ESA/CNES mission controllers on console in ATV-CC 22 March Credit: CNES

ESA/CNES mission controllers on console in ATV-CC 22 March Credit: CNES

Lots happening with ATV this weekend and next week! Here’s a quick review of ATV activities for 17-19 August, courtesy of ESA’s Mike Steinkopf at ATV-CC, Toulouse.

Skipping ahead a bit, note that after today’s ATV hatch closure, the Hatch will be reopened on 21 August; and on 22 August, we’ve got a slot for reboost manoeuvre No. 7 (starting at 15:35 CEST) that will run for about 40 mins (details to be confirmed). On Friday, 24 August, the 5th gas transfer will take place, comprising the second ISS atmosphere O2 repressurisation (using ~14kg Oxygen from ATV’s tank 2/3).

OK – back to the past three days:

Friday, 17 August – ATV-3 preparations for Russian EVA 31, set for 20 August.

[‘Spacewalk’ 31 comprises ISS Commander Gennady Padalka & Flight Engineer Yuri Malenchenko, who will spend approximately 1.5 hours outside the Station to relocate Strela 2 (the ‘space crane’), deploy the ball-shaped Sfera satellite and install 4 Service Module Debris Panels on external handrails (details via NASA).]

On board ATV, the crew secured temporary stowed cargo and took precautionary closeout photos in preparation for hatch closure prior (necessitated by EVA 31).

Later, the close-out photos of cargo were analysed by ESA with regard to centre-of-gravity (CoG) requirements, which include: no temporary stowage of any cargo and all cargo securely fixed. This was necessary to cater for an autonomous un-dock of ATV with no crew intervention in case of contingency. All cargo items were securely fixed and stowage of the items were nominal according to the stowage plan, therefore no CoG correction activity was necessary.

Sunday, 19 August – Preparations for Mid-Mission Isolation. The Mid-Mission Isolation activities were performed today. The crew removed emergency equipment from ATV (fire extinguisher, gas masks) and disconnected the Air Exchange Duct (AED – the white tube that you often see in ISS videos running from ATV into the Russian Service Module (SM) that sort of looks like the air duct for the clothes dryer in your basement) in order to be able to close the ATV hatch. Also: taking close-out photos, opening the Positive Pressure Relief Valves, removing the docking clamps and, finally, closing first the ATV hatch and then the SM hatch. Next: successful depressurisation and leak check.

“That means ATV hatch closure operations were nominally performed,” writes Mike.

What’s involved in closing the hatch? Here is the procedure by the numbers:

  • Prepare for ATV hatch closure
  • Removal of QD screw clamps
  • Transfer hatch closure
  • Downlink photo and video images of ATV and SM aft-ATV interface
  • Leak-check after hatch closure

Finally, you may be wondering: why is the crew closing the ATV Hatch? Well, it’s necessitated by the 20 August Russian EVA, which requires all ISS Russian segment hatches to be closed (more in our next post).