97 Functional Test:  The REACT actuator (QM) was connected to a standard power supply (40V/2.5A). Aft er  approximately 4 seconds, the HDRM was released successfully. The actuator reset carried out after the  release performed as expected without issue.  

Worst Case In- Plane Release Test:  The deployment jig was mounted with a gap on both main hinges to  creat e an angle offset between the screw and inner threads of the actuator. This was done via a practical  simulation of a solar panel in- plane shift by replacing the positions from the actuator to the HDRM. After  assembly, the actuator release was successful  with an actuation time of 4 seconds .  

Vibration Test:  In order to show that the actuator can withstand the mechanical qualification loads without  damage, frequency shift, damping change etc., the actuator was subjected to sine and random vibration   loads. As a result, it can be stated that no damage or debris  occurred (visual inspection), no amplitude  shifts greater than 20% and no frequency shifts greater than 10% were found. T he resistance measurement  (nominal/redundant) after vibration indicated no change.  

Release Shock Test (after vibration): To determine the release shock level at the interfaces (Spacecraft  and Photovoltaic assembly simulated interfaces) and the substructures, release shock tests were carried  out immediately after the vibration test (examined frequency range: 100 Hz to 10 kHz). During the first  attempt to measure the actuator release shock level, the release was not completed. After investigation, it  was confirmed that the screw thread engament exceeded the maximum allowed by the actuator. After an  incomplete release of the actuator, the actuator was newly pre- tensioned. Special attention was paid to the  thread depth control before the preload was initiated. The second attempt to release was successful.  

Further releases were carried out. There were no more malfunctions. The redundant cir cuit was used to  trigger the release. It should be noted at this point that the Engineering Model (EM) at SpaceTech GmbH  is in "continuous use". Of the approximately 150 releases, about 80 were triggered electrically and the other  70 were triggered mechani cally. In these tests, the shock accelerations were measured only sporadically.  

Life Cycle Release Test: To guarantee that the actuator can safely and reliably execute several releases in  succession with no negative impact on the assembly performance, the actuator was pre- tensioned and  released several times.  

Thermal Cycling Test:  During the thermal vacuum test, the actuator showed no noticeable problems. After  completion of the thermal cycle test, it should be noted that a n undersired (thermally -induced)  self-release  did not take place and the preload force was fully maintained. The  visual inspection was carried out and  showed no visible changes. The subsequently performed release test could be carried out without any  problems.  

Hot / Cold Self-Release Test: The actuator was subjected to thermal cycling with no self -actuation, and  released successfully after thermal cycling when the electrical pulse was applied.   

Long Storage T est: After a storage period of several weeks, no self -release and no signifi cant loss of  preload was observed.