H ( hydrogen ) is the answer I believe.
Answer:
See below
Step-by-step explanation:
An exothermic reaction tends to occur spontaneously because the products are more stable than the reactants.
Nature tries to get to the lowest energy state.
Explanation:
First, we will calculate fuel consumption is as follows.

= 4526 g/s
Now, we will calculate the power as follows.
Power = Fuel consumption rate × -enthalpy of combustion
= 
=
kW
Thus, we can conclude that maximum power (in units of kilowatts) that can be produced by this spacecraft is
kW.