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New ProPEP Ingredient File

The basic performance metric rocket propulsion systems is specific impulse, Isp. This is the measure of thrust per specific amount of propellant. Specific impulse directly dictates the payload, altitude and size of your rocket.Calculating Isp by hand is difficult; the equations are rather complex with lots of variables, a task where computers excel.

ProPEP (Propellant Performance Evaluation Program), a MSDOS program to calculate Isp has long been used for this task. You can download it here, here, here or here. ProPEP uses a propellant ingredient file called pepcoded.daf. Many people have added ingredients to this file over the years, but due to file format limitations, all new ingredients are added at the bottom, where they can be difficult to locate. A new pepcoded.daf file has been created, combining new ingredients from multiple sources, notably Art Lekstutis, Richard Nakka, John Wickman and Rick Newlands of Aspirespace. In this new version, all propellants are organized in alphabetical order, including the nearly 100 new ingredients. You can download it here. The FORTRAN source code can be downloaded here, thanks to Mr. Borza.

Command line program usage has gone out of fashion for most computer users since PARC popularized pointer driven applications. GUIPEP, by Art Lekstutis; GDL_ProPEP, written by James Lanier; and wProPEP, thanks to the Oklahoma Rocket Association (OkRA); are all graphical front-ends designed to make this experience easier for the MSWindows computer user.

Other Isp calculation software:

NASA's Chemical Equilibrium with Applications calculates chemical equilibrium compositions and properties of complex mixtures.

CProPEP is a modern version using the GPL open source model, written in the C programming language, available in source code for Linux and other operating systems, ready to run precompiled Windows program and online with a web browser interface.

CProPEP has two graphical user interfaces for Windows95 and above machines, CProPEPShell by Hans Olaf Toft (who hosts an excellent software downloads page); and Gpep by Steve Asman. ISP2001 is availible thanks to Dr. Dunn of Dunnspace and the USAF.

Dr. Wickman offers a complete book and software suite that includes Isp calculation software known as CHEM. The format is very similar to ProPEP, let me know if you need ingredient files for either ISP2001, CHEM or CProPEP.

PropEL is an Isp calculation spreadsheet from Terry McCreary in either Borland Quattro Pro (.wb3) or MicroSoft Excel(.xls) formats.

Rocket Motor Parts, Inc. hosts the Air Force Chemical Equilibrium Specific Impulse Code (AFCESIC).

Additional software:

Serge Pipko in Russia hosts additional utilities to convert the ProPEP output text files to a format easily imported into MicroSoft Excel, in MSDOS or MSWindows formats.

For further information, I highly recommend: Rocket Propulsion Elements, an excellent introduction to advanced rocket science textbook. We offer it here, and get a small commission for each sale to offset the expense of maintaining the website, your patronage is greatly appreciated.
Thank you and Ad Astra!

The CRC Handbook of Chemistry and Physics is an indespensable desk reference. It features a wealth of physical constants for nearly any chemical you would consider using in rocketry. I use it a great deal when adding new ingredients to the pepcode.daf file. Highly recommended!

Also highly recommended is the Merk Index, a wide-ranging chemical dictionary. Each chemical is listed by name, with a complete index in the back cross-referencing the entries by less common names, formula and index number. Typical entries include citations on synthesis, physical characteristics such as melting point, boiling point, solubility, decomposition, common uses, toxicity and much more. Truly an indespensible volume at a very nice price.
Thank you and Ad Astra!