Count among NASA’s growing list of underfunded priorities the venerable but increasingly creaky Deep Space Network, which enables scientists to keep in touch with probes operating throughout the vast solar system, and perhaps even beyond. Without major upgrades, the global network of big-dish antennas and related infrastructure likely will be taxed beyond its capabilities in the not-too-distant future. Meanwhile, NASA has not done a very good job of coordinating mission-specific upgrades to the system in a manner that best serves the agency’s long-term needs.

Those were the main findings of a recent U.S. Government Accountability Office (GAO) report dubbed “NASA’s Deep Space Network: Current Management Structure is not Conducive to Effectively Matching Resources with Future Requirements.” The report, released May 22, said necessary maintenance on the network infrastructure — much of it over 40 years old — is routinely skipped as funding gets diverted to more pressing needs. At the same time, NASA’s deep space probes are becoming ever-more bandwidth hungry, while current missions are getting lengthy extensions.

As critical as it is, the Deep Space Network is easy for outsiders to overlook. With a bunch of hulking, ground-based dish antennas as its most visible component, it does not have the sex appeal of the spacecraft that rely on it to receive commands and relay status and science data.

The GAO has helped focus more public and congressional attention on the Deep Space Network and the issue of its advanced age, but the report does not come as news to NASA.

In a written response included in the report, Shana Dale, NASA’s deputy administrator, concurred with most of its recommendations and noted that the agency already is taking steps that would implement them. She said NASA has developed a roadmap that proposes Deep Space Network upgrades to meet projected demands through 2030, identifies potential gaps and serves as the basis for a future architecture developed by an agency-wide working group.

As both Ms. Dale and the GAO noted, NASA has a tough job balancing the demands of individual missions with the health of the overall network. In response to the GAO’s citation of examples in which contact with probes was temporarily lost due to network outages, she pointed out that no NASA missions have ever been compromised by such an event.

That’s a perfectly valid point, but it would be of little consolation if a mission is lost because the Deep Space Network falters at a critical moment, such as a course correction or orbit insertion. It would be even more painful if the failure was caused by inadequate maintenance of equipment.

Ironically, NASA has eased the pressure somewhat by canceling or deferring for budgetary reasons science missions that would have placed heavy demands on the Deep Space Network. The agency has scaled back some of its near-term plans for robotic exploration of Mars, for example, while also canceling probes to the j ovian system.

But this is not a long-term solution, and neither are band-aid-type fixes, for obvious reasons: NASA plans to land astronauts on the Moon once again before 2020; and even absent an ambitious human spaceflight initiative, the Deep Space Network at some point must be overhauled to contain growing maintenance costs.

NASA has in fact been studying recapitalization options. Agency officials said last year that the most sensible option is replacing the network’s 30- to 70-meter dish antennas in Australia, California and Spain with arrays of 12-meter antennas — perhaps as many as 400 per site — that can be maintained with minimal service disruptions.

Asked how much something like this might cost, these officials demurred, saying only that the number would be consistent with NASA’s historical spending rates on communications infrastructure. It does not take a pessimist, however, to envision a price tag in the billions of dollars.

Which begs a simple question: How in the universe is NASA going to pay for this?