Hatch open, hatch closed, hatch open, hatch closed...

[Leovinus]

From timeline for tomorrow's spacewalk (all times Eastern):<br /><br /><i>Wednesday, August 3 (Flight Day 9):<br /><br />1:09 a.m.<br />Third spacewalk preparations begin<br /><br />1:30 a.m.<br />Flight director update<br /><br />4:14 a.m.<br />Spacewalk begins<br /><br /><font color="yellow">4:39 a.m.<br />Shuttle / ISS hatches open</font><br /><br />8:04 a.m.<br />Tile Gap Filler Removal<br /><br /><font color="yellow">9:09 a.m.<br />Shuttle / ISS hatches closed</font><br /><br />10:14 a.m.<br />Spacewalk ends<br /><br /><font color="yellow">10:24 a.m.<br />Shuttle / ISS hatches open</font><br /><br />11 a.m.<br />Mission status briefing (flight control team video replay follows)<br /><br />1 p.m.<br />Video File<br /><br />3:09 p.m.<br />Crew sleep begins<br /><br />4 p.m.<br />Flight day highlights<br /><br />6 p.m.<br />Post-MMT briefing<br /><br />10 p.m.<br />MMT briefing replay<br /><br />11:09 p.m.<br />Crew wakeup<br /><br />11:39 p.m.<br />ISS crew wakeup </i><br /><br />I understand why the hatches are closed before the spacewalk so that they can lower the shuttle pressure for pre-breathing. But when the spacewalk is winding down, what is the great need to close the hatches again? Is it just in case the airlock fails? Or do they play air pressure games again on the shuttle when an astronaut comes back in? <div class="Discussion_UserSignature"> </div>

 

[mikejz]

8 Hours of sleep, wow I wish I was so lucky.