(CNN) -- Water observed pooling inside an astronaut's helmet was reason enough for NASA to cut short a spacewalk Tuesday morning.
The spacewalk outside the International Space Station was planned to last for six and a half hours, but ended after one hour and 32 minutes, said NASA spokesman Kelly Humphries. That makes it, according to NASA's website, the second shortest spacewalk in the history of the space station.
Italian astronaut Luca Parmitano and U.S. astronaut Chris Cassidy were to install backup power equipment to critical station components and prepare cables for a new laboratory module that is due to arrive later this year, NASA said.
Parmitano and Cassidy were able to complete the first task in the spacewalk, Humphries said.
Both astronauts were called back into the station after they and mission control personnel noticed what appeared to be water pooling inside Parmitano's space suit, Humphries said.
Parmitano "reported water free-floating behind his head inside his helmet," NASA's website said.
Cassidy told mission control that Parmitano said the water didn't taste like normal drinking water, Humphries said.
This water was "not an immediate health hazard" for the astronaut, the website said.
Parmitano did not report any problems breathing, Humphries said.
"It was an orderly situation in which the crew members and the team on the ground reacted per their standard procedures, and determined that they needed to end to protect the safety of the astronauts that were out on the EVA," Humphries said. EVA stands for extravehicular activity.
The spacewalk, which began shortly before 8 a.m. ET, has yet to be rescheduled. NASA said that another attempt would not be made Tuesday.
Mission managers will determine when to reschedule the other tasks that the astronauts would have completed on this spacewalk.
An evaluation of what happened is under way, Humphries said.
CNN's John Zarrella contributed to this report