Pros and Cons of Standard Interfaces

Victor Matricardi, The Aerospace Corporation
Lt. Col. Randy Ripley, Space & Missile Systems Center

Abstract

Standard interfaces and components have the potential for lowering systems engineering costs and reducing time to integrate payloads on small (or large) satellites. In addition, after the first one is built and flown, the risks are reduced when subsequent identical items are built. For the case of spacecraft interfaces, once a standard interface is designed, it defines a set of all possible payloads that can be mated to it. Over-use and under-use of a standard interface is inefficient. Over-use, or putting a payload which demands more from the interface than what it was designed for, leads to additional system engineering and redesign tasks. Under-use of the interface is also inefficient because the interface provides more capability than what is needed. Given the high value (e.g. $/kilogram) of a space vehicle, the excess capability will require more mass and more complexity than an optimized interface; thus additional cost and time. A variety of sizes of payloads come to the Space Test Program (STP) for space flight. STP is in the process of acquiring an ESPA-class Standard Interface Vehicle (SIV). Those payloads that are designed to fit this standard interface are rewarded with a higher probability of flight. For the future, an analysis of the payloads that do not fit the ESPA-class SIV will likely define a new, larger and more capable standard interface; thus leading to quantized standard interfaces.

 
Aug 9th, 9:00 AM

Pros and Cons of Standard Interfaces

Standard interfaces and components have the potential for lowering systems engineering costs and reducing time to integrate payloads on small (or large) satellites. In addition, after the first one is built and flown, the risks are reduced when subsequent identical items are built. For the case of spacecraft interfaces, once a standard interface is designed, it defines a set of all possible payloads that can be mated to it. Over-use and under-use of a standard interface is inefficient. Over-use, or putting a payload which demands more from the interface than what it was designed for, leads to additional system engineering and redesign tasks. Under-use of the interface is also inefficient because the interface provides more capability than what is needed. Given the high value (e.g. $/kilogram) of a space vehicle, the excess capability will require more mass and more complexity than an optimized interface; thus additional cost and time. A variety of sizes of payloads come to the Space Test Program (STP) for space flight. STP is in the process of acquiring an ESPA-class Standard Interface Vehicle (SIV). Those payloads that are designed to fit this standard interface are rewarded with a higher probability of flight. For the future, an analysis of the payloads that do not fit the ESPA-class SIV will likely define a new, larger and more capable standard interface; thus leading to quantized standard interfaces.