Command Line Interface¶
Note that there is an official web frontend for kspalculator at: https://kspalculator.appspot.com/.
Here we explain how to use the kspalculator command line tool, but the basic concepts don’t vary.
Installation¶
Make sure you have Python, at least version 3.4 installed.
If you have pip installed, you may install kspalculator using
pip3 install kspalculator
Alternatively, fetch the most recent version of kspalculator at https://github.com/aandergr/kspalculator/releases. Installation is then done by unzipping the archive and calling
python3 setup.py install
Invocation¶
kspalculator is invoked on the command line. Syntax is
kspalculator [--boosters] [--cost] [preferences] <payload> <Delta-v[:acceleration[:pressure]] [...]>
where payload
is the payload in kg and
Delta-v[:acceleration[:pressure]]
are tuples of required Delta-v in
m/s, acceleration in m/s² and environment pressure in ATM (0.0 = vacuum,
1.0 = kerbin sea level pressure) for each flight phase. You have to
specify at least one of these tuples. Acceleration and pressure are
optional and default to zero.
If you add --boosters
, kspalculator will consider adding solid fuel
boosters. This is very useful for launcher stages.
Options for preferences
are:
--preferred-radius {tiny,small,large,extralarge}
: Preferred radius of the stage. Tiny = 0.625 m, Small = 1.25 m, Large = 2.5 m (Rockomax), ExtraLarge = 3.75 m (Kerbodyne),--electricity
: Prefer engines generating electricity,--length
or--lander
: Prefer engines which are short or radially mounted,--gimbal
: Prefer engines having gimbal. If you specify this option twice, a higher gimbal range is considered better.--rcs
or--monopropellant
: Prefer engines using RCS fuel (monopropellant), i.e. prefer the O-10 Puff engine.
In contrast to the constraints, preferences aren’t hard requirements for a design suggestion to be shown up. Adding preferences only adds criteria under which designs may be considered better than others. This means, specifying more preferences, more designs will be suggested.
If you specify --cost
, results will be sorted by their cost instead
of their mass.
For a brief reference for options, call kspalculator --help
. To
display the version of the tool as well as the corresponding version of
Kerbal Space Program, call kspalculator --version
.
Note that kspalculator calculates optimal designs for one stage only (or two if you allow boosters, where the first is a stage only utilizing solid fuel boosters). It will never split up your design into multiple stages.