Armadillo Aerospace

The company was a competitor for the Ansari X-Prize. Armadillo's X-Prize vehicle was unorthodox among modern rockets in that instead of using stabilization fins, which complicate the design and increase drag, Armadillo used an aerodynamically unstable design, where the computer controlled jet vanes based on feedback from fibre optic gyroscopes. Armadillo stated a preference for simplicity and reliability over performance, which was evident in its choice of hydrogen peroxide (50% concentration in water) and methanol as a mixed monopropellant for the vehicle. A monopropellant-based engine requires only a single tank as well as greatly simplified plumbing and other hardware.

Pixel attempting level 1. White tanks are insulated and contain liquid oxygen, grey tanks contain ethanol

Armadillo Aerospace competed in the 2006 X PRIZE Cup. Armadillo Aerospace was the only competitor in the Lunar Lander Challenge. The company took two similar vehicles, Pixel and Texel, to the event. The vehicles narrowly failed to win the Level 1 prize, after making three dramatic attempts totalling over 5 minutes in the air,[14] finally crashing out on the final attempt. Persistent landing problems were the main cause of failure, with the undercarriage breaking several times, and landing slightly off the pad on one occasion due to guidance difficulties. These flights were a highlight of the Wirefly X-prize cup.

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.

Armadillo Aerospace competed in the 2007 Lunar Lander Challenge event in the Wirefly X-Prize Cup 2007.

During testing one of the two Quad vehicles (named Texel) crashed on a tethered flight after a guidance problem caused the vehicle to rapidly gain altitude until 3 separate flight termination procedures were activated at approximately 20–30 feet. The vehicle fell, and the impact broke open one of the alcohol tanks and a large fireball engulfed the vehicle.[15] The vehicle was irreparably damaged, and only its sister Pixel could compete in the upcoming event. The plan was to have the first module (of the next generation modular design) compete at level 1, and have Pixel compete at level 2 challenge. [16]

In the level 1 events, Armadillo's craft MOD (actually, module #1) logged several attempts, including several successful first leg flights but was unable to complete the return trip during any attempt.

On its first attempt, a clogged igniter orifice prevented ignition. On the second attempt, the first leg flight was perfect; increased guidance and control capabilities allowed the module to, in Carmack's words, 'burn the X-mark off the target pad'. The return leg was delayed slightly, because the igniter had clogged again. When the second leg was attempted, a 'hard start' cracked the graphite combustion chamber. As the vehicle was still flying, Carmack flew the crippled vehicle through the course as quickly as possible and hovered 2–3 meters above the landing pad. With only a few seconds remaining in the required flight time, the damaged combustion chamber cracked again, which caused the vehicle to tilt enough to trigger a computer abort. The vehicle performed an auto-land, but the tilt caused the module to tip over on landing after only 82 seconds in the air.

The second attempt began with another perfect first leg, but the return was marred by another hard start. Seeing that the engine was badly damaged (although flying), the team commanded an abort. The module landed back on the pad after only a few seconds.

On the final attempt, MOD suffered a violent "hard start", resulting in engine explosion. The violence of the explosion embedded a piece of the graphite chamber in the ground 64 meters from the launch pad and ended their attempts in 2007 for the prize.[17][18]

"Mod" vehicle taking off at LLC 2008

The 2008 Lunar Lander Challenge took place October 24–25 at the Las Cruces International Airport in New Mexico. Armadillo Aerospace competed for the third year but for the first time had competition, from the TrueZer0 team. Both received waivers from the FAA to fly experimental rockets.

TrueZero attempted level 1, achieved hover, then lost roll control and was aborted and crashed.

Armadillo had an unsuccessful first attempt at level 1 and landed early due to inadequate thrust. On their second attempt they completed the first leg, but the second leg was cut short by the FAA closing the flight window. The second leg was held in the afternoon, and they were able to take the Level 1 top prize of $350,000.[19]

Armadillo's attempt at the level 2 prize on October 25 was aborted due to their vehicle toppling over after the engine casing burned through due to a fuel-line problem.

Armadillo attempted the Level 2 prize on September 12, 2009. Armadillo successfully flew both legs with their Mod vehicle, each flight lasting over 180 seconds, landing safely. However their landing accuracy was not sufficient to win the first prize, instead they won the US$500,000 second prize[4][5] while Masten Space Systems' Xoie lander won the US$1,000,000 Level 2 first prize.[20]

The Super Mod reusable launch vehicle is a vertical-takeoff, vertical-landing (VTVL)[23] 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.[23] It added aerodynamic fairings, partially extendable landing legs with lower aerodynamic drag, and systems improvements to the basic Mod vehicle structure and systems.

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  Lunar Lander Cup era Mod rocket hovering in free flight
• 
  The Mod rocket with an early nose cone, hovering in free flight
• 
  The SuperMod rocket during final assembly

The Armadillo Stig hovering in a tethered test flight

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.[24] 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. The second flight, which took place in 2012, reached 50 miles (82 kilometers), but the recovery chute did not work as planned.[25]

The third flight took place in January 2013, and the vehicle experienced a hard landing following a parachute failure-to-deploy,[9] though the launch was successful.[26]

In August 2013, Carmack indicated that following the crash of the STIG-B rocket earlier that year, he had wound down the company operations and had put the company in "hibernation mode." Armadillo had stopped accepting (profitable) contract R&D work two years prior in order to focus on development of a suborbital reusable rocket. During those two years, Armadillo operated at an approximately US$1 million per year burn rate funded personally by Carmack. Several reasons were offered for this outcome, including a failure to adopt a multi-test-vehicle build strategy, making the loss of a single rocket more significant than it would have otherwise been.[9]

As of August 2013, Carmack was "actively looking for outside investors to restart work on the company’s rockets."[9]

In 2015, the assets of Armadillo Aerospace were sold to EXOS Aerospace Systems & Technologies, Inc.[1]