Research and development principles
The company placed a strong emphasis on a rapid build and test cycle. Armadillo Aerospace designed and built more than 12 vehicles which used about 50 engine designs for over 100 rocket flights. Each design had several features in common. One was the use of modern computer technologies and electronics to simplify rocket control and reduce development costs. Another was the use of liquid propellants and VTVL to facilitate short launch-to-launch times.
Quad vehicle
The quad vehicle design is pressure-fed in blow down mode from an initial pressure of 320 psi for level 1 (400 psi level 2). The roll thrusters are cross-fed by gas drawn from ullage space of the opposite tank. The vehicle is able to transfer propellant through connecting pipes between opposite tanks by controlling ullage pressures with the thrusters; this helps it balance, minimizing gas use. The main engine has two-axis thrust vectoring. The vehicle is fully computer controlled; with guidance from GPS and fiber optic gyroscopes.
Vehicles
Super Mod
The Super Mod reusable launch vehicle is a vertical-takeoff, vertical-landing (VTVL) uncrewed rocket which was developed by Armadillo in 2010–2011. It was submitted to NASA as a potential suborbital vehicle for use as a suborbital reusable launch vehicle (sRLV) under NASA's Flight Opportunities Program. It added aerodynamic fairings, partially extendable landing legs with lower aerodynamic drag, and systems improvements to the basic Mod vehicle structure and systems.
Stig
In late 2010, Armadillo started development of a new, longer rocket design created for lower-drag, higher-speed high-altitude flights, which they named Stig in homage of the Top Gear driver The Stig. This rocket had similar systems, motors, and component weights as the Super Mod vehicles but was aerodynamically optimized for high-altitude flights with long 15 inches (38 cm) diameter cylindrical tanks instead of larger spherical tanks.
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The second flight, which took place in 2012, reached 50 miles (82 kilometers), but the recovery chute did not work as planned.
The third flight took place in January 2013, and the vehicle experienced a hard landing following a parachute failure-to-deploy, though the launch was successful.
Future research
Carmack stated in his monthly reports and in forum posts that he expected his path to an orbital vehicle to include modular rockets similar to OTRAG technology. Lutz Kayser, the founding engineer of OTRAG, visited Armadillo in May 2006 and loaned Carmack some of their original research hardware.
"I have been corresponding with Lutz for a few months now, and I have learned quite a few things. I seriously considered an OTRAG style massive-cluster-of-cheap-modules orbital design back when we had 98% peroxide (assumed to be a biprop with kerosene), and I have always considered it one of the viable routes to significant reduction in orbital launch costs. After really going over the trades and details with Lutz, I am quite convinced that this is the lowest development cost route to significant orbital capability. Eventually, reusable stages will take over, but I actually think that we can make it all the way to orbit on our current budget by following this path. The individual modules are less complicated than our current vehicles, and I am becoming more and more fond of high production methods over hand crafter prototypes." -- June 2006 Armadillo Aerospace Update
