OEX and MADS

Hey all--

I just want to make sure I've got something straight...

I've read a few conspiracy theories about Columbia that say the OEX
Recorder was planted in the debris field because "NASA documentation
shows that the Columbia's OEX Recorder along with all of its associated
equipment, wiring and sensors was removed during Columbia's last
overhaul in Palmdale."

So, my comments....

-The documentation I could find refers to the instrumentation and wiring
removed as part of the "Development Flight Instrumentation" (DFI). Did
the DFI record its data to the OEX Recorder?

-I noticed the CAIB begain referring to the data from the OEX Recorder
as the MADS data (Modular Axiliary Data System). I know each orbiter
has temperature, pressure, and strain sensors that are recorded to tape
for comparison of flight profiles between missions and orbiters. In the
other orbiters, there is a MADS recorder. In Columbia, the MADS
recorder is the OEX Recorder. So was any of the data recovered from
Columbia DFI data or was it all MADS data? Or, in another way--was any
of the data recovered off the OEX Recorder from sensors unique to
Columbia?

Hopefully that made some sense....
Matt

I appear to be able to answer some of my own questions after some more
research from the Columbia Accident Investigation Board's report.

Matt Markham wrote:

-The documentation I could find refers to the instrumentation and wiring
removed as part of the "Development Flight Instrumentation" (DFI). Did
the DFI record its data to the OEX Recorder?

Further research says no.

From:http://www.totse.com/en/technology/s.../avionics.html

"Three recorders are used in the DFI system to provide PCM and wideband
recording: PCM, wideband and ascent, and wideband mission recorders. The
operations of these recorders can be controlled only by the flight crew
through the use of switches on the flight deck display and control
panels. The DFI recorders cannot be dumped in flight; they are played
back via the GSE T -0 umbilical after the orbiter has landed."

This leads me to believe that the OEX Recorder on Columbia was a
separate unit than the DFI Recorders used. Since I know that the DFI
system was not used once the shuttle program was "operational," I think
it is safe to assume that these recorders have long since been removed.

I also found some info posted by Kim Keller on what wiring was removed
during Columbia's last OMDP:




-I noticed the CAIB begain referring to the data from the OEX Recorder
as the MADS data (Modular Axiliary Data System). I know each orbiter
has temperature, pressure, and strain sensors that are recorded to tape
for comparison of flight profiles between missions and orbiters. In the
other orbiters, there is a MADS recorder. In Columbia, the MADS
recorder is the OEX Recorder. So was any of the data recovered from
Columbia DFI data or was it all MADS data? Or, in another way--was any
of the data recovered off the OEX Recorder from sensors unique to Columbia?


Well, based on what I know from above-it would appear that there was no
DFI data recorded by Columbia as the system has been inactive since the
program was declared "operational." I can't find any direct evidence
that the recorders are gone, but on the most recent version of the space
shuttle reference guide from NASA, there is no mention of the system in
place at all. Besides, I found several references to DFI wiring being
removed in shuttle OMDP's. So ultimately, to answer my own question---

The DFI used its own recorders and was inactive at the time of the
Columbia accident, so the OEX recorder did NOT record any DFI data.

The second part of my question--"Was any data recovered from the OEX
Recorder unique to Columbia?"

The answer has to be yes, based on the definition of MADS in Columbia
versus the other orbiters.

From Volume 6, Part09.pdf, page 7

MR. WHITE: Well, the MADS system is the name of the entire system, which
is the avionics, the electronics to condition and report the signals,
and the sensors and the wires connected to them. The recorder itself was
an early model of the recorder, which was called the OEX recorder, the
Orbiter Experiments Recorder. In the subsequent vehicle, we just called
it the MADS recorder; but the version that was on 102 was called the OEX
recorder. On 102, it had the most sensors of any of the vehicles for
the MADS system because it was the first vehicle built. Through the
years, some of those sensors have broken and fallen offline and during
the recent major modification a lot of the sensors were removed or the
wires were cut and just left in place, but there were 622 measurements
onboard, located throughout the vehicle. Most of those are pressure,
temperature, and strain measurements; and I've broken down into three
large categories there. You can see the left wing, about 259 -- we had
more of our measurements there than anywhere else -- right wing, about
220; and then other places altogether, 143. The avionics to condition
all of these signals, all of these wires run to the mid-body, about Bay
8 of the mid-body, and then they're recorded actually on the OEX
recorder, which is in the crew module.

From Volume 2, part19.pdf, page 15

"The Modular Auxiliary Data System (MADS) exists on all of the orbiter
vehicles, but the configuration on Columbia (OV-102) was different to
support the larger number of sensors in the OEX system."

From Volume 2, part19.pdf, page 12

"The orbiter experiment instrumentation (OEX) is an expanded suite of
sensors for the MADS that was installed on the Columbia expressly for
the purpose of engineering development. Since the Columbia was the first
space shuttle orbiter to be launched, the engineering teams needed a
means to gather more detailed flight data to validate their calculations
of the conditions that the vehicle would experience during the critical
flight phases of the mission. The voluminous data generated by the OEX
suite required the installation of a particularly high capacity
reel-to-reel tape recorder, known as the OEX recorder. The three flight
phases of ascent, de-orbit, and re-entry are each recorded on chosen
tracks of the OEX recorder."

The OEX recorder also recorded data from named experiments in the OEX
program. I don't believe any were installed or active at the time of
the accident, but here's a few names of the experiments:

SILTS---http://www.spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/comm/inst/silts.html
This was the black pod on top of Columbia's tail. The experiment was
removed, but the pod remained.

SEADS---http://www.spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/comm/inst/seads.html
This experiment used a modified RCC nose piece. When the experiment was
over, it removed and a standard RCC nose was installed.

SUMS---http://www.spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/comm/inst/sums.html

ACIP---http://www.spaceflight.nasa.gov/shuttle/reference/shutref/orbiter/comm/inst/acip.html

There you have it...a lesson on MADS and the OEX Recorder....

Matt