A rocket that glides-- on the parachute.

[Rocketbuilder]

So, a few days ago, I was playing around with OpenRocket, and had a really cool idea that I think just might work.
The rocket itself is sort of a cross between the Estes Interceptor and an F-35. I could probably get it to glide on its own, like Hornet Driver's awesome mods to the Interceptor (which helped to inspire this design ) but I had a more interesting recovery technique in mind.
Basically, there is an angled bulkhead inside the rocket (if that makes any sense) that seals off the front end, but is open to the back. Above this bulkhead, the top half of a section of tube is cut away. This section is then reattached using tubes and rods so that it can separate from the tube when the ejection charge fires.
The parachute is situated behind the angled bulkhead, so the when the ejection charge fires, the section of tube above the angled bulkhead separates, and is attached to the parachute and shock cord in the same manner as a nose cone.
The key to this design is that the parachute is not a regular parachute, but a (homemade) parawing shaped parachute, that is attached to the CG of the rocket with two cords, to prevent the rocket from spinning under it. The cords will be trimmed so that the rocket glides down in a spiral for a safe recovery.
Yes, this is ambitious and difficult, maybe even impossible, but I sure intend to try it! It will probably take several flights to get it just right, but if I can, it will be worth it.
Clear as mud?

[Salvage-1]

neat idea.

I have seen a remote control 'plane' parawing at the local RC field and its impressive. Also seen a slight twist on the parawing idea for rocket recovery, which i want to try myself one day. The parawing was had the shroud lines longer at one side than the other (etc through the middle) so that the wing didnt sit flat in the air, but at an angle of about 20deg. When the guy explained the recovery before launch, we were all skeptical, but when it deployed, it caused the rocket to 'glide' down in a wide circle, very impressive.

[AfterBurners]

Interesting concept...that's what's cool about this hobby. You are only limited by your imagination...I say go for it!

[luke strawwalker]

Sounds like a cool project. I think that your parawing will be doing 99% of the "gliding" though... the airspeed necessary for a gliding recovery with a parawing and with a fixed wing is going to be so drastically different that the fixed wing is going to be far below the stall point all the time, will be my guess. The parawing will provide so much drag that the airspeed will never be high enough for the fixed wing to develop any appreciable lift.

Also, the CG/CP relationships are drastically different for the regular ballistic flight regime and the gliding phase of flight... that's why rocket gliders use either pop-pods, slide-out motor/noseweight mounts as ejectable pods, swing-wings, flop wings, slide-wings, etc. to change the aerodynamic characteristics from ballistic flight to gliding flight at the correct time in the flight profile. Just hanging the rocket from the CG at parawing ejection isn't going to be enough, if indeed the rocket actually contributes anything at all to the glide itself. When you say "hang it by two strings to prevent twisting under the parawing" I take it you mean by two well-separated shroud line groups arranged perpendicular to the direction of flight... Might work... interesting. I've been toying with ideas to get smoother descent video from rocket cams using clusters of regular parachutes and different means of affixing them to the rocket to minimize swaying and ESPECIALLY spinning... (of course so far it's been mostly research and a 'thought exercise').

Just a few things to keep in mind as you move forward. Good luck with your project and be sure to post updates... this is a very fascinating idea!

Later! OL JR

PS. Hobby Lobby International (not to be confused with the "Hobby Lobby" we all hit with the 40% off coupon for rocket motors and supplies and clearance kits) had a parawing skydiver that flew under RC control a few years back when I was messing with electric park flyers... don't know if it's still available or not... Google might help there. It was pretty cool, as it was intended to be carried under a plane to altitude and released via servo, unfurling the chute and then the 'skydiver' hid the servos and receiver and battery working the parawing glider control cables to warp the chute and get the desired flight path... might be someplace to start looking at designs and stuff...

[Rocketbuilder]

Slavage-1, that's pretty much what I was thinking, with angling the parawing. Otherwise, it might glide to far away.

AfterBurners, I will!

Luke strawwalker, yes, the parawing will be doing all of the gliding. The "wings" on the actual rocket are just to make it look cool. Yes, when I say "hang it by two strings to prevent twisting under the parawing," mean that it will have one string attached on one side of the rocket tube, and another string attached to the other side of the tube. I'm pretty sure that's what you said.
I've seen those RC parawings, but what really gave me the parawing recovery idea was this, the x-28:

[luke strawwalker]

Slavage-1, that's pretty much what I was thinking, with angling the parawing. Otherwise, it might glide to far away.

AfterBurners, I will!

Luke strawwalker, yes, the parawing will be doing all of the gliding. The "wings" on the actual rocket are just to make it look cool. Yes, when I say "hang it by two strings to prevent twisting under the parawing," mean that it will have one string attached on one side of the rocket tube, and another string attached to the other side of the tube. I'm pretty sure that's what you said.
I've seen those RC parawings, but what really gave me the parawing recovery idea was this, the x-28:

Yep, that's a cool one... I saw the real deal once on a tour of JSC... a few years ago, the tours weren't as "generic" as they are now... sometimes they'd go to unusual destinations and see stuff you didn't usually get to see. On one particular trip, we went out to a little hangar at the back of the JSC grounds (on the north side of the complex) and got off the tram and went inside... behind a "safety rope" was the X-38 Crew Return Vehicle... http://en.wikipedia.org/wiki/Crew_Return_Vehicle right there undergoing continuing tests and construction. They were preparing for the aircraft B-52 drops at the time, IIRC... They told us that NASA actually had employee volunteers and their families come out on nights/weekends and volunteering to glue tiles onto the thing, because they had SO little development money... It was cool because many of the panels were off it and you could see inside to the "guts" of it... VERY cool stuff... Of course that tour wasn't available the next time I went to JSC, and the thing had been in all likelihood been canceled by then...

Later! OL JR

[RocKiteman]

See my post {#5} in this thread:

http://www.rocketryforum.com/showthr...light=parawing