SOLAR-B Structural Model Comes Onstage

SOLAR-B
uses optical, X-ray and EUV telescopes with an unparalleled angular resolution
to make simultaneous and continuous coverage of solar activities. Under
the multilateral collaboration among Japan, the United States and the
United Kingdom, design and production work has been underway in each country.
Structural models of telescopes and their bus modules had already been
made, and they were brought to ISAS, along with test staff, at the beginning
of May for structural model testing.

The spacecraft after assembly was much larger and more
powerful than I had imagined. The optical telescope and its focal plane
package sit on the bus module with X-ray and EUV
telescopes surrounding them as if they were a sword-bearer and a forerunner.

The purpose
of vibration, shock and sound tests is to verify whether or not each onboard
instrument can stand structurally as well as optically the launch of the
M-V-5 rocket. In order to simulate launch conditions, vibration and shock
were applied by a motion table in the C Building of ISAS and sound by
a test facility in the Kamakura Factory of Mitsubishi Electric Company.
Before and after these applications, changes in the orientation of each
telescope are measured against the alignment cube. As for the optical
telescope, the keystone of this mission, a glass mirror is mounted to
it to verify its optical characteristics using an interferometer.

In order to achieve high attitude stability that even exceeds an arcsecond,
it is essential to assess minor disturbances produced by instruments such
as a momentum wheel. So, we plan to measure transmission of micro vibration
through a body structure using an acceleration sensor capable of detecting
micro vibration. Structural model testing continued til July.