I really hope NASA makes more of their data easily publicly available. I've seen some really cool public visualizations posted by NASA folk, but the data behind them is nowhere to be seen.
Vast amounts of NASA data is publicly available. For instance, the data from planetary science missions is available through the Planetary Data System (http://pds.nasa.gov). There are a number of other similar services available for other types of data. They are listed at NASA's Data Portal (https://data.nasa.gov/).
https://github.com/tkrajina/srtm.py
Info from NASA about the mission and data used by the library.
https://www2.jpl.nasa.gov/srtm/