MUOS 1

Spacecraft n°:

US spacecraft n°:

Launch data: Designation  38093 / 12009A Launch date  24 Feb 2011 - 22:15 UT Launch site  CC, SLC-41 Launch vehicle  Atlas-V(551) (AV-030) Mission  Military: Communication Geostationary orbit: Perigee / Apogee  35800 x 35800 km Eccentricity  0,00E+00 Inclination  0 deg Period  1436.1 min

Credit: Lockheed Martin

Spacecraft data: Prime manufacturer  Lockheed Martin (Prime), Boeing, General Dynamics Platform  A2100M Operator  DoD/US Navy Mass at launch  6740 kg (fully fuelled) Dry Mass  3812 kg Basic shape  Box + 2 panels + 2 dishes Dimension (m)  6.70x3.66x1.83m  dishes dia. 14.0m Equipment   Solar array  2 panels, span: 27.50m Stabilization   Propulsion  IHI BT-4 DC power  2 deployable solar arrays Design lifetime  > million years

Orbital slots for MUOS satellites. Credit: Lockheed Martin

Description:

• MUOS (Mobile User Objective System) is a next-generation narrowband tactical satellite communications system designed to significantly improve ground communications for U.S. forces on the move.
• MUOS will offer 10 times greater communications capacity to the mobile warfighter over the Navy's current generation of Ultra High Frequency Follow-On spacecraft to relay narrowband tactical information such as voice calls, data messaging, file transfers and email on rates of up to 384 Kilobits per second. From its eventual spot in geosynchronous orbit, matching Earth's rotation to hover in a parking spot 22,300 miles (35,888 km) up, the expansive footprint of MUOS 1 will cover a huge swath of the planet to serve ships, submarines, aircraft, land vehicles and terminals in the hands of troops.
• Under the new system, even troops in the most remote locations or buildings with no satellite access would see a big increase in communications capabilities, industry sources said.
• In its launch configuration with the two power-generating solar arrays stowed on the sides, MUOS is 22 feet tall, 12 feet wide and 6 feet deep.
• A pair of gold mesh antenna reflectors, built by Harris Corp., at the heart of the satellite's communications payload will be unfurled like umbrellas on deployable boom assemblies once in space. Coverage to legacy users will transmit through a 17.7-foot-diameter reflector on the bottom of the craft and the advanced, multi-beam features of MUOS to significantly increase the transmission capacity over the Navy's previous satellites will use a large 46-foot reflector atop the satellite.
• Lockheed Martin is producing five MUOS satellites, four primes and one in-orbit spare, to replace the Navy's current generation of Ultra High Frequency Follow-On spacecraft that were launched by Atlas rockets from 1993 through 2003. Eight of the 11 satellites remain in operation today.
• Following UHF comms experiments with Lincoln Lab's LES satellites in the 1960s, the US Navy began using the UHF payload on the Tacsat satellite (1969-1972). This was followed by the Marisat Gapfiller payloads (from 1976), the FLTSATCOM system (from 1978) and the 'UHF Follow-On' system (from 1993), which the MUOS system will supersede.
• The planned launch of the first MUOS satellite was delayed to 2012 after a part of the budget was used to fund operations in Iraq.
• Four primary satellites and one orbiting spare will comprise the MUOS system as it is fielded over the next few years to augment and then replace the Navy's aging Ultra High Frequency spacecraft constellation. Orbital parameters estimated.

Mission details:

• Soaring away from Cape Canaveral's Complex 41 at 5:15 p.m. EST (2215 GMT) on Feb 24, the Atlas 5 rocket sped towards space carrying the Mobile User Objective System 1 satellite.
• MUOS 1 became the heaviest payload ever launched by an Atlas rocket in more than 600 launches under the venerable booster's name, weighing nearly 15,000 pounds (6740 kg). The launch also marked the milestone 200th flight for the dependable Centaur upper stage, which conducted three critical firings over the course of three hours to position MUOS 1 into the proper orbit to score a successful launch.
• Just off the western coast of Africa, the Centaur main engine was restarted about 20 minutes after launch to propel MUOS to the second step on its way to the planned orbit. This six-minute burn put the rocket into a 120 by 21,400 statute mile orbit inclined 26 degrees.
• Then began a lengthy coast away from the planet for two-and-a-half hours, flying to a point about 17,000 statute miles above the far eastern Indian Ocean where the final burn would occur.
• One final push was given nearly two hours and 57 minutes into flight to raise the orbit's low point and reduce the inclination closer to the equator. The burn, lasting less than a minute, placed the payload into a 2,150 by 22,237 statute mile orbit at 19 degrees inclination.
• The satellite separated from Centaur at 8:16 p.m. EST (0116 GMT) to complete a highly successful launch, the first of 2012 for Atlas and 29th overall in the program's 9-year history.
  
  

  Illustration of the MUOS orbit raising plan. Credit: Lockheed Martin

  
  
• The MUOS payload was delivered to a 3463 x 35786 km x 19.0 deg transfer orbit.
• Deployment of the craft's power-generating solar arrays has occurred, now spanning more than 90 feet, and the pair of antenna reflectors on boom assemblies took place as planned.
• The cover name USA 234 as been given to the NROL 25 satellite (2012-014a) - implying that the MUOS satellite doesn't get a USA number for some reason.