Results 101–121 of 121

Secondary POL Conversion

Specification • JAS nodes should include POL conversion as needed. POL conversion has become very popular as the voltage requirements of electronic components have continued to drop. It is quite common for many digital electronic devices to use voltages of 1.8 VDC and below. Routing high current, low voltages around a printed...

Electrical Specification > Power Distribution Architecture > Secondary POL Conversion

Serial RapidIO

Specification • Serial RapidIO (or just RapidIO) is a high-performance packet-switched, interconnect technology utilizing either 8b/10b or 64b/67b encoding on data links, or lanes, with speeds up to 6.25 Gbps. Multiple lanes may be used in increase data throughput.

Electrical Specification > Communication Data Links > Serial RapidIO

Space VPX

Specification • While no specific node-to-node interconnection method is specified in JAS it is highly recommended that the nodes make use of a standards-based chassis and backplane. SpaceVPX is similar to VPX but intended for space applications. [Placeholder: There may be sub-specs we can reference here, similar to the subspecs for VITA...

Electrical Specification > Electrical Interconnects > Space VPX

Space Wire

Specification • SpaceWire is a full-duplex, point-to-point, serial data communications protocol in which the data is encoded on two differential signal pairs in each direction. This is the preferred JAS communication protocol for data rate below 200 Mbps. The electrical specifications for SpaceWire communications are described in the European Cooperation for Space...

Electrical Specification > Communication Data Links > Space Wire

SpaceWire Addressing

Specification • SpaceWire addresses shall follow the allowed allocation defined in the SpaceWire standard. Only logical addresses will be used for router and endpoint addresses which means they must be in the range of 0x20-0xFE. JAS applications shall use SpaceWire regional addressing in conjunction with header deletion within the SpaceWire routers. Two...

Communication Specification > SpaceWire > SpaceWire Addressing

System Monitor and Communication Profile

Other • The System Monitoring and Communication (SMAC) Profile defines a subsystem intended for integration into JAS nodes to provide control, communication, and state-of-health (SOH) monitoring capabilities. The SMAC subsystem consists of a single, common design applied to all nodes which provides a consistent interface to the system controller regardless of the...

Joint Architecture Standard Overview > JAS Profile Introductions > System Monitor and Communication Profile

System Monitoring and Communication

Profile • PS Node System Monitoring and Communication An important element that must be included in each PS node is described in the SMAC Profile. The SMAC monitors and controls the state of the PS node. The SMAC also provides standard network interfaces for connectivity to other nodes.

Power Supply Profile > Functional Description > System Monitoring and Communication

Thermal Impact

Specification • The JAS mechanical structure shall be designed to maintain the electronics/PCBs within given displacements while the system is in operation as applied by determining thermal impacts on the mechanical structure. The operational thermal environments of a nominal orbit need to be applied to the mechanical model as necessary to ensure...

Mechanical Specification > Environmental Exposure > Thermal Impact

Thermal Loads

Specification • Yield and ultimate thermal loads for hardware subject to thermal tests shall be calculated by either Alternate A or Alternate B, as defined below, whichever produces the maximum load. These thermal loads are not to be used for fatigue. Alternate A: Yield thermal load (YTL) = Predicted thermal load (PTL)...

Mechanical Specification > Design Constraints > Structural Integrity > Thermal Loads

Time Distribution

Other • The JAS architecture does not specify a time distribution scheme nor limit system implementations from incorporating their own methods. Two possible time distribution schemes are presented as examples: Fully Connected A fully connected distribution provides a direct interface between each node and the host. Fully connected time distribution is more...

Joint Architecture Standard Overview > Time Distribution

Useful Metrics for Analyzing Topology Candidates

Other • Emerging high-bandwidth, low-latency network technology has made network-based architectures both feasible and potentially desirable for use in satellite payload architectures. Network architectures are capable of routing large amounts of traffic with reasonable latency, allowing considerable amounts of data between nodes to be shared. However, care must be exercised when developing...

Joint Architecture Standard Overview > Network Topologies > Useful Metrics for Analyzing Topology Candidates

Vacuum Impact

Specification • The JAS electronics shall consider testing in a thermal vacuum environment because inadequately heat-sunk parts will fail/burn-up. Overheating is the issue, exceeding maximum junction temperatures.

Mechanical Specification > Environmental Exposure > Vacuum Impact


Specification • The JAS mechanical structure shall have no confined or captured volumes. Venting ports shall be provided to prevent damage, or the release of gases, due to pressure changes during testing, transportation, and launch. Threads need not be vented.

Mechanical Specification > Environmental Exposure > Venting

Vibration (Random)

Specification • The JAS housing support shall meet all performance specifications after being subjected to the vibration level prescribed by figure 5.5.1. This spectrum shall be applied, to the mounting brackets.

Environmental Specification > Vibration (Random)


Specification • While no specific node-to-node interconnection method is specified in JAS it is highly recommended that the nodes make use of a standards-based chassis and backplane such as VPX defined by VITA. The VPX standard provides high-speed switched serial interconnects between plug-in modules or nodes while providing for parallel bus interconnects...

Electrical Specification > Electrical Interconnects > VPX

X,Y, and Z Axis Random Vibration

Specification • The JAS support shall meet all performance specifications after being subjected to the random vibration environment prescribed by the figure below. Note that these are acceptance levels. This input should be used along with the program Strength Qualification Plan. Random Vibration

Environmental Specification > X,Y, and Z Axis Random Vibration

Results 101–121 of 121