See handout -- annex 10
No number for the reliability of the on board tape recorder is actually available, therefore it is difficult to have a comparison with the reliability of the solid state recorder. Confidence in the reliability of the tape recorder shall be achieved by other means, such as life testing. A value of unity for the reliability of the tape recorder has been assumed to relieve MMS from the necessity to calculate a figure, necessarily imprecise, to use for spacecraft calculations.
Nevertheless, the SWT feels that the assumed reliability of unity for the on board tape recorder is misleading. Bertaux reiterates SWT recommendation that mission be protected against systemic on board memory failure by choosing for mixed solution of one tape recorder and one solid state memory device. SWT agrees.