The fascinating thing is that it wasn't a primary part of the mission but got lots of excitement. For me it was the thing that it features many off-the shelf parts from smartphones, uses linux and other open source software and it beat the expectations on how long it will service - Planned ~30 days with 5 flights and it did almost 3 years with 72 flights. https://www.nasa.gov/news-release/after-three-years-on-mars-...