The conundrum is largely one of the agency's own making, says Roger Launuis, a former historian at NASA and now curator of planetary exploration programs at the Smithsonian Institution's Air and Space Museum in Washington.
The James Webb Space Telescope, the successor to the highly successful Hubble Space Telescope currently on orbit, has seen its price tag expand from a 1997 estimate of about $500 million to build and launch to nearly $9 billion today. Its launch date has shifted by more than four years to a planned launch in October 2018, according to the Government Accountability Office.
For all its success and promise, Curiosity also overshot its budget. Since 2008, the cost for the now-$2.5 billion mission grew by $881 million. Technical challenges during development delayed its launch by two years.
Given the current budget climate, Congress appears unwilling to offset the overruns, Dr. Launius says. Nor has the Office of Management and Budget been inclined to tuck anything extra into NASA's budget to ease the squeeze.
The change forced the agency to withdraw from a joint program of high-profile Mars missions for 2016 and 2018 undertaken with the European Space Agency.