Press Release


  This press release is issued by NASDA.

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New Launch Day of H-IIA launch Vehicle No.1

August 25, 2001 (JST)

National Space Development Agency of Jap

National Space Development Agency of Japan (NASDA) postponed the launch of the H-IIA Launch Vehicle No.1 because of the malfunction of the pressure- controlling valve for the second stage liquid oxygen tank.
As a result of the cause investigation, the malfunction was due to particles generated from the filter in the valve. (Please refer to the attached drawing.)

Today, a new cleanness-assured valve was assembled to the launch vehicle, and its function was successfully verified.
Therefore, NASDA set the new launch day on August 29 (Wed.), 2001 (JST).
The launch time is between 13:00 and 18:00 JST.

* This information is also in the Latest H-IIA Information

Cause and countermeasures of the malfunction of
the pressure controlling valve for the 2nd stage LOX tank

Generated phenomenon

Silicon dioxide came out from the filter.
Silicon dioxide clung around the moving part , and that caused the valve malfunction.




Countermeasures to the problem

The new filter in a valve assembly prepared for a future flight was tested in the actual operational conditions to verify that no silicon dioxide comes out from the filter and becomes obstacle. After the verification, the new valve assembly with the filter tested was assembled to the Flight No.1.

The same kind of filters were used in other valves of the Flight No.1. They were also used in the same operational conditions. Therefore, NASDA replaced those valves with the new ones prepared for future flights after verifying the filters in the valves not to cause the same problem. (Pressure control valves for the 1st and 2nd stage hydrogen tanks)