Friday, January 8, 2010
"The Mission begins with the rockets pointing to the sky in a near vertical position. The payload is shrouded beneath a nose cone to protect it during the ascent through the atmosphere. If suitable atmospheric conditions prevail, the launch sequence begins. A final check is made of all the operational equipment using the onboard telemetry system. The arm button is then activated to start the computer running. At T=0, the Terrier motor is fired. As the rocket leaves the launch pad, it pulls away the fuel lines and an umbilical chord which has enabled the scientists an engineers to control the payload systems whilst on the ground. The computer now has to control the experiment for the next 10 minutes by itself. With an acceleration of 22g (22 times the Earth’s gravitational force) the Terrier motor propels the system to 4000 km/hr after just 6 seconds. This motor is then jettisoned and the Orion motor and its payload coast for 9 seconds. The Orion motor is then fired and boosts the payload in 26 seconds to a speeds in excess of eight times that of sound (8300km/hr) and to an altitude of 56 km, approaching the edge of the atmosphere. Five seconds later the nose cone is blown off with compressed nitrogen. During the next 400 seconds, the rocket is maneuvered to point downwards, in readiness to re-enter the atmosphere. This is achieved by using a cold gas thruster which provides pulses of compressed nitrogen to gently nudge the spent Orion motor and the experiment into the correct orientation.
As the rocket and the experiment re-enter the atmosphere, the altitude is monitored by way of a Pitot probe. When it descends to 35km, hydrogen is supplied to the scramjet and the supersonic combustion experiment begins. Measurements of pressure and temperature in the combustor are transmitted back to three ground stations to be stored for later analysis. The flow of fuel is maintained for the next 5 seconds as the experiment descends to an altitude of 23 km. At this point the experiment is complete."
Some other article...