C2V2 Technical Requirements and Constraints Penny Roberts C2V2 SLPT Technical Chair

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

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

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

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

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

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

Antenna Locations Evaluated Reference SOW Section 1.2 and 2.3

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

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

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

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