Mission:

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Mission

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Mission

Part One: Human Factors Essay

Imagine that you are a human factors or spacecraft systems engineer and are responsible for one of the following space human factor issues. 

Determine whether your topic is an in-flight issue, an issue for astronauts living on the surface of the planet, or an issue for the entire mission. In your essay, discuss the problem, its causes, and your ideas for possible solutions and strategies to alleviate it. 

In addition, consider solutions that involve systems designs, preflight, and in-flight training, the need for specific crewmember skills or characteristics, and support from Earth. Remember that many problems that astronauts encounter will have to be handled internally. 

Before you begin, reread the chapter on the topic you have chosen and explore some of the corresponding links. Your essay should be one page (500 words).  Cite your sources. Topics you might consider include:

• radiation  
• meteoroid impact 
• dust storms 
• microgravity  
• Mars spacesuits 
• Mars (one-third) gravity  
• proper nutrition  
• exercise  
• communications  
• recreation 
• time-keeping 
• crew selections 
• interpersonal relationships

Mars Math: Part Two

The spacecraft is now going to be sent to Mars.  It has been lifted into low-Earth orbit.  It is now in the same orbit around the Sun as the Earth is.  In order to reach Mars it needs to do a Hohmann Transfer maneuver (like you learned about in Lesson 3, On Orbit Ops: Orbital Mechanics 101). 

This maneuver will enable the spacecraft to go from an orbit around the Sun that is equal to the Earth's, to an orbit around the sun that is equal to Mars'.

What you need to do is determine the characteristics of the ellipse in order to aid in calculating the Hohmann Transfer.  Please identify the length of the semi-major axis, the semi-minor axis, and the focal length of the ellipse. Specify each of these quantities in millions of km (Mkm).

You can work it out yourself, or use the hints and charts below.

The semi-major axis (a) is the distance to the center of the ellipse along the major axis.  As you learned previously, the center of the ellipse is halfway between the two foci (one of which is the Sun). 

1.  The distance from the Earth to the Sun is 150 million km (Mkm)
2.  The distance from Mars to the Sun is 230 million km (Mkm)

To determine the length of the semi-major axis first determine the length of the major axis (using the information above) and divide it in half.

To determine the focal length, subtract the Earth's distance to the sun from the semi-major axis.

To determine the length of the semi-minor axis, use the equation below.

f² = a² - b²   or  b² = (a²-f²) ^1/2   or b = SQRT (a² - f²)

Thank you to Joe Kolecki and NASA's Learning Technology Project at the Glenn Research Center for use of these questions and activities.

Here are a few on-line Math sites that might help you!

Ask Dr. Math

The Math Forum

Quick Math

The Math Help Desk

and check out, Interactive Algebra!
 

Rubric Assignment 9

Your assignment will be graded on your essay, answer to the math problem and quiz score using the following rubric. If your assignment is late, points will be deducted as follows:

•  If assignment is one day late, 1 point will be deducted.

•  If assignment is two or three days late, 2 points will be deducted.

•  If assignment is four or five days late, 3 points will be deducted.

•  If assignment is six or more days late, 4 points will be deducted.

Next... Extended Mission (optional)