Ulysses Upper Equipment Bay

You clicked on the Pyrotechnic Electronics Unit (PEU).

The Pyro Electronics Unit provides the current for the two radial boom release squibs and twenty experiment cover release squibs. The PEU is connected to the Main Bus via the Separation Switch for safety, to ensure that there was no possibility of squib activation while the spacecraft was still in the Shuttle cargo bay and attached to the Inertail Upper Stage (IUS). The PEU is no longer used as all the experiment covers were relased and the Radial Boom deployed very early in the mission.


The PEU is controlled by the following commands:

Z153 PYR PWR1 ON PEU on.

Z154 PYR PWR2 ON PEU on (redundant).

Z155 PYR PWR1 OFF PEU off.

Z156 PYR PWR2 OFF PEU off (redundant).

Z157 ARMING 1 Arm PEU.

Z158 ARMING 2 Arm PEU (redundant).

Z159 DISARM 1 Disarm PEU.