Project Timberwind

Project Timberwind aimed to develop nuclear thermal rockets. It was under the aegis of the Strategic Defence Initiative ("Star Wars"), later expanded into a larger design in the Space Thermal Nuclear Propulsion (STNP) program. Advances in high-temperature metals, computer modelling and nuclear engineering in general resulted in dramatically improved performance.

Whereas the NERVA engine was projected to weigh about 6803 kg, the final STNP offered just over 1/3rd the thrust from an engine of only 1650 kg, while further improving the specific impulse to 930 to 1000 seconds.

Timberwind 45 Specifications

* Diameter: 13.94 ft (4.25 m)
* Vacuum thrust: 99208 lbf (441.3 kN)
* Sea level thrust: 88305 lbf (392.8 kN)
* Vacuum specific impulse: 1000 s
* Sea level specific impulse: 890 s
* Engine mass: 3300 lb (1500 kg)
* Thrust to Weight Ratio: 30
* Burn time: 449 s
* Propellants: Nuclear/LH₂

Timberwind 75 Specifications

* Diameter: 6.67 ft (2.03 m)
* Vacuum thrust: 165347 lbf (735.5 kN)
* Sea level thrust: 147160 lbf (654.6 kN)
* Vacuum specific impulse: 1000 s
* Sea level specific impulse: 890 s
* Engine mass: 5500 lb (2500 kg)
* Thrust to Weight Ratio: 30
* Burn time: 357 s
* Propellants: Nuclear/LH₂

External links

* [http://www.astronautix.com/engines/timind45.htm Encyclopedia Astronautica link about the Timberwind 45]
* [http://www.astronautix.com/engines/timind75.htm Encyclopedia Astronautica link about the Timberwind 75]
* [http://www.astronautix.com/engines/timnd250.htm Encyclopedia Astronautica link about the Timberwind 250]