Palski & Associates Web Toolkit

Posted July 22, 2020

The Advanced Rendezvous Proximity Operations Course (ARC) Web Toolkit was developed by our team to allow students to practice the concepts taught in our ARC Course. The tools provide accurate simulations relevant to satellite mission planning and execution in an intelligent and intuitive interface. The tools are hosted in AWS GovCloud and are accessible to anyone, anywhere with internet access, a web browser, and a login. The tools are also useful for problem solving and visualization outside of the classroom.

Until now, the best option instructors had to provide hands-on activities when teaching these concepts was to develop simulations from scratch using AGI’s STK software. This takes a lot of time and is expensive. Typically, $100,000 per user for licenses and then $20,000 per year per user for maintenance. And while STK allows for visualizing and analyzing pre-scripted events like RPO, it does not allow the user to interact with other users and/or the instructor in real-time. The tool kit includes the following capabilities:

Orbit Visualizer:

The Orbit Visualizer provides an intuitive and digestible format for users to visualize the orbits of satellites relative to the Earth and relative to a target/chaser satellite. Our team of developers have worked with industry standard, open-source software to ensure the data that we’re generating is displayed in a visually enticing and convenient manner.

Waypoint Planner:

The Relative Motion Planner provides an intuitive interface to view and understand relative motion of objects in orbit. We use mathematical models to provide instant feedback of relative paths during RPO mission planning so that the users can focus on tactics rather than equations.

Inertial Orbit Transfer:

The Inertial Orbit Transfer tool allows users to solve for desired properties of both Hohmann and bi-elliptic transfers. The solution consists of all burn magnitude, directions, as well as the timing between burns for a given plan. This tool can be used for any range of transfer size, so it supports many cases such as transferring from inclined LEO to GEO, or moving from GEO to drift orbit.


The Simulator allows users to create, load, and join simulations of multiple spacecraft assigned to multiple teams. Within a simulation, users can control time, command spacecraft, create and tune Kalman filters, and visualize data. The user can also create widgets to visualize the data in the Orbit Visualizer, the Waypoint Planner, and in live data graphs. A key functionality this tool provides is the ability to have a Sim “Master”. The “Master” can create a sim, which others can join and see limited data making it a more real-world experience. The lead can then inject commands, such as maneuvers, to any spacecraft without the teams knowing, providing a great learning experience for RPO missions with unknown spacecraft, or simulating a sensor/spacecraft malfunction.

Situational Awareness Tool:

The Space Situational Awareness Webtool (SSAWT) allows users to query the database for the latest data on satellites in orbit, updated daily, as published by Users can construct queries based on the properties of the orbit as well as classification information such as the object’s name, country of origin, or NORAD Catalog ID. This query can be saved and reloaded for future searches. Once the results for the queries are found, the user can send the spacecraft to the Spacecraft Garage where the user can save the spacecraft, use them in the Waypoint Planner, the Simulator, or propagate and display them in the Orbit Visualizer

Covariance Visualizer:

The Covariance Visualizer displays to the user the observability of an object using an angles-only observer, a range-only observer, or an observer that takes both angles and range observations. It plots a heat map to display the calculated covariance of the object’s position based on your current measurement types/locations.


The Inertial Rendezvous Planner is a mission-planning tool that is used for setting up a rendezvous with a target and chaser spacecraft. It allows a user to target a desired state at a desired time for the chaser spacecraft. Users can plan missions with any two spacecraft, user-defined or loaded from, given their orbits are near-circular, coplanar, and are in the same orbital regime. Future iterations of the tool will expand on this capability, removing restrictions and providing users with more mission planning options.