multiple airstart cluster rockets

[Neil]

A friend of mine at school, who likes to come up with entirely silly and impossible rocket designs, gave me an idea at lunch today... I had already played around with the concept once or twice, daydreaming about 20" rockets firing 54MMs off three on-board rail systems mounted to the airframe. that would be rather impractical for someone with my income, but this got me thinking about a much smaller version of the same concept. one booster rocket, maybe a D12-3, and three 13MM rockets mounted to the side. These smaller rockets would be mounted on dual wooden rods, two rods, two lugs, per rocket (so 6 rods total), to prevent movement. these rockets would all have thier own fins, in addition to the main booster's fins. I love the fallaway boosters on some of the more advanced kits, but itd be even more exiting if each of those boosters continued to climb above the main booster.

what do you think? I would proabably use a Minitimer to light the airstarts. something like this might require a cluster of motors, maybe use a Fliskits Ricter Recter, with only the bottom two tubes.

could this be (safely) done? 3 13MMs would be hard to track, but with enough eyes... itd be like a drag race beginning at 300'.

if I used an Aerotech 29MM motor, maybe a G64, and only had two airstarts, I could use an ARTS to light them up more reliably. if I were to go with that design I'd want 18s or 24s in the airstarts.

just thought I'd run this design by yall and see what you think. I cant remember ever seeing this done, is there a good reason for that or has no one ever thought of it? it has a nasty potential for disaster if the motors ignited while horizontal, but you run that risk with any staging.

*opens floor to brainstorming*

 

[Ray Dunakin]

The technique you're talking about is what I call "parasite staging", aka "piggyback staging". As far as I know, I'm the only one who's ever done it, so it would be cool to see someone else do it.

I've always used Thermalite to ignite the smaller rockets but a timer would work just as well.

The way I mount them uses two fin-like supports at the aft end which are slotted to hold the fins of the smaller rocket. At the forward end is a short 1/4" rod or tube, mounted on a little standoff. The small rocket has a launch lug that fits over this.

Because of the bulky camera payloads, I have to set it up so that the smaller rockets are held a couple inches from the side of the main (booster) rocket. If you're not using cameras on them you could put them a lot closer to the big rocket and have better results.

I have a few pics of some of these rockets and the mounting hardware in this album:

https://albums.photo.epson.com/j/AlbumIndex?u=3009006&a=30072909&f=0

There's also a bit more info about parasite staging in my booklet, "A Guide to Staging High Power Rockets", available from Extreme Rocketry.

 

[marvSRG]

All of those ideas are plausible, and, as Ray showed, he's done pretty much the same thing.

There was also an article in Sport Rocketry a few years back on a rocket called the "6-Shooter". This was a tube-finned rocket powered by a single H motor which lit thermalite fuses which lead to 6 13mm (I believe) parasite rockets mounted in each of the 6 tube fins. They were mounted via mini "rails" which were made of balsa (from what I recall) and it utilized their fins, rather than launch lugs or rail guides, for mounting. So, there were 3 little slides for each fin of each parasite rocket in every tube fin. I don't have that mag with me here in school, so I don't know which issue it was. Just look around, though...it was a somewhat recent issue--it will come up.

Definately give your ideas a shot....they're very doable, and they sound really cool.

Please report back!

 

[Ray Dunakin]

Originally posted by marvSRG
All of those ideas are plausible, and, as Ray showed, he's done pretty much the same thing.

There was also an article in Sport Rocketry a few years back on a rocket called the "6-Shooter". This was a tube-finned rocket powered by a single H motor which lit thermalite fuses which lead to 6 13mm (I believe) parasite rockets mounted in each of the 6 tube fins. They were mounted via mini "rails" which were made of balsa (from what I recall) and it utilized their fins, rather than launch lugs or rail guides, for mounting. So, there were 3 little slides for each fin of each parasite rocket in every tube fin.

Oh yeah, I'd forgotten about that one, very cool indeed.

 

[by basher]

Excellent! There will soon be three 220 Swifts air-launching from my flying field.

I'm thinking about a min. dia. 24mm booster, 3FN, with 'chute recovery. I like the idea of the booster continuing on after the "payloads" launch. We'll see.