HYBRID ROCKET MOTOR COSTS

HPR HYBRID ROCKET MOTOR COSTS

Although most rocketeers use solid rocket motors, and many are unaware of hybrid rocket motors, the economic case for hybrid rocket motors over solid rocket motors is compelling.

The following table demonstrates a sensitivity analysis, showing at which a hybrid rocket motor using nitrous oxide as the oxidiser, and a solid rocket motor of equivalent total impulse, surpass each other on economic grounds. It can be seen that on propellant costs, and costs of propellant and motor casings and fittings, the hybrid is cheaper from the first flight onwards, even including the nitrous oxide oxidiser

If one factors in the cost of ground support equipment, then a hybrid rocket motor is more expensive until many launches have been made, however, for launches at organised launch events, hybrid ground support equipment is generally available. Additionally, factoring in an altimeter (required for a hybrid for electronic deployment) adds to the costs, however, this has not been factored in for this sensitivity analysis, because an altimeter can be used on any type of rocket, whereas the ground support is specific to hybrid rocket motors.

In the case of this comparison, a H-class, 29mm diameter, hybrid rocket motor (Skyripper H78) is compared with an H-class, 38mm diameter, solid rocket motor (Cesaroni H153). This is not a perfect comparison, since the Cesaroni H153 has a greater total impulse (244 Ns) as opposed to the Skyripper H78's total impulse of 180 Ns, but given the motors available in the UK, provides a comparison based on the nearest equivalent motors.

The recurring costs for the hybrid rocket motor, listed in the table below, also include ground support costs as well as the cost of the hybrid rocket motor. For the purposes of this comparison, the hybrid ground support costs have been set at a very pessimistic 260. In reality, this figure could be reduced.

Table 1

Number of Flights Hybrid consumables cost per flight Hybrid recurring cost (including casing) Recurring cost (including launch controller) Hybrid Total Recurring cost (including Ground Support Equipment) Solid consumables Cost per flight Solid recurring costs (including casing) Solid Total Recurring cost (including launch controller)
1. 15.45 48.45 143.45 403.45 25.00 55.00 85.00
2. 15.45 31.95 79.45 209.45 25.00 40.00 55.00
3. 15.45 26.45 58.12 144.78 25.00 35.00 45.00
4. 15.45 23.70 47.45 112.45 25.00 32.50 40.00
5. 15.45 22.05 41.05 93.05 25.00 31.00 37.00
6. 15.45 20.95 36.78 80.12 25.00 30.00 35.00
7. 15.45 20.16 33.74 70.88 25.00 29.29 33.57
8. 15.45 19.58 31.45 63.95 25.00 28.75 32.50
9. 15.45 19.12 29.67 58.56 25.00 28.33 31.67
10. 15.45 18.75 28.25 54.25 25.00 28.00 31.00
11. 15.45 18.45 27.09 50.72 25.00 27.73 30.45
12. 15.45 18.20 26.12 47.78 25.00 27.50 30.00
13. 15.45 17.99 25.30 45.30 25.00 27.31 29.62
14. 15.45 17.81 24.59 43.16 25.00 27.14 29.29
15. 15.45 17.65 23.98 41.32 25.00 27.00 29.00
16. 15.45 17.51 23.45 39.70 25.00 26.88 28.75
17. 15.45 17.39 22.98 38.27 25.00 26.76 28.53
18. 15.45 17.28 22.56 37.01 25.00 26.67 28.33
19. 15.45 17.10 21.85 34.85 25.00 26.50 28.00
20. 15.45 17.02 21.55 33.93 25.00 26.43 27.86

Table 1 above, was constructed from the figures laid out in Table 2 below.



Table 2
  29mm Hybrid 38mm Solid
H-class motor casing 33.00* 30.00*
Motor Reload 9.00* 25.00*
Igniter 1.00* -
     
Nitrous Oxide (Oxidiser) 3.80* -
Ejection Charge Igniter 1.50* -
Ejection Charge 0.15* -
     
Consumables Cost per flight 15.45* 25.00*
Total Motor Cost 48.45* 55.50*
     
Launch Controller 75.00* 20.00*
Launch Cable 20.00* 10.00*
     
Launch System Cost 95.00* 30.00*
Total Motor and Launch System Cost 143.45* 85.50*
     
Hybrid Ground Support Equipment (GSE) Costs
(Including oxidiser tank, solenoid valve, relay, battery)
260.00* -
     
Total Costs 403.45* 85.50*

* - Figures current as of December, 2005.

For more hybrid information on this website, the following web pages may be of interest:


Availability:

In the UK, the hybrid motor and hybrid motor ground support equipment can be bought from Uncle Bob's Rocket Shop, which is the largest hybrid rocket supplier in Europe. The Cesaroni solid rocket motor can be bought from Rockets and Things. The motors can be also be bought in mainland Europe at Rebel Rocketry, Europe's largest rocket shop / online store.



See Also

Hybrid Rocket Science, Hybrid Rocket Help Clinic, Amateur Hybrid Motors, Amateur Liquid Rockets, Guidance, Gimballed Motors, Launch Controller, UK Rocketry Vendors, UK Rocket Groups, UK Space Organisations