ADV3

ADV2's

Aspire Development vehicle 2a

ADV2a was fired up in the Highlands of Scotland, and used a flightweight H2 with a 1 litre paintball tank for its nitrous tank, giving a mid-range 'K' class motor.

It flew as if on rails up to 6000 feet where the onboard computer popped a small drogue parachute, and then the main chute was deployed at 1000 feet.

The computer recorded acceleration and barometric pressure during the flight, which was later used to back-calculate the hybrid thrust and the vehicle’s drag.

Aspire Development vehicle 2b

ADV2b is the same size and shape as ADV2a, but contains seven times more propellant, giving a Total Impulse of 10160 Newton-seconds, making it an upper-range 'M' class motor.

The fuselage and fins are made of carbon-fiber composite as the vehicle will exceed Mach 1.

When we launch ADV2b, simulation software predicts it’ll reach about 17,000 feet above the launchpad if carrying a commercial aluminium nitrous tank.

However, we're developing a lightweight Carbon/Kevlar composite nitrous tank with a fluorocarbon liner. The expected altitude is then 24,000 feet simply because of the reduced mass. (Composite tanks leak without an inner impervious liner, and a liner is required because the composite is highly flammable if exposed to nitrous. Composite resin can also make nitrous unstable.)

Aspire Development vehicle 2c

ADV2c is an upper stage designed to be carried aloft on top of ADV2b.

It uses a custom 1 litre nitrous tank, and fibreglass fuselage tubing. It's powered by an H2 motor of mid-range 'K' class. Its high performance and light mass means that it should reach about 12,000 feet when fired just on its own.

Rather daringly, Rickrock burns every last gram of propellant: there’s zero residual plastic left in the chamber.

When we launched ADV2c Mk1 up in the Highlands of Scotland, a valve stuck partially open which leaked a lot of nitrous before takeoff, and reduced the tank pressure.

It rose ponderously off its launcher and disappeared over the horizon on a low, flat trajectory.

Luckily, we got the top half of it back, because we’d fitted it with a homing device that transmitted on the HAM radio FM band.

The flight computer was in this top half and recorded a respectable altitude of 8000 feet despite the propellant loss.

The bottom half including the hobbled engine tore away from the ‘chutes and is still up there in the heather somewhere.

To see a video of the launch click here.

ADV2c engines 2 and 3 have now been completed; we’ve managed to shave 20% off the mass of ADV2c Mk1, and they’re getting launched soon.