TWO STAGE ROCKET GLIDER - CHALLENGINGAUTOMATED SEPARATION - UNPOWERED GLIDING - BELLY LANDING
Configuration:
Two-stage rocket glider. Vertical launch, booster separation, unpowered glide and belly landing.
Overall System
- Total height at launch: 6.44 meters (21.1 feet)
- Total weight at launch: 86 lbs (39 kg)
- Thrust-to-weight ratio at liftoff: 2.9:1
Stage 1 - Booster
- Height: 4.5 meters
- Weight: 63 lbs (28.6 kg)
- Skirt maximum radius: 2.65 feet (0.808 meters)
- Frontal area: 2.05 m² - comparable to a full-size Cessna 172
- Propulsion: High-impulse solid rocket motor cluster, ~6,100 Ns total impulse (L-M class equivalent)
- Thrust: 250 lbs
- Burn duration: 5-6 seconds
- Separation: Automatic, triggered at engine burnout + 2-second coast phase
Stage 2 Glider
- Wingspan: 3.5 meters
- Weight: 23 lbs (10.4 kg)
- Configuration: High aspect ratio wings, no powerplant, no fuel
- Landing: Belly landing, gear up for entire flight
- VNE: 130 knots indicated airspeed
Launch Sequence
- Arm switch ON + throttle input > 80% initiates 10-second countdown
- Engine auto-start at T-10
- Full throttle at T-0: ignition
- Gear auto-retract at liftoff: locked up for remainder of flight
- Booster burnout detected automatically
- 2-second coast phase begins: speed bleeds off, stable separation conditions established
- Stage separation: booster drops, glider continues in unpowered flight
Performance Analysis
The VBX booster's wide skirt body generates exceptional parasitic drag due to its large blunt frontal area of 2.05 m². At 130 knots, aerodynamic drag force approaches 220 lbs, nearly equal to motor thrust. This means the system naturally plateaus at approximately 130 knots indicated airspeed at burnout (full vertical trajectory scenario), without requiring artificial speed limiting. The physics are self-regulating by design.
The 2-second coast phase after burnout serves a dual engineering purpose: it allows airspeed to bleed slightly before separation, and establishes a clean separation window where booster and glider are momentarily at matched velocity with no thrust differential, minimizing re-contact risk. This mirrors the coast phase used in real staged rocketry.
After separation, the glider carries significant kinetic and potential energy. At 23 lbs over a 3.5-meter high aspect ratio wing, the glide ratio is favorable and speed management becomes the primary pilot task.
Construction Notes
The glider airframe assumes carbon fiber and fiberglass composite construction; consistent with real-world giant scale RC practice at this size and weight target. The booster skirt assumes fiberglass construction with motor cluster bay.
Although fictional, all figures are based on real-world RC rocketry motor specifications and composite airframe weight estimates.
