I'm currently doing "Defeat Enemy Signal Contacts" and some/most of my allies always get a head start on the killing. They seem to me doing something like a short sprint. For a short wile they shoot away at great speed like running when you are doing ground missions.

How do I do that and what is it called.

Lvl4 Engineer

Full Impulse

An arrow button right above your ship's speed bar

If they're not travelling at full impulse, maybe they're using Evasive Maneuvers + speed mode, possibly with an Engine Battery thrown in for good measure. Can't say I've seen it in DSEs (mainly because I don't bother with them), but this combo is often used for escaping in PvP.

It's called "Full Impulse", and has the side effect of completely draining ALL your ship's power and rerouting it to the engines.

That leaves you wiht no weapons power OR shield regen for a few seconds once you come out of it I.E stop short or you're a sitting duck for a bit.

To activate it EITHER put the "Full Impulse" ability on your hotbars and using it, OR click onthe upward-pointing double arro on the top of your "throttle". Click the double arrow again to come out of it. When you're using it, the throttle will flash.

Probably "Full Impulse Power". It gets mentioned in passing during the tutorial. Look for the double up arrow at the top of your speed selector.

The downside is that it puts all of your power into engines, and it takes time for your previous levels to re-establish when you drop out, so it's generally best to manually return to combat speeds about 12-15 km from your target so your weapons and shields have time to power up.

Thank you, just what I wanted to know.