STP-SIV and ORS ISET spacecraft-to-payload interface standards

Spacecraft standards can enable dramatic reduction in the cost, schedule, and risk of spaceflight. After the first build of a standard spacecraft the non-recurring engineering is complete which allows rapid, cost-effective production of subsequent units. Spacecraft standards can increase the supplier base by encouraging multiple organizations to build components, subsystems, or spacecraft according to the same standard. Interface standards promote rapid and low-risk integration. The Space Development and Test Wing (SDTW) of the Space and Missile Systems Center (SMC); and the Naval Research Laboratory (NRL), Applied Physics Laboratory (APL), and a consortium of aerospace industry and academia partners have developed standards for two independent projects with different, yet synergistic goals. SDTW leads the Space Test Program-Standard Interface Vehicle (STP-SIV) program with prime contractor Ball Aerospace & Technologies Corp (Ball Aerospace). STP-SIV is a small spacecraft bus with well-defined and documented standard interfaces to the payload, ground, and launch vehicle (LV). STP-SIV is designed to provide low cost space access to the science and technology (S&T) community. NRL leads the Operationally Responsive Space (ORS) standard bus development. The ORS bus standards were developed by the Integrated System Engineering Team (ISET) consisting of technical experts from over a dozen government and industry partners, chartered with generating standards for production of responsive spacecraft buses for the ORS Program Office. Both programs provide to the space community well-defined standard spacecraft (SC) to payload (PL) interfaces on which to base future PL designs. Rather than designing a unique SC for each payload; the standards provide adaptable interfaces to accommodate a range of payloads. STP-SIV offers a payload user´s guide (PLUG) which defines the mechanical, thermal, power and data interfaces to help facilitate PL design and integration. Simila- rly, the ISET developed a payload developers guide (PDG) describing capabilities and interface requirements for the ORS standard. Ball Aerospace has been contracted to standardize the ORS PDG such that the payload interface information and document organization follow the same outline and similar content as the STP-SIV PLUG. The complementary documents, including a payload questionnaire, along with a merged ldquoflysheetrdquo table containing summary-level capabilities of each platform will aid payload providers in selecting the appropriate spacecraft platform to host their payloads. This paper focuses on standard payload hosting capabilities, described in STP-SIV PLUG and ORS PDG, and the benefits of standardization of these small space vehicle platforms to the S&T, ORS, and other aerospace communities.