On April 28, 1993, the Chinese Great Wall Industrial Corporation and Motorola signed a launch services contract for multiple launch of Iridium communications satellites using CZ-2C/SD launch vehicles. The main differences between the CZ-2C and the CZ-2C/SD were: a modified fairing with a diameter of 3.35m; a newly developed Smart Dispenser; improved second stage fuel and oxidizer tanks; and second stage engines with higher expansion ratio nozzles. The Smart Dispenser included a solid rocket kick motor for insertion of the Iridium satellites into a 780 km circular orbit. Each CZ-2C/SD had the capacity of delivering two Iridium system satellites. A successful CZ-2C/SD demonstration launch was conducted from Taiyuan on September 1, 1997. The first three deployment launches for the Iridium program were successfully conducted on December 8, 1997, March 26, 1998 and May 2, 1998.

Payload: 1,400 kg. to a: 780 km, 86 deg inclination orbital trajectory. Liftoff Thrust: 302,000 kgf. Total Mass: 213,000 kg. Core Diameter: 3.4 m. Total Length: 40.4 m. Launch Price $: 25.00 million. in 1999 price dollars.

• Stage Number: 1. 1 x CZ-2C-1 Gross Mass: 153,000 kg. Empty Mass: 10,000 kg. Thrust (vac): 336,000 kgf. Isp: 291 sec. Burn time: 122 sec. Isp(sl): 261 sec. Diameter: 3.4 m. Span: 6.0 m. Length: 20.5 m. Propellants: N2O4/UDMH No Engines: 4. YF-20A

• Stage Number: 2. 1 x CZ-2C/SD-2 Gross Mass: 55,000 kg. Empty Mass: 5,000 kg. Thrust (vac): 77,700 kgf. Isp: 298 sec. Burn time: 190 sec. Isp(sl): 270 sec. Diameter: 3.4 m. Span: 3.4 m. Length: 10.0 m. Propellants: N2O4/UDMH No Engines: 1. YF-22A/23A

• Iridium Spacecraft: LM 700. Payload: Iridium s/n MFS 1. Mass: 689 kg.

  Plane 5. Ascending node 271.9 degrees. Dummy satellite.

• Iridium Spacecraft: LM 700. Payload: Iridium s/n MFS 2. Mass: 689 kg.

  Plane 5. Ascending node 272 degrees. Dummy satellite.

• Iridium 42 Spacecraft: LM 700. Payload: Iridium s/n SV042. Mass: 689 kg.

  Plane 6. Ascending node 325.8 degrees.

• Iridium 44 Spacecraft: LM 700. Payload: Iridium s/n SV044. Mass: 689 kg.

  Plane 6. Ascending node 325.8 degrees. Not in service.

• Iridium 51 Spacecraft: LM 700. Payload: Iridium s/n SV051. Mass: 689 kg.

  Plane 4. Ascending node 262.5 degrees. Not in service.

• Iridium 61 Spacecraft: LM 700. Payload: Iridium s/n SV061. Mass: 689 kg.

  Plane 4. Ascending node 262.5 degrees.

• Iridium 69 Spacecraft: LM 700. Payload: Iridium s/n SV069. Mass: 689 kg.

  Plane 2. Ascending node 199.4 degrees. Not in service.

• Iridium 71 Spacecraft: LM 700. Payload: Iridium s/n SV071. Mass: 689 kg.

  Plane 2. Ascending node 199.3 degrees. Not in service.

• Iridium 76 Spacecraft: LM 700. Payload: Iridium s/n SV076. Mass: 689 kg.

  Plane 2. Ascending node 199.4 degrees.

• Iridium 3 Spacecraft: LM 700. Payload: Iridium s/n SV078. Mass: 689 kg.

  Plane 2. Ascending node 199.4 degrees.

• Iridium 20 Spacecraft: LM 700. Payload: Iridium s/n SV089?. Mass: 689 kg.

  Plane 2. Ascending node 197.2 degrees. Parking orbit.

• Iridium 11 Spacecraft: LM 700. Payload: Iridium s/n SV088?. Mass: 689 kg.

  Plane 2. Ascending node 197 degrees. Parking orbit.

• Iridium 14A Spacecraft: LM 700.

• Iridium 21A Spacecraft: LM 700.

• 455 - Isakowitz, Steven J,, International Reference to Space Launch Systems Third Edition, AIAA, Washington DC, 2000.