It is still in beta form, so there may be a couple of bugs. You can contact me at nick at if you find any bugs or want to request feature enhancements.

Version 0.98.1 released (April 2020)
 1. Atmosphere calculations rewritten
 2. Thrust plotting improved
 3. Addition of Lapse values at altitudes
 4. Engine tab rewritten and calculations revised
 5. Many bug fixes

Version 0.97.1 released (October 2019) 
 1. Bug fixes 
Version 0.97 released (September 2019) 
 1. Many bug fixes 
 2. Code clean-up 
 3. Addition of the Altitude slider bar 
 4. Graph functionality to plot Thrust against NPR 
 5. Calculation of temperature rise due to compression (i.e. when NPR is set) 
Version 0.96.2 is released (February 2019) 
 1. Bug fixes 
Version 0.96 is released (November 2018) 
 1. Generate picklist to populate drop down boxes 
 2. Improvements to read and save 
 3. Save and read pick lists to file 
Version 0.95.3 is released (July 2018) 
 1. Iterative gamma calculation at the nozzle throat 
 2. Various Bug fixes 
 Version is 0.95.2 (17/1/14) 
 1. Bug fixes 
 2. Implementation of installer 
Version 0.95.1(26/2/2013) 
 1. Bug fixes 
Version 0.95 
 1. Removal of a direct excel exporter and replace with an XML exporter 
 2. Drop down boxes of commonly used values 
 3. Mass flow selection 
 4. Various bug fixes