RocketIsp is in the early stages of development... should stabilize soon.

Rocketisp Calculates Delivered Specific Impulse (Isp) For Liquid Rocket Thrust Chambers.

See the Code at: https://github.com/sonofeft/RocketIsp

See the Docs at: http://rocketisp.readthedocs.org/en/latest/

See PyPI page at:https://pypi.python.org/pypi/rocketisp

Rocketisp uses a simplified JANNAF approach to calculate delivered specific impulse (Isp) for liquid rocket thrust chambers.

Note that RocketIsp gets propellant properties from the companion project RocketProps and ideal Isp performance from the companion project RocketCEA .