Overall view of the auxiliary hydrogen peroxide
Picture 3 of 3.
Recall that, for Project Mercury, the Redstone's tanks were stretched (as
compared to the ballistic missile
version of the Redstone) to hold additional propellants, providing for an
engine burn time of 143.5 seconds, 20 seconds longer than the original Redstone
missile. As the A-7 used a steam generator powered by a dedicated hydrogen peroxide supply (rather than a gas
generator burning the same fuels as the main booster) to drive its turbopumps, it was necessary to install an
auxiliary H2O2 tank (holding an additional 13
gallons of peroxide) to sustain turbopump operation for the extended burn time.