\CAPE CANAVERAL, Fla. (AP) — The Italian astronaut who nearly drowned in his helmet during a spacewalk last month is sharing more details about the terrifying experience, revealing how he felt all alone and frantically tried to come up with a plan to save himself.

Luca Parmitano wrote in his online blog, posted Tuesday, that he could no longer see as the water sloshed around in his helmet outside the International Space Station.

"But worse than that, the water covers my nose — a really awful sensation that I make worse by my vain attempts to move the water by shaking my head," the former test pilot wrote. "By now, the upper part of the helmet is full of water and I can't even be sure that the next time I breathe I will fill my lungs with air and not liquid."

Parmitano, 36, a major in the Italian Air Force making just his second spacewalk, wasn't sure which direction to head to reach the station's hatch. He tried to contact his spacewalking partner, American Christopher Cassidy, and Mission Control. Their voices grew faint, and no one could hear him.

"I'm alone. I frantically think of a plan. It's vital that I get inside as quickly as possible," he wrote.

Parmitano realized Cassidy — making his way back to the air lock by a different route — could come get him. "But how much time do I have? It's impossible to know," he said.

That's when Parmitano remembered his safety cable. He used the cable recoil mechanism, and its 3 pounds of force, to "pull" him back to the hatch. On the way back, he pondered what he would do if water reached his mouth. The only idea he came up with, he said, was to open the safety valve on his helmet and let out some of the water.

Parmitano said it seemed like an eternity — not just a few minutes — until he peered through "the curtain of water before my eyes" and spotted the hatch. Cassidy was close behind. The astronauts inside quickly began repressurizing the air lock, to get to the spacewalkers.

"The water is now inside my ears and I'm completely cut off," he said.

He tried to stay as still as possible to keep the water from moving inside his helmet. He knew that because of the repressurization, he could always open his helmet if the water overwhelmed him. "I'll probably lose consciousness, but in any case, that would be better than drowning inside the helmet," he wrote.

"Finally, with an unexpected wave of relief," Parmitano saw the internal door open, and the crew pulled him out and his helmet off.

NASA has traced the problem to his spacesuit backpack which is full of life-support equipment. But the precise cause is still unknown as the investigation continues into quite possibly the closest call ever during an American-led spacewalk. NASA has suspended all U.S. spacewalks until the problem is resolved.