Stuck on Duna

[QuirtTheDirt]

Hey, fairly new player here.

Recently I decided to take on my first interplanetary return mission. I went to Ike and back, with no issues. I decided to do the same with Duna, but I modded my lander by adding a propeller engine with 6 helicopter blades attached to it. I landed on Duna without issues. This craft has the gear on board to refuel, so I hopped out, planted a surface base, started the drills, and waited. Once the tanks were filled, I quicksaved in case I messed up, and tried to take off. This is my problem right now.

My propeller engine seems to be broken. I've linked it to custom group 9 for easy use, and it worked fine during testing at Kerbin. On Duna however, the blades only spin at 6-7 rpm, and all of the info the motor can give me is 0. Basically, it thinks it has no fuel, no air, and no power. This is most definitely not the case, and without my prop, I don't have the delta v to return to Kerbin.

Advice?

[Guest]

What kind of engine are you using? If it's a turboshaft then you're out of luck, it needs intake air to work, and Duna's atmosphere has no intake air.

[AHHans]

20 hours ago, QuirtTheDirt said:

Basically, it thinks it has no fuel, no air, and no power.

This makes me think that this:

3 hours ago, Brikoleur said:

If it's a turboshaft then you're out of luck, it needs intake air to work, and Duna's atmosphere has no intake air.

is indeed your problem.

To get into some more detail: Duna does have an atmosphere, but this atmosphere does not contain oxygen so it cannot fuel a regular air-breathing engine. In game those are the turboshaft engines and all jet-engines.

What does work (after a fashion) on Duna are electric rotors, so you can power a propeller with those. (And use solar panels to provide the electricity for example.) An additional problem is that Duna's atmosphere is so thin that propellers don't generate much thrust. Lifting a craft with the stock helicopter blades can be done, but is not an easy task.

[Guest]

1 hour ago, AHHans said:

What does work (after a fashion) on Duna are electric rotors, so you can power a propeller with those. (And use solar panels to provide the electricity for example.) An additional problem is that Duna's atmosphere is so thin that propellers don't generate much thrust. Lifting a craft with the stock helicopter blades can be done, but is not an easy task.

Can confirm. Stock props are almost useless on Duna, I did manage to make a craft that can barely fly with them but I had to pile on, like, 16 blades per motor, and even then it just barely made it -- there's no way that would've been a practical craft.

However, rotors built out of elevons work fine on Duna, although only at fairly low altitudes -- there are mountains that are too high for a rotorcraft to fly over, at least any rotorcraft I've managed to build.

[QuirtTheDirt]

I appreciate all the support, everyone. I was using a turboshaft. I've modified the design to use an electric rotor instead, and sent it empty to pick up the 3 kerbals that were stranded. Thanks!

Edited October 6, 2019 by QuirtTheDirt