Rapid accommodation of payloads on the Standard Interface Vehicle through use of a standard payload interface

The STPSat-3 mission is the second flight of the Space Test Program Standard Interface Vehicle (STP-SIV) spacecraft platform. STP-SIV is a small spacecraft bus with well-defined, documented, and controlled standard interfaces for up to four payloads, a ground system, and a variety of launch vehicles. It was developed by the Space Development & Test Directorate (SD) of the USAF Space and Missile Systems Center (SMC) with prime contractor Ball Aerospace & Technologies Corp. (BATC) STP-SIV provides the space community with a defined yet configurable standard spacecraft-to-payload interface on which to base payload designs for rapid mission development. Rather than designing a unique spacecraft for each payload, the standards provide adaptable interfaces to accommodate a range of payloads. The flexibility to make payload manifest decisions after completion of spacecraft bus integration was demonstrated on both the first (STPSat-2) and second (STPSat-3) SIV missions. For STPSat-2, which is currently on-orbit, accommodation included the late addition of a new 3rd payload after the bus was complete. For STPSat-3, the ability to rapidly accommodate new payloads was demonstrated by the manifest of replacement payloads following cancellation of one primary instrument, with only harness and bracket modifications. In both cases, payloads were added and removed without impacting the baseline design, the spacecraft bus, or the ILC date. This paper will discuss how a wide range of payloads can be rapidly accommodated though the use of a Standard Interface Vehicle, as demonstrated on the STPSat-2 and STPSat-3 missions. A detailed discussion of the changing payload manifest on STPSat-3 will provide a real-world example of how a standard payload interface can provide many payloads with rapid access to space.