LAKE HAVASU CITY, Arizona USA -- One of the primary drawbacks of current hybrid motor design is the inability to interchange parts due to cross-compatibility.  Combined with each design's unique needs in relation to ground support equipment, most hybrid motors rely on equipment common only to that particular manufacturer's design. 

A new retail market idea is being explored by Tom Sanders of Contrail Rockets and comes in the form of adapting existing hybrid manufacturers' nitrous oxide tanks and injectors to Contrail's hybrid combustion chamber and fuel grains.  This design reduces the cost to the end flier by eliminating the price of purchasing nitrous oxide tanks and injectors for those who have already purchased those components from other companies.

New Trojan Rocket Motors hybrid rocket system. Click to enlarge

That concept, to be marketed under the name "Trojan Rocket Motors", mates the Contrail hybrid combustion chamber and fuel grains to existing Hypertek hybrid rocket propulsion system, and promises the availability of high-thrust fuel grains and different fuel compositions.  The end product will retain the same external dimensions as the existing Hypertek product, so no airframe modification is required for those rockets already outfitted to fly the Hypertek system.

The concept was disclosed on a couple hobby rocketry discussion forums after a blurb about the new products appeared on the Pratt Hobbies website (http://www.pratthobbies.com/) late last month.  After many interesting exchanges, including comments from several of the major hobby rocketry hybrid motor manufacturers, Sanders revealed that the Trojan motor concept would mate a Contrail combustion chamber to a Hypertek cylinder and injector.

Included in exposition were several photographs of the new product, include one that showed the adapter in detail, revealing an enlarged port to increase the flow of nitrous oxide — a requirement to increase the thrust of the motor.

Picture of upsized port to increase nitrous flow Click to enlarge

When Sanders was questioned about filling the motor, he stated that with a little modification, the Hypertek ground support equipment could be made to work with the Trojan hybrid motors, but that they do not use the Hypertek fill stems or the patented Kline Valve.  According to Sanders, Contrail "took a step back and viewed the [Hypertek motors] from an outsider's perspective."  After carefully considering feedback from hybrid fliers around the country over the past 18 months regarding Hypertek motors, Sanders indicated that many complaints stemmed from the Hypertek fill stem so the decision was made to eliminate this from the new design.
 
Hypertek hybrids enjoyed a healthy rise in market share when increased regulatory concerns surrounding government-regulated propellants combined with a fire at AeroTech, the hobby's largest high power rocket motor provider, provided an environment for alternatives such as hybrid motors to emerge rather than flying traditional ammonium perchlorate composite propellants, which at the time was in short supply.

Motor with Hypertek tank in place Click to enlarge

Even though hybrid motors reduced the cost per flight due to their use of paper and plastics as solid fuel combined with a liquid oxidizer, the resulting total end use cost was increased because of the need to purchase additional ground support equipment such as unique launchers, solenoids and nitrous oxide tanks.  As a result manufacturers such as Hypertek structured deals to encourage the sponsoring club to purchase the ground support equipment to make available to their club's members.

As the ammonium perchlorate composite propellant market corrected itself with the rebuilding of the AeroTech facility and additional motor makers bringing new solid propellant products to market, hybrid use wanned.  As such, the equipment began to gather dust or was used infrequently.  Sanders' approach is to dust off that equipment and bring higher-impluse hybrid motors to the people who have already purchased Hypertek products.

While Sanders doesn't yet know if they will stock a large number of top tanks for the Trojan Motors, he has sourced top tanks and states he can get reasonable prices on all of the standard sizes. They are currently developing motors for the following top tank sizes: 300cc, 440cc, 835cc, 1685cc, 2800cc, 3500cc, 4630cc and 5478cc. If, Sanders said, there is demand for the top tanks or if they become hard to get for some reason, Trojan will begin providing them. 

Contrail promises to publish videos of the motors along with thrust curves, prices and more information as soon as they become available.  For more information, visit the Trojan Rocket Motors website at: http://www.trojanhybrids.com/.

Tom Sanders
Contrail Rockets LLC.
High Performance Hybrids
49 N. Acoma Blvd. / Suite #2
Lake Havasu City, AZ 86403
http://www.contrailrockets.com/

09-06-2006 09:15 AM  #1
crontab Certified Level Three   Joined: Aug 2006 Posts: 204	I wonder what Anthony Cesaroni has to say about that?

10-06-2006 05:33 PM  #2
Boogeyman Certified Level One   Joined: Aug 2006 Posts: 24	Probably "I smell a desert RAT" B

11-13-2006 08:32 PM  #3
empoweryou Certified Level Two   Joined: Nov 2006 Posts: 36	He doesn't have too much room to be angry. I read a while back that he is making reload casings that are compatable with Aerotech reloads. I'm sure Gary is thrilled. -Blair