SP's entry

[James Brown]

I just done my mission in wrong section.
So see this new one.
View attachment 50159 View attachment 50160 View attachment 50161 View attachment 50162 View attachment 50163
View attachment 50164 View attachment 50165 View attachment 50166 View attachment 50167

What? You can just use the small part back to the Earth!?

 

[Pink]

What? You can just use the small part back to the Earth!?

Yes, that's how it works.

 

[Space pilot]

What? You can just use the small part back to the Earth!?

???

 

[James Brown]

???

I mean, how can you get back to Earth with just small part of the fuel tank?

 

[Pink]

I mean, how can you get back to Earth with just small part of the fuel tank?

Let's say you need 1000 m/s to get back to Earth from the surface of the Moon.
(I took the numbers from this map from Altaïr and doubled them because gravity losses)

This has a full mass of 15.4 tonnes, is 6.4 tonnes when empty and has an isp of 260 seconds.
Put those numbers in a calculator...
Delta-V Calculator


See? Twice the deltaV that we need. Maybe 3 times more than we need if you're a good pilot. So we only use part of the fuel.

For extra credit, figure out how heavy is the remaining fuel that Space Pilot has, and add that to the dry mass to figure out how much deltaV he used.

 

[James Brown]

Let's say you need 1000 m/s to get back to Earth from the surface of the Moon.
(I took the numbers from this map from Altaïr and doubled them because gravity losses)
View attachment 51043
This has a full mass of 15.4 tonnes, is 6.4 tonnes when empty and has an isp of 260 seconds.
Put those numbers in a calculator...
Delta-V Calculator

View attachment 51044
See? Twice the deltaV that we need. Maybe 3 times more than we need if you're a good pilot. So we only use part of the fuel.

For extra credit, figure out how heavy is the remaining fuel that Space Pilot has, and add that to the dry mass to figure out how much deltaV he used.

Yeah Altair’s delta V map is a good delta V map for those who don’t know how to accelerate

 

[Pink]

Yeah Altair’s delta V map is a good delta V map for those who don’t know how to accelerate

Or figure out exactly how much fuel you need to bring...

 

[James Brown]

Or figure out exactly how much fuel you need to bring...

Is there a formula on how much time does the fuel stay in the fuel tank when the throttle is on?

 

[Space pilot]

What is delta v map ??

 

[James Brown]

What is delta v map ??

∆ of rocket velocity

 

[Pink]

Is there a formula on how much time does the fuel stay in the fuel tank when the throttle is on?

Yes.
Fuel consumption (in tonnes/second) is thrust (in tonnes) / isp (in seconds)
But that doesn't matter for figuring how much fuel you need to go somewhere, only deltaV matters.

What is delta v map ??

A map that shows how much faster your rocket needs to speed up to get somewhere.

 

[Marmilo]

What is delta v map ??

It's a map that tells you how much DeltaV is needed for different transfers, captures etc.

 

[James Brown]

So let's say F/s
QUOTE="Mooncrasher, post: 119998, member: 2238"]Yes.
Fuel consumption (in tonnes/second) is thrust (in tonnes) / isp (in seconds)
But that doesn't matter for figuring how much fuel you need to go somewhere, only deltaV matters.


A map that shows how much faster your rocket needs to speed up to get somewhere.[/QUOTE]

 

[Pink]

So let's say F/s

no, tonnes/s
SFS gives the thrust in tonnes and the isp in seconds. It also uses tonnes for how heavy parts are. So everything is in tonnes and seconds.

 

[James Brown]

no, tonnes/s
SFS gives the thrust in tonnes and the isp in seconds. It also uses tonnes for how heavy parts are. So everything is in tonnes and seconds.

Ok

 

[Horus Lupercal]

Yeah, cos the game doesn't give you consumption in the tooltip for some reason.

Fuel consumption (in tonnes/second) is thrust (in tonnes) / isp (in seconds)

Almost.

It's thrust / (isp x g)

Titan II = 1.695
Hawk II = 0.508
Frontier III = 0.351
Valiant = 0.145
Kolibri = 0.059
Ion = 0.001
RCS = 0.013

Tons of fuel per second.

 

[Marmilo]

What are the II's And III's about? Is it the versions of engines differing in different versions?

 

[Horus Lupercal]

What are the II's And III's about? Is it the versions of engines differing in different versions?

Yeah. Because I still use 1.4.06, most people are on 1.5 but others are on 1.35, if I say Frontier, it could be one of 3 different variants depending on version of game.
It just saves confusion

 

[Space pilot]

Titan hawk l

 

[James Brown]

Yeah, cos the game doesn't give you consumption in the tooltip for some reason.




Almost.

It's thrust / (isp x g)

Titan II = 1.695
Hawk II = 0.508
Frontier III = 0.351
Valiant = 0.145
Kolibri = 0.059
Ion = 0.001
RCS = 0.013

Tons of fuel per second.

Thx