Leasat
Leased Satellite

The Leasat series was developed as a commercial venture to provide dedicated communications services to the U.S. military. The program was initiated as a result of Congressional reviews in 1976 and 1977 which advised increased use of leased commercial facilities. Owned by Hughes Communications, the satellites were designed to provide global UHF communications to military air, sea, and ground forces. The system's primary user is the US Navy, with some support also provided to the Air Force and ground mobile forces (using FLTSATCOM terminals). Hughes was paid $84M per year for each operational satellite. At the end of each satellites' designed 7 year life, the Navy has the option of purchasing the satellite for $15M. The Leasats, along with the Navy's FLTSATCOM spacecraft, are being replaced by the UFO (UHF Follow-on) spacecraft.

Spacecraft
Hughes HS-381 bus. Spin stabilized at 30 rpm with despun communications and antenna section. Body mounted solar cells provide 1500 W BOL and NiCd batteries provide power in eclipse. Solid rocket motor for perigee burn, bipropellant system for apogee burn. Hydrazine system for station-keeping. The design is optimized for Shuttle launch and deployment.

Payload
Five antennas on the despun platform provide full Earth coverage. Two UHF helices (30 cm diameter, 3.8 m long) one transmit, one receive. Two X-Band horns (one beacon, one receive). One omni TT&C antenna. Channel 1: X-Band uplink, UHF downlink, 25 kHz bandwidth for fleet broadcast using spread-spectrum anti-jamming protection. Channel 2: UHF, 500 kHz bandwidth. Channels 3 to 8: UHF, 25 kHz bandwidth. Channels 9 to 13: UHF, 5 kHz bandwidth.

Country of Origin	United States
Customer/User	USAF, US Navy, DCA
Manufacturer(s)	Hughes
Size	Cylinder: 4.2 m diameter, 2.7 m tall
Orbit	Geosynchronous
Design Life	7 years

Launch Facts

Name	Int'l Desig.	Date	Site	Vehicle	Orbit	Mass(kg)
Notes
Leasat 1 (Syncom 4-2)	1984-093C	8/30/84	ESMC	STS 41D	GEO	1315
Released from STS 41D 8/31/84; 105 deg W; leased to U.S. government
Leasat 2 (Syncom 4-1)	1984-113C	11/8/84	ESMC	STS 51A	GEO	1315
Released from STS 51A 11/10/84; 105 deg W; leased to U.S. government
Leasat 3 (Syncom 4-3)	1985-028C	4/12/85	ESMC	STS 51D	LEO	1315
Released by STS 51D 4/13/85; failed to orbit and subsequently repaired by STS 51-I on 8/31/85; 178 deg E; leased by U.S. government
Leasat 4 (Syncom 4-4)	1985-076D	8/27/85	ESMC	STS 51I	GEO	1388
Released by STS 51I 8/29/85; 178 deg E; leased by U.S. government
Leasat 5 (Syncom 4-5)	1990-002B	1/9/90	ESMC	STS 32	GEO	7711
Deployed from STS 32 1/10/89; 177 deg W; leased to U.S. government