M-24 SIM-3 Static Firing Test

This test is the third of a series of firing tests intended to improve the reliability of the M-V rocket. The motor tested this time is the second stage M-24 motor of M-V-2 rocket scheduled for launch in summer 2003. Whereas in the last two tests on M-34-3TVC and M-14-3TVC, flight-type motors that had already been manufactured at the time were used, we used this time part of SRB of H-II rocket No.7 that had been developed by NASDA but whose launch had been canceled. We adopted SRB because it had been left unused after the cancellation and the combination of two segments of 4-segment SRB seemed suited for the evaluation of M-24.

The main objectives of this firing test, a joint research project between ISAS and NASDA, were to make a final verification of nozzle performance after the change in its nozzle throat materials from graphite to more heat resistant 3D-C/C, and to obtain data on aging of solid propellant, which was an objective of NASDA. Considering that the NAL-735 static firing test performed last year was also a joint research between ISAS and NAL, it is not too much to say that the move toward cooperative work of three aerospace organizations started from Noshiro.

As the preparation procedures for this firing test were almost the same as those of M-14-3TVC, which also had a 2-segment flight-type motor, performed last December and the experiment group members had undergone severe work then, the preparatory work this time went quite smoothly. With good ignition and combustion and excellent nozzle condition after burning obtained, this test finalized the nozzle design of M-24.

Lastly, representing all the group members, let us express our deepest appreciation and esteem for Mr. Narita who played an active role in testing as a member till the last moment of his retirement, demonstrating the spirit of ISAS experiment members to us juniors: Mr. Narita, thank you so much for your long, warm guidance and for all the trouble you have taken.

July 10, 2002