About a tablespoon. Each teaspoon is 5 ml.
That is how careful NASA is with space scientists. 15 ml of water stopped a space walk.
I think the concern revolves around the leak into the interior of his space suit. But, an astronaut can inhale that water inadvertently because of weightlessness. That isn't good. If a water bubble goes into the lungs it compromises their 'air exchange space.' The water will block the tiny alveolars where oxygen and carbon dioxide exchange.
That tiny bit of water if inhaled translates into a lot of air space exchange in the human lungs. That is a great picture of Major Peake.
Tim Peake prepares to leave the ISS to help repair a broken power unit (Nasa screengrab/PA)
15 January 2016
By Press Association
Tim Peake's (click here) historic first walk in space ended early after a water bubble was detected in the helmet of his colleague Tim Kopra.
The British astronaut helped complete the crew's primary task of repairing a broken voltage regulator and headed back to the International Space Station (ISS) after four hours and 43 minutes instead of the planned six-and-a-half hours.
Live footage showed them safely returning to the ISS's airlock area and the thermal cover being closed behind them....
