The combination of budgetary uncertainty and travel restrictions on U.S. federal employees has caused fewer government scientists to attend space-related conferences that organizers say provide a critical venue for interchanges that lead to innovation.

Some conferences have been canceled outright. In November 2012, for example, the American Astronautical Society nixed its national conference, in part, because of budget frustrations. The American Institute of Aeronautics and Astronautics (AIAA), meanwhile, has canceled its annual U.S. Missile Defense Conference, which had been scheduled for March here.

Recognizing the murky outlook for federally funded travel, the head of the Space Foundation moved to reassure prospective participants in the National Space Symposium, one of the industry’s premier conferences, that the event is going forward.

“We understand the confusion and concern surrounding the present government travel environment,” Elliot H. Pulham said in a widely distributed email Feb. 1. “The Space Foundation, probably more than any other organization, has been proactively engaged with our government customers at all levels to ensure that the vital exchange of information and ideas that takes place annually at the Space Symposium is not adversely affected as government agencies adapt to new travel and meeting guidelines.”

Conference organizers say lighter government attendance stems from a confluence of factors, including tighter travel restrictions imposed by the White House Office of Management and Budget that have stretched into this year.

The various affected federal agencies subject to the restrictions have crafted their own responses, with some giving employees more flexibility than others.

Compounding the situation is budgetary uncertainty due to the lack of any appropriations bills for 2013 and the looming threat of sequestration, a massive, across-the-board federal funding cut set to take effect March 1 barring a long-term deficit reduction agreement between the White House and Congress. Currently all U.S. federal agencies, including the Pentagon and NASA, are operating under a continuing resolution that funds their activities at 2012 levels.

To prepare for sequestration, U.S. Deputy Secretary of Defense Ashton Carter issued a memo Jan. 10 curtailing spending on travel and conferences. In the case of the AIAA, this meant no funding for its March U.S. Missile Defense conference, which the Defense Department sponsors.

More recently, the U.S. Air Force, in a document outlining its plan to cope with sequestration, said it would cancel attendance at all conferences and symposia that are not “mission critical.”

Leaders at aerospace nonprofits say the problem has been simmering for months, with some saying government attendance at their events has been down by as much as 60 percent. Reshuffling conference agendas at the last minute after presenters backed out was commonplace last year, they said.

But conference organizers say the impact goes well beyond inconveniences and lost luster for their events. The biggest casualty, they say, could well be the innovation that springs from face-to-face interaction among scientists at trade shows.

“I think it’s had a huge impact,” said Keith Seitter, executive director of the American Meteorological Society. “The agencies whose scientists can’t get to these meetings suffer greatly.”

Seitter and others say conferences provide an irreplaceable venue for presenting work to the public, talking to colleagues in hallways and making connections that could lead to future collaborative research.

To help address the problem, a collective of 14 heads of science organizations wrote Jeffrey Zients, director head of the White House Office of Management and Budget, in November to explain how its travel restrictions “have the effect of restricting the open exchange of ideas between scientists, engineers, and technologists, thereby adversely impacting the national interest.

“Taken to the extreme, the proposed new policies will have a chilling effect on scientific discovery and engineering advancement, thereby damaging our nation’s unique innovation engine, which is a major contributor to job creation, economic growth, our global competitiveness, and our national security.”

The Space Foundation, meanwhile, is helping government employees navigate their agencies’ internal processes to help assure their attendance at the National Space Symposium in April in Colorado Springs, Colo.

Pulham said he expects to have record attendance at this year’s event, even as he sought to prod those who might be wavering. “If you’re getting to the point of cutting our conference, you’re basically putting out a ‘going out of business’ sign,” he said.

Mike Gruss is a senior staff writer for SpaceNews. He joined the publication in January 2013 to cover military space. Previously, he worked as a reporter and columnist for The Virginian-Pilot in Norfolk, Va. and The Journal Gazette in Fort Wayne, Ind. He...