Given the last flight of the Space Shuttle is not too far off, the future role of NASA is in question. That eventually leads us to ask "Who should fund research?" "Who should bear the costs of high risk ventures?"
The argument for private funding (corporate, etc.) is that knowledge then is proprietary and can be used for private gain. Losses are part of the risk. The argument for government funding is that knowledge should be available to everyone, and the cost should thus be spread as any gain should be for everyone.
However, this cartoon reminds me that many of the discoveries that are part of the "Age of Discovery" ended up being for the benefit of government (kings, etc.). Anyway, it's something you can use to stir debate.