Columbia Space Initiative Rocketry: Airframe Lead

Introduction

The Airframe System comprises 2 parts—a fin can that fits below the oxidizer tank, and both a body tube and nose cone that fit above the oxidizer tank. The Airframe System has magnetic quick disconnects that connect to the Ground Station Electronics outside the rocket.

The Airframe System consists of nose cone, body tube and fin can parts. The nose cone and upper body are made of G12 fiberglass (purchased off the shelf for precision), which contain the internal superstructure of recovery, payload, and avionics modules and sit above the ox tank. The fin can is manufactured from composite fins attached to another G12 fiberglass body tube, which contains the combustion chamber and sits below the ox tank. The fins are manufactured from G10 fiberglass with four carbon fiber layers epoxy resin-bonded together.

Design:

We selected a delta wing design to reach 26k ft apogee and maintain ~1.4-1.5 stability with the following specifications:

• Root chord: 11.633 in

• Tip chord: 0.7 in

• Height: 5.4 in

• Sweep angle: 63 ̊

• Sweep length: 10.609 in

• Thickness: 0.5 in

Manufacturing:

• G10 fiberglass 12in x 48in board layed up with 4 carbon fiber sheets on each side (composite total: 8) in vacuum chamber & vacuum sealed

• Composite board waterjetted to desired delta fin shape

• Laser-cut jig used for precise fin attachment to fin can with additional carbon fiber layups (3 additional sheets per attachment bend)

• Sanding entire airframe for smooth finish

• Epoxy resin/hardener bonding for all layups