Sooner To Space

PnP Spacecraft Flight Software Cuts Development Cost/Schedule/Mission Risk

3 Ratings

Imagine you are the project manager for a new spacecraft program. It is 4 days before launch and the star tracker vendor issues a recall. You must immediately install a backup star sensor, which is an older model with a different interface and I/O data. Instead of having to delay launch and undergo several weeks of integration and test activity, you plug the replacement star tracker in and the onboard PnP attitude software reconfigures the system automatically to function with the new device.


A typical spacecraft development schedule includes a significant amount of new flight software development, especially for the Attitude Determination and Control System. A software development cycle typically takes three years. Imagine cutting that time to just a few months or weeks, and ending with a final software module ready to fly, even though the sensor suite for the new mission is completely different than the last mission. Traditionally, spacecraft attitude control flight software has been developed as a point design for a particular spacecraft’s mass properties, hardware components, and mission requirements. This process means starting over with a “clean sheet” of paper each time a spacecraft control system is required. Microcosm has developed flight software that makes use of standard sensor and actuator interfaces, as well as common controller interfaces that make use of these elements and also contain common, reusable elements themselves.


A streamlined method for implementing attitude control software is needed to reduce spacecraft development & test cost, time, & risk. Reusability, reconfigurability, scalability are critical aspects. With reusable PnP software & associated sensors & actuators, spacecraft development time & costs will decrease dramatically. As space missions become more complex & budgets more constrained, streamlining the software architecture & reducing the overall spacecraft integration & test effort becomes more imperative. To create a truly responsive space capability, reusable, reconfigurable, modular, scalable & adaptable software must be a core component of new spacecraft development programs. The traditional process of developing spacecraft software involves a “one-off” approach whereby the software is designed specifically for that spacecraft & attendant hardware, especially so with attitude control software—highly tailored to the specific attitude sensors & actuators. The modular, reconfigurable PnP software allows significant reuse for future missions with widely varying mission goals & sensor/actuator suites, providing reduced development cost & time, & reduced mission risk.


Microcosm and our team member, HRP Systems, working closely with AFRL, developed an approach for building a fully modular, reusable attitude software package. Microcosm has been developing PnP spacecraft avionics for AFRL since 2001 and fully understands the goal of dramatic reduction in spacecraft development schedule and cost. Our team contributed to the software development for both the PnPSat program & the Modular Space Vehicle (MSV) program, subcontracting to Northrop Grumman on the MSV program.

"Embedded flight software (FSW) is often one of the larger costs of creating a spacecraft; FSW development efforts should focus on software reuse, application modularity, and functional scalability." — L. Jane Hansen


The Plug-and-Play (PnP) attitude control software is reusable and can significantly reduce spacecraft integration and test time, ultimately reducing cost while allowing for ease of integration for new attitude sensors and actuators from mission to mission. Implementing standard PnP interfaces allows subsystem components to be fully checked out prior to integration with the spacecraft, using common test equipment for all missions. The attitude software initializes, configures, controls, and reports telemetry of the following devices: inertial reference unit, reaction wheel assembly, control moment gyro, magnetometer, magnetic torquers, star tracker, sun sensors, Earth sensors, and GPS sensor. For the Modular Space Vehicle (MSV) program, the Microcosm team collaborated with Northrop Grumman to develop attitude software using this modular approach, allowing the software to be quickly adapted for varying mission requirements as well as allowing for the insertion of different attitude hardware components to accommodate component availability which often affects cost and schedule, or to meet performance needs as requirements evolve through the program. During the MSV development process, one star tracker was changed out for a different star tracker and because of the partitioning of the software and the use of a standardized interface definition from the star tracker to the software, the change was easily implemented with little impact to the development schedule.


As it was crafted to respond to the needs of Operationally Responsive Space (ORS), the Plug-and-Play (PnP) flight software helps to create space systems that can more quickly be fielded to support the needs of the service members deployed all over the world, in combat and in many support roles. It is a key component of an overall modernized, responsive infrastructure that will enable rapid response surveillance, augmented communications capabilities, and more effective command and control.

Developing the PnP software was the culmination of years of R&D work in the PnP Avionics area Microcosm has been involved with for AFRL. Seeing this product incorporated on Northrop Grumman’s MSV for the Air Force ORS program lends significant credibility to our overall PnP space technology development effort. Microcosm is also implementing this approach to software development for a low cost, responsive Earth imaging spacecraft concept we have developed over the past 5 years called NanoEye.

The PnP flight software increases the U.S. competitive advantage in state-of-the-art spacecraft systems, enabling a much faster development/test cycle than traditional spacecraft. This also allows more resources to be available for developing mission-specific software for new state-of-the-art payloads, enhancing the operational performance of U.S. satellites over other nations. U.S. spacecraft will be able to do much more for less total dollars than competing space systems of other nations.

The Microcosm team successfully prototyped and evaluated key elements of the Plug-and-Play (PnP) paradigm as part of developing the PnP flight software, validating many years of R&D in this area. The efforts associated with the program resulted in development of a baseline attitude software architecture and implementation, test results, interaction with the larger community implementing PnP responsive space systems, and an evaluation of the return-on-investment for PnP responsive space systems.

Developing Plug-&-Play Spacecraft Software

The Plug-and-Play (PnP) attitude control system flight software is one instantiation of reusable, reconfigurable flight software for spacecraft. While the attitude control system flight software is usually the largest portion of overall spacecraft subsystem software, we plan to extend this to the full complement of onboard software for our low cost, responsive NanoEye spacecraft, making all major subsystem components PnP-compatible, including the payload. This is work in progress at Microcosm.

Microcosm, Inc.

Hawthorne, CA

Microcosm is committed to providing low cost access to & operations in space. We specialize in “reinventing space.” We are recognized for innovations in space mission engineering; guidance, navigation, & control; and development of technologies & methods to substantially reduce space mission costs.

Jane Hansen Jane Hansen

Jane Hansen

Lead Software Designer

James Wertz James Wertz

James Wertz

Microcosm President

Alexander Krul Alexander Krul

Alexander Krul

Software Designer


Plug-and-Play (PnP) Responsive Space Technologies





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