DARPA Phoenix Payload Orbital Delivery System: Progress towards Small Satellite Access to GEO

The emerging practice of hosting payloads on commercial geosynchronous Earth orbit (GEO) satellites is gaining traction throughout the space community because of the flight opportunities and budgetary savings that it offers. Using the hosted payload model, the DARPA Phoenix Payload Orbital Delivery (POD) system is meant to enable a higher tempo to GEO for small‐mass hardware items. The POD system proposes a departure from the typical hosted payload. The POD would provide a controlled release of the hosted payload from the commercial host near GEO. The POD standard user\u27s guide developed under the Phoenix program ensures compatibility with most of the approximately 15 commercial launches to GEO each year. By hosting with a standard user’s guide, commercial satellite providers would be capable of bringing hosted payloads quite late into the typical launch integration cycle. The combination of hightempo commercial launches and late integration would create an “express delivery” capability to GEO orbit. This POD capability would continue the paradigm shift of working with the commercial satellite provider directly to leverage the efficiencies of mass to orbit, reducing interactions with the launch provider. Phoenix is completing the design and ground testing of the POD system to help make access to new orbits more affordable and more routine for small‐mass systems

Engineering a Responsive, Low Cost, Tactical Satellite, TacSat-1

The Secretary of Defense’s Office of Force Transformation (OFT) is currently undertaking an initiative to develop a low-cost, responsive, operationally relevant space capability using small satellites. The Naval Research Laboratory (NRL) is tasked to be program manger for this initiative, which seeks to make space assets and capabilities available to operational users. TacSat-1 is the first in a series of small satellites that will result in rapid, tailored, and operationally relevant experimental space capabilities for tactical forces. Components of the resulting tactical architecture include a highly automated small satellite bus, modular payloads, common launch and payload interfaces, tasking and data dissemination using the SIPRNET (Secret Internet Protocol Routing Network), and low cost, rapid response launches. The overall goal of TacSat-1 is to demonstrate the utility of a broader complementary business model and provide a catalyst for energizing DoD and industry in the operational space area. This paper first provides a brief overview of the TacSat-1 experiment and then discusses the engineering designs and practices used to achieve the aggressive cost and schedule goals. Non-standard approaches and engineering philosophies that allowed the TacSat-1 spacecraft to be finished in twelve months are detailed and compared with ‘normal’ satellite programs where applicable. Specific subsystem design, integration and test techniques, which contributed to the successful completion of the TacSat-1 spacecraft, are reviewed. Finally, lessons learned are discussed

TacSat-4 Mission and the Implementation of Bus Standards

This paper provides an overview of the TacSat-4 mission with a focus on the COMMx payload. It discusses the lessons-learned to date and the challenges of building a payload to fly on the prototype spacecraft Bus built to the ORS Phase III Bus standards. Each TacSat experiment tests key elements of an operational system by taking frequent tangible steps to spiral capability and receive operational feedback, while moving toward Operationally Responsive Space (ORS) acquisitions. The TacSat-4 experiment’s mission was selected by a Joint panel. Tacsat-4 has several ORS system level objective including using a prototype bus to mature spacecraft bus standards for acquisition and to fly in a “low” highly elliptical orbit, enabling a new set of ORS missions that require dwell, such as communications. TacSat-4 provides a Communications-on-the-Move and Data-Exfiltration payload. Building a TacSat that operates in a high radiation, highly elliptical orbit is quite challenging for the low cost class and short schedules that TacSats must support. The COMMx payload is currently undergoing system level environmental testing. The ORS Bus Standards flight prototype is complete and ready for integration with the payload. Space vehicle integration and test will be performed from August to October 2008 with launch scheduled for September 2009

TacSat-4 Early Flight Operations Including Lessons From Integration, Test, And Launch Processing

TacSat-4 is an experimental Ultra High Frequency (UHF) communications satellite that launched on a Minotaur IV+ from Kodiak, Alaska on September 27, 2011. The spacecraft and ground capabilities are briefly described for context. The integration, testing, launch processing, early flight operations, and initial end user results are then discussed. Unique approaches and lessons learned are highlighted. For example, the “launch powered off” approach used to test new Operationally Responsive Space (ORS) bus standards worked particularly well, and had several benefits during launch processing. The ORS Office is leading the Joint Military Utility Assessment of the TacSat-4 mission