WORLD WIDE WEB — Paul Holmes of Tripoli Motor Testing has announced today new motor certifications for six Contrail Rockets hybrid motors as well as for Contrail's sister company, Trojan Rocket Motors, marking the very first Trojan hybrid motor certified for consumer use.

According to Holmes, these Contrail certifications are additional reloads for established 38mm, 54mm and 75mm hardware, as well as a new "White Smoke" propellant formula was certified in the 54mm motor line and a new 60" 54mm K motor was certified with the Fast Sparky propellant.

Leading off the new certifications is a G170PVC motor, a 16" medium 38mm PVC motor with 82.92 total NS, which accounts for a 3% G with a .5 second burn motor. Holmes identified it as "a good motor for those applications requiring a high average output in the low G range." 

The new White Smoke propellant line was certified in three 54mm sizes: an I247WS, a 28" 54mm 98% I motor with 637 NS total with a 2.65 second burn time; a J277WS, a 36" 54mm version of the previous motor, certified with 1031.6 NS total with a 3.8 second burn time; and a K525WS, a 48" version with a fast injector, and certified with 1620 total NS and a 3 second burn time.

A new 28" 75mm K motor, the K654BS, was certified as a 66% K, with 2132 total NS with a burn time of 3.5 seconds.

The final Contrail hybrid certified was a new 60" 54mm hybrid motor with the Fast Sparky propellant formula. This motor has 2237 NS total with a 4.3 second burn time.  Contrail is expected to certify additional motors in this case length in the near future.

Contrail's sister company, Trojan Rocket Motors, enjoyed their first certified hybrid, an 54mm H motor.  The Trojan hybrids, a concept introduced in the fall of 2006, mate a Hypertek nitrous tank with a Contrail-style case and reload, called a case-contained grain system. 

They utilize the same operations profile of the standard Contrail hybrids, featuring fill-and-fire at the pad utilizing a Pyrodex preheater.  The plan is to offer reloads in all of the standard Contrail grain formulations.

The H200BS is a 54mm hybrid motor with a 3/16" injector mated to a 300cc nitrous tank, and was certified as a 68% H with 268.96 NS total and a 1.37 second burn time.  TMT has scheduled testing of the 54mm Trojan motor line throughout the summer in all tank sizes, injector and propellant types.

05-30-2008 01:20 PM  #1
Garoq Warp-9 Certified   Joined: Aug 2006 Posts: 25	Re: TMT certifies new Contrail and Trojan hybrid products Congratulations Tom!

05-30-2008 01:29 PM  #2
NiallOswald Caught the bug again...   Joined: May 2008 Posts: 38	Re: TMT certifies new Contrail and Trojan hybrid products Is there a typo? 83Ns from a 16" motor doesn't seem like an awful lot compared to similarly sized hybrids. I guess there's a big tradeoff between length of grain to give high thrust and size of nitrous tank for impulse. These long, high-thrust motors sound like an ideal candidate for modification into coaxial hybrids. I recently did some calculations which suggested that the 42" RATTWorks L600 could be condensed into a size similar to the Aerotech 98/5120. This I think would make the use of hybrids in existing or non-specialised rockets far easier. I recently saw a very neat 54mm adapdation of the 29mm RATTWorks motor fly - not sure about the details of the motor design but it was a great flight and off the top of my head I think the motor length was 250mm. Just my £0.02

05-30-2008 02:26 PM  #3
ddmobley Administrator   Joined: Jul 2006 Posts: 3165	Re: TMT certifies new Contrail and Trojan hybrid products Quote: Is there a typo? 83Ns from a 16" motor doesn't seem like an awful lot compared to similarly sized hybrids. I guess there's a big tradeoff between length of grain to give high thrust and size of nitrous tank for impulse. It almost sounds like a 38mm nitrous mono-propellant motor, doesn't it? I wonder how many times you can fly the grain?

05-30-2008 03:06 PM  #4
UncleVanya If pigs had fins...   Joined: Sep 2007 Posts: 2711	Re: TMT certifies new Contrail and Trojan hybrid products Quote: Is there a typo? 83Ns from a 16" motor doesn't seem like an awful lot compared to similarly sized hybrids. I guess there's a big tradeoff between length of grain to give high thrust and size of nitrous tank for impulse. These long, high-thrust motors sound like an ideal candidate for modification into coaxial hybrids. I recently did some calculations which suggested that the 42" RATTWorks L600 could be condensed into a size similar to the Aerotech 98/5120. This I think would make the use of hybrids in existing or non-specialised rockets far easier. I recently saw a very neat 54mm adapdation of the 29mm RATTWorks motor fly - not sure about the details of the motor design but it was a great flight and off the top of my head I think the motor length was 250mm. Just my £0.02 By coaxial are you talking about a tank that surrounds the motor chamber or are you talking about a grain design that allows for burning surface outside and down the core? I have long been interested in shorter coaxial tank designs but didn't know if anyone had built any. One downside to the shorter hybrid design is that it locates weight of the nitrous farther to the rear of the rocket which could negatively affect stability.

05-30-2008 04:20 PM  #5
ddmobley Administrator   Joined: Jul 2006 Posts: 3165	Re: TMT certifies new Contrail and Trojan hybrid products Plus it adds to the overall diameter in consideration.

05-30-2008 04:22 PM  #6
NiallOswald Caught the bug again...   Joined: May 2008 Posts: 38	Re: TMT certifies new Contrail and Trojan hybrid products Yep - a few details here: http://rockets.feis.herts.ac.uk/news.htm and a launch pic (grabbed from a distance) here: http://www.flickr.com/phot...n/set-72157604882235760/ Definitely one of the better small hybrid flights I've seen. There's a video of a coaxial prototype here: http://www.ukrocketman.com/rocketry/videos.shtml - I think that motor was supposed to be something like a J30 for the latest iteration of GYROC - http://www.ukrocketman.com/rocketry/gimbal.shtml What I was wondering is whether the heat transfer to the nitrous from the combusion chamber could be made to work in your favour and maintain a more constant nitrous pressure. From the plots on the RATTWorks site you can see that nitrous pressure drops quite significantly over the course of the burn as it boils off. Of course if things went too far the other way you could have a problem and I'm not sure what the implications for closure design and sealing of having something very hot and something very cold in close proximity are.

05-31-2008 05:49 AM  #7
NiallOswald Caught the bug again...   Joined: May 2008 Posts: 38	Re: TMT certifies new Contrail and Trojan hybrid products Quote: Plus it adds to the overall diameter in consideration. For most 'sport' rockets I'd say diameter is generally easier to accommodate than length. The coaxial I80 is 1/3 the length of the original. Unless you were going to fly it in a 29mm or 38mm airframe, that's a very useful difference.