AspireSpace: The ASPIRE II Rocket

				AspireSpace
				The British Amateur Space / Rocket Programme

ASPIRE II HYBRID MOTOR

The ASPIRE II Rocket makes use of a hybrid motor. Hybrid motors combine good features of both Solid and Liquid Fuelled rockets. They are controllable, semi storable, cheap and simple. They are based on the principle of a solid propellant and a liquid oxidiser.

The hybrid motor under development for ASPIRE II was originally designated the H100 motor (due to the fact that it uses 100 kg of propellant), but due to slight growth, is now known as the H1xx motor.

AspireSpace Small Hybrid Motor Static Test Firing)

Test Duration = 60 seconds

ASPIRE II SPECIFICATIONS (Provisional)

Length = 4.50 metres
External Diameter = 0.35 metres
L:D ratio = 12.86:1

Gross Lift off Mass = 145 kg
Propellant mass = 100 kg +
Payload Mass = 10 kg
Dry Mass = 35 kg

Mass flow rate = 1.5 kg /second (average)
Total Impulse =330,000 Newton seconds
Specific Impulse = 270 seconds (sea level)
Average thrust = 4 KiloNewtons
Burn time = 65 seconds (consider a propellant ullage of 1% marginal)
Apogee = 100 kilometres with 10 kg payload

ASPIRE II THRUST PROFILE

T0 - T+5 seconds: Thrust at 8000 Newtons (Initial acceleration of +5G).

T+5 - T+65 seconds: Thrust at 4000 Newtons (This gives ASPIRE II a sustained burn which provides heavy acceleration at between 40 to 50 Km which accelerates the rocket to Mach 7.5).