Orbcomm

Orbcomm satellites are low Earth orbit communications satellites, operated by the United States satellite communications company Orbcomm, Inc. As of 2008, 44 such satellites are in orbit.

Satellite types

Orbcomm-CDS

Orbcomm-CDS (Concept or Capability Demonstration Satellites) are spacecraft which were launched to test equipment and communication techniques used by the other satellites. The first three CDS satellites, Orbcomm-X, CDS-1 and CDS-2, were launched before any operational satellites, in order to validate the systems to be used in the operational constellation.

Orbcomm-X, also known as Datacomm-X, was launched in 1991. It carried communications and GPS experiments, but failed to contact or respond to ground controllers after launch.^[1]

CDS-3 is an operational satellite, launched in 2008, which also carries experiments for relaying signals from the United States Coast Guard Automatic Identification System through the satellite constellation.^[2] As an operational satellite, it is designated Orbcomm FM-29,^[2] the designation of an unlaunched satellite, which later became TacSat-1.

Orbcomm-1

Orbcomm-1 satellites make up most of the current Orbcomm constellation. 43 were built, of which 35 were launched, and one more, Orbcomm FM-29, was rebuilt as TacSat-1 for the United States military.^[1]

Orbcomm-QL

Orbcomm Quick Launch (QL) satellites are satellites which were intended to replenish the constellation. The first five such satellites were launched in 2008, with at least one more to follow at a later date. The satellites are based on the CDS-3 satellite, which was launched on the same rocket as the first five QL spacecraft. The sixth will be launched as a secondary payload to a Russian Government satellite, also on a Kosmos-3M. Orbcomm holds options for two further satellites.^[3] The satellites experienced a power system anomaly, and Orbcomm said it believes that all of six of the satellites launched eventually will fail and that the company will be unable to recover them.^[4]

Orbcomm-G2

Orbcomm Generation 2 (OG2) satellites are intended to supplement and eventually replace the current first generation constellation. As of October 2008^[update], eighteen satellites had been ordered, which were planned to be launched in three groups of six between 2010 and 2014. At that time, Orbcomm held options for a further thirty OG2 spacecraft.^[5] The satellites will be launched by SpaceX, using Falcon 1e rockets.^[6]

The first two second-generation messaging service satellites will be launched in 2011 as secondary payload on a SpaceX Falcon 9 flight on which the primary mission contractor is NASA (second demonstration test launch of the Dragon spacecraft).^[7]

"The ORBCOMM OG2 satellites are being manufactured by an industry team led by Sierra Nevada Corp and Boeing’s Argon ST subsidiary. A total of 18 ORBCOMM next-generation OG2 satellites are currently in production. ORBCOMM OG2 satellites will offer enhanced ORBCOMM messaging capabilities, increased capacity, and automatic identification systems (AIS) service. The planned Falcon 9 launch will place ORBCOMM’s first two OG2 satellites into a 52° inclined 350 by 750 km insertion orbit. The satellites’ onboard propulsion systems will then be used to circulize the orbit at 750 kilometres (470 mi)."^[8]

Launches

See also

• Globalstar
• Iridium Satellite LLC

References