Creating a new THS space drive

[mindbound]

That link doesn't have enough information

Yes, perhaps the specific example I picked wasn't ideal.

That being said, many thanks for the worked example! I think I'll be able to continue from here.

Edit: A few questions here for the-red-scare.

Example: I want my fusion rocket to get 0.005 G from an engine massing 1/20 of loaded mass. I multiply 0.1 by 4/0.05 to get 0.4. The THS thrust is therefore 0.4 tons.

What is the 0.1 in the calculation, how does the 0.005 factor in there, and how do you get 0.4 from 0.1*4/0.05? I assume I have misunderstood the formula there.

Thrust is based on the thrust-to-weight ratio of the drive. Atomic Rockets generally provides this. You just multiple the T/W by 4 and you’re done.

Do I understand it correctly that by multiplying the TWR by 4 (presumably the mass per space of drive?) I'll get the THS' thrust per space of drive figure?

Thank you in advance!

[the-red-scare]

Originally Posted by mindbound

What is the 0.1 in the calculation, how does the 0.005 factor in there, and how do you get 0.4 from 0.1*4/0.05? I assume I have misunderstood the formula there.

The 0.1 is a mistake! Should be 0.005 because that’s the Gs I specified. I rewrote the example and that got left in by mistake. Fixing it now above.

Originally Posted by mindbound

Do I understand it correctly that by multiplying the TWR by 4 (presumably the mass per space of drive?) I'll get the THS' thrust per space of drive figure?

Yep, T/W is unitless, so multiplying by any weight gives you the thrust for an engine of that weight. All THS drives are 4 tons per space, so multiplying 4 by the T/W is the tons of thrust.

[the-red-scare]

Here’s an example from Atomic Rockets. All I’m using is the info from the Engine List.

ACMF (Antimatter-Catalyzed Micro-Fission/Fusion)
Thrust: 2.7
Mass: 4
Cost: 0.8
Output: 0
Power: 0
RMC: 0.005N
ISP: 13,500

Thrust is 4 * 0.680
F is 24,030
Ve is 132,300
Flow rate is 0.0154 kg/s
Or 0.061 tons/hour
RMC is 0.061/12

All pulse drives use generic “nuclear pellets” which are 12 tons per space and we don’t really have anything better to base density on. But as you can see, pretty easy!

[mindbound]

Originally Posted by the-red-scare

The 0.1 is a mistake! Should be 0.005 because that’s the Gs I specified. I rewrote the example and that got left in by mistake. Fixing it now above.

Yep, T/W is unitless, so multiplying by any weight gives you the thrust for an engine of that weight. All THS drives are 4 tons per space, so multiplying 4 by the T/W is the tons of thrust.

Makes sense, I was just checking if I hadn't accidentally misunderstood any of your points. Thanks for the correction w.r.t. the G numbers!