Space

Pakistan and Satellite Communication Systems

Pakistan has experimented with basic store/dump communications relays in LEO.

With support from the Pakistan Amateur Radio Society, SUPARCO started building a small amateur radio satellite in late 1986. It was called Badr, after the Urdu language word for "new moon." This first satellite, Badr-1 or Badr-A, was to have launched on the US Space Shuttle, but the plan changed after the 1986 Challenger explosion delayed American flights. SUPARCO's first satellite BADR-A was launched as a secondary payload into low orbit by a Chinese LM-2E booster on 16 July 1990. Originally designed for a nearly circular orbit of 400-500 km, Badr-1 was inserted into an orbit of 205 km by 990 km.

Intended to provide technical experience in telemetry, control, transponder and digital communications in preparation for further launches, the 150-lb satellite provided valuable data for 5 weeks After contact with the vehicle ceased on 20 August, all efforts to restore contact with the missing satellite failed. However, during its short mission, the satellite successfully completed store/dump message tests. Badr-A carried a digital communications system patterned on the British amateur radio satellite UO-11 launched in 1984. Badr-1 offered one radio channel for digital store-and-forward communications. Uplink was near 435 MHz, downlink was near 145 MHz, and the telemetry beacon was near 145 MHz. Badr-1's orbit was so low it reentered the Earth's atmosphere after 146 days, on 09 December 1990.

Although Pakistan has expressed an interest to develop a GEO communications system, the country was still several years away from deploying the first satellite. The Pakistan GEO constellation was being designed with a capacity of 4,800 long distance telephone channels, 2,400 rural circuits, and two direct broadcast television channels in the 14/11 GHz band. PAKSAT GEO locations near 38 degrees E and 41 degrees E are planned (References 221-222). The first satellite – PAKSAT-1 – was first owned by the international aircraft manufacturing company, Boeing. Manufactured by an American company, the communication satellite was handed to Indonesia which abandoned it sometime later due to technical reasons. Pakistan then acquired the same satellite PAKSAT-1 on lease. Unlike PAKSAT-1R, PAKSAT-1 did not have high-powered frequency adjustment, broadcasting coverage, data carrying and signal relaying features.

At 00:15'04, August 12th, 2011 (Beijing Time), the Pakistan Communications Satellite 1R (PakSat-1R) owned by Pakistan Space & Upper Atmosphere Research Commission (SUPARCO) was launched from Xichang Satellite Launch Center (XSLC) aboard a Long March 3B launch vehicle (LM-3B or CZ-3B) and successfully entered into the pre-determined orbit. It was the first time for China aerospace industry to export a communications satellite to an Asian customer on an in-orbit delivery basis.

About 1542 seconds after the LM-3B lift-off, the orbital parameters received by Xi’an Satellite Control Center (XSCC) showed that the launch vehicle and spacecraft separated normally and the satellite entered into a super Geo-stationary Transfer Orbit with an apogee of 41985.18km, a perigee of 203.72 km and an inclination of 24.79. The launch was declared a mission success.

PakSat-1R, with a lift-off mass of 5119.5 kg, was based on Dong Fang Hong 4 (DFH-4) satellite platform manufactured by China Academy of Space Technology (CAST), a subsidiary of China Aerospace Science & Technology Corporation (CASC). Its payload includes 30 transponders (12 C band and 18 Ku band) and three antennas. The satellite beams cover the cities and regions in South Asia, the Middle East, Eastern Africa and a part of Europe areas and cities. The satellite service life was 15 years and its end-of-life power was 7.75KW. The Customer Furnished Items (CFI) developed by SUPARCO are also on-board the Satellite to verify SUPARCO’ s satellite development capability.

The LM-3B launch vehicle used for this launch mission was developed by China Academy of Launch Vehicle Technology (CALT), a subsidiary of CASC. LM-3B was China’s most powerful launch vehicle for GTO mission,capable of launching a payload up to 5,500 kg into standard GTO. This was the 15th launch of LM-3B and the 143rd launch of the Long March family.

The launch of PakSat-1R was conducted on an In-orbit delivery basis according to the PakSat-1R Communications Satellite System Contract signed by and between China Great Wall Industry Corporation (CGWIC) subordinated to CASC, and SUPARCO on October 15th, 2008 in Beijing, China. According to the Contract, CGWIC, Prime Contractor, together with its subcontractors, CALT, CAST and China Satellite Launch and Tracking Control General (CLTC) shall deliver this large powerful communications satellite into orbit, related training services and two TT&C ground stations located in Lahore and Karachi to SUPARCO.

PakSat-1R performed a series of orbit maneuvers under the control of XSCC before reaching its final orbital position of 38 degree East longitude over the equator. It would be delivered to Pakistan after in-orbit tests, and thus to satisfy the needs of Pakistan in telecommunications, broadcasting and broadband multimedia services etc.

PakSat-1R was the third communications satellite delivered to its international customers on an in-orbit delivery basis by China space industry, and it was also the second space program between China and Pakistan after the piggy-back launch of BADR-A by an LM-2E on July 16,1990. PakSat-1R program was a major milestone event for space cooperation between the two countries.