Lesson 1

CAD or CADD is the acronym for Computer-Aided Drafting and Design. CAD has been around for about 50 years , but drawings have been part of design and engineering since ancient times. Using computers to make the creation of these drawings easier was a natural step. (To learn more about the history of CAD, check out History of CAD.) CAD has many advantages over manual drafting. Some of these are:

	Higher precision
	Quicker, easier revisions
	More efficient because of capability to copy, mirror, and array entities
	Choice of output formats
	Electronic exchange of drawings over Internet, etc.
	Easier to share projects and project information with other people and programs

SpaceCAD features an easy-to-use, free CAD software program, CadStd®. This software was created by John Apperson, who kindly agreed to let us use it for SpaceCAD. CadStd® has commands and features that are similar to those in other CAD programs, such as AutoCAD®. (There is also a professional version of CadStd which only costs $25. It has some useful CAD features that are absent from the free version: trim, layers, offset, etc. Check the CadStd web site for information.)

To download the free, lite version of CadStd® click here or visit the CadStd web site. You will need CadStd® or another CAD program to do the lessons in SpaceCAD. The lessons are all based on CadStd®, so if you are using another CAD program, the command names and locations will be different.

You may also wish to view the drawings as Scalable Vector Graphics.(SVG). To do this, you need Adobe's free SVG viewer plug-in for your browser.

Follow through the lessons in SpaceCAD, and in a very short time, you will have learned a valuable skill that will help you in your geometry studies, as well as any technical, engineering, or scientific work you may be pursuing. You will also learn about the history of the U.S. manned space program, while completing projects based on authentic NASA technical drawings. We think that makes SpaceCAD more interesting than other CAD curricula.

Once, you have downloaded and installed CadStd®, you are ready for Lesson 2, Drawing Setup.

If you have questions, comments or suggestions regarding this lesson, please email us.feedback form.