Ship stalls at 4.5-5km trying to escape planet's gravity.

[A Pebble]

Noob here trying to go to space for the first time. I have a ship comprised mostly of hydrogen thrusters for movement and regular atmosphere thrusters for hovering. For some reason while flying up my ship stalls out at around 5km and starts falling back down even though im moving at around 100m/s... Any reason why this would be happening?

[Smokey]

My first thought is you're just using atmospheric thrusters however my second is you're running out of hydrogen before escaping the atmosphere.

[Demented]

You might end up traveling 100m/s sideways. Make sure your traveling direction is generally upwards and not sideways (there's an indicator for what direction you're headed). You may also need more hydrogen thrusters; they're not much stronger than atmos.

It can take several minutes to reach low grav and still more to escape gravity entirely.

[nemshammer]

It likely means you don't have enough hydrogen thrust to escape the planets gravity. It sounds like your atmos are getting you a good ways up and if your going at a good amount of speed it will likely carry you a fair ways past atmosphere but without enough hydrogen thrusters you wont be able to keep your craft moving against planetary gravity.

Two things to look at off hand is one just adding more hyd thrusters but second look at how much weight you are carrying. Weight can get out of hand if you have the amount of weight your vehicles can carry set on the high side. You may end up having a vehicle that would never be able to lift off the ground if it uses even a small amount of its overall capacity.

[mid endian]

okay, if your ship is getting hydrogen directly from O2/H2 generator, you might not be getting enough to your thrusters. did you have a hydrogen tank filled up at least halfway? is this a large or small grid ship you're using?

[A Terrible Modder]

i get this quite a bit, lag tends to instantly drop your momentum to 0 for some reason, i don't really know of any fix to it

[Buzzard]

H2 thrusters go through gas at a RUINOUS rate, while the O2 gen supplies it at... a steady trickle. H2 thrusters can work at a reduced rate if they aren't fully supplied with gas, similar to Ion/Atmo thrusters working with reduced thrust when power is lacking. In order to keep up with demand, you'd pretty much need a ship MADE OF O2 gens. Even that wouldn't work so well due to the extra thrusters needed to haul all that ice, and power for all those O2 gens. (It could be done, but... you're not gonna like it)
Fill up a big H2 tank or two and run from that. Leave the ice and O2 gens at home. A H2 tank is considered to have the same mass, no matter how much gas is stored.

For further information on how fast the gas will go, look in the control panel for the max consumption numbers on those thrusters. If you calculate for a full burn for the entire trip up, you'll have H2 for navigation in space, as well as being able to stop (when you choose) when you return to the planet. Open space, outside of gravity, will be 38-42km above ground, depending on how high you started. 42km @ 100m/s gives you ~420 seconds of burn time to calculate. At about 9km above 'sea level', atmosphere, already thin, will absolutely stop, making your atmo thrusters so much extra mass to haul.

When making your ascent, don't keep the thrusters at max all the time. This burns fuel needlessly since you can't go past the max speed. Turn OFF inertia dampeners and do a burn-coast routine, keeping your speed up CLOSE TO max, but don't keep it pegged at max. Close to ground, you'll be burning more than coasting, but as gravity drops off, you'll coast more and more. When travelling in space, you'll want to generally keep the dampeners off as well, to save fuel/power. When you want to stop, or change direction, it's easy enough to hit the dampeners to make it all happen (or stop happening. whatever.)

On the way down... who needs thusters to accelerate when there's all that gravity just CALLING to us? You did remember to save some fuel, right? Parachute hatches, supplied with some Canvas can help to slow the descent, just in case you come back a little heavier/faster than you thought you would be.

[Karmaterrorᵁᴷ]

Swap your hovering atmos for hydros, or put hydros aswell as facing down. Atmo thrusters will stall at about 5km up, ions will start to work better from that point on, and hydro thrusters work the same wherever you are :)

[mid endian]

Also if you are able to, if you plan to move cargo from planet to space you will want to test whether the hydrogen thrusters will be enough to keep your ship hovering. Regardless, just hover above the ground with all your thrusters on, then turn off your atmo thrusters. If you sink, you need either more hydrogen or more hydrogen thrusters. Check your ice and hydrogen consumption during that. And if you need to add another tank or more generators to keep up with the demand your thrusters require.

Some of the jump capable ships sold at the stations will be able to get you into space.

[A Pebble]

Just gonna bump this thread to say that I figured it out. I had my Large Hydrogen Tank set to Stockpile: ON... I didn't realize that would stop it from letting the thrusters use the Hydrogen. I know now. I appreciate the responses though as they did lead me to checking the Tank.

Idk how to lock a thread so a forum mod can lock it if they see this.