NASA’s recent decision to discontinue work on the overbudget Gravity and Extreme Magnetism Small Explorer (GEMS) mission was justified given the independent estimates of what it would cost to complete and launch the spacecraft. Yet the action was disconcerting, not only because of its direct impact but also when viewed against the larger set of circumstances facing NASA.

For openers, it’s always unfortunate when a space project must be canceled during development: Scarce resources are wasted and the scientists and engineers who devoted so much time and energy to the mission have nothing to show for their labors. Worse, the prospect of unemployment looms for those who work for contractors that might not be able to place them on another program. GEMS satellite prime contractor Orbital Sciences Corp. warned, for example, that the program’s cancellation puts 150 jobs at risk at the company’s Northern Virginia campus.

In a white paper distributed on Capitol Hill, Orbital also said its Pegasus XL air-launched rocket might have to be retired if the GEMS cancellation is allowed to stand. Pegasus, which ably served for more than a decade as NASA’s workhorse for deploying small science payloads, has no post-2013 missions on its manifest without GEMS. To be fair, though, Pegasus launch rates have dropped considerably since the vehicle’s heyday in the 1990s, and its costs have soared as a result. If the rocket is retired after 2013, it’s safe to say the GEMS decision only hastened the decision.

A larger, if mostly symbolic, issue is the inequity that cannot go unnoticed when a $100 million-class mission gets canceled for what NASA said is roughly 50 percent cost growth when the James Webb Space Telescope, whose price tag has risen from less than $3 billion to more than $8 billion, is allowed to continue. This seems a bit like a police officer issuing a citation to someone for littering while ignoring the factory down the street that regularly dumps toxic waste into a nearby stream.

There are real and valid reasons that small programs tend to be more vulnerable than the big ones. Webb is NASA’s next astronomy flagship, by all accounts a worthy successor to the most productive scientific spacecraft ever launched, the Hubble Space Telescope. In spite of Webb’s massive cost growth and lengthy delays, the space-based astronomy community still identifies the infrared observatory as its top priority given its potential to revolutionize the field.

There are of course less high-minded — but no less compelling — arguments for continuing work on Webb, including the number of jobs at stake and the amount of money already sunk into the project. This same line of reasoning applies to small missions like GEMS, but just like certain space technologies, the logic doesn’t scale up very well: It’s a lot harder to write off a multibillion-dollar investment — even if staying the course means spending several billion more, with no certainty of the final cost — than it is to walk away from tens of millions of dollars. Similarly, the prospect of losing over 1,000 jobs in multiple states necessarily carries more weight than 100 or 200, especially for the politicians who ultimately decide the fate of federal programs.

The unmistakable message is that the phenomenon popularly known as “too big to fail” is not limited to auto companies and financial institutions. But just as there are serious reasons for sparing a program like Webb, there are serious consequences. Among them is a dearth of opportunities for new missions and perhaps a shorter leash for those that do manage to get funding. NASA might have felt compelled to kill GEMS under any circumstances — tolerating excessive cost growth only encourages it. But seeing a far bigger offender escape the same fate, no matter what the reason, makes it difficult to applaud the decision.