As the Pentagon studies what its military satellite communications architecture will be in light of dwindling funding, engineers at Lockheed Martin are preparing the first new-generation anti-jam military communications satellite for launch early next year.

The initial Advanced Extremely High Frequency (AEHF) satellite will mark a dramatic change in the capacity of secure communications available to Pentagon users between 65 deg. N and 65 deg. S latitudes. It's expected to be launched on an Atlas V next January.

Lockheed Martin is conducting the final series of tests on the spacecraft while, in Washington, Pentagon officials are reviewing plans for the entire future milsatcom architecture. Air Force officials hope to craft a fiscally realistic plan for the successor to AEHF, the Transformational Satellite (TSAT) program, understanding that funds will continue to be diverted to support operations in Iraq and Afghanistan.

The government has provided about $500 million each to Boeing and Lockheed Martin to develop TSAT designs, which are expected to incorporate highly secure laser links. They will transmit massive amounts of data using lightwaves rather than radio frequencies. TSAT is also expected to make use of Internet protocol routing, essentially providing a secure Internet in the sky.

The initial operational capability for TSAT - one of then-Defense Secretary Donald Rumsfeld's "transformational" programs designed to exploit leaps in technology - is expected to slip, possibly to 2018, according to a senior Air Force official. Plans originally called for a 2009 first launch, or earlier. Now contractors' work has been extended to June, at which time they hope to have direction from the Air Force on how to proceed.

Boeing and Lockheed Martin have both submitted proposals for the TSAT development contract, but a downselect date is uncertain. Despite a $150-million cut in the Fiscal 2008 TSAT budget, Air Force officials at the Milsatcom program office say funding is still available for a decision by October. However, a cut of roughly $3.9 billion through 2013 has left planners scrambling to figure out how to field as much advanced technology with TSAT as possible, given a resource shortage.

"The Department of Defense is reassessing the optimal strategy for satisfying future satellite communication requirements in light of economic realities, program interrelationships and user demand for these services," according to officials at the Milsatcom program office at Los Angeles AFB, Calif. "Until this assessment is complete, the long-term TSAT program schedule remains to be determined."

AEHF will replace the Milstar constellation now in orbit. The last Milstar was lofted in April 2003. AEHF Space Vehicle-1 (SV-1) will be "backward compatible" with the Milstar constellation, meaning it will be capable of cross-linking - or transmitting data in space - to Milstar spacecraft until the full complement of AEHF satellites reaches orbit. SV-1 will also be compatible with Milstar terminals now in the field with ground units, including special operators; AEHF signals employ a low-probably-of-intercept and -detection capability as well.

Lockheed Martin says its AEHF will provide 10 times the capacity and six times the channel data rates over what is offered by the most advanced Milstar satellites today. AEHF will add a "higher data rate" to the low- and medium-rate modes on Milstar II, the most recent "block" of that system. The higher data rate will allow for transmission of up to 8.2 Mbps. to future AEHF Army terminals.

One mechanical challenge remains for the AEHF SV-1. Lockheed Martin plans to install a redesigned reaction wheel onto the spacecraft later this year. The same device experienced a premature in-orbit failure on a NASA spacecraft, prompting the company to look for improvements before launching the communications system next year, says Leonard Kwiatkowski, vice president of Lockheed Martin global communications systems. "While we have redundancy - we have four - everybody wants to ensure our mission life will last," he adds. "Before we and the Air Force feel comfortable, we've got to go exonerate the heritage of our parts to make sure they are satisfactory." Spacecraft have flown successfully without reaction wheels, he says, but AEHF is not designed to do it. Because the problem was discovered after the bulk of AEHF SV-1 was finished, a single company is able to supply a new reaction wheel.