AI Natrix: very nonstandard takeoff procedure

[craigo-]

savegame (2023-02-03 level): Vark Sijyn (The Breadmaker) KILL NATRIX.zip

Observed behaviour

So I'm on Leclercq in the Tsuhotakko system [-3, -5, -2 for you geospatial nerds]. It's sort of Earth-sized, but without the useful atmosphere. Let's just say I'm not buying a condo here any time soon.

My current mission is to kill Cornelius Huber, in Natrix TS-3270. This is a high-value target and I don't ask questions. I'm parked right beside him in my innocent-looking Mola Mola, looking out the left side of the cockpit as he's about to take off less than a minute from now (at 10:31:13).

Then I see Cornelius attempt to takeoff, and my jaw drops. The ship leans right and starts pitching up, as if the landing pad is buckling under an earthquake. I check my sensors, but my Mola Mola is straight and level. Then I notice the Natrix's RCS thrusters firing, and I slowly grok that this is what Huber wants the ship to do.

Tortured alloy sparks shoot upwards as Cornelius' Natrix slowly but surely wrenches itself into a vertical position, surely tearing ragged holes into itself and the pad. Is he gonna get billed for that?

Finally, the ship (or what remains of it) is somehow vertical, Cornelius engages the Natrix's main thrusters and the ship wrenches itself clear of the pad and gains altitude.

I love the Natrix. Hey, I started out in its little brother the Xylophis space van, so I have a soft spot for anything OPLI-Barnard. I've read the Natrix's sales brochure many times, but it never talked about needing a flippin' launch tower so it could take off vertically. They should have said, "10% hull damage free with every takeoff!" Suffice to say, I'm never buying one.

I let Cornelius Huber go. He has enough problems.

Expected behaviour

The Natrix is able to take off in 0.94G

Steps to reproduce

Unzip and load attached savegame

Screenshot

My pioneer version (and OS):

Master (f79db1d)
Windows 10 Enterprise 22H2

NB: possibly related to issue #5243

[sturnclaw]

This is quite possibly the best issue description I have read in the last year, possibly two years. Well done!

...The issue itself is probably related to the Natrix being unable to gain altitude above the pad before rotating towards its "takeoff" vector like most ships do. There is at least one configuration issue with the Natrix; it's a much larger ship than its stats would otherwise imply, and its thrusters are setup to only provide 0.24g of upwards thrust when fully laden.

[bszlrd]

that might be on me. It was a space-only ship back then, but in the rebalance I forgot to prohibit equipping an atmospheric shield to it to keep from landing on planets. (at least that's how that limitation worked back then), It's space-only nature is why I kept the lateral thrusts so low. I'm open to up its thrust values and accel limits.
This also points to a more general problem when TWR becomes a more pressing problem when the switch to volume based cargo and equipment comes around: there will be a need to check TWR against a given body before landing or when a module places a ship there to see if it could take off. Especially for trading, where the given ship will need to decide whether it should by that heavy cargo based on that too.

I second that this report was hilarious. That's some good writing, :)

[sturnclaw]

Natrix is now fixed to be able to take off from 1g planets, however this is a more general problem in that mission modules need to intentionally validate and restrict their selection of ship hulls on a per-mission basis.