ATV3: Interior hatch seen from inside ATV. Credit: ESA

Hatch closed! Interior hatch seen from inside ATV (in this photo ATV-3). Credit: ESA

It was another busy day with the ATV-4, but after this it will be quiet until 23 August. 

First message is from ESA Mission Director Mike Steinkopf at ATV-CC, Toulouse: 

This morning a successful bladder integrity check on ATV water tank No. 2 was performed. The purpose of this test is to ensure that the water tank bladder is not damaged and the tank, which was flown up empty, can be filled with liquid waste transferred from ISS to ATV. Basically the test consist of applying a small over-pressure on the water tank bladder using the on-board compressor. This delta pressure is monitored during 1 hour to ensure it stays constant before the water tank is again depressurized.

This afternoon, we start the ATV hatch-closure activities. The hatch closure is planned for 14h30 GMT; this is required for the Russian EVAs, which are taking place in the coming days. The hatch will be opened again on 23 August. During that time it will be unusually quiet at the ATV Control Centre in Toulouse.

Then, at 19:30 CEST, Marcus de Deus Silva, mission director on console, confirmed the hatch closure:

The ATV-4 hatch has just been closed by the ISS crew. This was part of a “mid-mission isolation” procedure carried out before each Russian EVA (Extra-Vehicular Activity; more commonly known as a spacewalk).

The ATV-4 hatch will be closed for one week during which time the ISS crew cannot enter ATV-4’s pressurised module. Just before the hatch closure the crew entered ATV to carry out a leak check on water tank 2. This was successful, meaning that water tank 2 is ready to accept waste liquid.

With all these good messages from orbit, the ATV blog wishes a relaxed time for the hard-working teams at ATV-CC!