microgravity
it offers the promise of new techniques
and new technologies in pharmaceuticals
materials manufacturing
and microgravity studies are a key
component of fundamental research on the
shuttle today
but vibrations from shuttle maneuvers
operating equipment even movement of the
crew within the cabin can mimic the
effects of gravity
experiments set up to take advantage of
a weightless environment are subtly
affected yet when researchers know the
strength and frequency of these
vibrations
they can determine and account for the
forces acting on these microgravity
experiment samples
the space acceleration measurement
system or sams developed by the lewis
research center measures conditions and
records forces of low gravity
accelerations on the shuttle
from the united states and international
microgravity missions to the space lab
life science series sams has provided
vital information on shuttle experiments
this information guides scientists to a
better understanding of the effects of
microgravity accelerations on these
experiments
the sams hardware
consists of a main signal processing
unit and three remote tri-axial sensor
heads
by mounting a sam sensor head on or near
an experiment
the accelerations affecting the
experiment can be sampled directly
the triaxial sensor heads detect
accelerations along three orthogonal
axes
these inertial sensors measure positive
and negative accelerations over a
specified frequency range
sams has provided researchers with
measurements of these accelerations
since its first flight in june of 1991
aboard sts-40 the space lab life science
series 1 mission
since that first mission the unit has
flown in a variety of locations
including both the space lab center
aisle and its mid-deck experiment rack
the shuttle's mid deck the space hab and
the cargo bay
to accommodate the different
environments of these locations
sams offers three configurations to
researchers
in the spacehab center aisle
configuration
the sams unit allows the flight crew
access to the optical disks which they
can periodically rotate or exchange to
provide unlimited data recording
also accessible are the control switches
and indicators of the main unit located
on the front panel
in the mid deck configuration the unit
is mounted either in a smidex rack or in
place of a stowage locker
it is fastened to a bulkhead by a
mounting plate the mission office
provides
disks and controls are accessible
throughout the mission
the tri-axial sensor heads are mounted
either prior to launch or by the flight
crew once in orbit
flight crew members can place the sensor
heads at predetermined locations to
accommodate the needs of the
experimenter
the sensor heads can be mounted directly
on the experiment or
up to a maximum distance of 20 feet from
the main unit
the sensor head cables can be easily
connected to the rear right side of the
main unit in the center aisle
configuration
and to the unit's face plate when at
mid-deck
the last configuration for the sams unit
is known as m-pass for mission peculiar
experiments support structure
here the unit is placed in the cargo bay
inaccessible to the flight crew
the mpes main control unit and data
storage unit are safely enclosed for
operation in this harsh environment
in this configuration the sams unit can
retain 0.8 gigabytes of data
raw data in this configuration can be
downlinked to the payload operations
control center or poc
this provides researchers with the
opportunity to monitor and analyze data
displays in a time frame which
approaches real time
three switches power data record and
disk change are located on the control
panel
five indicator lights or leds are also
located on the control panel
the leds are designed to confirm basic
operating functions of the sams unit
additionally they will indicate certain
failures of the sams unit should they
occur
during normal operations the tri-color
leds on the recording drive will pulsate
from yellow to red
yellow indicates that the optical disk
is spinning in the disk drive while red
indicates that the drive is reading from
or writing to the optical disk
this concludes module one the background
and system familiarization of the space
acceleration measurement system
in this module
we will demonstrate the nominal
operations of the sams unit
first you need to unstow the optical
discs
rotate the door screws counterclockwise
to open the drive doors
next rotate the disc ejection levers
counterclockwise
stow the dummy discs and unstow two
blank discs
insert the blank discs side a up
into drives one and two
making sure that the discs lock into
place
then rotate the disc ejection lever
clockwise
until they are pointing up with respect
to the top plate of the unit
to activate the sams unit turn the power
on
verify that the power indicator light is
green
record the mission elapsed time
the drive one full light and the drive
to full light should be lit during
initialization
allow two minutes for the initialization
process to be completed
after the initialization process is
complete and the drive one and drive two
indicator lights are off
notify the pot that the power is on and
note the mission elapsed time
after allowing the unit to warm up for
15 minutes you are now ready to operate
sams first close the disk drive doors
and rotate the screws clockwise to the
lock position
then turn the data record switch on
verify that the data record light is on
and record the met
after three minutes verify that the
drive one and drive to full lights are
off
notify the park that the sams unit is
recording data and indicate the current
met
before you rotate the disc in drive one
check to see if the system error light
is on
this should not occur during normal
operations but if it does consult the
puck
verify that the drive one full light is
solid yellow
next rotate the drive door screws
counterclockwise
rotate the disc ejection lever
counterclockwise to eject the disc from
drive 1
then log the mission elapsed time and
the drive number on side a
insert the disk side b facing up into
drive 1 until the disk locks into place
rotate the disc ejection lever clockwise
pointing up
toggle the disc change switch
momentarily
after three minutes the drive one full
light should turn off
verify that the drive to full light is
also off
close the drive door and rotate the
screws clockwise to the lock position
notify the puck that you have completed
disk rotation steps four through seven
to rotate the optical disk in drive two
simply repeat the procedure we just
demonstrated
before exchanging the disc in drive one
check to see that the drive one full
light is on
next
rotate the drive door screws
counterclockwise
then eject the disk
log the met and drive number on the disk
side b
stow the full disk and unstow a blank
disk
now insert the blank disk side a facing
up into drive one until it locks into
place
turn the disk ejection lever clockwise
press the disk change switch
momentarily allow up to three minutes
for the drive one full light to turn off
then close the drive door
and rotate the screws clockwise to lock
notify the puck that you have completed
replacing the disk in drive one
to exchange the disk in drive two repeat
the procedures just demonstrated
to deactivate the sams unit turn off the
data record switch
wait two minutes and verify that the
data light is off
next turn the power switch off
the power indicator light should
extinguish
to stow the discs
turn the drive door screws
counterclockwise
now rotate the disc ejection levers
counterclockwise to eject the disks
log the met and drive number on the disk
label
stow both disks
unstow the two dummy disks and insert
them into drive one and drive two
making sure they lock into place
turn the disc ejection levers to the
lock position
close the disk drive doors
and rotate the screws clockwise so the
doors are locked
to check the status of the sams unit
turn the door screws counterclockwise
at the specified intervals voice the
status of the five control panel lights
and the two disk drive lights
close both drive doors
and turn the screws clockwise to the
lock position
alternate procedures for operation of
the sams unit are utilized only when one
drive has failed
rotation and exchange of the optical
disk is performed in the same manner
demonstrated for nominal operation with
one notable exception
for single drive operation of sams the
drive that is non-operational is put on
standby for the duration of the mission
also during rotation or exchange the
recording of data on the operational
drive is temporarily aborted in order to
eject the disk without damage to the
recorded data
for example
if disk drive 2 fails
place it in the standby position by
rotating the disc ejection lever to the
nine o'clock position
the lever should remain in this position
for the duration of the mission
then to temporarily abort drive one
wait to the tri-color led flashes from
red to yellow
then turn the drive one disk ejection
lever clockwise to the one o'clock or
abort position
this concludes module two the nominal
and alternate procedures for the space
acceleration measurement system
in module 3 we will briefly review
malfunctions of the sams unit and the
procedures to follow should a
malfunction occur
if the power light does not illuminate
when power is initially applied to the
sams unit
perform malfunction procedure 1.
to determine the cause of this condition
you would cycle the power
and examine the status of certain leds
the sams unit could be in one of three
states
the power light is transient
the power light has failed or there has
been a system power failure in the unit
if the unit is in one of the first two
conditions it can still be operational
however if it is determined that the
unit is in the third condition a power
system failure then it would remain
non-operational for the duration of the
mission
after powers applied to sams the
initialization process begins
nominally the drive full lights will
illuminate to indicate the start of the
initialization process
and extinguish after the process is
complete
this takes about two minutes
if after two minutes one or both of the
dry full lights are on solid or blinking
then perform malfunction procedure two
if this happens one of the following has
occurred
a disc may not be seated properly
reseeding the disc would eliminate the
error
the discs may be faulty
rotating or exchanging them would solve
the problem
the unit may be recording on a single
drive only
if this occurs refer to the alternate
procedures described in module 2.
the system may have failed
and again will be non-operational for
the duration of the mission
following initialization of sams and a
15-minute warm-up period the data record
switch is ready to be enabled
if the data record switch is thrown
and the data record light does not
illuminate
perform malfunction procedure 3.
one of three errors has occurred
the data record switch is faulty
the data record light could have failed
there is an uncorrectable fault in which
case the unit will be non-operational
for the duration of the mission
when one side of an optical disk is full
the drive full light corresponding to
that disk will illuminate
the time it will take to fill one side
of a disk is predetermined based on the
frequencies of the tri-axial sensor
heads
if the drive full light does not
illuminate as scheduled perform
malfunction procedure 4.
in this case the drive may have had a
previous malfunction and has corrected
itself thus becoming operational again
it may also have prematurely quit
recording on the drive that was
scheduled to be full and is now
recording on the other drive
finally
again there may have been a system
malfunction that could possibly be
corrected after consulting the park
following rotation or exchange of a full
disk and the disk change switch having
been toggled
it will take up to three minutes for the
corresponding drive full light to
extinguish
if after three minutes the corresponding
drive full light fails to extinguish
perform malfunction procedure five this
could indicate that the disc is not
seated properly and may have to be
reseeded
the disc may be faulty and may have to
be rotated or exchanged
there may also have been a disc drive
failure in which case the alternate
procedures would be implemented
at any time during normal operation of
sams or after any crew interface with
sams one or both of the drive full
lights may suddenly begin to blink
if this happens perform malfunction
procedure six
this indicates that the corresponding
drive has failed either temporarily or
permanently
if the drive has temporarily quit
recording the malfunction can be
corrected however the drives will now be
out of sequence
the system error light is another
indicator of a malfunction
if this led should illuminate perform
malfunction procedure 7.
this indicates that there are 30 minutes
or less of recording time available on
both optical discs
note that the system error light will
not come on alone either one or both of
the drive full lights will also be
illuminated if only one drive full light
is on the unit is still able to record
data
if both drive full lights are on the
unit is not recording and valuable data
is being lost
when you are either rotating or
exchanging an optical disc there is a
possibility that the disc will not eject
from the drive
if this should happen perform
malfunction procedure 8.
the disc may not be seated properly in
the drive
reseat the disc
if the disc will not eject at all
use needle nose pliers to extract the
disc
if you cannot retrieve the disk with the
pliers the disk has jammed or the disk
ejection system has failed
during single drive operation the drive
full lights may illuminate
if this happens perform malfunction
procedure nine
this could indicate that the disc in the
functioning drive is faulty
it could also indicate that the
previously faulty drive has corrected
itself and is now functioning properly
if this is the case
the disk in the previously faulty drive
is full
and needs to be rotated or exchanged and
the alternate procedures for single
drive operation would no longer be
necessary
this concludes the third and final
module of this video if you have any
questions please review the appropriate
module and good luck on your upcoming
shuttle flight
you