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Explore Interplanetary Spacecraft Maneuvers with FreeFlyer®


Areas of Science
Time Required
Average (6-10 days)
Sabine De Brabandere, PhD, Science Buddies
*Note: For this science project you will need to develop your own experimental procedure. Use the information in the summary tab as a starting place. If you would like to discuss your ideas or need help troubleshooting, use the Ask An Expert forum. Our Experts won't do the work for you, but they will make suggestions and offer guidance if you come to them with specific questions.

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If you are interested in space travel and willing to do some coding, this project is for you! It uses FreeFlyer®—powerful software that allows you to simulate space travel—to explore essential mission questions.

Space travel is complex. Many factors influence the trajectory of a spacecraft. Simulations like the ones generated by FreeFlyer are powerful, as they allow you to analyze each factor in isolation, and then visualize the effects in various ways.

Once you familiarize yourself with the software, you will find several interesting topics to study. Below is a short list of questions that can be investigated using FreeFlyer:

 An elliptical transfer path, labeled Hohmann transfer, connects the initial smaller orbit to the target larger orbit. Black arrows are placed at the connection points of the Hohmann transfer with the initial and target orbits.
Figure 1. A diagram of the Hohmann transfer between two orbits. The black arrows represent points where a burn will happen.
 An elliptical transfer path labeled 1st elliptic transfer connects  the initial smaller orbit to a point far out of the initial and final orbits. A second elliptical transfer path, labeled 2nd elliptic transfer, connects the 1st elliptic transfer to the target orbit. Black arrows are placed at the connection point of the initial orbit with the 1st elliptic transfer, at the 1st elliptic transfer with the 2nd elliptic transfer, and at the 2nd elliptic transfer with the target orbit.
Figure 2. A diagram of a bi-elliptical transfer between two orbits. The black arrows represent points where a burn will happen.

Visualization of a Hohmann transfer from Earth to Mars where the different stages of the transfer are visualized by different colored lines.
Figure 3. Visualization of a Hohmann transfer from Earth to Mars generated by FreeFlyer software.

Whatever specific topic in interplanetary spacecraft propagation or spacecraft maneuvering sparks your interest, this software can likely help you explore it. Once you familiarize yourself with the software, you can specify your central question. Depending on the chosen topic of study, you might be able to calculate the effects by hand using orbital mechanics and flight dynamics. A simulation can then validate or contradict your calculation and help extend the calculation to more-complicated scenarios. A simulation can also help visualize the findings. Other topics do not allow you to calculate the effect by hand. For these, you rely solely on the simulation to study their effect. For instance, a topic such as the influence of perturbating forces like solar flares or the effect of irregularities in gravitational fields can only be studied with the help of simulations.

Unless you already have access to a computer with FreeFlyer installed and running, your first step will be to obtain a free student license and install FreeFlyer on your computer. The software will run on computers using Windows as the operating system or on a virtual system created on computers using Linux as the operating system. You can check the minimum system requirements to run FreeFlyer before installing FreeFlyer.

Follow these steps to get FreeFlyer running:

  1. Register online on the a.i. solutions registration webpage using your academic (.edu) or school email if you have one.
  2. Once you have received the registration approval email, return to the ai registration webpage, log in, and download the latest version of FreeFlyer from the Downloads area.
  3. Install and run FreeFlyer, it will give you detailed instructions for steps 4—5. Although it might happen sooner, allow a few days for FreeFlyer's technical support to get back to you with the license file.
  4. Write down the computer information listed in the "Register a New License" dialog box. Send it to fflicense@ai-solutions.com so they can send you a license file. Mention in your email the class or project that you plan to use the software for.
  5. Once received, load the license file in FreeFlyer. You are now ready to use FreeFlyer!
  6. Your license will most likely be valid for a semester. You can repeat the procedure if you need to update your license after it has expired.

There are a few easy ways to get familiar with the software. The FreeFlyer Fundamentals training video is a series of three easy-to-follow videos with hands-on exercises. The FreeFlyer University Guide provides a more in-depth view; it is an introduction to orbital mechanics and spacecraft flight dynamics, in addition to an introduction to FreeFlyer. Once you are familiar with the basics, the FreeFlyer Software help files included with FreeFlyer are another valuable tool. You can also access it from within the software directly with a right-click on the element about which you would like help.

It's best to start your exploration with a simplified mission and work your way up to more-complicated situations. FreeFlyer provides sample mission plans. The sample missions listed under the 'interplanetary Analysis' and 'Maneuvering & Targeting' folders might be useful as starting points for an exploration, or as examples to see how similar situations can be tackled. Check them out once you are familiar with FreeFlyer.

As you finalize your analysis, try as best as you can to list the shortcomings and approximations you used in your calculations and simulations. For your report, be sure to check out the many graphing and visualization options available in FreeFlyer. Well-presented data can be an enormous help to clearly communicate complicated data.

Visualization of a spacecraft flying above a planet with its velocity visualized as a yellow vector.
Figure 4. Visualization of a spacecraft's velocity and attitude generated by FreeFlyer software.
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MLA Style

De Brabandere, Sabine. "Explore Interplanetary Spacecraft Maneuvers with FreeFlyer®." Science Buddies, 24 Oct. 2020, https://www.sciencebuddies.org/science-fair-projects/project-ideas/SpaceEx_p029/space-exploration/interplanetary-spacecraft-maneuvers. Accessed 22 May 2022.

APA Style

De Brabandere, S. (2020, October 24). Explore Interplanetary Spacecraft Maneuvers with FreeFlyer®. Retrieved from https://www.sciencebuddies.org/science-fair-projects/project-ideas/SpaceEx_p029/space-exploration/interplanetary-spacecraft-maneuvers

Last edit date: 2020-10-24
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