Because it was deep space . (the joke is how the outer space was very deep)
redundancy.
A joke.
X-post) http://www.reddit.com/r/AskHistorians/comments/2krnv8/whatistheoldestjokewehaveonrecord/
Some people may call it a log journal, while others call it a diary-a.
Because I hear that in space there is no ice-cream.
You planet.