Lunar Transfer Orbit Calculator
JAQAR's Lunar Transfer Orbit Calculator (LTOC) version 2 is now available for downloading.The LTO Calculator is a tool to optimise trajectories to the Moon. Transfer types can be direct, free-return, bi-elliptic, low-thrust or Weak Stability Boundary transfers. See instructions at the bottom of this page on how to download the LTOC.
A summary of the features of the LTO Calculator:
- Launcher performance estimation of Soyuz(ST)-Fregat, Proton-K/Block-DM, Dnepr-Varyag, Delta-III, IV-Medium and IV-heavy, Atlas II, III and V, Zenith 3 and Ariane 5 (ESV/ECA/ECB). Possibility to include analytical launcher performance and link to Dynamic Link Libraries (DLL’s) calculating launch performance.
- Built-in analytical and JPL planetary ephemeris of the Sun and Moon.
- Direct Earth-Moon and Moon-Earth patched-conic transfers with automatic detection of mid-course manoeuvre.
- Launch window determination using the ‘opportunities’ file showing all launch opportunities that match a given minimum final mass.
- Create trajectory output files compatible with STK (both free as ‘Pro’ version), Excel, and Matlab.
- Create STK/Astrogator Mission Control Sequence via STK/Connect allowing recreation of the trajectory using numerical propagation.
- Mission specific parameter input for correct mission analysis: engine Isp, launcher adapter mass.
- Optimisation using gradient optimiser with possible adjustment of constraints weight factor.
- Define the parameters using a user-friendly GUI. The GUI shows the status of the optimisation and allows the user to start and stop an optimisation.
- Visualisation of the optimal trajectory with easy-to-use graphical window that allows for copying the plot to your own documents, print it or save it as a bitmap.
- Three initial guess generators available for bi-elliptic and WSB transfers: Monte Carlo, Genetic algorithm and Differential Evolution.
The commercial version of the LTOC includes, in addition the following features:
- Free-return trajectories (Earth-Moon-Earth) using final Earth perigee and inclination as inputs.
- Moon to Earth trajectories by patched-conic method.
- Bi-elliptic patched-conic transfers using mid-course manoeuvre at given apogee.
- Weak-Stability Boundary numerically propagated transfers using Solar gravity perturbation.
- Transfers via the Earth-Moon L1 or L2 points.
- Low-thrust transfers from Earth to the Moon and back.
The program runs under Windows XP & 2000 or higher environment, and was developed by JAQAR.
LTOC is part of JAQAR Astrodynamics package and the core files of this package must be downloaded and installed first to make LTOC work properly. Press here to download the JAQAR Astrodynamics core files. To download the LTOC 2 installation files click here: Download LTOC 2. Note that this file is 7.4 Mb. To download the upgrade from LTOC 1 or LTOC 2.0 to LTOC 2.1 (5.4 MB) click here: Download LTOC 2 upgrade. Unzip the contents to the LTOC program directory and overwrite the files with the ones stored in the zip file.