Wolfman and Dracula have been hired by Universal Missions (a space services spinoff from Euphoric State University) to investigate if it is possible to send their next planetary lander to Mars. They want to be able to work on the plans at the same time, but they have run into problems doing this in the past. If they take turns, each one will spend a lot of time waiting for the other to finish, but if they work on their own copies and email changes back and forth things will be lost, overwritten, or duplicated.
A colleague suggests using version control to manage their work. Version control is better than mailing files back and forth because:
Version control is the lab notebook of the digital world: it's what professionals use to keep track of what they've done and to collaborate with other people. Every large software development project relies on it, and most programmers use it for their small jobs as well. And it isn't just for software: books (like this one), papers, small data sets, and anything that changes over time or needs to be shared can and should be stored in a version control system.
In this lesson we use Git from the Unix Shell. Some previous experience with the shell is expected, but isn't mandatory.