WASHINGTON — A soldering problem has delayed completion of the third satellite in the U.S. Navy’s next-generation mobile satellite communications system, prompting a change in the constellation’s launch order, according to a top executive from, prime contractor on the program.
Because of the delay, Lockheed Martin and the Navy plan to move the fourth satellite in the Mobile User Objective System ahead of the third satellite in the launch queue. The launch of the fourth satellite is now slated for January 2015.
Previously the third satellite was expected to launch in late 2014. It is now unclear when the satellite will launch.
The soldering issue was discovered last spring during thermal vacuum testing on a component of thelegacy UHF payload provided by Boeing Space and Intelligence Systems of El Segundo, Calif. Boeing, which built the Navy’s earlier-generation UHF Follow-On mobile communications satellites, is a subcontractor to Lockheed Martin on MUOS.
During the test, the payload unexpectedly shut down and an investigation followed. The component is now being replaced.
Navy and Lockheed Martin officials said the problem is not expected to significantly delay MUOS deployment.
“This discovery should not keep the MUOS constellation from being ready for full operational capability,” Lockheed Martin said in a March 11 statement provided to SpaceNews.
The MUOS program encompasses four on-orbit satellites, one on-orbit spare and four ground stations. Two MUOS satellites have been launched to date.
The program is expected to achieve full operational capability in 2017 and provide service through 2025.
Mark Valerio, Lockheed Martin vice president of military space business, said in an interview at the Satellite 2014 conference here that Lockheed Martin would recommend the third satellite move to the end of the launch order and become the on-orbit spare.
Lockheed Martin and Navy officials said the MUOS satellites, which were ordered as part of a block buy, are interchangeable. Once the problem was discovered, Valerio said, Lockheed pulled the third satellite out of the assembly line and accelerated the production rate for the fourth.
Shuffling the MUOS launch schedule will not have cost implications for the program, John Zangardi, deputy assistant secretary of the Navy, told members of the Senate Armed Services strategic forces subcommittee during a March 12 hearing.
“Since we have gained efficiencies in production, we will maintain a launch schedule that positions the program for full operational capability on time, though the Navy coordinates launch dates,” the Lockheed Martin statement said. “The next satellite will be ready to ship for launch later this year, and the following one will be ready to ship in early 2015.”
Diana Ball, a spokeswoman for Boeing, said the problem affected one component on one payload and did not impact the two other satellites in production. “Boeing is committed to delivering high-quality, mission-compliant products, and is working closely with Lockheed to correct the issue,” she wrote in a March 12 email.
Meanwhile, more than 90 percent of the first MUOS satellite’s on-orbit capabilities are being underutilized because of delays with the terminal program, according to Cristina Chaplain, director of acquisition and sourcing management of the U.S. Government Accountability Office.
“Military forces are relying on legacy communication terminals and are not able to take advantage of the superior capabilities offered by the MUOS satellites,” Chaplain said in written testimony submitted to the strategic forces subcommittee.
Zangardi’s written testimony said the Army expects to field MUOS-capable Manpack radios as early as fiscal year 2015, which begins Oct. 1. The Navy expects to have 196 digital modular radios fielded by 2020. Three vendors are expected to begin using Navy test labs this month to develop terminals, Zangardi said.
Zangardi said the next major milestone for the MUOS program is an operational test later this year involving the terminals, ground stations and satellites. The final ground station, in Niscemi, Sicily, whose construction was delayed by local protests, is now expected to be completed by the end of the year.