The presentation provides an overview of the current SSFP attached payload accommodations on the U.S. truss. The overview includes discussions on the four attach sites, the power architecture, thermal control, DMS provisions, and the mechanical attach mechanism. The presentation concludes with a description of a McDonnell Douglas concept for an attached payload pallet designed to take advantage of the four sites and existing SSF hardware. This presentation should provide the payload community with a basic understanding of the SSF attached payload utility ports and aid in attached payload concept development

Scheib, Jim

English

NASA Technical Reports Server

N93-22641
WP-2 ATTACHED PAYLOAD ACCOMMODATIONS
Presented by Jim Scheib
Space Station Division
McDonnell Douglas
ABSTRACT
The presentation provides an overview of the current SSFP attached payload accommodations on the
U.S. truss. The overview includes discussions on the four attach sites, the power architecture, thermal
control, DMS provisions and the mechanical attach mechanism. The presentation concludes with
a description of a McDonnell Douglas concept for an attached payload pallet designed to take
advantage of the four sites and existing SSF hardware. This presentation should provide the payload
community with a basic understanding of the SSF attached payload utility ports and aid in attached
payload concept development.
415
https://ntrs.nasa.gov/search.jsp?R=19930013452 2020-03-17T06:23:47+00:00Z

WP-2 ATTACHED PAYLOAD
AC ,OMMODATIONS
ORIG_1_AL PAOE IS
OF POOR QUALITY June 1992
Space Station Freedom
618/92
Jim Scheib, Manager
User Engineering Integration
MDSSC Space Station Division
(714) 896-3311 x60457
McDonnell Douglas * GE • Honeywell IBM o Lockheed
1
Space Station
WP.2 Pre-lntegra!
Attached Payl_ao
NOVEMBER 12 SSCB AND ATTACHED PAYLOAD CR
The November 12 SSCB and the parameters set forth in the Attached
Payload CR #BB003113B require accommodations for attached payload
as follows:
• Number of sites: at least 4 separate sites for attached payloads
• Viewinq: view nadir, zenith, ram and wake direction without
significant occultation by SSMB
• Clearance Envelopes: attach faces of about 5x6 ft on $2 and 6x13 ft
on the $1 and P1 sites, and 7 ft height at each site
• Utility Ports: each site contains at least 1 port
• Power: 3 kW peak per port (redundant power feed)
6 kW total peak aggregate supplied to all ports
• Thermal: payload provided
• Data:1553 Payload Local Bus with external FDD! network fibers and
cables for later hook up
• Mechanical Attachment: each attached payload site will contain 1
suitable mechanical attachment
Space Station Freedom McOennell Douglas GE Honeywell ° IBM Lockheed
ATTACHED PAYLOAD UTILITY PORTS
• Starboard (MTC) Locations:
S2-F4-B1" pre-integrated attachment on Face 4 (5' x 6' attach face) with
viewing in the Nadir and Wake directions (potential for Ram and Zenith
viewing also)
S1-F4-B6: attachment over the grapple fixtures with no structural
impact (6' x 13' attach face), viewing in Nadir, Zenith, Ram and Wake
directions
• Port (post MTC) Locations:
• P1-F2- B2: attachment over the utility trays (6' x 13' attach face),
unobstructed view in Zenith, Ram and Wake directions
P1-F6- B2: attachment over the utility trays (6' x 13' attach face),
unobstructed view in Nadir, Ram and Wake directions, common with
P1-F2 location
Note: all sites provide a minimum height of 7 ft - see operational envelopes
pages 10 through 12
418 m Space Station Freedom
McDonnell Douglas • GE • HoneyweTI IBM Lockheed
ON-ORBIT CONFIGURATION SHOWING PRIME
PAYLOAD ATTACH_iT SITES
S2-F4-B1 P1-F2-BI&2
Z
Space Station Freedom McDonneltDoLK:JlaS • GE ° Honeywell • IBM • Lockheed
lO
$2 (MB-2) SEGMENT
ATTACHED PAYLOAD OPERATIONAL ENVELOPE
S-Band Antennas
/ \Sta'r $2/$3
f Trackers _ Bulkhead
V
10
Propulsion
_.= Module
Space Station Freedom
McDonnell Douglas ° GE • Honeywetl ° IBM • Lockheed
11 419
$1 (MB-3) SEGMENT
ATTACHED PAYLOAD OPERATIONAL ENVELOPE
S1/M1 Bulkhead
I I
I X
Space Station Freedom
S1/M1 Bulkhead
\
Radiat(
Z
(hidden)
r Sweep
McDonnell Douglas • GE ° Honeywell • IBM • Lockheed
12
42O
Space Station Freedom
P1 (MB-8) SEGMENT
ATTACHED PAYLOAD OPERATIONAL ENVELOPE
Radiator
Sweep
Boundary
Y._X
McDonnell Douglas • GE • Honeywel] • IBM • Lockheed
13
POWER ACCOMMODATIONS APPROACH
The existing Electrical Power System (EPS) design was used
• No new DC to DC Convertor Units (DDCUs) are required, which would
also require adding new Main Bus Switching Units (MBSUs)
• Existing Secondary Power Distribution Assemblies (SPDAs) already in
place along the truss are used
• No impact on the growth of the overall EPS system to PMC
Power accommodations provide payloads with continuous power (power
levels depend on Station loads but do not exceed 6 kW total)
Each port is connected to a utility SPDA on each side of the truss
making the ports single failure tolerant (in case of SPDA failure up to
500 Watts may be available)
If a utility SPDA fails on one side of the Station and the Mobile
Transporter is using the utility SPDA on the other side, no keep-alive
power to payloads can be guaranteed
Space Station Freedom _oOoooe,oo._,., GE • Hooe_e, • _SM • ,._.,,_
614/92 15
PROPOSED ATTACHED PAYLOAD
POWER ARCHITECTURE
Payload I
Sl
RP
J I1_" I I spE
--Jl=" J
MI P1
PIF2B2oa d ]
DA
P1-F6-B2
P/L POWER { (2) 8 GAUGE WIRES, (1) 1 2 GAUAGE WIRE)
LATCH AND UMA POWER (T-120 GAUGE WIRE)
Space Station Freedom Mcoo°ne,Douglas° GE ° Honeywell
614/9 2 17
IBM • Lockheed
421
ATTACHED PAYLOAD THERMAL CONTROL
Payloads are required to provide their own thermal control
Payloads must be assessed on an individual basis to determine thermal
effects at the appropriate attached site and orientation. The following
considerations must be addressed:
• Operational/non-operational temperature ranges experienced by the
payload components or its individual ORUs
• What types of thermal coatings/insulation can be used to enhance the
desired temperature range
• What size radiators are needed to dissipate heat and what size heaters
are needed to make-up heat
Design-to thermal optical properties, radiator sizes, and insulation
requirements at each payload site must be determined by integrating the
payload model into a full Space Station model to properly size Passive
Thermal Control Systems (PTCS) for each payload
Preliminary thermal analyses for two example payloads: the Cosmic Dust
Collection Facility and the Orbital Debris Collision Warning System were
performed under this study
Space Station Freedom McDonnell Douglas • GE • Honeywell IBM • Lockheed
6)4/92 19
DMS ACCOMMODATIONS
[] SSCB has baselined 1553 local bus service
[] FDDI scarring is possible but has not been finalized yet
[] Interface Description:
• DMS accommodations are provided by extending two 1553
local busses from SDP 7 in the Lab Element Control
Workstation rack in the U.S. Lab
• One 1553B bus to the port APP sites and a second
separate 1553B bus to the starboard APP sites
• The two Local Busses share the same Bus Interface Unit (BIU)
with separate Bus Interface Adapters (BIA) to service each of
the Payload Local Busses
Note: requires the addition of one BIU in SDP-7
_,_r....v....e Station Freedom McDonneuoo,9_as• GE ° Honeywell • 18M • Lockheed
614/92 22
1553 ATTACHED PAYLOAD LOCAL BUS ARCHITECTURE
S2 Sl
APP 1 ,,PLI"\ APP 2 n
TGU: Core Time Generation Unit
APP: Attached Payload Port
S¢bd 1553 i
M1 P_t
.....pp3
\
Po_ 1553
\\
\\
I
I Node1
(@ MS-11)
........... Twlsied Shielded Pair (TSP)
in UUllty Trays
--''", TSP Umblllcals
N Utility Breakouts
_] TSP Segment Connector
[_. TSP Stub Connector at APP
\'_ _APP 4
NOTE: This Is a top level
representation ol the
proposed DMS external
accommodations for
payloads. The actual
number and locations of
wiring harnesses and
connectors are TBD.
en_-....r,.c..Station Freedom McDOooe,Oou0,as• GE
6/5R2 23
Honeywell • iBM Lockheed
ATTACHMENT ACCOMMODATIONS SUMMARY
II Accommodations include provisions for Propulsion Module Attach
Structure (PMAS) at each payload port
• PMAS is composed of mechanical latch, umbilical mechanism,
guide vanes, wire harness and support structure
• PMAS and support structure are not pre-integrated and are installed
with EVA at the time of payload first use
• Installation of attached payload pallet to PMAS will utilize the RMS
for positioning and EVA for final alignment
• PMAS standard attachment interface provides payload community
with the flexibility to connect single or multiple payloads at each
location (e.g, large payloads, gas cans or SARR pallet)
On segment P1 faces 2 and 6 the PMAS and the payload(s)/payload
pallet will swing away from the utility trays if on-orbit utility tray
servicing is ever necessary
_r__,.__e Station Freedom McDonnell Douglas , GE ° Honeywell • IBM * Lockheedm
615/92 26
423
PROPULSION MODULE ATTACH STRUCTURE (PMAS)
...... G F _ ................
i;',I
if, l/
_c-,.2;1
;Rt_N_i _ elf _iM_ iJ
Space Station Freedom
McDonnell Douglas
28
,/
I
I
1
l
H I
-._
' i
\ _',. I _'' -'
.... ',_, _ .... ¢_;,_,_W"=_
t';_'X_7_
i...
"I:P,:. ° []
PRELIMIIARY
GE • HoneyweH • IBM • Lockheed
424
Small and Rapid WP-2 Standard Boxes
Response Payloads for Scientific Payloads
Payload (2 Options)
Payloeda (PEP)
Mini Pallet for
External Payloads
(MPEP) Center Adaptable
Subplate for
Atlached
Z Payloads (Center
_"'--.L"_-_S-_ J I- /i ASAPI
\ _'_/ "'................. : .J .-;_W_ / i Pointing
.... ,_...-_ _-s::-_ -_ - _'->,. "_. :
.... n- ASAP ._ _._';.,-., _-:---_-_-'_ : Payload
i:::'_:_,__
,, _ ,,, ""#t"-.:_i ,_-_ _
Options RobotiSe .... " L
"'°'i ....................
Space _TtPU_S'_r M_u_U?%_"_ Wts_gP
Station (PMAS)
Provided
McDonnell Douglas Attached Payload Assembly (APA)
SESSION3:
MICROGRAVITYRESEARCHAND
BIOTECHNOLOGY
SPACESTATIONFREEDOMUTILIZATIONCONFERENCE
AUGUST5,1992
pRE_,F..DING PPI_E BLANK NOT FILM/_D



WP-2 attached payload accommodations

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