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L1 Minimal Configuration

Decision

Fly the certification flight in minimal L1 configuration rather than full dual-deployment setup.

Configuration Differences

Full L2 Configuration (IMG_6434)

  • Main body tube
  • Electronics bay (e-bay) with altimeter
  • Coupler tube between e-bay and nose cone
  • Nose cone
  • 18" drogue parachute (upper section)
  • 48" main parachute (lower section)
  • Dual deployment (altimeter-controlled)

Minimal L1 Configuration (IMG_7824)

  • Main body tube (shortened - no e-bay section)
  • Nose cone attached directly to body tube
  • 48" main parachute only
  • Motor ejection charge deployment (no electronics)

Removed Components

Component Weight Estimate Reason
Electronics bay tube ~100g Not needed for motor ejection
E-bay bulkheads, sled, hardware ~150g No altimeter deployment
18" drogue parachute ~30g Single deployment only
Coupler tube (e-bay to nose) ~80g Shorter rocket
Altimeter ~50g Motor ejection is sufficient

Total removed: ~400g estimated

Rationale

Simplicity

L1 certification demonstrates basic HPR competency. Adding dual-deployment electronics introduces failure modes:

  • Altimeter malfunction
  • Wiring issues
  • Battery problems
  • Charge firing timing
  • Multiple separation events

For certification, minimize variables.

Reliability

Motor ejection is proven technology:

  • No electronics to fail
  • No batteries to die
  • No wiring to disconnect
  • Single separation event

Regulatory

No pyrotechnic electronics to explain to Swedish authorities. Simpler = less questions.

Reversibility

After L1 certification:

  • Re-install electronics bay
  • Add drogue parachute
  • Full dual-deployment for L2

All removed components are stored safely.

Weight Impact

Configuration Approximate Mass
Full L2 config (empty) ~1.9 kg
L1 minimal (empty) ~1.46 kg
L1 with motor (H128W) ~1.67 kg

The lighter rocket with H128W will fly higher than needed for a conservative certification flight. See L1 Weight Budget for ballast calculations.

Photos

Configuration Photo
Full L2 (painted) L2 configuration
L1 minimal (window view) L1 configuration

References