Star Trek TOS "The Galileo Seven":
UHURA: The Columbus is aboard, sir. The flight hatch is closed. Transporter room reports last of the landing parties have beamed safely up. All systems report secured for warp factors.
KIRK: Mister Sulu, proceed on course for Makus Three, at space normal speed.
SULU: Space normal, sir?
KIRK: Those are my orders. Lieutenant Uhura, order all sensor sections to direct beams aft. Full function, continuous operation until further orders.
UHURA: Yes, sir.
Normally in Star Trek the speed of the ship is ordinarily given in very specific terms. In TOS Kirk would say for example, "Ahead Warp Factor 3." Picard would say, "Warp 2, engage." They might say "Ahead Maximum Warp." If it wasn't warp then they would say something like, "impulse engine only" or "thrusters only."
It's obvious from the episode that Kirk wanted to go as slowly as possible to give Spock a chance to rejoin the ship. My question isn't "why did Kirk want to go slowly" or is "Space normal is slower then warp" because that's obvious from the episode.
What speed is "Space Normal speed?" Is it thrusters, Impulse, etc?