Raw data downloaded from NASA's Data Portal: Extra-vehicular Activity (EVA) - US and Russia. However, these data do not include China's first EVA in 2008, nor do they include EVAs from US or Russia since August 2013; see additions.csv.
The EVA dataset used for this visualization is spacewalks.csv produced by process.R. This csv file is up-to-date as of October 2, 2015. Please submit a pull request with corrections to process.R or additions.csv if I have missed anything!
Additionally, visualize.R uses ggplot2 and gridExtra to build a visualization titled Spacewalks: A Fifty-Year History and saved as spacewalks.png.
Producing the processed data and visualization is easy with Make. In the command line, navigate to this directory and enter
make
If you simply want the processed data and do not care to build the visualization, enter
make data
Finally, to remove spacewalks.csv and spacewalks.png from your directory, enter
make clean
Of course, you don't have to use Make and can simply run process.R and visualize.R from within RStudio, so long as the working directory is set to spacewalks.