The most common and most likely answer to this crossword clue is the 6 letter word APOLLO
I've seen this crossword clue in The Daily Telegraph
A
P
O
L
L
O
More clues leading to the result APOLLO
- Everyone outside potty over handsome young man
- Permit briefly restricting work held back space program
- Another leader and vote? Oh, God!
- Article exploring Merchant of Venice having extra line in for youth
- One vote’s nothing for this looker
- God appearing in an election round
- Theatre god
- A head linked to old US space programme
- God, a top leader on Olympus
- A survey on old god
Buddy explains!
The straight part
We know that "Good-looker/mission that was out of this world" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case good-looker/mission that was out of this world = apollo.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does APOLLO mean?
APOLLO noun- A very handsome young man.
- Any of several papilionid butterflies of the genus Parnassius, especially Parnassius apollo of Eurasia (also known as the mountain apollo).