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MicroSat Systems
Low Cost Satellites — Nanos, Minis and Micros Making Headway…
by Dr. Todd Mosher

With technologies changing so rapidly, low cost satellites are viable in today’s marketplace. MicroSat Systems, Inc. is serving the needs of customers that aren’t being met by large aerospace companies. In addition to military customers, MicroSat is actively pursuing the commercial and civil satellite markets.

MicroSat was founded in April 2001 as a spin-off to a high technology research and development company, ITN Energy Systems, in order to execute an Air Force contract for three, high performance 200kg class satellites with Synthetic Aperture Radar (SAR) payloads. This was named the TechSat 21 program and provided MicroSat its foundation in the satellite business.

Are Microsats a Disruptive Technology?

MicroSat’s spacecraft bus products have the potential to be a disruptive technology. MicroSat is providing reliable and capable spacecraft at an affordable price with merely an 18-month lead-time. The missions they support are not necessarily as complex as larger spacecraft, but for the price and schedule, they still meet important needs. MicroSat provides the satellite industry a product line of small satellite buses based on a modular bus design that enjoys proven flight success. The bus can be customized as needed for different mission applications and customer requirements. Unique capabilities of MicroSat’s buses include: better payload mass fraction, power, data processing, and pointing accuracy than comparably priced satellites.

“Time will tell if MicroSat’s offerings will prove to be a disruptive technology in the satellite industry the way that things like digital cameras and personal computing devices have been in other high-tech markets,” said MicroSat President John Roth. “However, we do study and incorporate practices from those disruptive innovations from other industries directly into the way MicroSat does business.”

TacSat-2 Is An 814 Pound Eye in The Sky

MicroSat gained flight heritage on December 16, 2006 with the launch of TacSat-2, the first operationally responsive space satellite. The launch and operation of TacSat-2 demonstrated MicroSat’s ability to provide a high performance satellite in a rapid development timeline, for a low cost.

The TacSat-2 program was the first Air Force Research Laboratory (AFRL) flight demonstration program under the Operationally Responsive Space initiative. TacSat-2 was specifically designed to allow military commanders on a battlefield to request and obtain imagery and other data from a satellite as it passes overhead. Collected data could be delivered to field commanders in minutes, rather than hours or days. The sensor on TacSat-2 can collect color images sharp enough to distinguish ground objects as small as one meter in diameter.

“I am excited because Tacsat-2 is another demonstration of a new way of doing business,” said Neil Peck, AFRL’s Tacsat-2 Program Manager. “The push that we are getting from high levels will cause real change in how we procure space systems. Tacsat-2 is step one in that process.”

MicroSat Systems designed, built, and environmentally qualified the satellite bus with a 59 percent payload mass fraction, delivered the basic bus structure to AFRL in 12 months, and built the primary solar arrays and the experimental thin-film solar arrays.

MicroSat demonstrated its ability to significantly reduce satellite bus costs on TacSat-2 through the reuse of a modular, common bus structure and subsystems from its prior program, TechSat 21. The reuse of specific components and subsystems, and MicroSat’s continued evolution of a bus development process for a high performance spacecraft, resulted in a flexible design that is easily adapted to accommodate a variety of military, scientific and commercial applications.

AFRL’s TacSat-2 Program will complete its tenth month of flight operations in October. Over 95 percent of the mission objectives have been accomplished to date and each of the 13 hardware and flight software experiments have been operated.

Results from some of those experiments have already been made available to the aerospace community in technical publications and at conferences. The MicroSat bus is operating normally and has surpassed the flight lifetime requirement. MicroSat, and their subcontractor Advanced Solutions Inc., continue to support Air Force mission operations from their Littleton, Colorado facilities. In addition to individual experiments, TacSat-2 has participated in several military exercises to demonstrate Operationally Responsive Space concepts in support of the Warfighter.

A key objective of the Operationally Responsive Space concept is to provide space-based resources and products directly to the tactical user at their demand. The potential benefits of TacSat-2 revealed by the military exercises have resulted in an extension of the mission through 2007 to perform more complex tactical user support demonstrations. The spacecraft is expected to operate beyond 2007. Options for a transition of the spacecraft operations from experimental status to an operational status are under consideration.

Their Air Force has recognized MicroSat with several awards celebrating this significant milestone, including the Aviation Week and Space Technology Magazine Small Company Product Breakthrough Award for the TacSat-2 Satellite.

Ready, Set, Launch

Following this launch success, MicroSat has additional satellite contracts underway, as well as the Road Runner bus product, (a generic version of its TacSat-2 satellite), being offered via NASA’s Rapid Spacecraft Development Catalog (RSDO).

The Demonstration & Science Experiments (DSX) Mission will research technologies needed to significantly advance Department of Defense (DoD) capability to operate spacecraft in the harsh radiation environment of medium-Earth orbits (MEO). The ability to operate effectively in the MEO environment significantly increases the DoD’s capability to field space systems that provide persistent global targeting-grade space surveillance, high-speed satellite-based communication, lower-cost GPS navigation, and protection from space weather on a responsive satellite platform. DSX uses a modular design that allows for launch either as a primary satellite on a smaller launcher, such as a Minotaur, or as a secondary payload on a larger rocket, such as the Evolved Expendable Launch Vehicle (EELV). A key enabler to this modular design is the use of a standard micro satellite bus.

A Non-Conventional Orbit with a Non-Conventional Spacecraft

MicroSat’s role is the design, fabrication, testing and delivery of the spacecraft bus for DSX, which is built around the Evolved Expanded Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) Ring. The ESPA ring was originally designed to accommodate secondary payloads, which were to separate and fly as individual spacecraft after the upper payload separated from the launch vehicle.

The DSX concept is to use the ESPA as the primary structure of the spacecraft. In other words, instead of deploying secondary microsatellites, the ESPA ring becomes part of the spacecraft. The spacecraft avionics and science payloads are housed in a pair of modules that are mounted on opposite ends of the ESPA ring. The Avionics module will provide the primary bus functions for DSX payloads and experiments. This includes power generation and storage, power management and distribution, attitude determination and control, thermal control, communications, command and data handling, and structural support and mechanisms, thus providing an 800 kg “satellite” for the cost of a 180 kg bus.

The two modules are derivatives of the bus developed by MicroSat for the currently flying TacSat-2 mission. This innovative approach demonstrates the versatility of the bus design and validates the primary design goal of developing a spacecraft bus that could easily be adapted to accommodate a variety of spacecraft mission and science objectives. The bus will be delivered to AFRL in the spring of 2008 and the complete satellite is scheduled to be flight ready in 2009.

The Calibrated Orbiting Objects Project Spacecraft

MicroSat Systems is also developing the core spacecraft system for the Calibrated Orbiting Objects Project (COOP) for the Missile Defense Agency (MDA). The primary intended purpose of COOP is a flight mission incorporating a target simulation payload that will send down encrypted truth data to validate the data acquired using the Ballistic Missile Defense system. The spacecraft has been officially manifested for launch in 2009.

MicroSat has been innovative not only in producing a spacecraft for this unusual mission, but also by using an extensive coordinated set of Small Business Innovative Research (SBIR) grants in partnership with the MDA sponsor to fund much of the program.

All Board MicroSat’s Modular Bus

Earlier this year, MicroSat’s Road Runner bus was added to the NASA RSDO bus catalog. This catalog allows mission designers to rapidly compare with current available bus offerings to determine mission feasibility and to choose a bus once a mission goes forward. MicroSat’s Road Runner bus is a modular, reliable bus capable of accommodating a large payload mass. The bus design utilizes components with proven flight heritage that enable parallel processing of components on separate panels, allowing for a great deal of the bus and payload production and testing to be performed in parallel.

Road Runner’s launch vehicle adapter has a standard interface size that accommodates multiple launch vehicles and separation systems including Falcon 1/Minotaur 1, larger launch vehicles, and secondary flight opportunities. The Road Runner bus can be flight ready in 18 to 24 months.

Unique Subsystem Products

MicroSat is also starting to offer some of the subsystem technologies that have helped make their satellites extremely capable as stand-alone products. One example is MicroSat’s unique space qualified thin-film solar array that can provide power to a spacecraft from an array that can be stored in a small volume and weighs far less than comparable rigid arrays. MicroSat was able to fly a small demonstration of this technology on TacSat-2 and is looking at several future missions in which this may be used as the primary array.

Another subsystem technology that shows promise is MicroSat’s Intelligent Power and Data Ring (IPDR) avionics architecture. IPDR is a low cost, modular alternative to mission unique, highly specialized, high cost avionics. IPDR provides inputs and outputs for spacecraft components and the payload interface as well as the power management and distribution function. Demonstrations of this technology are planned for the TacSat-3 and TacSat-4 satellites planned for flight in 2008.

The Future of MicroSat?

MicroSat’s future business horizon could include building replenishment satellites for numerous commercial constellations in orbit. MicroSat has already been recognized as one of the finalists for the Orbcomm replenishment, which would start with the purchase of 18 satellites plus an option for 30 more. The company has also been working with Iridium on their early efforts to define how to replace their 80-satellite constellation with the Iridium NEXT system.

MicroSat continues to stretch the missions it can perform with its Road Runner modular bus. MicroSat is currently working on a project with two of the country’s top universities call the Mars Gravity Biosatellite Program. This program is a collaboration between the Massachusetts Institute of Technology (MIT) and the Georgia Institute of Technology Space Systems Design Laboratory. The goal of the Mars Gravity program is to investigate how Martian gravity — about one-third that of Earth — will affect mammalian health, helping to pave the way for human missions to Mars and beyond.

“The opportunity for students to work side-by-side with such a terrific industry collaborator is just amazing,” said Erika Wagner, BioSat program manager at MIT. “MicroSat’s dedication to affordable small satellites and their commitment to education are the perfect fit for Mars Gravity.”

Working together, MicroSat and the Mars Gravity Team aim to launch the small research satellite into low Earth orbit in 2010 for a 5-week mission with a crew of 15 mice on-board. Once in orbit, the satellite will spin, simulating Mars gravity. When the five weeks are completed, the mice will return to Earth in a re-entry capsule. Data gathered on-board and following reentry should provide the first information on how mammals are affected by Mars’ reduced gravity environment.

While MicroSat spent most of the first six years of its company life attempting to get its first mission into space, the next six years hold great promise for flight of two more innovative Department of Defense missions, significant new satellite orders, and even helping to gather biological data that could prove useful as humans look to fly to Mars. MicroSat is an innovative small company worth watching!