ISS MER Status 17 Apr 2001

Failed to engage

Indications that the latch is rubbing the bearing support for a portion of the rotation. Plan to cycle the latch just before 6A EVA 2.

After sucessful R& R of the CDRA Airsave pump, the CDRA was unable to pump down the AD/ DES 1 bed.

Highest probable cause is FOD in the check valve. Will attempt to purge check valve; if not successful will have to decide how to replace.

The Ku Band system could not consistently acquire and track TDRS. The few times Ku was successful, it had acquired on a sidelobe.

Problem determined to be a bias in the pointing data from the GN& C system. PPL to correct the bias scheduled for uplink evening of 4/ 5

CDRA Air Save Pump not responding during ABIT of the system

Pump and cable flown on 5A. 1. Preparing to do ppl pump higher current test in next few days. Cable visual/ continuity/ RR/ Pump RR planned for 5A. 1 stage.

Multiple unexplained shutdowns

The crew performed troubleshooting on Vozdukh valves and the Voszdukh was restarted successfully and has continued to operate.

Concern TVIS in it’s off- nominal bungee config could be inducing higher than expected loads into the structure based on CMG data

Team looking to correlate CMG accel. data with TVIS exercise

MCA unexpectedly shuts down

Troubleshooting underway.

Did not work during nominal configuration

Troubleshooting showed USL to Orbiter good. Part 2 troubleshooting indicated crossed wires from USL to Node H/ W. Will consider fix via software.

RPC feeding Node Smoke detector trippedunexpectedly after performing maintance on the adjacent HEPA filter

ART has forward plan in work

Unexpected flow rates during the vent event

Under investigation for possible freezing/ blockage

Node Nadir CBM thermal cover left open unexpectedly

Impacts to XPOP attitude (window to ram).