The U.S. Air Force Academy has shuffled the payload on its next cadet-built satellite after funding issues forced it to take on a second major sponsor with different research priorities

, according to a school official overseeing the project.

The satellite will carry a suite of space-environment sensors as originally planned, but a propulsion experiment has been dropped in favor of an avionics payload at the request of the new sponsor, said Lt. Col. Timothy Lawrence, director of the Space Systems Research Center in the Astronautics Department at the Air Force Academy in Colorado Springs, Colo.

That sponsor, the Air Force Research Laboratory,

was not interested in the propulsion experiment and made the switch a condition of coming on board in February, he said.

The primary sponsor of the mission originally was

the Air Force Space and Missile Systems Center’s Space Development and Test Wing, which is responsible for finding rides to space for experiments proposed by

various Defense Department organizations.


called for the wing, based at Kirtland Air Force Base, N.M., to fund both construction and launch of the Air Force Academy satellite. But the wing informed the academy in December that it only had enough funding to possibly cover the launch, Lawrence said.

The satellite’s name was changed from

Falconsat-4 to

Falconsat-5 to reflect the payload swap, Lawrence said in an interview. The Air Force Academy still might launch the propulsion experiment – designed to help pave the way for highly maneuverable satellites that would be able to respond to the immediate needs of troops in the field – at some future date, he said.

For now, however, the focus is on Falconsat-5, which is a candidate for a fall 2009 launch aboard a Minotaur rocket, a vehicle based in part on excess ICBM motors assembled by Orbital Sciences Corp. of Dulles, Va. The Air Force Academy’s last cadet-built satellite, Falconsat-3, was launched in March along with several other experiments aboard the secondary payload adapter ring on an Atlas 5 rocket.

Falconsat-5 will include two space environment sensors to demonstrate capabilities that could be incorporated into future military satellites, Lawrence said. The Smart Miniaturized Electrostatic Analyzer (MESA) is designed to detect and predict bubbles of plasma, or charged particles, in space that could interfere with satellite signals, he said. It is more advanced than the MESA sensor aboard Falconsat-3 because it will process its own data rather than rely on other systems either on the spacecraft or on the ground, he said.

Falconsat-5’s Wafer-Integrated Spectrometer, meanwhile, is designed to detect propulsion exhaust from other spacecraft, Lawrence said. This capability could alert spacecraft operators to the presence of another, potentially hostile, spacecraft maneuvering nearby, he said.

Details of the experimental avionics payload requested by the Air Force Research Laboratory

still are being worked out, Lawrence said


The cost of the revamped Falconsat-5 is expected to be $2.3 million, not including the launch, Lawrence said.

Air Force Undersecretary Ron Sega has taken note of the Air Force Academy’s work on small satellites, saying in a recent interview that this type of activity helps train the next generation of U.S. military space professionals.

Lawrence agreed. He said that while the cadet-designed satellites

represent competition for other military customers seeking rides into space, their value goes well beyond the onboard experiments: Such missions give

future Air Force officers critical experience managing space program budgets, schedules and requirements.

In addition to designing satellites, academy cadets are working on launch vehicle technology with the help of a program begun in 2003 that supports annual suborbital missions.

The cadets designed, built and launched a suborbital rocket from Wallops Island in Virginia

May 22, with hopes that the rocket would achieve a speed of Mach 5 and an altitude of approximately 60,000 meters, Lawrence said. However, the rocket lost a fin, causing it to lose stability after reaching a speed of Mach 3.8 and an altitude of about 4,420 meters, he said.