Add the Earth science and climate research community to NASA’s growing list of disgruntled constituency groups. A National Research Council (NRC) panel recently gave NASA poor marks for its progress in addressing the top research priorities laid out in a 2007 decadal survey of Earth science missions. In its May 2 report, the panel cited the lack of sufficient budget as the primary reason, and warned of a looming 25 percent drop in the number of U.S. civilian Earth observation sensors on orbit given the current rate of replacement.

Aside from last year’s successful launch of the Suomi NPP satellite, NASA has precious little to show of late for its annual investment in Earth science, which peaked at $1.76 billion this year. But that satellite, intended in part to continue some of the core measurements of NASA’s aging Earth Observing System flagships — the Terra, Aqua and Aura satellites are all well past their design lives — had to be pressed into operational service due to the delays and subsequent cancellation of an overbudget civil-military weather forecasting system. Operational demands could limit Suomi’s availability for research.

Bad luck has been a big factor in NASA’s slow progress getting new Earth observing sensors on orbit: Back-to-back Taurus rocket failures destroyed the Orbiting Carbon Observatory and Glory satellites in 2009 and 2011, respectively. NASA is building a replacement for the carbon-monitoring mission but is now leery of using Taurus, which highlights a related problem: Rising costs on the U.S. government’s workhorse satellite launchers — the United Launch Alliance Atlas and Delta vehicles — are crimping agency budgets for new missions.

Climate research has been identified by the administration of U.S. President Barack Obama as a top priority for the space agency. But the resulting budget growth has not translated into fast action on the top priorities identified in the 2007 Earth science decadal survey, also prepared by an NRC panel. Of four missions targeted in the survey for launch by 2013, only two have actual launch dates, and those are for 2014 and 2016.

NRC decadal surveys are known for optimistic budgetary assumptions, and the 2007 roadmap was no exception — it assumed NASA’s Earth science budget would climb to $2 billion annually by 2010. Given the current U.S. fiscal outlook, spending on this activity is not likely to reach the $2 billion level for the foreseeable future.

Like their counterparts in the planetary science and astrophysics communities, climate researchers are going to have to dial back expectations for the years ahead. NASA, meanwhile, needs to rethink its space-based Earth observation architecture, and place greater emphasis on leveraging opportunities to piggyback on commercial and especially international missions. India has long had a robust Earth observation program, for example, while Europe faces funding issues with its |Sentinel series of flagship-class environmental monitoring spacecraft.

NASA and its partner agency, the U.S. National Oceanic and Atmospheric Administration (NOAA), already have longstanding cooperative ties in Earth observation with Japan and Europe. The latter relationship suffered last year when NOAA was forced by budget constraints to abandon plans to supply instruments for a next-generation European weather satellite system.

But America’s funding woes have not reduced the pressing need to maintain and expand capabilities to monitor the changing global climate and environment. Given that, plus the fact that international cooperation is a cornerstone of President Obama’s National Space Policy, NASA and NOAA should be working overtime to repair relations with Europe while forging new partnerships to maximize their Earth observation opportunities in fiscally challenging times.