# Why did they bother closing the hatch on the LM while doing EVA?

In the transcript of the Apollo 11 EVA on the Moon, Buzz Aldrin mentions closing the LM's hatch and being careful not to lock the two astronauts out.

109:41:28 Aldrin: Okay. Now I want to back up and partially close the hatch. (Long Pause) Making sure not to lock it on my way out.


Why bother closing it at all, why not just leave it open?

Bonus question: Could they have actually locked themselves out?

• I like your bonus question. I imagine "Houston... we've had a problem here. We just locked ourselves out" – Manu H Jul 25 '19 at 11:33
• thanks for the link! ;-) – uhoh Jul 25 '19 at 12:33
• Keeping dust out maybe? – Steve Linton Jul 25 '19 at 14:33
• Because their mothers trained them well. – PJNoes Jul 25 '19 at 16:44
• Dust was certainly known to be a problem from the Surveyor missions. That's why they were given the Equipment Transfer Bag, to keep the replacement LiOH canisters clean when transferring them from the drawer in the descent stage to the cabin. i.stack.imgur.com/mKBaN.png But I don't know about the reason to close the hatch, probably also dust. – DrSheldon Jul 25 '19 at 18:31