More than 3,000 Johnson Space Center employees were among the 750,000 federal workers that were sent home from work Tuesday morning.
The government shutdown means almost all of the Space Center's 3,200 employees had to stay home.
At least 3,000 full-time workers and an unknown number of contractors were forced to take the day off, unpaid.
About 99 workers were allowed to work at the Space Center on Tuesday. Those employees are responsible for sustaining astronauts on the International Space Station.
Everyone else is furloughed indefinitely, until the shutdown is over.
Space Center Houston, however, will be open to visitors. That's because the tourist spot operates independently from Johnson Space Center.