H-IIA F3: Preparing for the Launch Vehicle Cryogenic Test: 19 days before a launch

We have only 19 more days to the launch day of H-IIA F3. The whole launch
operations since the first and second stages arrival at the Tanegashima
Space Center take about one and half months. The most critical event during
this entire period is the cryogenic test scheduled on Aug. 24, (Sat). The
launch vehicle, which has been assembled and inspected in the Vehicle
Assembly Building (VAB) until today, will come out of the building tomorrow
morning (the 23rd) for the first time to move to the launch pad. At the
pad, -180 degrees liquid oxygen and -250 degrees liquid hydrogen will be
loaded into their respective tanks, and the final countdown rehearsal will
start.

Both the first stage main engine, LE-7A, and the second stage engine,
LE-5B, combust with liquid hydrogen as fuel and liquid oxygen as oxidizer.
The combination of these two propellants can generate the fastest injection
velocity at combustion in the current possible methods, thus the most
efficient for launch vehicle flights. The difficulty is that, even though
both liquids are extremely low in temperature, the combustion gas of their
combination reaches extremely high temperature, about 3,000 degrees in
Celsius, hence it requires very advanced technology to cope with this
combustion. During the cryogenic test on the 24th, the propellants will be
loaded into the launch vehicle tanks from the ground storage to check if all
countdown operations progress smoothly.

The launch vehicle is scheduled to start moving from VAB to the pad around
11 o’clock.