing (after loosing it for a split second watching the booster going straight in).

The other 10 percent... a 35 cent snap swivel connecting the shock cord to the Booster harness failed. Which ment that the motor mount / parachute piston came down just fine... but the booster augerd. Soft mud saved most of the model (about 9 inches of the forward body tube was crushed). Amazingly, the wing and all the other hard to build parts were undamaged. The nose cone is getting replaced with 8 lb/cuft pour foam, cast in vacuformed .020 in. thick PVC skins (more on that next post).

Regards,

DJ Miller


Photo credit: Lee Spinner NHRC

[FlyBack]

Sorry.. no photos of the wreckage. However the photo below with me holding the motor mount/parachute piston does show the booster harness clearly. The part that failed connects the parachute and motor assembly to the booster. Also attached a few setup pictures with the now destroyed nose section.

Photos of the new foam nose and floating canard will be the subject of the next update.

Regards

DJ Miller


Photo Credit: Lee Spinner NHRC

[GregGleason]

Nice liftoff photo sequence!

Sorry to read about the damage. :(

I love the dual flame. Are you using stock AeroTech Copperheads, or something else?

Greg

[FlyBack]

Thanks Greg,

Lee Spinner does some terrific camera work at our launches. All credit goes to Lee for capturing that sequence. Thanks Lee!

The damage is easily repaired. I had planned on redoing the nose section after a few more flights anyway. The crash just motivated me to finish tooling for the new parts. I had already done the design work for a floating/active canard that will be used on the R/c booster version. (Very similar to what I did with an Edmonds ECEE Thunder R/c conversion a couple of years ago.)

Igniters.. First Fire Juniors only (12in leads). NO COPPERHEADS! No twisted connections either. All connections are crimped or friction fit plug-in connectors.

Regards,

DJ Miller

[FlyBack]

Finally finished the vacu-formed nose cone. All repairs complete. Ready for next launch window.

The new nose and forward fuselage are built from tooling that I will use for the R/c version of the booster/carrier vehicle. It is made from three .020" PVC plastic vacu-formed parts. They are reinforced with molded 8lb density two part urethane foam. The canard flap is designed to "float" up and down for testing on this version. The nose cone has been ballasted to weigh close to what it will weigh with a receiver, battery pack, voltage converter and canard flap servo. The center of gravity has also been adjusted to mimic the dynamics of a R/c version.

Assuming I get her back in one ( err... two) pieces, I can finish the CAD drawings and print up some decals. Next update... flight report for the final configuration. Stay tuned, this is the last series of mods planned for this version.

Regards,

DJ Miller

[FlyBack]

Well, I finally got a chance to fly it with an F25-3W and E15-PW motor combo. Due to a failure of the E15 in the Orbiter to light, and the failure of the hold backs, I made a very important discovery…

The stack flies just fine on just the F25 motor in the Carrier Vehicle. This is huge. It means I can simplify and lighten the Orbiter model by about 25 percent. It also means the elimination of the hold back requirement and about four different launch failure modes. Looks like it’s back to the drawing board… time to build the Mark II version.

Until I can get a good start on that… here are some pics of the R/c Carrier Vehicle mock-up. It will initially be flown without the Orbiter. Power will be from two electric motors turning counter rotating pusher propellors.

Enjoy.

DJ Miller