QuoteOrbiter Obvious - 7/11/2006 8:37 PMQuotejcopella - 25/7/2006 1:50 PMQuotepsloss - 25/7/2006 6:20 AMQuotejcopella - 25/7/2006 12:44 AMP.S. Prerequisite Control Logic (PCL) is a little GOAL subroutine that console engineers could associate with a particular command. The idea was you would put safety checks inside the PCL sequence to ensure that the command never resulted in an unsafe situation. In this case, MPS apparently made some kind of procedural change which caused the PCL (which would normally allow the command to go thru) to block the command. I remember a little bit of a fire drill after this incident to hunt down all the GLS-issued commands that had PCL sequences associated with them so we wouldn't be quite so surprised if it ever happened to us again.Thanks, John. On the comm loop that was broadcast on NASA Select, SPE says it was PCL sequence 18 (if I'm hearing right). Also sounds like Ms. Pape's voice at the GLS console.Yep. GCL18. That's the PCL sequence for V41K1515XL, the LO2 outboard f/d valve close command (I still have my GLS "brain book" here in the office, which I keep around for sentimental reasons. Never thought I'd have to use it to look up a PCL sequence again! LOL)How long does it take someone to train up and know all these sequences like this?The short answer is, years. But you should keep in mind a couple of things. Not everyone in a given system knows every single PCL sequence for that system cold. Usually only the system specialists (very small number of very senior people) had that sort of in-depth knowledge, and even they relied on source code listings and other reference material to supplement their grey matter.I was a GLS engineer, and we executed a lot of commands on behalf of the subsystems, and we were software weenies anyway, so we were sort of expected to have that sort of knowledge. But even we realied on our "brain books" for this sort of thing, and of course that knowledge is supplemented by messages and displays that we saw in real-time on launch day.On my first tour thru KSC, I worked with GLS for about 4 years, and at the end of that 4 years I felt like I was just starting to really know what I was doing. At that time (early 90s), we had a training and certification program for new engineers that generally took about a year to complete, depending on what the launch schedule was like -- you had to complete X number of S0044s, X number of S0017s and X number of S0007s (both as early shift support, backup operator, and primary operator). There were also classes you were required to attend, and we had some assignments and tests as well. That was on top of your daily job assignments which would've included software development & maintenance, data review, paperwork, attending meetings (yay!!), etc. After your training was complete, you really needed a few (3 or 4 years) of hard experience before things really settle in and you get confident in the role.Maybe some of the other Shuttle vets who worked on the hardware can chime in on what sort of training they received and how long it took them to get comfortable with the job. And if they worked console for any length of time, and dealt with high energy systems, I'll be they even remember some of their PCL sequences! LOL
Orbiter Obvious - 7/11/2006 8:37 PMQuotejcopella - 25/7/2006 1:50 PMQuotepsloss - 25/7/2006 6:20 AMQuotejcopella - 25/7/2006 12:44 AMP.S. Prerequisite Control Logic (PCL) is a little GOAL subroutine that console engineers could associate with a particular command. The idea was you would put safety checks inside the PCL sequence to ensure that the command never resulted in an unsafe situation. In this case, MPS apparently made some kind of procedural change which caused the PCL (which would normally allow the command to go thru) to block the command. I remember a little bit of a fire drill after this incident to hunt down all the GLS-issued commands that had PCL sequences associated with them so we wouldn't be quite so surprised if it ever happened to us again.Thanks, John. On the comm loop that was broadcast on NASA Select, SPE says it was PCL sequence 18 (if I'm hearing right). Also sounds like Ms. Pape's voice at the GLS console.Yep. GCL18. That's the PCL sequence for V41K1515XL, the LO2 outboard f/d valve close command (I still have my GLS "brain book" here in the office, which I keep around for sentimental reasons. Never thought I'd have to use it to look up a PCL sequence again! LOL)How long does it take someone to train up and know all these sequences like this?
jcopella - 25/7/2006 1:50 PMQuotepsloss - 25/7/2006 6:20 AMQuotejcopella - 25/7/2006 12:44 AMP.S. Prerequisite Control Logic (PCL) is a little GOAL subroutine that console engineers could associate with a particular command. The idea was you would put safety checks inside the PCL sequence to ensure that the command never resulted in an unsafe situation. In this case, MPS apparently made some kind of procedural change which caused the PCL (which would normally allow the command to go thru) to block the command. I remember a little bit of a fire drill after this incident to hunt down all the GLS-issued commands that had PCL sequences associated with them so we wouldn't be quite so surprised if it ever happened to us again.Thanks, John. On the comm loop that was broadcast on NASA Select, SPE says it was PCL sequence 18 (if I'm hearing right). Also sounds like Ms. Pape's voice at the GLS console.Yep. GCL18. That's the PCL sequence for V41K1515XL, the LO2 outboard f/d valve close command (I still have my GLS "brain book" here in the office, which I keep around for sentimental reasons. Never thought I'd have to use it to look up a PCL sequence again! LOL)
psloss - 25/7/2006 6:20 AMQuotejcopella - 25/7/2006 12:44 AMP.S. Prerequisite Control Logic (PCL) is a little GOAL subroutine that console engineers could associate with a particular command. The idea was you would put safety checks inside the PCL sequence to ensure that the command never resulted in an unsafe situation. In this case, MPS apparently made some kind of procedural change which caused the PCL (which would normally allow the command to go thru) to block the command. I remember a little bit of a fire drill after this incident to hunt down all the GLS-issued commands that had PCL sequences associated with them so we wouldn't be quite so surprised if it ever happened to us again.Thanks, John. On the comm loop that was broadcast on NASA Select, SPE says it was PCL sequence 18 (if I'm hearing right). Also sounds like Ms. Pape's voice at the GLS console.
jcopella - 25/7/2006 12:44 AMP.S. Prerequisite Control Logic (PCL) is a little GOAL subroutine that console engineers could associate with a particular command. The idea was you would put safety checks inside the PCL sequence to ensure that the command never resulted in an unsafe situation. In this case, MPS apparently made some kind of procedural change which caused the PCL (which would normally allow the command to go thru) to block the command. I remember a little bit of a fire drill after this incident to hunt down all the GLS-issued commands that had PCL sequences associated with them so we wouldn't be quite so surprised if it ever happened to us again.
GLS is go for main engine start at T-10 seconds but I note that unlike at other points in the GLS sequence below T-9 minutes this was not marked as auto in S0007. Was an action required by CGLS to allow the RSLS to start the engines?
At this point GLS & RSLS run in parallel, interacting directly only when there's a countdown clock hold/resume (e.g., the T-9m built-in hold), and at T-31 sec and T-10 sec when the two LPS "go" flags (auto sequence start & SSME start, respectively) are sent.
Does anyone know what the upmass used on a Hubble Servicing Mission was?
Which one?
Quote from: Hog on 12/12/2016 01:37 pmWhich one?Any generic one (a rough total mass for a generic Hubble servicing), but all if possible. I looked in L2, but the documentation I found is very in depth on the systems carried up while not actually mentioning total mass.
Can anyone provide links to audio/video/transcript/articles of instances when an orbiter burn was not responded to with "no trim required"...and needed to be trimmed? Curious as to what instructions were given, what corrections were made to meet the targets, and any other information.
Listening to some old Shuttle audio, before the full TDRSS network was operational. The Orbiter was instructed to "Configure LOS" and "Configure AOS" as its orbital path moved from ground station to ground station...and TDRSS. What did these procedures entail?
Forgive me if this rather simple question was asked and answered already, but...My understanding is that Discovery was to be assigned to Vandenberg for the polar launches. Would Discovery have stayed there, or been "shuttled" to KSC for other missions?