Acquisition Systems and Recorders
There has been a great
deal of confusion regarding the numbers of data acquisition
systems and data recorders onboard the Space Shuttle. The
questions may have more to do with exactly " what" data is being
collected and " when" rather than with what equipment is
involved. There have been at least 4 different data
acquisition systems and associated recorders described for the
Flight Instrumentation (DFI)
Auxiliary Data System (MADS)
following information is as of 1988, (see No. 1 bottom).
Space Shuttle has a total of three data recorders onboard.
There are two Operational Recorders located in Avionics Bays 1 and
2. There is a third recorder known as the Payload Recorder
located below the Mid-deck floor close to the payload bay.
The Payload Recorder may also be known as the MADS/OEX Data
Recorder depending on which data acquisition system is in use.
Experiments Program (OEX) allowed for placement on the
shuttles Columbia and Challenger certain special experiments
and instrumentation focusing exclusively on the entry phase of
flight. One of the primary components installed on the
OEX equipped shuttles was an extra large capacity data
recorder in place of the standard payload recorders mounted on
the other shuttles.
Flight Instrumentation Package (DFI) was a single package containing
a number of experiments that sat in the back of the orbiter's payload
bay on missions STS-1 through 4 (Columbia) and STS-8
(Challenger), as one of the experiments planed for the
OEX program. Comprised of over 4500 sensors the
primary purpose of the DFI package was to provide post flight
certification of the orbiters subsystem designs prior to the
start of operational shuttle missions. The DFI package
also contained its own data recorder.
Instrumentation (OI) is the standard telemetry and voice data
collected on all shuttle missions and recorded to the
Operational Recorders located in Avionics Bays 1 and 2.
Since the establishment of the Tracking and Data Relay
Satellite (TDRS) system in the mid 90's it has probably been unnecessary
to record all the data on a shuttle mission when it can be
continuously transmitted to Mission Control. It is
therefore unknown if this data is still recorded during every
shuttle mission as standard practice.
Auxiliary Data System (MADS) refers only to certain data
collected by the Payload Recorder during specific periods of
ascent and reentry. After the DFI package was removed
from Columbia and Challenger their OEX recorders would have
simply been recording this same data if it was needed.
When this recorder was not recording MADS data it would be
recording data from any experiments in the orbiters payload
bay and or Mid-deck. At some point the astronauts began
recording experiment data to laptops made for that purpose
making the Payload Recorder obsolete. With the
establishment of the TDRS system the shuttle could transmit
data to Mission Control continuously even through the reentry
blackout period. Therefore it is unknown if the MADS
data was even being collected after the TDRS system was in
Fig. TA-G1-1 is a diagram of a Space Shuttle with the
DFI experiments package installed in the payload bay.
After the DFI experiments had been completed over the course
of several shuttle missions utilizing both the Columbia and
Challenger, the DFI payload was removed. Because the
DFI used both internal instrumentation as well as external
sensors located at different areas of the shuttle, its
removal left many sensors with un-terminated wires where the
DFI payload had been. Besides being located where
their removal would have been difficult and costly, many of
the sensors collected raw date that may at some point be
useful. Therefore the wiring to those sensors was
rerouted to signal conditioning units so that the data could
be collected on the OEX data recorder.
These two website links contain identical data that is dated
The information from this link is dated 10/6/98 but
its accuracy is unknown