What happened during this shuttle simulation malfunction involving a failure of a shuttle arm joint while moving the JEF?

Question

This author (cough) begins to relate the details of a particular training incident during simulations for STS-127. However, they very sadly have not finished the tale. Does anybody (cough cough) know what happened?

Answer 1

tl;dr It went as planned except that vetting of the revised ISS robotics procedure took longer than expected, causing some friction internal to the training team.

The setting is an STS-127 joint integrated simulation. The planned malfunction was a one-way jam of the shuttle arm's shoulder yaw joint as it moved the Japanese Exposed Facility (JEF) towards a handoff to the station arm.

For details, please refer to the timeline shown here:

At the top is Greenwich Mean Time (GMT) and Mission Elapsed Time (MET). ... The fat gray bar at the bottom is the crew schedule and shows Houston time just above it.

The first vertical red line is the sim start time. Houston time it's 8 am Tuesday, April 21, 2009. The simulation start point is GMT July 18, 2009 just after 13:00 hours, which corresponds to MET 2/15:00:00 (2 days, fifteen hours after launch). ... The last vertical red line is the end of the sim, 27 hours later....

I have highlighted the robotics activities in yellow.

• Timeline point A: Insertion of the malfunction while the shuttle arm was moving the payload to the second handoff position.

The malfunction worked beautifully. There were no alarms or annunciations - I had chosen a point at which the payload was moving quite parallel to the payload bay sill and the primary joint driving was the one I broke. So the payload's trajectory did not diverge from the projected one enough to cause a ... alarm. The crew noticed that motion had stopped, and about that time, the ground called to have them take the brakes on.

• Timeline point B: After troubleshooting, STS and ISS robotics teams have converged on a revised handoff position.

However, after this point, things went a little sour. Even though the new handoff position was determined, it took longer than we had expected for the ISS team to prepare, test, and doublecheck their procedure revisions. The training leads started to get antsy. To be fair, we had committed to them that we could still get the JEF installed before the crew went to sleep on FD4, but it was looking increasingly unlikely that it was going to happen by then. The training leads started talking about "King's Xing" the mal - meaning that we would take it out and pretend like it never happened. I was not a fan of this plan at all because it would leave the planning shift with nothing to work on. There were some "frank exchanges of views" both on the airwaves and over the loops. Finally it was decided that the STL would ask ISS Flight Holly Ridings what she thought about the situation. To my everlasting gratitude, ISS Flight said (paraphrasing) that she liked the case and preferred that we let the teams work through it. The JEF would be placed in a pre-install position and left there overnight, the install would be done on FD5.

• Timeline point C: The shuttle arm moved the JEF to the new handoff position.

• Timeline point D: The station arm grapples the JEF.

• Timeline point E: The station arm has moved the JEF to the pre-install position. Everyone except the planning shift went home for the night.

• Timeline point F: The JEF has been berthed by the station arm.

• Timeline point G: The attachment mechanism has completed its process of coupling the JEF to the JEM-PM. The station arm has ungrappled.

To sum up, I relearned once again that it would not be the technical things that bit me, but the human and administrative ones.

Acronymology:

• FD Flight Day
• JEM-PM Japanese Experiment Module - Pressurized Module
• STL Station Training Lead

Overly long and detailed reference here.