H-IIA Status Report: Cryogenic Test Completed – 15 days before a launch
On Aug. 26, the cryogenic test of the H-IIA Launch Vehicle No. 3 (H-IIA F3)
was conducted. The test was completed at 7:00 p.m. (JST), and the result
seems to be fine according to the post-test quick review.
In the afternoon of the 25th, H-IIA F3 was transported from the Vehicle
Assembly Building (VAB) to the pad. On the 26th, before dawn, propellant
loading operations were started, and it took six hours to fill the launch
vehicle tanks with liquid oxygen and hydrogen. The test liftoff time was set
to 19:00, and the launch day operations up to one second before the first
stage engine, LE-7A, ignition (six seconds before liftoff) were rehearsed.
By the test, launch operators confirmed inspection items and operation
procedures. Also, NASDA checked and confirmed the radio frequency link
between the launch vehicle and the Uchugaoka Station, which is scheduled to
perform tracking on the launch day.
When -180 degrees liquid oxygen and -250 degrees liquid hydrogen are loaded
into the tanks, H-IIA gets extremely cold. The test made sure if all valves
worked well, signals for electric systems were transmitted properly, and the
engine nozzles for attitude controlling moved appropriately in the cold
condition. The confirmation of those critical items is essential.
According to the quick review data issued one and half hours after the test,
the test result seemed well.
The result and acquired data will be further reviewed, and troubles happened
during today’s test will also be further analyzed to avoid recurrence. (The
troubles are explained below.)
As the test went well, NASDA does not make any change on the launch day
schedule. The launch day is September 10 (Tue).
Today, NASDA postponed the test liftoff time three times before the test was
finally performed at 19:00. The following are the reasons why the test had
to be put off.
The original X time (=T time or liftoff time):
10:30 a.m. on the 26th (JST) Pre-cooling of the tubes for loading liquid
oxygen took longer than expected, and that caused two hours of delay. The X
time was re-scheduled.
Re-scheduled X time:
13:00 on the 26th The countdown continued till X-47 seconds, but anomaly was
detected in the measurement data of the equipment that controlled the
pulsatory motion inside the liquid oxygen tube to the engine, and the
countdown was automatically stopped. It was confirmed that no problem was
found. While checking the anomaly, however, nearby areas of the launch site
was struck by lightening 13 times. Therefore, for safety, the operations
were suspended for a while.
Re-re-scheduled X time:
17:00 on the 26th The countdown continues till X-25 seconds, but the
switching of the power supply source from the ground facility to the launch
vehicle internal power was not confirmed. The power is for the launch
vehicle heater. As the shutdown of the ground power source was not
confirmed, the countdown was automatically halted. The X time was finally
set at 19:00, and test was performed successfully.
The causes of the above troubles were studied, corrected, and made sure that
they would not cause any problems on the launch day before re-scheduling the
new test X time.
More detailed analyses of the troubles will be carried out before the launch
day.
