George Abbey, former director of the Johnson Space Center located in Houston, told Xinhua that 97 percent of the center's staff were furloughed, leaving only a small number supporting the International Space Station (ISS) on line.
The ISS, therefore, has not been affected by the shutdown, Abbey said.
"The flight controllers that support the ISS are working. The control center in Moscow of course supports the station," he said.
However, he warned that the shutdown could have a marked effect on the schedule for missions down the line.
Abbey explained that astronauts have to accomplish training and other activities before their flying missions.
But people who usually provide support for them are not working now. The same was true with a few programmes such as the Orion spacecraft, he said.
"Orion is a multi-purpose crew vehicle whose capsule has been developed to carry crews to orbit and take them beyond the orbit on exploration missions. Researchers working on this programme have been furloughed," Abbey said.
The vehicle, planned to be launched in 2017, is projected to carry a crew of two to six astronauts for manned missions to the Moon, asteroids and Mars. It is also planned as a backup for ISS cargo and crew delivery.
Abbey added the launch system for the Orion and other unmanned robotic spacecraft programmes were also affected by the shutdown.
Among NASA's facilities, the Johnson Space Center was probably hurt the most from the shutdown, he said.
The center is home to the US astronaut corps and is responsible for training astronauts from the United States and its international partners.
Other affected facilities include Marshall Space Flight Center near Huntsville, Alabama, the Goddard Space Flight Center in Greenbelt, Maryland, the Glenn Research Center in Cleveland, Ohio, and the Dryden Flight Research Center in California, he said.
Abbey had gone through the last government shutdown in 1995 and 1996 when he was the director of Johnson Space Center.
The last shutdown, nevertheless, had virtually no impact on the center, Abbey said.
"There was not really major impact then because we were able to keep people working here in Houston and also people working in Florida at Kennedy Space Center. NASA headquarters in Washington, DC, were furloughed though," Abbey recalled.
"This shutdown has probably much greater effect than the one we had in the '90s. The other shutdown was not that major and didn't have any real effect I think. But this one really has some impact."
A partial federal government shutdown entered its 14th day Monday as Senate Democratic and Republican leaders remained at odds over spending.
The shutdown has furloughed 350,000 federal workers, blocked various government services, stopped the federal tax agency from processing tax refunds, and forced several parks and monuments to remain closed.