Failure Puts Navy Satellite Off Orbit

The U.S. Navy's fourth Mobile User Objective System (MUOS) satellite at Cape Canaveral's Space Launch Complex-41. (Photo courtesy United Launch Alliance/Released)
The U.S. Navy's fourth Mobile User Objective System (MUOS) satellite at Cape Canaveral's Space Launch Complex-41. (Photo courtesy United Launch Alliance/Released)

The Navy is trying to remedy an orbital failure on a "next generation" military communications satellite launched June 24 that was supposed to reach geosynchronous orbit 22,000 miles above Hawaii for testing.

Instead, the Navy last week said the fifth Mobile User Objective System satellite, known as MUOS-5, experienced a propulsion system failure that prevented the satellite from moving from elliptical orbit to its final geosynchronous orbit.

"The MUOS-5 satellite is currently stable, safe and under positive control," the Navy's Program Executive Office for Space Systems in San Diego said in a news release.

The Navy added that the "MUOS team is continuing to evaluate the situation, considering alternate orbit adjustment options, calculating mission impact and investigating all options before proceeding."

Spaceflight Now reported that the 15,000-pound satellite, which cost $340 million, is more than 12,000 miles away from a usable orbit.

MUOS-5 was launched as an in-orbit "spare" to provide "immediate redundancy" to the MUOS constellation, which includes four other satellites that will soon provide cellphonelike communications for the Defense Department, the Navy said.

The Navy said the "delay" in the satellite reaching its test orbit location has no impact on military communications.

Hawaii figures prominently in the MUOS system, with the first of four ground stations around the world with three 60-foot antenna dishes on 53-foot pedestals built in 2008 at Naval Computer and Telecommunications Area Master Station Pacific in Wahiawa. Other ground stations are in Virginia, Australia and Italy.

"MUOS covers everywhere," said General Dynamics, which led the deployment of the ground system, in a fact sheet. "It has a worldwide reach to support warfighters on patrol in hostile environments, whether urban, canyon, mountains or jungles."

The system was successfully demonstrated during a Navy submarine Arctic exercise and at McMurdo Station, Antarctica.

MUOS will replace the military's current narrow-band tactical satellite communications system, known as the Ultra High Frequency Follow-on system, General Dynamics said. The newer system "offers crystal clear, cellphone-quality voice communications" at 10 times the capacity of the "legacy" constellation, with a single MUOS satellite providing four times the capacity of the entire legacy system of eight satellites, the company said.

The MUOS satellites, which were launched with payloads to support continuing use of the older technology, adapt commercial Wideband Code Division Multiple Access 3G cell technology that uses the geosynchronous satellites as very tall "towers" to provide more capable military communications.

The first terminal to use the new waveform was the Army's Handheld Manpack radio, which in early 2013 completed the first voice and data calls using the MUOS-1 satellite routed through the Wahiawa ground station.

Earlier this year the Army in Hawaii tested the new satellite system with a logistics support vessel and soldiers in five locations on land and at sea who were able to talk, text, share data and track the ship's progress. With the additional bandwidth that MUOS provides, U.S. Army Pacific units that deploy to Southeast Asia -- where there is limited bandwidth -- can stay connected, the Army said.

Messages bouncing between radio, satellite and ground stations arrive in less than 1-1/2 seconds -- even after traveling more than 100,000 miles, the Army said. The new system is particularly applicable to the vast distances in the Pacific.

"MUOS fills an urgent need for additional tactical satellite (capability) within the Pacific," Lt. Col. Joseph Pishock, the 25th Infantry Division's communications officer, said at the time in an Army-produced news story. "There currently are not enough channels to support units deployed into the Asia-Pacific theater reliably."

MUOS-5 was to be eventually moved over the Indian Ocean to operate alongside MUOS-4, Spaceflight Now said.

Show Full Article

Related Topics

US Navy Topics Satellites