Activity 3.2.5 Orbital Mechanics ModelingIntroduction

Aerospace engineers design satellite orbits to suit the unique requirements of the mission. The orbit is described with six parameters to cover an area on the ground aligned with the mission.

In this activity you will apply your knowledge of orbital mechanics to describe the orbit of a satellite based on its ground trace. You will also use Analytical Graphics, Inc. (AGI) Orbit Tuner application within the Satellite Tool Kit software to adjust the orbit of a satellite to achieve a mission objective.

Equipment Engineering notebook Pencil Calculator Notes from Orbital Mechanics Models presentation PC with STK software Options for Orbital Tuner Software (teacher will specify):

Option 1 (Orbital Tuner viewed within STK v10)o OrbitalTunerModel.zip file

Option 2 (Orbital Tuner as a executable application)o Orbit Tuner applicationo Orbit Tuner Java Script folder

© 2011 Project Lead The Way, Inc.Aerospace Engineering Activity 3.2.5 Orbital Mechanics Modeling – Page 1

Procedure1. Determine the inclination and period of the satellite which produced the ground trace below.

Show all calculations.

2. Determine the inclination and period of the satellite which produced the ground trace below. Show all calculations.

© 2011 Project Lead The Way, Inc.Aerospace Engineering Activity 3.2.5 Orbital Mechanics Modeling – Page 2

3. Watch the Orbit Tuner tutorial video.

4. Start the Orbital Tuner application using the option specified by your teacher.

a. Option 1 (Orbital Tuner viewed within STK v10)

i. Copy 3.2.5.A Option1OrbitTunerModel.zip into an accessible area on your PC and unzip it.

ii. Start STK and open OrbitalTunerModel.sc file from the unzipped location.

iii. Click View, HTML Viewer, then Browse (looks like a folder opening).

iv. Click Example HTML Utilities, Creating and Manipulating Objects, Orbit Tuner then click OrbitTuner.htm.

v. If allowable at your school then click Yes to the ActiveX control warning.

vi. Arrange the STK view to look similar to the window below.

b. Option 2 (Orbital Tuner as a standalone application)

i. Copy the 3.2.5.A Option2OrbitTunerFiles.zip file into an accessible area on your PC and unzip it.

ii. Double click on the Orbit Tuner.exe file and allow STK to fully launch. The software should look similar to the image below.

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Orbit Tuner using Satellite Tool Kit, STK, Software

5. The government of Ecuador has contracted your company to place a communications satellite in orbit over the city of Quito to prepare for a potential earthquake threat in the region. You are the aerospace engineer tasked to design the orbit to fulfill the mission requirements.

6. The University of New Brunswick in Canada won a grant from the Department of the Environment to study the thinning of the northern polar ice cap in an effort to quantify global warming. The imaging system to monitor the ice thickness will be carried on the Polar Sheet satellite to be launched this spring. Design the orbit of a satellite to maximize oversight of this region.

7. Create a detailed mission description. Use Orbit Tuner to design the orbit to complete the mission, create a print screen of the solution, and document why this orbit fulfills the mission.

8. Exchange your mission description with another student.

9. Design the orbit to fulfill the mission assigned to you by another student.

10.Discuss your solution with the student who designed the mission and come to an agreement on the final design.

11.Reverse roles and follow the process described in the previous steps.

Conclusion1. Explain why the period affects the usefulness of the satellite.

2. Explain the impact of the six parameters on the ground trace.

© 2011 Project Lead The Way, Inc.Aerospace Engineering Activity 3.2.5 Orbital Mechanics Modeling – Page 4