Question Cost of Propellent for real?

[ThaGuy]

Hi guys and gals, i was just completing an alignment burn to correct a mistake and realized i just wasted another 100000 kg of fuel... time to put Kutch and his Space Tankers to work again but was interested how much that would cost me if it were real?


Thanks again Kulch!

 

[jedidia]

100 tons? a hell of an alignement error that must have been... :shock:

Do you mean the cost in actual currency? Hard to say, really... no sanely built spacecraft has such error margins, so the cost is whatever the mission cost.

If you mean the cost of flying the stuff up there, that depends heavily on what kind of propellant, and what trajectory the target is in... depending on these circumstances, it can be almost as expensive as your initial mission.

 

[ThaGuy]

Yeah 112.3 tons just to save the spacecraft. im new) lookin for a general estimate per kg. most vessels i have tried do not specify what fuel they use. I thought longtime fans would have assigned a hypothetical value to "propellent" already

 

[statickid]

ive wondered something along the lines of "how much US dollars is a liter of hydrazine...if there is a xr gas station... or alternatively how much would a kg of liquid fuel cost at the space station refueling dock :hmm:

 

[blixel]

Here's one way you could make up some numbers to go on.

According to NASA's website, "The average cost to launch a Space Shuttle is about $450 million per mission."

"At liftoff, an orbiter and External Tank carry 835,958 gallons of the principle liquid propellants: hydrogen, oxygen, hydrazine, monomethylhydrazine, and nitrogen tetroxide. The total weight is 1,607,185 pounds." (729007 kg)

450,000,000 USD / 729,007 = $617.278 per kg.

So if you want to use those numbers, you wasted $61.7 million dollars.

And by the way, you're fired.

 

[ThaGuy]

Yeah i know it. but there were circumstance ie. Dansteph's Arrow Freighter + Nuke+ a big rock and me at the helm but that was the info i was after.
Thanks Guys

 

[dgatsoulis]

@blixel
Yeah but that's not the cost of the fuel itself, but the cost of the mission.

According to astronautix, in the 1980's NASA was paying less that 4$/kg for the LOX/LH2 (which was the majority of the fuel) of a Shuttle mission.
I don't remember the source, (I'll have to look it up), but I remember something like 1.4 million $ per launch for each Shuttle mission for fuel.

@ThaGuy
I guess it depends on the fuel and where you got it from. That's why you don't find "an assigned hypothetical value".
LOX/LH2 on Earth is less than 4$/kg (1980's prices for the Shuttle) but if you get it from low Earth orbit, the cost is 3 orders of magnitude higher, because you needed to pay ~5,000$/kg to get the fuel into space. Not to mention the cost of running a dedicated space refueling station, which would also add to the final price.

Some of the ships in Orbiter don't specify the fuel they use but you can look at the thrust and specific impulse of the engines, combined with the propelant tank capacity to deduce what kind of engine/fuel combination is being used. (real/near-future/sci-fi/magic) You can find a helpful list here.

 

[ThaGuy]

Fantastic link man thanks

 

[blixel]

@blixel
Yeah but that's not the cost of the fuel itself, but the cost of the mission.

Exactly. I realized the figure was fairly meaningless, but I have no idea how much the total mission cost breaks down as far as payroll, facility cost, and so on.

 

[dgatsoulis]

Yeah i know it. but there were circumstance ie. Dansteph's Arrow Freighter + Nuke+ a big rock and me at the helm but that was the info i was after.
Thanks Guys

The Arrow has an exhaust velocity of 500 km/s and 50 MN of thrust, from 6 engines, so we have 83.33 km/s and 8.33 MN per engine. The engine that is close to those values from the list is the NTR: Gas/Open 2nd Gen.

The reaction is maintained in a vortex tailored to minimize loss of uranium out the nozzle. Fuel is uranium hexaflouride (U235F6), propellant is hydrogen. However, in one of the designs, U235 is injected by gradually inserting into the fireball a long rod of solid uranium. The loss of uranium in the exhaust reduces efficiency and angers environmentalists.

The vast majority of the mass of the fuel you used was hydrogen, and since we are talking about the Arrow, the fuel had to be launched into space and then loaded.
With a price of 3.8 $/kg on Earth, and 4,106$/kg (SpaceX prices 2013) to launch it into space, your 112.3 tons "correction" cost 461,530,540 $

The sum will be deducted off your next paycheck.

 

[jedidia]

and 4,106$/kg (SpaceX prices 2013) to launch it into space

You'll probably have to add a bit to that because I should think that the per kg price isn't accurate for something with such an insane volume, but it's a really useful estimate.