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?

  • 2
    I agree that it's at most full impulse. It may, however, be possible to get a more precise estimate of the velocity from the episode itself, as it had a pretty big ticking clock, meaning we'd have an estimate of time, and then we could use how far away they appear to have gotten.
    – trlkly
    Aug 16, 2015 at 4:09
  • This phrase also occurs in Arena: "They came in space normal speed, using our regular approach route, but they knocked out our phaser batteries with their first salvo."
    – Ixrec
    Aug 30, 2015 at 19:44
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    I think Sulu picked a random speed to avoid looking ignorant, Kirk reiterated his order to avoid admitting he made the term up on the spot, then accepted Sulu's guess for the same reason. From that point on, "space normal speed" was established as whatever Sulu thought was reasonable. :)
    – chepner
    Jan 10, 2020 at 14:56

1 Answer 1


The Star Trek Reader series of books features James Blish's adaptations of TOS episode scripts. These adaptations were approved by Gene Roddenberry himself. In particular, Star Trek Reader IV (1978) contains the adaptation of "The Galileo Seven", where we find the following passage:

It was the thought of the big hairy things that had brought Kirk to his decision. He uncupped his chin from his hands. "Mr. Sulu, proceed on course as ordered for Makus III. At space normal speed."

Sulu was startled. "But all systems report secured for warp factors, sir. Space normal speed?"

Hence, as you correctly surmised, "space normal speed" is slower than any warp factor, and hence is slower than the speed of light (since warp factor 1 is precisely that).

As for what "space normal speed" is in terms of impulse vs. thrusters, the Star Trek: The Next Generation Technical Manual (pp.75-80) indicates that the impulse drive is powered by deuterium fusion reactors and can attain speeds that are capped at around 1/4 the speed of light (which works out to 75,000 km/s, i.e. 46,602 mi/s ). This speed is what is meant by "full impulse" (Star Trek: Voyager Technical Manual, p.13).

On the other hand, the manuals explain that thrusters use high-efficiency reactant propellants and are employed mainly for very slow approaches, for piloting in space dock and dry dock, for high-precision maneuvers, or for transit when both the warp drive and impulse drive are offline.

I believe these meanings are the same in the TOS era.

Based on the comparison above, I would imagine that space normal speed is the speed attained by the impulse drive in its normal operation (which is at most 75,000 km/s).

  • are you sure it's not 74,775/s km? lol and can you convert that to miles/sec for me, I'm American. Do they use metric or standard system in Canada. +1 Good answer, want to see what others come up with, otherwise I'll award this one and I'm not going to make you wait for me to write a speech either, lol.
    – JMFB
    Aug 16, 2015 at 1:45
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    @JMFB : Thanks! Yeah, I copied that figure from Memory Alpha, but of course it's 75,000 km/s. (Another reason why every fact from Memory Alpha should be checked before being used!) I also put the miles per second in the answer for you, which is 46,602 mi/s. Canada uses the metric system, and the Technical Manuals use it, too. :-)
    – Praxis
    Aug 16, 2015 at 4:31
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    @JMFB Heh, metric is the standard system, and it is what is used in Canada and almost everywhere else on the planet (not to mention the Federation). The US is one of the last countries left to still use the imperial measurements.
    – user8693
    Aug 16, 2015 at 19:20
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    @MichaelHampton educationoasis.com/curriculum/Math/ff/standardsystem.htm Standard is simply a formal name. It has nothing to do with which is more useful, beneficial, or used more often, it's simply what they're called. The imperial system which was designed in 1824 is not what is in use in the United States. So that is incorrect. In any event there are advantages and disadvantages to each system. One advantage to the Standard system is that it's easy to do 1/3rds and 1/4ths in a system based on 12. It's not so easy in a system based on 10.
    – JMFB
    Aug 16, 2015 at 21:08
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    @JMFB Ah. You're right, there are differences. As for doing fractions, you have to wonder how the rest of the world manages to cook, or build houses, without them...
    – user8693
    Aug 17, 2015 at 0:45

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