Impulse drive The impulse drive was a common propulsion system used on starship s to achieve high sublight speed s . Technology . In Federation starship s , the impulse drive was essentially an augmented fusion rocket , usually consisting of one or more fusion reactor s , a driver coil assembly , and a vectored thrust nozzle to direct the plasma exhaust . The fusion reaction generated a highly energized plasma . This plasma , ( " electro - plasma " ) could be employed for propulsion , or could be diverted through the EPS to the power transfer grid , via EPS conduit s , so as to supply other systems . The accelerated plasma was passed through the driver coils , thereby generating a subspace field which improved the propulsive effect . This technology remained largely unchanged from the 22nd century to the 2360s . ( ) On August 12 , 2152 , approached a black hole at impulse because of the extreme gravity . ( ) T ' Pol mentioned that it would take 17 minutes to reach a point within 2 million km of the black hole . Though the ship ' s distance from that point is somewhat ambiguous , she mentioned two days before that it would take two days to be within 5 million km of the black hole , implying an impulse speed of about warp 0 . 05 , if the distance were 3 million km . In 2267 , Science Officer Spock calculated the explosive force of an overloaded Starship - class impulse engine to be 97 . 835 megaton s . The Enterprise was fast enough to stay ahead of the Planet Killer under " emergency impulse power " , but doing so would exhaust their fuel supplies in less than a day . ( ) By the 2270s , impulse was capable of sustaining warp 0 . 5 without the warp drive even being on - line . ( ) The impulse drive of Bajoran interceptor s could not operate within an atmosphere . ( ) The Type 15 shuttlepod s were equipped with two long range 750 millicochrane impulse driver engines , also known as impulse nacelles , which were located on either side of the craft . ( " display graphic " ) Aboard the starship s , there were a main and saucer impulse propulsion systems . In 2368 , on a schematic of the ( viewed at Commander William T . Riker ' s station on the " Enterprise " - D bridge ) , the location of the main and saucer impulse engines ( port and starboard ) were labeled . ( ) Later that year , after the computer systems of the " Enterprise - D " were disrupted by a energy wave from a Satarran starship , Geordi La Forge accessed the basic system directories of the Engineering Department . According to the department , the main and saucer impulse propulsion systems were off - line . ( ) Several ships , including Jem ' Hadar fighter s , " Galileo " - type shuttlecraft ; runabout s , the " Delta Flyer II " and Class V planetary probe s use impulse thruster s for sublight propulsion . ( ; ; ) Magnetic constrictor s were a component in the " Danube " - class impulse thrusters . ( ) Appendices . Background information . Dialogue from several episodes , including and , suggests that the impulse drive could be used in some manner to propel a ship at faster than light speeds , albeit with a lower maximum speed and a higher rate of fuel consumption than the main warp drive . This could possibly make the relationship between impulse and warp drive analogous to the relationship between electric and combustion engines in a modern hybrid car . It would also explain Scotty ' s remark in about the Romulans ' power being " simple impulse " and allow it to be reconciled with their clear capacity for interstellar travel . In " The Motion Picture " , The " Enterprise " traveled at warp 0 . 5 from Earth to past the planet Jupiter , a distance of ( at a minimum ) 390 , 674 , 900 miles , in 1 . 8 hours , making that speed approximately equal to 97 , 026 kilometers per second ( 217 , 041 , 611 miles per hour ) , or roughly 1 / 3 light speed . The difference may be explained by differences in orbital precession between the two planets at the time , or , as with warp drive , there may be other variables involved . According to Jo ' Bril in the episode , ' I am one million kilometres from the star ' s corona . Proceeding at three quarters impulse . I should reach it in approximately three minutes . ' That is approximately 12 , 400 , 000 miles per hour or 5 , 543 kilometers per second . ¼ impulse for the shuttle could be estimated at 1 , 852 km / s . The ' Star Trek Voyager Technical Manual ' page 13 has full impulse listed as ¼ of the speed of light which is 167 , 000 , 000 mph or 74 , 770 km / s . ¼ impulse for Voyager would be 18 , 665 km / s . Voyager ' s ¼ impulse is 10 times faster than the shuttle ' s . Therefore , the term " ¼ impulse " isn ' t a fixed speed as much as it ' s ¼ of the full speed of the impulse engines ' maximum .