1.  And you never knew whether the trouble was with your clumsy fingers or with one of the three batteries or the five vacuum tubes.

2.  At least three of the six batteries must function in order for the two currently orbiting modules to link with the Russian crew module.

3.  The ampere meters in Zarya are not properly charging the half-dozen batteries launched on the power module last November.

4.  The two batteries run the pump for four to five hours.

5.  Only four batteries of the eight batteries are needed to provide normal levels of power.

6.  Two of the six batteries are brand new, while four of them are updated versions of systems currently in place.