November 1997



October 1997

Prepared by

Original signed by DO3/Mark Swaby

DO3/Mark Swaby, SSC Lead Coordinator

Approved by

Original signed by DO3/Neil Woodbury

DO3/Neil Woodbury, Chairman, Station Portable Onboard Computer Control Board



HOUSTON, TEXASTable Of ContentsPre-5A Operations 5Early Support Computers 5Hardware Manifesting 5Hard Drive Software Updates 7Psychological Support Drive 7Multi-Purpose Support Drive 75A Operations 8Architecture 8Topology 8Hardware 9Network Software 9Network Assembly 11OOCI 11Inventory Management System 12Software Updates 12Failure Scenarios 12Longterm Operations 141553 Connectivity 14Payload LAN Connectivity 14OCA/UCA Connectivity 15Node 2 Connectivity 15OOCI 16File Server Backup 16System Administration 16Acronyms 17Chapter




This section focuses on Operations Concepts preceding LAN implementation. There will be no LAN available until flight 5A. However, Station Support Computers (SSC's) will fly prior to 5A for limited crew support and utilization functions. This includes Electronic Procedures, the Inventory Management System (IMS), standard office automation tools, and other crew support applications. These early flights will also be used to build up hardware in preparation for the LAN . Concepts discussed in this chapter continue through successive build up and sustaining stages unless otherwise noted.


  1. Early SSCs - Beginning with 2A.1, a limited number of Early Station Support Computers (ESSC's) will be provided for crew utilization support. These laptops will use the same hardware platform (IBM Thinkpad 760ED) as the Early Portable Computer System (EPCS). The ESSC will be a Windows 95 based platform, with a limited application manifest, and is a precursor to the SSC client load that will be developed for the OPS LAN beginning on 5A.
    1. The laptop manifest for the early flights is shown in table 1. It is based on requirements from the Joint Operations Panel (JOP), and provides the first ESSC computer beginning at 2R. The ESSC hardware has been approved for stowage by the Manifest Working Group (MWG). However, this manifest is subject to change. The CB office request is for 1 (E)SSC per crewmember, along with 1(E)SSC per station module.
    2. Shuttle manifest space limitations necessitate the manifesting of hardware beginning on 2A.1 to achieve the desired number of laptops by 2R. The manifesting of these laptops during early flights is a buildup for the OPS LAN laptop inventory.

  1. Table 1


  1. Scheduled Updates during Shuttle Rendezvous - As on Shuttle flights today, it is expected that the software will be dynamic and continually changing. This is due to new applications, data files, modifications, and improvements that will be made flight to flight. The update method will entail some type of update disk, and/or a CD ROM if the changes between loads are extensive. In any case, the plan is to upgrade the previous machines so that all of the SSCs are configured the same. It is anticipated that crew members will likely make some amount of minimal personalized changes to the SSCs (Ex. Desktop Configuration) during onboard use. For SSC loads requiring only minor updates, attempts will be made to retain these personalized configurations during software load upgrades. However, for SSC loads requiring major hard drive updates, crew personal configurations may be lost.
  2. Real Time (R/T) Updates - The capability exists to incorporate file updates in R/T. This is expected for data files (Ex. IMS Database) and for off-nominal fixes. These uplink changes will be sent to the Early Comm laptop, and then transferred via transportable medium (PC Flash Card, PC Card Hard Drive…etc.) to the individual SSCs. Uplinked fixes to software will be tracked on the ground and included in subsequent scheduled updates during Shuttle Docking Missions to ensure all affected Laptops are reconfigured appropriately. This method may be used for the R/T updating of other laptops (such as PCS).

    1. To enhance crew morale and for psychological support, a separate storage drive(s) will be flown containing crew preference 'non operations' related software. Items on this drive will not have network connectivity, and will incur no operations impacts if rendered non-functional.
    2. To reside on this drive, applications must not have any ground distribution requirements. Drives will only be provided for flight, are intended to support crew increments, and will be return with crewmembers. The drives will contain such things as Family Photo Albums and Games. These items are being manifested separate from the standard SSC software load for a variety of reasons, and will be given very limited ground support.

    1. Some unique crew support applications will not be part of the standard SSC load. Items on this drive will be operations tools for which the expected use is infrequent, and no ground distribution is required. The loss of this capability will have limited operations impacts. The Drive will contain such things as IFM tools and programming tools, and will be configured to be used with the standard SSC load. This Drive will involve only limited crew training and is manifested independently of crewmembers.





This section focuses on Operations Concepts being developed to support the first stage of the Operations LAN (5A).

  1. Due to limitations with shuttle manifesting space for up-mass hardware, the first LAN at 5A will have to rely upon existing Laptop hardware already on-board the ISS. At 5A, the laptop computers used for Command and Control of the ISS pre 5A (IBM 760ED) will be replaced by a newer model (IBM 760 XD) for Command and Control capability with the C&C MDM. The 760 ED laptops are not planned for C&C MDM use after 5A. The Hard Drives of these units (EPCS), and the ESSCs, will be reconfigured (or replaced) to support the Ops LAN. This allows the Ops community to take advantage of existing hardware while not imposing additional laptop manifest requirements on the program.
  2. A mixed fleet of H/W (IBM Thinkpad 760ED's and 760XD's) is expected, with the goal of replacing older units as quickly as possible based upon shuttle manifesting availability.
  3. No vehicle scaring was required for the 5A LAN implementation phase.


The Ops LAN will use standard Ethernet as the network architecture for communication. It will support the IEEE 802.3 (Standard Ethernet) and 802.11 (RF) protocols.


The Ops LAN will consist of both wireless Radio Frequency (RF) and hardwire bus (10base2) connections. When used, the RF links behave like the standard Bus Topology normally associated with Ethernet Architecture, being seen as a bus connection to the network. The SSCs will connect to the LAN using RF via PC Cards with RF capability. These cards will communicate through RF Access Points (Repeaters) to the File Server. The File Server itself will be connected to its RF Access Point via a hardwire, for performance reasons relative to data transfer. (For Network Assembly, see figure 1)


Beginning at 5A, the LAN will consist of the Following Components:

  1. File Server - The File Server will be an existing ISS Portable Laptop Computer (IBM 760 XD. It will be the only upgrade IBM 760 XD at this time allocated to the Ops LAN.
  2. Station Support Computers (SSC) - The SSCs will be the IBM 760 ED until they can be exchanged for XDs.
  3. OCA/ECOM - The Early Comm Laptop will be a Thinkpad 755C.
  4. RF PC Cards - Connection to the LAN for the SSCs will be via these wireless cards. (2.4GHz frequency range currently under evaluation).
  5. RF Access Points - The Topology requires Access Points (minimum 3) to be placed strategically throughout the modules to provide network access coverage throughout the ISS. Includes Power Supply connections.
  6. Hardwire Cable - Limited cabling for File Server Connection to RF Access Point.


Table 2 shows a preliminary estimate on the software manifest configuration of the File Server and SSCs load in this timeframe.

  1. File Server - This File Server will contain "Windows NT Server" as the Operating System. The Standard Communications Protocol will be TCP/IP.
  2. SSC - These laptops will contain "Windows 95" as the Operating System. The SSCs will connect to the File Server as Clients, in a "Client/Server" relationship.

Preliminary Manifest for SSC Software Applications
SSC Load
SVR Load
Psyche Load
MPS Drive
Internet Explorer
IMS Database (TBD)
IMS Viewer
MS Exchange SRV
MS Office
Netmeeting (eq)
Norton Antivirus 95
Norton AntivirusNT
ODF Procedures
OSTP Activity Records
Photo Viewer (TBD)
Photoshop Light
Recreational Games
Thumbs Plus
Video CD Player
Visual Basic
Windows NT Server
World Map/STK

Table 2

Preliminary Manifest for SSC Software ApplicationsNETWORK ASSEMBLY

Figure 1


  1. Onboard Short Term Plan (OSTP) - The OSTP Viewer will reside on the SSC. The Activity Records required to support the OSTP viewer will reside on and be uplinked to the File Server.
  2. Manual Procedures Viewer (MPV) - The Manual Procedures Viewer will reside on the SSC. This is expected to begin prior to the LAN for the early flights (2A.1), with the use of EDP. All procedures files for MPV will reside on the File Server. This includes both SODF and Payload Procedures. A Solaris version of the MPV will reside on the PCS as a backup in a standalone mode. In a contingency situation, using the PCS commanding function from the ground, manual procedure files can be sent up S-Band to the C&C MDM and transferred to a PCS via a file transfer script. A secondary option is moving the files via removable media (Ex. PC Card) from the File Server.
  3. Automated Procedures Viewer (APV) - The APV will reside on the PCS, with no LAN connectivity.
    1. The IMS Database will be located on the File Server. The IMS application software will be available on the SSCs. Using the basic Client Server philosophy, crewmembers will be able to access IMS information from anywhere in the ISS to the central repository on the File Server. Modifications to the Database will be downlinked daily to keep the ground records synchronized. Updates to the database can be sent to the server via the OCA.

With the addition of the LAN, software updating concepts are slightly changed.

  1. Scheduled Updates during Shuttle Rendezvous - Updates to the File Server Software will occur as before. This will likely entail some type of update disk, and/or a CD ROM if the changes between loads are extensive. Updates to the SSC load will be transported in a similar manner (Disk, CD ROM), but implementation will change to take advantage of the File Server. Instead of each SSC being updated individually, the update software will be placed on the file server. It will then be moved to the SSCs across the LAN to simplify update operations. It is not known at this time if the updates will use a File Server Application to perform this upon login of each SSC, or if an update icon with batch file execution will exist on the SSCs to allow the crewmember to perform this as required. For SSC loads requiring only update disk changes, as before, attempts will be made to retain these personalized configurations during software load upgrades. For major SSC load upgrades requiring Hard Drive reloading, attempts will be made where possible to retain crew personal configurations.

  1. Real Time (R/T) Updates - These uplink changes will be sent to the OCA laptop, and then transferred via the LAN to the File Server. SSC changes will be forwarded to the laptops as required, with the method on implementation currently undefined (see 1 above) . R/T updates for other Laptops (i.e. PCSs, etc.) will occur via the C&C MDM, or if desired can be sent to the OCA laptop, and then transferred via transportable medium (PC Flash Card, PC Hard Drive…etc.) to the individual laptop.


It is desired to minimize crew time required to support LAN system administration activities. While it is inevitable that some amount of crew involvement will be required, the SSC Coordinators will be responsible for working as much routine workload as possible from the ground. True 'Remote Logon' capability may not be available on 5A. Off nominal situations will likely involve some crewmember time allocation. The SSC Coordinators will work from the Ops Planner MPSR on a phase support schedule to perform remote System Administration activities. Access to the Network will initially be through the Early Comm System and the on-board OCA Laptop, similar to what is available today for Shuttle.


In the event the Ops LAN or pieces of it experience downtime, for whatever reason, alternative Operations Concepts are needed for many of the capabilities being provided by the LAN.

  1. Hardware Workaround - For a failure of an SSC client, or the OPS LAN Server, the following initial options are available:
    1. Swap Hard Drive with backup (Hard Drive Problem)
    2. Swap/use different machine (platform problem)
  2. Capability Workaround - An OPS LAN server failure can cause data loss. The following cases have specifically been examined:
    1. IMS - An OPS LAN server failure could cause loss of the IMS database. However, the ground could uplink a new copy that would be accurate to within 1 day (based on a planned daily downlink of the database).
    2. OSTP - An OPS LAN server failure could cause loss of Activity Records. The ground could uplink a new copy of the activity records to support the OSTP
    3. Manual Procedures - An OPS LAN server failure could cause loss of Manual Procedures. Manual Procedures could be accessed via the original increment CD, and/or via procedures uplinked from the ground.
  1. The above Capability Workarounds assume the following:
    1. Uplinks to the Early Comm OCA laptop are moved to the individual laptops as required (PC Card, PC Hard Drive etc.) until the File Server contingency is fixed.
    2. The OSTP Viewer and MPV can access procedures from the SSC local Hard Drive (Standalone Mode)
    3. As an additional precaution, there will be a Solaris version of MPV on the PCS that can read procedures from its Hard Drive.





This section focuses on Operations Concepts being developed to support Longterm Operations. These concepts add to, but do not replace, the Operations Concepts described in the 5A Plan. These concepts are currently very dynamic, and only represent a snapshot of longterm LAN Planning.


It is anticipated that connectivity to the 1553 MDM architecture will eventually occur. This concept arises out of the multitude of systems and payloads data available on the 1553, for which a variety of crew utilization applications can be written to support both crew and payload activities. It is understood that a safety concern exists with the concept of a connection between the OPS LAN and the 1553/PCS/MDM system. Hence, it is believed that access to the 1553 architecture will occur in three stages, and will likely include both 1553 core and payload busses.

  1. Data-Receipt Only - The first stage will be to gain 1553 access to display data only, with no commanding capability involved. This connection will likely involve some type of monitoring software, either on the SSC or an interim hardware connection (PCS), to ensure the LAN connection does not interfere with 1553 commanding operations.
  2. Limited Command Capability - The Second stage will be to gain 1553 access to a limited amount of template commands. The most likely candidates involve automated procedure. Again, it is believed some type of monitoring software will be used to ensure the LAN connection does not interfere with 1553 commanding operations, or perform any erroneous or illegal commands itself.
  3. Extensive Command Capability - The third and final stage will be to gain 1553 access to extended commanding capabilities to perform most, if not all, crew required commanding activities.


For improved global operations, eventual connectivity to the Payload Ethernet is expected. It is anticipated that the Payload Ethernet will desire to take advantage of the File Server Opportunities provided by the Ops LAN.OCA/UCA CONNECTIVITY

For improved Real TIme operations relative to data transfer, it is desired to eventually provide a hardline connection between the Early -Comm (OCA) or Early KU laptop and the File Server. Current 5A physical locations will not allow for a hardline connection between the ECOM laptop and the server. This will necessitate moving the location of the OCA machine from Node 1 into the U.S. Lab. This may occur as part of the transition from ECOM to Early KU. It is also anticipated that the SSC will integrate the OCA software load, and the SSC will be used as the laptop for this activity.


LAN expansion throughout Assembly Operations will be aided by the design implementation of hardline connections from the U.S. Lab into Node 2. Node 2 will provide subsequent hardline connections to adjacent modules, allowing direct access to the File Server in the U.S. Lab. This will allow for improved operations capabilities, including File Transfer and Video Teleconferencing. See Figure 2 for a preliminary concept of longterm Network Connectivity.

Figure 2


Depending upon what type of 1553 connectivity is available, all OOCI functions may move to the SSC.


Backup capability for the File Server will be required as soon as possible. This may or may not be in the form of a backup file server itself. It may include external Storage Devices (Ex Jazz Drives) for performing Routine backups of the Server.


To aid in the Operations Concept of minimizing crew involvement with System Administration Activities, it is highly desired to provide the ground with a remote login capability to the LAN. This will improve ground Sys Admin capabilities and decrease crew time required for the supporting this activity. This capability may be provided by the proposed "NDIS" drivers for the OCA card.

APVAutomated Procedures Viewer
C&CCommand and Control
CD ROMCompact Disk Read Only Memory
ECOMEarly Communications
EDPElectronic Data Project
EPCSEarly Portable Computer System
ESSCEarly Station Support Computer
FGBFunctional Energy Block
FSFile Server
IBMInternational Business Machines
IFMIn-Flight Maintenance
IMSInformation Management System
ISSInternational Space Station
JOP Joint Operations Panel
LABLaboratory (US)
LANLocal Area Network
MDMMultiplexer Demultiplexer
MPLMMini-Pressurized Logistics Module
MPSMulti-Purpose Support
MPSRMulti-Purpose Support Room
MPVManual Procedures Viewer
NDISNetwork Driver Interface Standards
OCAOrbiter Communications Adapter
ODFOperations Data File
OOCIOSTP (Onboard Short Term Plan) ODF (Operations Data File) Crew Interface
OSTPOnboard Short Term Plan
OSTPVOnboard Short Term Plan Viewer
PCPersonal Computer
PCSPortable Computer System
PEHGPayload Ethernet Hub Gateway
R/TReal Time
RFRadio Frequency
RMSRemote Manipulator System
SMService Module
SSCStation Support Computer
STKSatellite Tool Kit
TCP/IPTransport Control Protocol/Internet Protocol
UCAUniversal Communications Adapter
VDCVolts Direct Current