In the poker game Texas Hold-Em "pocket rockets" refers to a "starting hand" that consists of two aces. Sometimes called just "rockets". The odds of receiving this hand are 1 in 221. It is the best starting hand.
The name "pocket rockets" is given because the letter "A" that is printed on the Ace looks like a primitive rocket. The "pocket" is just another term for the starting cards (or hole cards).
Contrary to legend the computer hand, Q-7 offsuit, is not the best hand to play against aces. In a 2 player game 5-6 suited has the highest chance of beating 2 aces. It has all the potential of the other suited connectors with the added benefit that it will win when the board has 2-3-4-5-X (and the 2 aces will pay off with their losing straight).
A single ace is not normally called a pocket rocket.