1. C2V2 Technical Requirements and Constraints
Penny Roberts
C2V2 SLPT Technical Chair

2. High Level Requirements
Two-way communications for all future ISS Visiting Vehicles (VVs)
Crewed VV docking
Uncrewed VV berthing
Uncrewed VV docking
Provide a system that can meet each of these VV needs for the life of the ISS program
Maximize the system’s capabilities to ensure supportability throughout the life of the ISS
Provide coverage to all ISS docking ports
Provide coverage throughout the VV trajectory
Meet National Telecommunications and Information Administration (NTIA) requirements
Meet safety requirements
Single fault tolerance
Reference SOW Section 1.2 and 2.3

3. Coverage for VV Trajectories
(200m radius)
Reference SOW Section 1.2 and 2.3

4. VV Data Communications
Data types are VV dependent
All VVs
ISS and VV state of health and navigation states – two-way exchange
Relative navigation state – from ISS to VV
May be used as a third string of redundancy for the VV’s navigation
Crewed VV
Audio – two way
Uncrewed VV
Commands from ISS to VV and associated VV to ISS command responses
VV pass through commands and data due to space-to-ground
Video from the VV to the ISS – the best possible within the bandwidth available
Data types are range dependent
Data required for VV navigation or commanding is time and safety critical
Reference SOW Section 1.2 and 2.3

5. Coverage, Range, and Data Types
Reference SOW Section 1.2 and 2.3

6. ISS Communication Coverage Constraints
During nominal operations, the following must not be constrained
Solar panels
Thermal radiators
ISS attitude
ISS configuration is not constant
Reference SOW Section 1.2 and 2.3

7. Reference SOW Section 1.2 and 2.3
ISS Constraints
Antenna mounting locations limited
Keep out zones must be avoided
Vehicle penetrations limited
Minimize Extravehicular Activities (EVAs)
C2V2-related EVAs should be limited to installation only – the fewer, the better
High Mean Time Between Failure for external ISS-C2V2 – EVAs due to failed ISS-C2v2 are HIGHLY undesirable
If equipment is launched in pressurized volume (maximum launch possibilities), then external ORUs must fit within the airlock for EVA installation
Internal locations limited –available volume in USL Mobile Servicing System (MSS) rack
ISS software transitions occur in September once a year – C2V2 capability must support this transition date in 2014 in order to support early 2015 operational need date
Telemetry definitions required in 2012 to support onboard and ground system implementation by onboard SW transition date
Reference SOW Section 1.2 and 2.3

8. Antenna Locations Evaluated
Reference SOW Section 1.2 and 2.3

9. Internal Cable Routing and C2V2 Location
Maximum of Two Available Coax Feedthrough Pins
Maximum of Seven Available Coax Feedthrough Pins
Reference SOW Section 1.2 and 2.3

10. Reference SOW Section 1.2 and 2.3
Deployment Plan
Perform integrated test
Data rate changes may be performed during planned holds
Perform system check-out
Check-out minimal if passive elstronics only
Reference SOW Section 1.2 and 2.3
Perform subsystem check-out, may involve ISS attitude manuevers

11. Manifesting and Launch Constraints
Launch vehicles
Progress
Automated Transfer Vehicle (ATV)
H-II Transfer Vehicle (HTV)
Dragon
Cygnus
Delivery before launch requirements
Late stow is typically 3 months before launch and limited to “small” items
Typical delivery dates are 6-9 months before launch
Unpressurized cargo launches require even earlier delivery dates to support integration on launch pallet
Reference SOW Section 1.2 and 2.3

12. Visiting Vehicle Requirements
VV-C2V2 launches installed – higher vibration and loads than the soft-stowed launch for ISS installations
Size, weight, and power constrained - minimize
Need data, hardware, software, and ground support equipment to support VV development and integrated testing
Standard command, control, and data interface
28 Volts Direct Current (VDC) interface
Reference SOW Section 1.2 and 2.3