Kerbal Space Program is an awesome spaceflight simulator. Achieving escape velocity or orbit is fairly easy, but even just hitting the moon is pretty hard! I haven't managed a soft landing yet, not to mention returning safely to Earth, I mean Kerbal.

+Craig Brown might enjoy this too.
Mike Lawther's profile photoCraig Brown's profile photo
I never cease to be amazed that Apollo made it to the moon in nine years, in the 1960s!
Mike, I don't know you but we have a mutual friend (acquaintance for you?) in Tobias Thierer. He sent me this link to the Kerbal Space Program because I've written an essay called "The Man in the Moon" at I don't know, but maybe you'd be interested. Check it out! G'day! Craig Brown