The U.S. Air Force has delayed a planned June launch of a small satellite from Wallops Island, Va., until mid-September while it works
to better protect the experimental spacecraft’s hyperspectral sensor during the ride into space, according to the service official overseeing the effort.


The Air Force awarded the contract for the TacSat-3 payload to Raytheon Space and Airborne Systems of El Segundo, Calif., in May 2005 prior to its selection of a launch vehicle for the spacecraft, according to Thom Davis, program manager for TacSat-3 at the Air Force Research Laboratory’s space vehicles directorate, located at Kirtland Air Force Base in New Mexico.


The service awarded a contract in 2006 to Orbital Sciences Corp. of Dulles, Va., to launch both TacSat-2 and TacSat-3 aboard the Minotaur-1 rocket, which features two stages from Minuteman ICBMs, and provides a somewhat rougher ride than some other rockets, Davis said in an April 24 interview.


During testing last summer, program officials found that they needed a stiffer mounting mechanism for the payload’s optical mirror to properly withstand the stress of launch aboard the Minotaur, Davis said. Testing associated with that work also uncovered several other issues that Raytheon resolved in order to reduce the risk of encountering any problems on orbit, he said.


Advanced Responsive Tactically Effective Military Imaging Spectrometer (ARTEMIS)
is of particular interest to military users because of the
ability of hyperspectral sensors to see through enemy camouflage
and natural barriers such as a forest canopy.


The Pentagon had planned at one point to launch TacSat-3 in early 2007, but the launch has been delayed by several
factors including issues with securing sufficient funding to award a contract for the satellite platform.


Davis declined to name the government agency that initially had planned to fund the work, but said that the Air Force later found the money to keep the effort going after the initial customer backed out. The Army also contributed some funding to the TacSat-3 program, he said.


The Air Force awarded the contract for the spacecraft platform to Swales Aerospace in May 2006, a year later than the payload award to Raytheon. In addition to giving Swales a late start, it also complicated Raytheon’s initial work in developing interfaces for the payload with the spacecraft, Davis said.


John Barksdale, a Raytheon spokesman, said
the company has worked closely with the Air Force Research Laboratory on the TacSat-3 effort, and looks forward to demonstrating the advanced capabilities present with the ARTEMIS sensor following the September launch. The company’s work with the Air Force Research Laboratory on the effort has given it valuable experience that can be applied to future Operationally Responsive Space missions, he said.


During development of TacSat-3, program officials took a variety of lessons learned from the military’s experience with TacSat-2, which launched in December 2006, and ceased operations a year later, Davis said. One of those lessons involves securing the proper approval from military and intelligence officials regarding use of TacSat sensors, he said.


The Air Force was unable to use the main sensors aboard TacSat-2 for several months following its launch due to a debate between the military and intelligence community over tasking authority. TacSat-3
currently is going through a formal approval process that was created due to the experience with TacSat-2, and Davis said
he does not expect any holdup in using the sensor.


TacSat-3 officials also chose to space qualify the Common Data Link used aboard TacSat-2, Davis said. The link, which was built by L3 Communications of Salt Lake City,
was designed for aircraft to communicate with the ground.


The link had run into difficulty shortly after launch that limited TacSat-2’s ability to communicate with the ground, but the issue was resolved by a software fix, according to Air Force officials.


Air Force Research Laboratory officials worked with L3 to improve the component’s ability to stand up to the space environment, and envision future changes that could shrink its size from about 30 kilograms today to around 5 or 6 kilograms, Davis said. Officials from the lab and the Operationally Responsive Space program office also envision reducing the data link’s power requirement – currently the highest of any component on the spacecraft – by about 25 percent, he said.

Once TacSat-3 reaches orbit, the military is planning to experiment with different methods of tasking, processing, exploiting and disseminating the data from the spacecraft, according to U.S. Army Lt. Col. James Pruneski, deputy director of the Operationally Responsive Space program office, which
also is located at Kirtland Air Force Base.


The military is planning to analyze the utility of the data from the hyperspectral sensor, and plug it into models that can examine the value of a constellation of satellites with similar capabilities, Pruneski said in an April 21 interview.


While TacSat-3 was designed for experimental purposes, Air Force Space Command has a team looking at possible residual operational capability once the demonstrations conclude, Davis said.