NASA’s flagship missions, robotic space probes that cost over $1 billion, have returned spectacular science. Recent examples include Cassini, currently orbiting Saturn and examining that gas giant and her moons, and Mars Curiosity, the car sized rover rolling across the Red Planet. NASA has already authorized a second Mars Curiosity class rover for 2020.
However, according to a December 4, 2013 post in Space Policy Online, NASA Administrator Charles Bolden has told the planetary science community that the space agency can no longer afford these huge high cost/high payoff missions. However his announcement is running contrary to the desires of Congress, if not that body’s willingness to pay for such missions.
Congress is very keen to fund a mission called Europa Clipper, which would examine that particular moon of Jupiter for signs of life. Europa is a celestial body encased in ice, but with a warm ocean beneath that layer that many suspect might contain life. Enceladus, a moon of Saturn that has been seen to eject water vapor geysers, is also a target for a mission that would search for extraterrestrial life. Both missions would be costly enough to be flagship missions.
It is, however, an open question as to whether Congress is willing to pay for such missions. If it is not, Congress can want these kinds of missions all it wants. But they will not happen without the money.