How much fuel does the Constellation need?

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Fuel. Fuel is nice. It brings you from one planet to another as long you don’t blow yourself up. Today we are very good at doing both. But we don’t blow our rockets as often as 20 years ago. And I think we better our quotes in the bright future of Star Citizen. We also can create our own fuel.

At least that’s was CIG says. Quatum fuel aside it is possible to create the fuel for our ships in mid-flight, and as long as we don’t use the afterburner or super cruise mode we should go with a black zero out of this.
But be aware that some ships like racers and short range Fighters don’t have this ability!
This nice mechanic got me thinking. How much fuel do these ships need?I started digging a little bit in the web and found the Tsiolkovsky Rocket Equation which applies for every rocket like accelerated object, which is fancy for getting speed by throwing stuff in the other direction.

Delta-V = Ve * ln(Mo/Mf)

For example: when you sit in a shopping cart and throw your grocery’s out of the back you should move forward. If you throw enough at the same time to overcome your friction:

Ve * ln(Mo/Mf) > cR* Fn

Okay we make it easy and place our shopping cart on horizontal ground. Now we have

Fn = Fg = 9.81*m

Well I researched full 30 seconds to find the first data on how much a shopping cart weights: 28 kg. To be convenient, our weight is now 72kg. Total = 100kg.

Fn = Fg = 9.81*100 = 981

From Wikipedia I got data for the resistance coefficient cR. I went with 0.003 to be in the middle of a mine car.

Ve * ln(Mo/Mf) > 0.003 * 981

Now we come to the variables in our rocket equation:Delta-V is our target velocity Ve is the velocity our propellant is flying away. Mo is our mass before and Mf our mass after we used our propellant.

Ve * ln(Mo/100) > 2.943

Let’s guess our propellant is a 200g butter pack:

Ve * ln(100.2/100) > 2.943

Okay we had to throw the butter with 1472.97 m/s. That would be probably deadly if we hit someone. And I don’t think I can do it. Let’s do it the other way around. The internet says a average man can throw a ball with 60 mph = 26 m/

26 * ln(100+x/100) > 2.943

With 12kg of Butter would it work. But I guess it’s quite difficult to throw 12 kg with 26m/s. But let’s go back to Star Citizen: Same equation but we have a 274815 kg heavy Constellation Andromeda (Values are from http://starcitizendb.com). They say we can accelerate the Constellation to 910m/s in 23.8 seconds. I say the weight is with a full tank and the thruster of the Constellation is 10 times better than current ones:

910 = (4500*10) * ln(274815/Mf)

Mf = 269313

That means we lose 5502kg on hydrogen just to reach super cruise mode. That would probably mean that we need to refuel very often.

But if we get the engineers at RSI a little bit more credit and allow them to bring up the thruster speed up to 100 times than the current ones, we only need 550kg to reach scm. Still much but reasonable (remember the Constellation weight over 274 tonnes)


If you’re interested in playing Star Citizen yourself use this referral link to get 5000 UEC to start your jurney: https://robertsspaceindustries.com/enlist?referral=STAR-2FM2-QM6Z

See you in the verse


Quellen

https://robertsspaceindustries.com/comm-link/engineering/16517-The-Shipyard-Fuel-Mechanics

http://starcitizendb.com