NERVA buffed?

[Wizard Kerbal]

I made a Gilly lander, and i had to use a separate lander because the NERVA’s TWR was too low. Now, out in space, it says I have a TWR of 138.19, and while that may be an exaggeration, she does move pretty fast. Has it been buffed since patch 6?

Edited February 3, 2021 by The wizard of me
Oh and the reason I said patch 6 and not 1.10 is because I’m on Xbox

[Guest]

6 minutes ago, The wizard of me said:

I made a Gilly lander, and i had to use a separate lander because the NERVA’s TWR was too low. Now, out in space, it says I have a TWR of 138.19, and while that may be an exaggeration, she does move pretty fast. Has it been buffed since patch 6?

Gilly has such ridiculously low gravity that a single Nerv could shift the entire VAB there. A TWR of 138.19 sounds possible if you're comparing against Gilly gravity; if it's against Kerbin gravity, no way. I.e. I'm pretty sure your atomic lander would have worked there. 

What are you using to see the TWR? The built-in dV tools, KER, or something else?

[Wizard Kerbal]

23 hours ago, Brikoleur said:

What are you using to see the TWR? The built-in dV tools, KER, or something else?

The deltaV in the right-hand side of the VAB set to Vaccum

Edited February 3, 2021 by The wizard of me
The DeltaV chart was set to Kerbin-Vaccum

[JcoolTheShipbuilder]

Just now, The wizard of me said:

The deltaV in the right-hand side of the VAB set to Vaccum

Ok, is it set to gilly?

[Guest]

6 minutes ago, The wizard of me said:

The deltaV in the right-hand side of the VAB set to Vaccum

I made a quick experiment, and a craft powered with a single Nerv, carrying one Mk 1 lander can and two full Mk 1 liquid fuel fuselages has a TWR of a hair under 150 under Gilly gravity, and 0.75 under Kerbin gravity.  So I'm pretty sure that's what you've been looking at.

[Streetwind]

12 hours ago, The wizard of me said:

The deltaV in the right-hand side of the VAB set to Vaccum

By default, it shows Kerbin-relative TWR. There is a dropdown menu where you can choose other celestial bodies. If you want to figure out if it can land on Gilly, you must select Gilly.

Spoiler alert: you can land there on ion drives, even

[jimmymcgoochie]

Gilly has puny gravity. Weight is a function of mass times gravity, so even though the mass of your lander is high (resulting in a low TWR around Kerbin which has 1g gravity) the weight around Gilly is extremely low because of the meagre gravity and a NERV could probably land a few hundred tons on Gilly with no real difficulty.

Landing on Gilly is best done using RCS thrusters or tiny engines like the Ant/Spider, which will probably still have a high TWR but a very low overall acceleration rate. Don’t go for a similar TWR as for landing on, say, the Mun or Duna as this will result in painfully slow acceleration and a very long landing, and don’t turn the springs up too high or you’ll bounce back off the surface and have to wait even longer for it to settle to the surface.

[Zhetaan]

2 hours ago, jimmymcgoochie said:

a NERV could probably land a few hundred tons on Gilly with no real difficulty

Gilly's surface gravity is .049 m/s².  The Nerv has a thrust of 60,000 N.  This would mean that a Nerv can, at least theoretically, land a craft of anything up to 1,224.5 tonnes, though for a safety margin it's probably best to limit the weight to 90-95% of the thrust.  It'll still take a long time (a Nerv pushing that mass will have the same acceleration as Gilly's gravity, so 5 cm/s²), but you're underrating the Nerv by a factor of about four.

[jimmymcgoochie]

13 minutes ago, Zhetaan said:

Gilly's surface gravity is .049 m/s².  The Nerv has a thrust of 60,000 N.  This would mean that a Nerv can, at least theoretically, land a craft of anything up to 1,224.5 tonnes, though for a safety margin it's probably best to limit the weight to 90-95% of the thrust.  It'll still take a long time (a Nerv pushing that mass will have the same acceleration as Gilly's gravity, so 5 cm/s²), but you're underrating the Nerv by a factor of about four.

While 1200 tons might be mathematically feasible, the practicalities of actually landing a vessel on a celestial body  like Gilly would require greater acceleration to avoid crashing into the lumpy bits as you oh so slowly shave off orbital velocity without adding too much vertical speed. Burn times would get impractically long and fuel requirements impractically high so realistically one or two hundred tons on one NERV would be the limit while maintaining a semblance of control and getting it done in a sensible amount of time.

[Zhetaan]

24 minutes ago, jimmymcgoochie said:

While 1200 tons might be mathematically feasible, the practicalities of actually landing a vessel on a celestial body  like Gilly would require greater acceleration to avoid crashing into the lumpy bits as you oh so slowly shave off orbital velocity without adding too much vertical speed. Burn times would get impractically long and fuel requirements impractically high so realistically one or two hundred tons on one NERV would be the limit while maintaining a semblance of control and getting it done in a sensible amount of time.

I thought that the impracticality was implied by the 5 centimetre acceleration.  You have my apologies if that was not clear; to be unequivocal, though, allow me to state for the record that you certainly won't see me trying to push a kilotonne craft with only one Nerv engine, whether at Gilly or anywhere else.

[Wizard Kerbal]

I remember the start mass of the mothership was somewhere near 18 or 20 tonnes, so that definitely answers it

[FleshJeb]

13 hours ago, Streetwind said:

Spoiler alert: you can land there on ion drives, even

Heck, you can land on Duna and Moho on ion drives. They're ridiculously OP.