With just 46 seconds left before NASA's new Orbiting Carbon Observatory-2 was set for launch, the agency called it off.
NASA said that they discovered a water flow issue, which required the launch to be temporarily scrubbed, Discovery reports. The OCO-2 was originally set to launch early Tuesday morning from California's Vandenberg Air Force Base.
The launch was set for 2:56 a.m. and had to be within a 30-second window in order for the OCO-2 to become part of the A-Train, which is a constellation of several other satellites.
NASA spokesman Steve Cole said that the water flow problem was "in the pad structure itself, not in the rocket," according to the Los Angeles Times.
"The pad folks are troubleshooting what the cause of the issue was," said Cole. "They're working that right now. We expect to know within a fairly short time whether we're a go" or not for now Wednesday morning.
The OCO-2, which cost $465 million, will orbit the earth and both map and measure carbon dioxide in the Earth's atmosphere.