Sunday, July 10, 2011

Home, Home on the Rocket Range

This morning I witnessed the maiden flight of a friend's rocket.

The Northern Colorado Rocketry Club was hosting a weekend launch fest, and rocketeers flocked to the remote prairie launch site at the Pawnee National Grassland to blast holes in the sky. Most of the rockets were skinny little things, mere overgrown darts.


My friend's rocket, won at a charity auction, was a comparative behemoth. After assembly, it looked like this.


The man who had donated the rocket for the auction arrived to make sure the launch went smoothly. Last week he had shown my friend how to mix the chemicals for the solid fuel motors. Now the man had come to tutor my friend on rocket assembly.

They set up a work table (shown below) and got busy. At the upper right you can see the purple nose cone and a small portion of the green fabric of the main parachute. To the left of these is the metal housing for the rocket motors. Next to the housing are two cylindrical rocket motors, a short one on its end and a long one beside it, each consisting of dark propellant wrapped in tan cardboard. A hole runs down the center of the motor, permitting uniform combustion along the motor's entire length. This center hole is a clever refinement that never occurred to me when I was making crude gunpowder rockets (structurally equivalent to leaky pipe bombs) during my elementary school days back in Iowa. The tangle of cord is the line for the drogue parachute.



The drogue parachute is deployed as the rocket reaches apogee. ('Apogee' is derived from the Greek words signifying the farthest point off the Earth, the point where the awe-struck observer exclaims "Gee, that's really high!") Unfurled, the gold and purple drogue was about the size of a newspaper page.



After the drogue and its cord were stowed in the rocket, it was time to pack the motor. First the long motor was gently stuffed into its metal housing.


Then the housing was inserted into the rocket.


Finally, the nozzle, a black metal fixture shaped like a stack of three hollow hockey pucks, was clamped into the very bottom of the rocket.


The rocket was now launch ready.


My friend slid the rocket onto its guide pole on the pad. He hooked up the ignition wires.


Mission Control huddled to determine who got to push the launch button.


The crowd went silent. Every eye was on the pad. Mission Control said, "Ready on the pad. We have continuity. Three! Two! One!"


Owing to sluggish reflexes, I missed snapping the photograph of the rocket's ascent. The picture shows the portion of sky that the rocket has just passed through.

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