X-106 "Christa", the Hyper Dart

[mattblack]

I've always loved the F-106: It's one of the most beautiful jets ever. And to adapt it to a rocketplane or even a spacecraft would be cool. Imagine: Kitset spaceplanes for millionaires! What a "cottage industry" that could be!! <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[mlorrey]

Thanks for that, here's a quick and dirty morph to the X-106....

 

[mlorrey]

Here's a slight improvement

 

[rocketman5000]

mlorry, I don't know the exact velocities that you are proposing so it is hard to do the math but with the tank hanging off the top fin I think you might run into shockwave problems at high velocities. (read hypersonic) the oblique shock wave coming off the front of the tank will probably land somewhere on the vertical stab. It would act much like an plasma cutter. Do a search on scramjet expirements on with the x-15 and you should find an instance where they hung mock engines under the wing. Through oversite or general misunderstanding of compressible flow at the time the shock wave wasn't accounted for and it cut the engine off the plyon in mid flight nearly causing the plane to crash. One way around this is to use active cooling on the leading edge. An appoach used in the past.

 

[mlorrey]

I'm aware of what happened with the X-15 on the scramjet experiment. I have planned on using C-C on the leading edge of the stub of the vertical stab (as indicated by the grey zones on the graphics previously loaded). <br /><br />I believe, though, that one of the major problems with the belly mounted scramjet pylon was that the airflow below the x-15 was already significantly compressed from body lift. The dorsal side of the vehicle should have much lower dynamic pressures and temperatures than the ventral side so that, for example, the STS OMS pods do not create shock waves that cut off the vertical stab of the shuttle orbiter. This may require some Navier-Stokes analysis, though, to determine what the real effects will be, but I suspect I'm at least somewhat right on this.<br /><br />You do have a point in wanting to minimize potential risks as much as possible. I've been thinking of just getting rid of the stab stub completely and replace it with a conformal shroud (that thing isn't a tank, it is the payload module/upper stage) for the payload that mounts in place of it. This would probably save a significant amount of airframe mass as well, though this means losing the airbrake mounted in the aft end. I'd been hoping to keep it given its apparent utility in coming out of control excursions, according to what I've read from F-106, X-15, and NF-104 records, but perhaps the wing tips provide sufficient stability...

 

[rocketman5000]

Sounds like you have thought a lot of the issues out, but this is just my opinon that if you can keep from having to use exotic parts such as C-C it would be cheaper to build and maintain. perhaps the pod could be mounted on the belly of the plane w/o many modifications to the landing gear. Then to launch the upper stage you could roll the Hyperdart on its back. Alternatively the payload area could be filled with fuel tanks for longer duration flights or orbit velocity. Also my moving more of the mass to the center of the plane it could reduce the structure needed to support it and lower the moment of inertia, which may or may not be helpful. I guess that depends on the design intent of the aircraft

 

[mlorrey]

Well, C-C is a 30 year old technology, I wouldn't consider it 'exotic' in this day and age. Metal matrix composites are the more exotic materials that I've been considering, especially considering the work done with them during the X-33 program, I've heard they still have all the MM tile segments for the 33 in a warehouse somewhere.<br /><br />I've already filled the weapons bay with a 5,000 lb capacity fuel tank. Right now I'm working on expanding the LOX tank design to try to get more oxidizer for the rocket mode. I've been thinking that using the dorsal fin mount point for a small LOX tank to be used for powered takeoff, then dropped below Mach 2 would obviate any hypersonic shock issues. This would, however, eliminate its use for launching an upper stage.<br /><br />I've looked at the weapons bay for use as a payload bay. This would be possible if the Six were able to reach orbit, shrinking the length of the fuel tank to carry unpressurized cargo/consumables for the backseat passenger to use in orbit at ISS/Bigelow Suites, but the geometry of the bay really isn't useful for a decent sized upper stage unless it has a few strap-ons like a miniature Titan IV. It is approximately 1' x 3' x 17' which is significantly less space than, for instance, the RASCAL program proposed for its upper stage.<br /><br />I've also been considering two alternatives to my current ramjet under the rear belly:<br /><br />a) as someone proposed, wing mounted to the tank hardpoints, two ramjets, droppable at altitude, and either parachute or swing wing guided recovery.<br />b) an ejector shroud around the merlin, providing a ramjet of about 9 feet diameter surrounding the Merlin, which will have the added benefit of boosting the Isp of the Merlin when it is used for takeoff (operating in fuel rich mode, the exhaust velocity will boost intake air to ram speeds at low vehicle velocity as well as improve the performance of the engine). This shroud would also be droppable at altitude when going to pu

 

[mlorrey]

I received in the mail today copies of F-106B blueprints, tech manual, and weights and balance report, from the folks who maintain the Convair engineering archives (thanks a bunch, folks!!!! The check is in the mail!). Needless to say, I'm stoked, this is just what I've been needing to take this project to the next level. I need to get in-town to get a scanner that can handle 11"x17" paper to get it all digitized. I'll be setting up a website shortly for folks interested in working on the project to get involved... <br /><br />Also: payload bay: I think that instead of the weapons bay, that getting rid of the Hughes MA-1 weapons system in its entirety is going to open up a huge amount of space forward of the cockpit. With modern miniaturization, all avionics should be able to be fit inside the cockpit, and the avionics and radar bays will house the nose RCS and the payload compartment. The nose cone will have a hinge and locks to allow it to open up to deploy payload. Getting rid of the entire central vertical stab (in favor of the wingtip stabs) will allow a conformal compartment to be added back there that can be either additional LOX or an upper stage and payload (in which case a LOX tank would be installed in the nose for that mission).

 

[mlorrey]

Weight of airframe: I am more optimistic than ever. The amount of mass that is going to be dropped from this airframe is astounding. Here is a list to start:<br /><br />AN/ASQ-25 (radar/guidance/interception<br /> electronics) 364 lb<br />CVAC Solvent (used as liquid ballast) 1170 lb<br />Rocket Mission Evaluator 80 lb<br />Tail airframe 665 lb<br />Propulsion Group 7855 lb<br />Electronics Group 2970 lb<br /><br />That is over half of the empty weight that can just be dumped (over 13,000 lb). Then there are things that can be replaced with newer, better materials. The radome and its attachments are 155.7 lb. Going to a C-C radome should save 20% on that. The weapons bay doors are almost 449 lb. Replacing them with a single fuel tank module with C-C covered honeycomb heatshield should be much lighter. The landing gear and flight controls are all hydraulic. Removing the hydraulic system and going to electric actuators will save a bunch more.<br /><br />At this point, I'm convinced that even the 15,000 lb emty weight estimate for the X-106 is high, even if we add some significant TPS as others have recommended. <br /><br />The Merlin engine is only about 700-800 lbs, a LOX tank would be a few hundred lbs, and the additional structure to seal up the intakes to make them fuel tanks is far less than the savings from eliminating the intake duct work, using a wet body tank scheme for the kerosene. The wing tanks are larger than I'd hoped for, so capacity for peroxide is also larger. This will expand MIPCC capability for the ramjets and we might look at whether peroxide injection can be done with the Merlin as well.

 

[argosy]

What material are you guessing to use for cocpit "windshield"? I'm guessing you're gonna change it to something less glassy? I remember reading that they had to change the original when they runned for M2.39 record due to overheating

 

[mlorrey]

No, the record was made with a stock 106. They had stripped and gussied up another plane, but it had engine problems so the pilot decided to fly with a stock aircraft off the flightline.<br /><br />I'd love to use that aluminum oxynitrate, though I don't know how big a sheet of it we can get. One thing I was planning on doing was to mount a wedge of C-C ahead of the center windshield column. This would create the shock wave ahead of the windshield and keep the plasma away from the glass, like a leading aerospike as is used on missiles like Trident. You can see this wedge on the drawings I posted.

 

[rocketman5000]

If the LOX tank is stuck anywhere near the skin on the upper side of the airframe it is possible its walls could be part of the outer skin. Tanks already have to be insulated so it could save some on weight and the upper sking would be the coolest region during reentry. Also a relief valve could be installed on the tank (like it already should be) and excess left over LOX could be vented as it boils off from the heat helping to cool some of the structure.

 

[rocketman5000]

The wedge is a good idea. If given enough room and weight allowance it might be prudent to study being able to retract it for lower speed flight to save on your wave drag penality when it isn't neccessary. I look forward to seeing you have a site up and posted drawings. Is posting the drawings legal?

 

[mlorrey]

The area the LOX tank is in has some rather robust airframe ribs that I'd rather not screw with. They have the tunnel the J75 engine fits in pretty well defined, and at this point I was expecting to just put a composite or AlLi tank in that space to minimize work and expense. Unless we are going to turn a whole section of the airframe into a tank with the ribs internal, I think we may be limited in this respect. I also thought that switching to all peroxide oxidation would allow us to avoid cryogenics and pressurization issues with LOX and expand the volume of the main oxidizer tank significantly, but the trade-off in Isp penalty would need to be examined. I know Mitchell Burnside Clapp likes H2O2 with kerosene as for some reason better than LOX, but I don't see it, outside of being able to carry more oxidizer in less volume and avoid cryo and pressure issues. The use of H2O2 instead of LOX may solve the thermal issues with using boronated kerosene: the water part of peroxide would certainly absorb a lot of heat generated by the boron, and may just trade off the Isp advantages of boron in exchange for a much denser fuel supply and lower tank weight.

 

[mlorrey]

Thanks. Don't know if the weight of a retraction system would be worth the weight penalty versus the drag penalty. It may just aid in stability given how much of the center stab is being nixed. <br /><br />Looking at the USAF X-24C, it had a similar wedge between the windshields that wasn't retractable.<br /><br />Retracting it into the nose would likely conflict with the new payload bay layout, and a non-fixed mounting would likely cause vibration problems that could lead to failure and damage to the windshield (like putting foam upstream of C-C on the STS).<br /><br />The drawings and other documents are not marked as copyrighted, and do have "unclassified" stamps, so they appear to be public domain and not classified. Ergo, posting the drawings should be legal. Particularly as I'd like to launch this project as a means of founding a McAuliffe Space Academy, as well as the purposes of these forums is educationally oriented, these should be both public domain and fair use compliant.

 

[rocketman5000]

I didn't think about the vibration failure of the linkage, not used to not thinking about air and its dampening qualties. In my everyday work I do engineering on large compactors that produce large vibrations with eccentric forces that are up to 300kN. <br /><br />As for aluminum oxynitrate is that the "transparent alumnium" that was in the press not too long ago? Since this is the first time I heard about your"McAuliffe Space Academy" what does it really entail? Spacecraft design or astronaut training?<br /><br />

 

[mlorrey]

Well, I'd like it to do both, with whatever venture corp we get started as the prime contractor overseeing construction of vehicles, the Space Academy would provide both engineering and vocational training in spacecraft design, construction, operations, and maintenance, as well as astronaut training at three levels: pilot, mission specialist, and tourist. <br /><br />While the space tourism industry will be growing, I think providing a lot of the construction and operations manpower in an educational setting will also significantly reduce costs of the standing army. This goes along with my opinion that "tourists" should be workers in space ventures, and I also believe that, for example, pilot astronauts should be volunteer positions, given the huge boost to ones earning potential having "astronaut" on your resume provides.<br /><br />With the X-106, having a payload bay that could launch satellites, the backseater would be more than a tourist in such missions, and would be paying for and training to be a mission specialist, and thus we should be able to charge more for that seat than a plain old space tourist, also due to the boost that the title has on ones resume.<br /><br />Yeah, thats the 'transparent aluminum'. It is supposed to be very temp resistant, up to I believe 1200 C.

 

[rocketman5000]

All of this sounds very exciting. Keep me informed. I'm looking for future business oppportunites, I don't plan on being an employee forever...

 

[rocketman5000]

that is where a good engineer, espically one that will be working largely for himself will go back to the drawing board and find places to save additional weight. It is largely the same as going back after a design is complete and looking for ways to make things in a more cost effective manner.

 

[mlorrey]

Yeah, the weight and balance report I received from the Convair archives makes it clear that I grossly underestimated how much weight will be shaved from this airframe before we add new things. The weight of the radar and other electronics is immense: all tubes and inductors, etc: pre-IC technology. We'll save at least 6,000 lbs on radar and electronics. Other instrumentation can also be replaced with modern stuff for significant weight savings. Note my prior post with the weights: the original radar/intercept system was a sub for the MA-1 from Hughes. The liquid ballast listed was to make up for the rest of the expected weight of the full system install. The propulsion system is also more than just the 5700 lb engine: it is fuel pumps, lines, generator, hydraulic pumps, etc. We could add a 2,000-3,000 lb TPS to this thing and still be under 15,000 lb dry weight.

 

[rocketman5000]

Even if the electronics did work I would assume you would want to go with new equipment that hasn't been sitting around a boneyard for years. Also Data integration in the cockpit would be a big plus and Glass cockpits are available off the shelf that shoudl be possible to modify the software and imputs to display and integrate your data. since there would only essentially be only one pilot you would want to have the computer be monitoring all non critical events and only informing the pilot when there is something that is out of parameters<br />

 

[mlorrey]

Quite so. Modern health management software is a lot better than it used to be, and most sensor modules today can be IP network addressable devices with self diagonostics. Rutan developed a pretty good system for SS1 based on the X-Plane sim software. Essentially, though most all of the electronics is stuff that will be totally unnecessary for us.<br /><br />I've scanned in the docs I received from the Convair archives into PDFs. I'm working on the website. Will let you know when its available. If anybody has good OCR software, I'd like to get the weight and balance report OCR'd.

 

[rocketman5000]

I am not familiar with what the TLA (three letter acronym) OCR stands for, it is possible I might have something that is useful. Or perhaps I could use something here at work.

 

[mlorrey]

OCR is Object Character Recognition. Essentially I have several Adobe Acrobat PDF files that are scans of the documents, but the text is all graphics: the text is not searchable, editable, or copyable (for cutting and pasting into, say, an excel spreadsheet). To do this, we need to OCR the scanned PDFs, correct errors the software makes, and save. <br /><br />I just bought this software, Scan To PDF to be able to produce these PDFs without having to buy Adobe's full Acrobat application ($39 vs $400), and would like to not have to buy some OCR software too...<br /><br />Also: do you know of any good trace software that can turn the bitmap images of the blueprints into vector images like DXF or other CAD formats?

 

[Swampcat]

<font color="yellow">"OCR is Object Character Recognition."</font><br /><br />Minor nit here...I believe OCR stands for Optical Character Recognition. <div class="Discussion_UserSignature"> <font size="3" color="#ff9900"><p><font size="1" color="#993300"><strong><em>------------------------------------------------------------------- </em></strong></font></p><p><font size="1" color="#993300"><strong><em>"I hold it that a little rebellion now and then is a good thing, and as necessary in the political world as storms in the physical. Unsuccessful rebellions, indeed, generally establish the encroachments on the rights of the people which have produced them. An observation of this truth should render honest republican governors so mild in their punishment of rebellions as not to discourage them too much. It is a medicine necessary for the sound health of government."</em></strong></font></p><p><font size="1" color="#993300"><strong>Thomas Jefferson</strong></font></p></font> </div>