These are the minutes of the Teleconference number 11 (TC1011).

Held between MSSL and NRL, Thursday, July 1, 1999, 4 pm BST.

Minutes prepared by MWT (8 July, 1999).

Reminder - documents referred to as EIS-xxx-xxx-xxx are available in the documents archive at the project website see http://www.msssl.ucl.ac.uk/solar-b/docs/doclist.html .

MWT reviewed the week’s activities (see EIS-meet-sdt-minutes9). The groups briefly discussed the meeting in MSSL at the end of the month.

Remarks from NRL.

The development schedule for EIS should be aligned with the spacecraft development schedule.

Several documents are needed for the requirements review, organised by Larry Hill. Among them are a Requirements Document for each subsystem and Interface Control Documents for subsystems.

There is also a need for a description of the data throughput and for a brief System Specification Document.

Louise Harra has initiated the Compression group. Dave Pike, of RAL, has agreed to act as co-ordinator. Description of the 12 bit JPEG software and will be needed to evaluate the use of the MDP chip.

The XRT radiator study document should be sent to NRL. Action: MWT. What is the likely performance of CCD detectors at -50 degree C? Chris reported that he was in dialogue with EEV about several CCD performance issue. CMB reiterated that there was zero tolerance to misalignment with the 512-pixel device.

Roger Thomas had not yet started on the 4200 lines per mm grating optical layout.

Mechanisms. Bob Morris has been going over the mechanism designs. Charlie has been studying the motion of the primary mirror. He has been looking at the best for straight line approximation to the true circumferential motion of the primary mirror.

There had been several requests mechanism and other information from a Hara-san. The response to these requests was discussed. Further (definitive) information on these topics will be forwarded via MWT.

Temperature range. The non-operational temperature range is likely to be determined by the properties of the glues used in the optics assemblies.

Co-Alignnment capability. Does XRT to still have a white-light imager?

Disturbance level of moving components. Further analysis was being done on this issue. A series off moment calculation spreadsheets will shortly be placed on the Web site.

See: EIS-opt-desnote-moi_mir, EIS-opt-desnote-moi_grt, EIS-opt-desnote-moi_shut, EIS-opt-desnote-moi_slit, EIS-opt-desnote-moi_sns

Some experiences of SOHO were reported. In the case of the SUMER instrument, the SOHO spacecraft did not ever detect any disturbance as a result of its primary mirror.

Necessity of launch lock in this camera mechanism. The current design goal is that a launch lock will not be required in this mechanism.

Next meeting – same time in one week’s time.