Enerjet 1340/20, Part 2

In building my Enerjet 1340/20 replica, I largely followed the original design as shown in Enerjet's 1340/20 Sounding Rocket flyer of the 1970s. For example, I installed a 29 mm motor mount but concurrently also constructed a dedicated, removable 24 mm adapter for use with this rocket. A small deviation was made with regard to the parachute material; instead of the original two 12" silk parachutes, I used a hexagonal Rogue Aerospace PP-45 (45 cm diameter) nylon parachute and chose a combined recovery of airframe and payload section.

The most significant difference to the original 1340/20 rocket is the launch lug. Enerjet had fitted the rocket with wire loops for guidance during launch. While this likely made sense aerodynamically, I always felt unsatisfied when looking at the iconic 1970s photos prominently showing the #13 plastic fin unit's integrally moulded launch lug left without any purpose on the front side of the rocket. This was a design decision I didn't quite comprehend. I thus modified the top section of the moulded launch lug to hold a plywood stand-off, on which I later glued the lower of two conventional launch lugs. This worked flawlessly and left the front aspect of the rocket pleasantly uncluttered.

Epoxy adhesive was used throughout the construction of the rocket.

Vehicle 77 Redux

A clear personal favourite in my fleet, the Enerjet Nike Ram-inspired Vehicle 77, photographed in northeast Switzerland on July 30, 1999, on the occasion of a flight powered by a 24 mm Aerotech E28-7T RMS composite motor. This flight took place in the early afternoon of a beautifully clear day, with low winds, and a temperature of around 30 degrees Celsius.

Launched off an Aerotech Mantis pad, Vehicle 77 carried a 6 volt piezo sonic locator. The rocket flew fast, very stable, and out of sight, to a computed altitude of slightly over 800 meters. The parachute deployed perfectly, but the rocket's payload section and parachute became entangled in a barn drain pipe upon landing. The tallest member of our little launch group was just able to pull it free, but the piezo sonic locator was lost during the retrieval, and the plastic parachute was damaged. Vehicle 77 itself survived in perfect condition.

A few weeks later, I replaced damaged parachute (it had likely been the wrong choice for such a rocket at any rate) with a nylon parachute by Rogue Aerospace.

Last Launch Of The Century, Part 2

Late afternoon maiden flight of the newly completed Vehicle 81 C Into The Pandemonium during our "last launch of the century", northeast Switzerland, December 22, 1999. Vehicle 81 C was the third variation of a design originally sketched in late summer of 1999, and the first version to actually be built. It measured 1173 mm in length and 66 mm in diameter, and it was powered for this flight by an Aerotech G35-7W Econojet 29 mm composite motor.

The payload carried in the nose cone compartment was a Missile Works RRC2 altimeter for passive altitude determination. The flight was extremely stable and near flawless, and so was the recovery sequence, using Rogue Aerospace and Top Flight parachutes. Minor damage suffered by the rocket at parachute ejection and touch-down was subsequently repaired.

Vehicle 96

Vehicle 96 E, the final iteration of a minimum diameter, maximum performance design, photographed at my workshop in November of 1999. At a length of 620 mm (including a payload section measuring 185 mm) and a diameter of 31.2 mm, vehicle 96 E was designed to fly under the power of either an Aerotech G25-15W or G125-15T motor, carrying a Transolve P 1 altimeter and a piezo sonic locator.

Based on the smaller Vehicle 99 H Supersonic 36 design, Vehicle 96 E was constructed using mainly LOC/Precision parts and a Rogue Aerospace nylon/Kevlar recovery system, and it featured three through-the-fin epoxy "rivets" per fin. The rocket featured no launch lug, requiring launch from a tower launcher.