Launch Services

Mission Goal

Build a two-bottle rocket airframe that improves stability and/or performance, while remaining safe, inspectable, and repeatable. Demonstrate at least 3 logged launches.

Why it matters

Scaling a launch vehicle means solving integration problems: stronger joints, alignment, mass distribution, and consistent build quality. Real rockets fail at interfaces — where stages, tanks, or structures meet.

Inputs from other teams

• Structures: safe joining methods, reinforcement without sharp/hard hazards.
• Command & Control: risk review, pre-flight inspection checklist.
• Payload: optional “dummy payload” spec (mass + placement).
• Recovery: keep landing zone safe; plan for larger footprint.

Constraints

• Water rockets only.
• No metal pressure vessels, no glass, no dangerous projectiles.
• Only one pressurised bottle (the main pressure chamber). The second bottle is structural/aerodynamic.
• All joins must be smooth (no sharp edges); tape and lightweight materials only.
• Teacher-controlled pressurisation and release; staff-approved pressure limits.

What you must produce (deliverables)

• 1 double-bottle rocket design + build sheet.
• A pre-flight inspection checklist specific to your design (joints, symmetry, fin security).
• Launch log for 3 launches + one improvement you made based on the data.
• Short “trade-off note”: what you gained and what you risked by adding complexity.

Build & test steps

1. Decide your architecture: inline extension, fairing, or stability body.
2. Plan the join: alignment is everything. Mark centre-lines before taping.
3. Build fins bigger/stronger than LS2 (more mass needs more stability).
4. Dry-fit on the pad: ensure the pressurised bottle interfaces correctly.
5. Static checks: symmetry, fin angle, secure joins, no sharp edges.
6. Launch 1 (teacher-managed): safe pressure; note stability and any flex.
7. Iterate: strengthen weak points; re-check symmetry.
8. Launch 2–3: repeat and log for consistency.

Launch-day checklist

• Extra inspection time (interfaces fail first).
• Range clear + safety perimeter confirmed.
• Roles assigned + recorder ready.
• Clear call: “Hold” if anyone sees a joint peeling or fin coming loose.
• Recovery team waits for “all clear”.

Success criteria

• Rocket remains structurally intact through 3 launches.
• Flight is safe and mostly straight (no hazardous lateral launch).
• Team identifies at least one improvement made from logged evidence.
• Pre-flight checklist is used, not just written.

Evidence checklist

• Photos focusing on the joint/interface.
• Video of at least one full launch sequence.
• 3 completed launch logs + highlighted “change we made” note.
• Pre-flight checklist (completed) for at least one launch.

Safety rules

• Teacher-controlled pressurisation/release only.
• No one over the rocket; eye protection near the operations area.
• Stop if joints peel, bottle deforms, or alignment shifts on the pad.
• Use soft, lightweight materials for structure; avoid hard nose weights.
• Keep the range larger than LS2 (bigger rocket, bigger drift).

Common failure modes

• Misaligned bottles → wobble and sideways thrust at release.
• Weak join → mid-flight separation (unsafe debris risk).
• Extra mass without bigger fins → instability.
• Checklist ignored → repeating the same mistake.

Stretch goals

• Create a “build quality standard” poster for your team (symmetry, joint strength, fin alignment).
• Compare two join methods and decide which is best for safety + repeatability.
• Introduce a simple “go/no-go” review board (2 students + teacher) before launch.