What's the work from home policy like at Lockheed Martin?

Lockheed employees rarely, if ever work from home. It's mostly the nature of the work. Some corporate work such as Annual Performance Evaluations can be done from home but must be performed on uncompensated overtime. You'll be encouraged to do this because you'll still be required to complete all your other work on time if you intend to remain competitive.

It completely depends on the nature of work that you are doing. Some groups simply can't offer telecommuting - but... I wouldn't be here if they didn't offer it, so it works for me.

It depends on what type of work you are doing.

Allowed but not encouraged.