Resonant Orbit Explorer
Interactive V∞ globe and planet-resonant orbit visualization with planet, epoch, V∞, α, and γ controls.
Astro Tools
Astro Tools
Openly available tools and reference services for trajectory exploration, ephemeris queries, observation geometry, spacecraft simulation, and planetary mission studies.
Interactive Tools
Lambert Leg Sandbox
Interactive single-leg Lambert transfer visualization with selectable planets and dates.
Porkchop Explorer
Interactive porkchop plots with linked 3D Lambert trajectory visualization for Earth-Mars and Earth-Venus cases.
*The interactive tools are made with ChatGPT/Codex.
Online Search and Reference
JPL-WPI Trajectory Tool
WPI-hosted trajectory design tools and resources for early mission-analysis exploration.
NASA Ames Trajectory Browser
Web tool for broad searches of interplanetary transfers to planets and small bodies, including launch windows, flight time, and Delta V.
JPL Small-Body Mission-Design Tool
JPL Solar System Dynamics tool and API for small-body accessibility searches, precomputed mission options, and porkchop-style data.
JPL HORIZONS
Public ephemeris service for solar system objects, spacecraft, vectors, observer tables, and related geometry.
NAIF WebGeocalc
Browser interface to SPICE-based observation geometry calculations for missions, instruments, targets, and observers.
NASA SmallSat Mission Design Tools
NASA SmallSat Institute resource page collecting public tools and references for small spacecraft mission design.
Mission Analysis and Optimization
NASA GMAT
Open-source mission analysis, optimization, and navigation software for Earth-orbiting, lunar, libration-point, and deep-space missions.
NASA EMTG
Evolutionary Mission Trajectory Generator, an open trajectory optimization package for preliminary interplanetary mission design.
NASA ODTBX
Orbit Determination Toolbox for early mission analysis, orbit determination, formation flying, and exploration-system studies.
Astrodynamics Libraries
ESA PyKEP
Scientific Python/C++ library from ESA for interplanetary trajectory design, optimization problems, and astrodynamics research.
Tudat / TudatPy
Open astrodynamics libraries from TU Delft for propagation, estimation, trajectory analysis, and space research.
Orekit
Open-source Java library for astrodynamics, orbit propagation, event detection, frames, time systems, and mission analysis.
poliastro
Python library for orbital mechanics and astrodynamics, including orbit propagation, Lambert problems, and visualization workflows.
Spacecraft Simulation and Geometry
Basilisk
Open-source spacecraft-centric astrodynamics simulation framework for dynamics, guidance, navigation, and control studies.
NAIF SPICE Toolkit
NASA/JPL toolkit for spacecraft, planetary, instrument, pointing, and event geometry used across planetary missions.