The Kerbal Space Program Introduction Documentation

The Kerbal Space Program

Fall 2013 Phy 223- Semester Project Documentation due Monday November, 25 11:59PM

Introduction

The goal of this project is to begin a space program on the planet Kerbin. Luckily, there is software available to help you with this task, aptly named Kerbal Space Program (KSP). You will ﬁnd this software at kerbalspaceprogram.com. Since you are only starting the space program, and therefore your primary goals are relatively modest, you will only need the demo version of the software. Download and install it.

Goals

Your objective is to build and launch a spacecraft that is capable of reaching orbit and returning to the planet Kerbin. Speciﬁcally, your spacecraft must:

1. Obtain an approximately circular orbit at 100 km. 2. Once a circular orbit has been achieved, perform a maneuver that puts the spacecraft in a circular orbit with an apoapsis of 350km. 3. Deorbit and land safely.

Your budget for this mission is 25000 Kerbin dollars. Note that while it is a good idea to try and land as close as possible to the Kerbal Space Center and that a water landing is acceptable, a safe landing anywhere on Kerbin is the only mandatory goal of this phase of the mission.

In order to achieve these goals, you need to learn how to build, launch, and maneuver a spacecraft within the program. Additionally, you will need to learn a little bit about orbital mechanics. These tasks are left up to you to perform individually, as there are many resources available online that will provide you with guidance. In order to provide proof of the success of your space program, you will document your efforts.

Documentation

At the completion of your project you will create a brief report summarizing your space program. This will include a detailed budget of your spacecraft that includes a chart itemizing the

1 components that you used and their associated cost. You should list the components of your spacecraft and that reason that you have selected them. You will describe the steps that you took to achieve the goals outlined above. This description does not have to be a list of steps that you took within the program, but rather a short summary of the maneuvers that you performed and the rationale behind them. For example, Launch: the spacecraft was launched using full throttle with a heading directly overhead until you reached an altitude of 10000 m, etc. Each stage of the mission should have, at minimum, a few sentences describing the stage. At the very least, you should summarize:

• the launch,

• orbit insertion at 100km,

• transfer to 350km orbit,

• deorbit,

• and landing.

In addition to a written summary of the ﬂight, you should provide images showing your spacecraft at each stage of the mission. The easiest way to do this is by taking screen shots of the spacecraft and the map. You should include images of:

• the spacecraft in the vehicle assembly building,

• the spacecraft on the launch pad,

• the map when the spacecraft is at an orbit of approximately 100 km (see Figure 1),

• the map when the spacecraft is in an orbit of approximately 350 km,

• the spacecraft at an orbit of 350 km (see Figure 2)

• the spacecraft after it has landed.

Note that on the map images, the spacecraft name (‘simple’), the altitude of the orbit and the orbit prediction itself is shown. Your images should be similar. This part of your documentation, not including ﬁgures should be no more than 1.5 pages in length. If you cannot complete one or more of the primary goals, you should document those that you could complete and those that you could not.

2 Figure 1: A view of the Kerbin Space Program spacecraft’s orbit 350 km.

Figure 2: A view of the Kerbin Space Program spacecraft in orbit at 350 km.

3 The Physics of Space Flight

In addition to the documentation described above, you must also answer the following questions (page limit = 2):

1. When building your spacecraft, there are 3 different liquid fuel engines to choose from. What must you consider when selecting which engine(s) to use and why?

2. Each of engines has a value for Isp, or speciﬁc impulse. What is this and why is it important?

3. In the vehicle assembly building, there are buttons that allow you to view the center of mass and the center of thrust of the spacecraft. What are these things and why is their relationship important?

4. How do the effects of steering your spacecraft east a few moments after launch differ from steering your spacecraft west (or any other direction)?

5. What is the difference between a spacecraft’s apoapsis and periapsis?

6. When setting up a maneuver in KSP using a maneuver node, you will notice that 3 new values appear next to the NavBall. One of those values is the ∆V, or Delta V, required to complete the maneuver. What does this mean and why is it important?

7. In order to increase the altitude of an orbit, is it more efﬁcient to use a prograde burn or a radial burn? Explain why.

8. Once in orbit, how can you change the orbital inclination?

9. What steps would be required to get your spacecraft into a Sun Synchronous Orbit for a short amount of time (don’t worry about achieving an orbit that has the correct precession rate required to actually stay in such an orbit for an extended time period)?

10. When doing a deorbital maneuver, why does the orbit prediction in KSP always over predict your landing (i.e. predict your landing to be further from your current position than it will be)?

Determining Success

This project will be evaluated using a 100 point scale. Table 1 summarizes the evaluation criteria and the maximum score for each component of the project. You will receive full credit for completing each mission element. No partial points will be awarded. Your mission summary should be concise and to the point and written in a technical manner. Full credit will be awarded if you adequately describe all mission elements and the important maneuvers taken during them. Answers to the physics questions should also be technical. Important equations should be written and discussed where appropriate. Speciﬁc physics concepts should be used in the answers to most, if not all, questions. Full credit will be awarded for correct, physically sound, answers.

4 Roughly half credit will be awarded for correct answers that lack discussion of the physics taking place.

It is expected that your document be well organized, readable, and contain no grammatical or spelling errors. Points will be deduced from the organization and quality metric for each error found.

Project Component Maximum Points Mission Success: Launch 5 100 km orbit achieved 15 350 km orbit achieved 5 Deorbit 5 Safe landing 5

Mission Summary: 25 Physics of space ﬂight 25 questions: Organization and qual- 15 ity of documentation:

Table 1: Summary of evaluation criteria

Submission of your project report should be done via email to [email protected]

Extra Credit

If you are able to successfully complete the mission outlined above, you may try to accomplish a more advanced mission: orbiting Mun.¨ You may build a new spacecraft and use any components that you wish, with any budget necessary to accomplish this mission. If you are able to adequately document your success, you can earn 20 extra credit points.