In rocketry, the Armadillo aerospace

Armadillo Aerospace

Armadillo Aerospace is an aerospace startup company based in Mesquite, Texas. Its initial goal is to build a manned suborbital spacecraft capable of space tourism, but it has stated long-term ambitions of orbital spaceflight. The company was founded by John Carmack.On October 24, 2008, Armadillo...

 Quad vehicle is a computer controlled VTVL

VTVL

Vertical takeoff, vertical landing is a form of takeoff and landing using rockets . Multiple VTVL craft have flown. , at least five VTVL rocket vehicles are currently under development at four different aerospace companies...

 rocket that is used to compete in the Lunar Lander Challenge.

General description

The quad vehicle design is pressure fed

Pressure-fed cycle (rocket)

The pressure-fed cycle is a class of rocket engine designs. A separate gas supply, usually helium, pressurizes the propellant tanks to force fuel and oxidizer to the combustion chamber. To maintain adequate flow, the tank pressures must exceed the combustion chamber pressure.Pressure fed engines...

 in blow down mode from an initial pressure of 320 psi for level 1 (400 psi level 2). The cold gas

Cold gas thruster

A cold gas thruster is a rocket engine/thruster that uses a gas as the reaction mass.A cold gas thruster usually simply consists of a pressurized tank containing gas, a valve to control its release and a nozzle, and plumbing connecting them...

 vernier engines 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 gyros.

Specification

The specification for Pixel/Texel for level 1:

• Width: ~75 inches
• Height: ~75 inches
• Dry weight: 650 pounds
• Gross Lift Off Weight (GLOW): ~1500 pounds (360 pounds ethanol
  Ethanol
  Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...
  
  , ~500 LOX
  Lox
  Lox is salmon fillet that has been cured. In its most popular form, it is thinly sliced—less than in thickness—and, typically, served on a bagel, often with cream cheese, onion, tomato, cucumber and capers...
  
  )
• Payload: 55 pounds
• Engines: 1 (+ 4 cold gas attitude jets)
• Thrust (sl): ~3000 pounds

Engine (XPC-06):

• thrust: ~3000 pounds (throttleable to 25%)
• chamber pressure: 300 psi
• Nozzle area ratio: 2:1
• Isp (sl): ~140-~200 seconds (low-high throttle)
• length: 20 inches
• diameter: 8 inches
• chamber: carbon fiber reinforced graphite built by Cesaroni aerospace
• Burn time: >100 seconds, expected >180 for level 2, with approximately double the propellant mass.

Purchase by NASA

On Mar 8, 2010 Matthew Ross Of Armadillo Aerospace confirmed that Pixel had been converted to methane/LOX propellant and sold to NASA

NASA

The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

 as a testbed for the ALHAT LIDAR

LIDAR

LIDAR is an optical remote sensing technology that can measure the distance to, or other properties of a target by illuminating the target with light, often using pulses from a laser...

 range finding system under development by JPL.