Louis how she got up

One day there was a rocket ship that got into space I was in the space ship. When I was in the mission I saw a young girl out in the open just siting on a chair. I was so confused. How was she alive with out oxygen. Then I realised that she was a alien in disguise as a human girl. she jumped strait at my space ship and started to destroy it. I had about 1 minute until she will get in the engine and start to mess it up. I was domed. More like I am dead.