Minotaur 4 Launches FASTRAC, STPSat-2, FASTSAT and FalconSat-5

Four satellites sit atop the Minotaur 4 rocket that launched them into space Nov. 19.

Clockwise from bottom are FASTRAC, STPSat-2, FASTSAT and FalconSat-5. Credit: NASA/Lou Hernandez/Air Force Space & Missile Systems Center

Built by the Virginia-based company Orbital Sciences, Corp., the Minotaur 4 rocket is expected to deliver all seven satellites, which carry a total of 16 separate experiments among them, to an orbit about 404 miles (650 kilometers) above Earth. The $170 million mission, STP-S26, is part of the Air Force's Space Test Program.
The payload on board:
FASTSATThis NASA craft — short for Fast, Affordable Science and Technology Satellite — weighs about 325 pounds (148 kilograms) and is about the size of a washing machine. It's part of a broader NASA effort to find ways to perform research in space cheaply and reliably.
The agency spent less than $12 million developing the spacecraft, agency officials have said.
FASTSAT is carrying six different scientific experiments. One of those is a smaller satellite called NanoSail-D, an 8.5-pound (3.9-kg) probe designed to eject from FASTSAT and deploy a solar sail in orbit. Solar sails catch photons from the sun much as ships' sails catch the wind.
NanoSail-D will use its solar sail to deorbit itself, potentially demonstrating a new way to bring satellites and debris back to Earth without any chemical propellant, NASA officials have said.
Also onboard FASTSAT are three NASA instruments designed to monitor space weather, as well as two payloads managed by the U.S. Air Force. One is a low-cost star-tracking instrument, and the other is a device that will evaluate techniques used to measure how beams of light move through Earth's atmosphere.
O/OREOS
NASA's O/OREOS (Organism/Organic Exposure to Orbital Stresses) is another demonstration satellite that was developed on the cheap (less than $1.75 million, officials have said).
O/OREOS is about the size of a loaf of bread and weighs 12 pounds (5.5 kg). It contains two experiments that will activate once the nanosatellite reaches low-Earth orbit.
One of these will characterize how microbes grow and reproduce in space, as well as how they adapt to the stresses of the space environment. The other will look at how space conditions affect four different classes of organic molecules, which are the building blocks of life.
STPSat-2
This U.S. Air Force microsatellite is the Minotaur 4's primary payload. STPSat-2 carries two payloads of its own: the Ocean Data Telemetry Microsat Link, which will relay data from ocean and terrestrial sensors, and the Space Phenomenology Experiment, which will evaluate sensor compatibility in space.

STPSat-2 will be the first satellite operated by a new command and control system called the Multi-Mission Space Operations Center. This ground system is designed to fly multiple constellations of spacecraft with various missions.

FASTRAC, FalconSat-5 and RAX.Also aboard the Minotaur are three other satellites called FASTRAC, FalconSat-5 and RAX.
FASTRAC — short for Formation Autonomy Spacecraft with Thrust, Relnav, Attitude and Crosslink —was developed by grad students and undergrads at the University of Texas, Austin.
FASTRAC consists of two satellites, each about the size of two car tires, that will separate from each other in orbit to demonstrate communication and coordination capabilities.
FalconSat-5 was also built by students — cadets at the U.S. Air Force Academy in Colorado Springs, Colo. The $11 million microsatellite carries several different payloads, which will monitor space weather and its effects on radio signals.
The Radio Aurora Explorer, or RAX, is a 6-pound (2.8-kg) nanosatellite. It's a joint effort of the University of Michigan and SRI International, and it's sponsored by the U.S. National Science Foundation.
RAX's primary mission is to study dense plasma clouds in Earth's upper atmosphere. These clouds can disrupt communication between Earth and orbiting spacecraft, and RAX's operators hope the little satellite's measurements can help minimize communication problems in the future.
All of these satellites — from FASTSAT to RAX — are launching as part of the U.S. Department of Defense's Space Test Program, which is managed by the Air Force.