Design Notes
The Ambition-III is a spaceshot rocket designed for maximum efficiency. As a "sub-minimum diameter" rocket, its body and motor are one and the same, leaving no room for unnecessary weight.
Major Systems
- Propellant Grains
- Nose Cone
- Thrust Chamber
- Fin Assembly
- Nozzle Assembly
Technical Specifications
| Propellant type | Ammonium Perchlorate Composite Propellant (APCP) |
|---|---|
| Propellant mass | 76.0 kg (167.5 lbs) |
| Nozzle | Graphite potted in MSC |
| Thrust chamber | S-2 Fiberglass |
| Insulative liners & bulkhead | MSC |
| Nose cone | Fiberglass reinforced MSC |
| Nose cone tip | 3D-Printed Inconel Alloy |
| Gross Lift-Off Mass (GLOM) | 184.00 kg (405.65 lbs) |
| Burnout mass | 88.50 kg (195.11 lbs) |
MSC refers to our experimental Microsphere Composite — epoxy or polyurethane with glass microspheres.
Nose Cone
Profile: Von Karman Ogive · Material: Fiberglass reinforced polymer
The nose cone has been optimized to minimize both mass and drag. The nose cone body is made of radio-transparent fiberglass for our avionics systems and tipped with a "bluffed" Inconel tip to survive aerodynamic heating.
Propellant
The propellant uses ammonium perchlorate as an oxygen source, aluminum powder as fuel, and HTPB polymer resin as fuel and binder. The grain has a hollow core to burn from the inside out. The Space Shuttle Solid Rocket Boosters used a related APCP formulation.
Thrust Chamber
Material: S-2 Fiberglass
The thrust chamber provides the primary structure of the rocket. It must be strong and rigid to contain the heat and pressure of the motor burn.
Nozzle
Type: De Laval convergent-divergent · Material: Medium and fine grain graphite
The nozzle accelerates hot, high-pressure gases into a high-velocity stream at ambient pressure. Two grades of graphite balance cost and high-stress performance.
Fins
Material: Fiberglass and MSC · Shape: Trapezoidal
The fins keep the rocket flying straight. Placed at the rear, they move the center of pressure well behind the center of gravity, ensuring flight stability.