Do ships in Star Trek that can land on planets use impulse drive to reach space?

Question

I have read many sources and understand that impulse drive can be very fast. A quarter of impulse can be way faster than the escape velocity on Earth (11 km/s) or on the Sun (600 km/s).

Does this mean that the impulse drive is used by ships that can land on planets, like Voyager, to get the ship back into space?

If so, is it therefore true that thrusters, struts, and dampers are what make starships have planetary landing capability? (All relate to helping the ship land, not propelling the ship to space.)

Answer 1

Your question kind goes all over the place, but you seem to be asking, essentially:

Why does a ship like Voyager need special equipment to take off from a planets surface when the impulse drive is more than sufficient.

The answer is that the impulse drive is way overkill for lifting a vessel out of a planet's gravitational field into space. The impulse drive operates at something like 0.5 warp (150kish km/sec); you can escape from an Earth-sized planet for less than 5% of that. (The space shuttle, for example, only travels about 4km/sec while on solid booster). So, clearly the impulse engines are capable of pushing a ship out of even the biggest planet's gravity.

However, the impulse engines are not designed to operate in an environment with an atmosphere. The drive runs on an impulse reactor, a kind of nuclear reactor that, in order to produce its thrust, churns out the same kind of plasma, as the warp engines do. The plasma is so high energy, in fact, that the warp reactor output is one of the power sources used to run the ship; any excess is simply dumped into space via the "plasma exhaust".

In space, the plasma will simply radiate away as it cools, probably getting pulled along behind the ship. In a gaseous atmosphere, it could easily ignite the surrounding gas or cause extreme damage to any nearby structures or vegetation.

Instead, the ships use the much smaller kinds of gravitational nullifiers that smaller vehicles did in that time (e.g. anti-grav cars) to move the ship into a safe range to start up the real engines.

The other two things you mentioned have nothing to do with creating thrust:

• The inertial dampeners were used to prevent sudden changes in the ships velocity from causing everything inside the ship to fly around. They basically counter-act the normal inertial behavior in the face of acceleration or deceleration of the ships hull. Inertial dampeners were always operating while the ship was in motion, they just need to be properly adjusted for the deceleration of a landing.
• The landing struts are just landing gear for ships. You don't want to set the ship's actual hull down on a solid object, as it could cause damage and would probably not balance very well, so they put out struts for the ship to rest on while immobile.

Answer 2

If you accept any of the books as canon, then impulse drive is indeed used to to get ships from ground to orbit. In the book A Flag Full of Stars, which takes place shortly before the first movie, the Federation had taken the Enterprise saucer section down to the Earth's surface for its part of the refit. When it was time to take it back to orbit to join the newly refit secondary hull, they used "1/10th impulse power" for forward thrust and thrusters for the initial vertical thrust off of the to ground.

Also, in the movie Star Trek III, when Kirk and crew steal the Enterprise in spacedock, they use 1/4 impulse power while still inside the space dock. If impulse, as the technical manual states, were indeed .5 warp, then 1/4 of that would still be fast enough for the Enterprise to have smashed into the side of that enclosed space and ripped both the Enterprise and space dock into little bits.

That's the problem with Star Trek. Much of it is very inconsistent from one show to another and between the shows and the novels. It's hard to come up with consistently valid answers to questions.

Answer 3

It's important to understand that, in addition to thrusters and impulse drive, Star Trek ships have the ability to manipulate gravity. If a ship is able to control gravity sufficiently to provide normal gravity within the ship in the depths of space, the same technology can be used to make the ship effectively immune to standard gravity while on a planet.

Essentially, for a ship which has anti-gravity capabilities (like all ST ships from TOS onwards), there is no such thing as escape velocity as they do not have to escape a gravity well.

Finally, in answer to another question you seem to be asking, impulse drive is what all Federation ships use when not at warp speed. There's no indication that it is unsafe to use within atmosphere, so it is also what ships like Voyager use to take off after a landing.

Answer 4

In the pilot episode of Enterprise, young Archer builds and flies a model. The model's "engine" doesn't look like anything that could produce thrust in any conventional sense, especially considering the nature of its installation. That would suggest it is some sort of reactionless drive - not an "impulse" drive, and a scaled down version of what would be fitted to full-size craft.

Answer 5

Imo the answer is Yes. Depends on source. Impulse can be over 150,000 mph. I'm thinking a Defiant Class Ship, so Voyager could easily achieve escape velocity, as it did get back into space in those episode, as evidence. Your question was clear to me.