# DFH-4
DFH-4 (Dong Fang Hong 4) is a large geostationary communications satellite bus (the standard service module platform shared by different satellites) developed by the [China Academy of Space Technology](https://www.edgepedia.org/china-academy-of-space-technology) (CAST), designed for communications, direct broadcast, data relay, and high-orbit remote sensing missions and sold internationally through China Great Wall Industry Corporation (CGWIC).[1](https://www.cast.cn/news/2884) CAST describes it as a new-generation large satellite bus with large capacity and long life, usable for communications, direct broadcast, data relay, and high-orbit remote sensing satellites.[1](https://www.cast.cn/news/2884)
| Key fact | Value |
|---|---|
| Lift-off mass | 5,200 kg nominal; 5,000–5,300 kg range[2](https://www.cgwic.com/In-OrbitDelivery/CommunicationsSatellite/DFH-4Bus.html) • [1](https://www.cast.cn/news/2884) |
| Solar array power (end of life) | 10.5 kW[2](https://www.cgwic.com/In-OrbitDelivery/CommunicationsSatellite/DFH-4Bus.html) |
| Payload power | 8 kW official datasheet; up to 10 kW reported by independent sources[2](https://www.cgwic.com/In-OrbitDelivery/CommunicationsSatellite/DFH-4Bus.html) • [3](https://spacenews.com/china-looks-boost-satellite-manufacturing-dfh-4-line/) |
| Payload capacity | 450–700 kg (CAST); ~595–800 kg in independent accounts[1](https://www.cast.cn/news/2884) • [3](https://spacenews.com/china-looks-boost-satellite-manufacturing-dfh-4-line/) • [6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/) |
| Station-keeping | ±0.05° (3σ)[2](https://www.cgwic.com/In-OrbitDelivery/CommunicationsSatellite/DFH-4Bus.html) |
| Service life | 15 years[2](https://www.cgwic.com/In-OrbitDelivery/CommunicationsSatellite/DFH-4Bus.html) |
| Mission record 2006–2016 | 15 launches on CZ-3B/E from Xichang, 13 successful spacecraft missions, 2 spacecraft failures[6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/) |
## Design and specifications
CGWIC's export datasheet gives DFH-4 a body of 2360 × 2100 × 3600 mm, a lift-off mass of 5,200 kg, solar array output of 10.5 kW at end of life, and 8 kW of power available to the payload. The bus supports transponders in C, Ku, Ka, and L bands, holds station to ±0.05° (3σ), points antennas to better than 0.1° (3σ), and is designed for 15 years of service.[2](https://www.cgwic.com/In-OrbitDelivery/CommunicationsSatellite/DFH-4Bus.html) That is a large step from its predecessor [DFH-3](https://www.edgepedia.org/dfh-3), which massed 2,320 kg, delivered 1.7 kW at end of life with 1 kW to the payload, and served more than 8 years.[2](https://www.cgwic.com/In-OrbitDelivery/CommunicationsSatellite/DFH-4Bus.html)
Independent reporting fills in figures the official datasheet states differently. SpaceNews reported the bus carries some 800 kg of payload, four times the capacity of DFH-3, weighs up to 5,300 kg at launch, and operates 15 years, double DFH-3's life. CAST tested the design to a maximum of 54 transponders (38 Ku-band, 16 C-band) with an upper launch-mass limit around 5,600 kg.[3](https://spacenews.com/china-looks-boost-satellite-manufacturing-dfh-4-line/) China Space Report gives a narrower intermediate figure of 5,100–5,400 kg launch mass with 600–800 kg payload, and roughly 3,100 kg of fuel.[6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/)
The payload-power figure differs by source: the CGWIC datasheet, GlobalSecurity, and China Space Report state 8 kW delivered to the payload, while [SpaceNews](https://www.edgepedia.org/spacenews) and Encyclopedia Astronautica report up to 10 kW at end of life.[2](https://www.cgwic.com/In-OrbitDelivery/CommunicationsSatellite/DFH-4Bus.html) • [3](https://spacenews.com/china-looks-boost-satellite-manufacturing-dfh-4-line/) • [5](http://astronautix.com/d/dfh-4.html) • [6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/) The 8 kW datasheet value is used here as the official figure.
## History and development
The State Commission for Science, Technology and Industry for National Defence (COSTIND) approved the DFH-4 program in October 2001, and engineering development began in January 2002 with CAST as prime contractor.[6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/) The first satellite, SinoSat 2, launched on 28 October 2006 on a [Long March 3B](https://www.edgepedia.org/long-march-3b)/E (CZ-3B/E) from Xichang.[6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/) Every logged DFH-4 mission through 2016 flew on the same vehicle from the same site.[6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/)
The program started badly. The first two satellites, SinoSat 2 (28 October 2006) and NigComSat-1 (13 May 2007), both failed to deploy their solar panel wings. After CAST switched from a two-stage to a single-stage deployment sequence, subsequent missions succeeded.[6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/)
## DFH-4 by the numbers
Fifteen DFH-4 launches are logged between 28 October 2006 and 15 January 2016, when Belintersat 1 flew; 13 succeeded and 2 failed, all on CZ-3B/E from Xichang.[6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/) Export customers in that period included Nigeria, Venezuela, Pakistan, Laos, Bolivia ([Túpac Katari](https://www.edgepedia.org/tupac-katari) 1), and Belarus.[6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/)
CGWIC reported that as of 31 December 2013 it had delivered five communications satellites in orbit to international customers: NigComSat-1, VeneSat-1, PakSat-1R, NigComSat-1R, and TKSAT-1. NigComSat-1 was replaced by NigComSat-1R after the original failed in orbit.[2](https://www.cgwic.com/In-OrbitDelivery/CommunicationsSatellite/DFH-4Bus.html) • [6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/) The commercial package CGWIC marketed was in-orbit delivery: satellite, launch, ground stations, training, and financing, at discounted prices; Nigeria, Venezuela, Pakistan, Laos, and Belarus signed up for it.[6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/)
## How it compares
GlobalSecurity judged the DFH-4 platform comparable in technology level and capability to the Lockheed Martin A2100AX, HS601HP, and Space Systems/Loral FS1300, and the SB4000 ([Spacebus](https://www.edgepedia.org/spacebus) 4000), citing launch masses up to 5,100 kg and 10 kW of power from high-efficiency GaAs/Ge solar cells.[4](https://www.globalsecurity.org/space/world/china/dfh-4.htm) China Space Report likewise classes it with the A2100AX and FS1300.[6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/)
Within China's own lineage, DFH-4 sits between DFH-3 (2,320 kg, 1.7 kW end-of-life, >8-year life) and the enhanced DFH-4E.[2](https://www.cgwic.com/In-OrbitDelivery/CommunicationsSatellite/DFH-4Bus.html) CAST describes DFH-4E as a new large-capacity bus developed on the DFH-4 base to meet market demand and improve international competitiveness, adding electric propulsion, high-power supply and distribution, a multi-layer communications module, and a high-load-bearing structure. Launch mass rises to 5,500–6,000 kg (from 5,000–5,300 kg) and payload capacity to 800–1,000 kg (from 450–700 kg), with output power of at least 13,500 W.[1](https://www.cast.cn/news/2884) Encyclopedia Astronautica adds 10,000 W of payload power, a 2,700 kg dry mass, lithium-ion batteries (saving 80 kg versus nickel-hydrogen) and triple-junction GaAs cells generating 65 W/kg for the DFH-4E.[5](http://astronautix.com/d/dfh-4.html) No source in this record covers DFH-5, so its status cannot be described.
## Reliability and early failures
The failure record centers on the first two airframes. SinoSat 2 and NigComSat-1 both failed to deploy their solar panel wings; NigComSat-1 then failed in orbit on 11 November 2008 after running out of power due to a solar array anomaly, and was replaced by the ground-spare NigComSat-1R.[6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/) The two failures among 15 launches give 13 successes in the documented 2006–2016 window.[6](https://chinaspacereport.wordpress.com/spacecraft/dfh4/)
## References
Reference note: CAST's official platform page (reference 1) is the primary source for DFH-4E figures and baseline mass ranges.
1. 东方红四号增强型平台 (DFH-4E) — 中国空间技术研究院 (CAST) — https://www.cast.cn/news/2884
2. DFH-4 BUS — Communications Satellite — In-Orbit Delivery — CGWIC — https://www.cgwic.com/In-OrbitDelivery/CommunicationsSatellite/DFH-4Bus.html
3. China Looks To Boost Satellite Manufacturing With DFH-4 Line — SpaceNews — https://spacenews.com/china-looks-boost-satellite-manufacturing-dfh-4-line/
4. DFH-4 — Chinese Communication Satellite Systems — GlobalSecurity.org — https://www.globalsecurity.org/space/world/china/dfh-4.htm
5. DFH-4 — Encyclopedia Astronautica — http://astronautix.com/d/dfh-4.html
6. China Space Report — Dong Fang Hong 4 — https://chinaspacereport.wordpress.com/spacecraft/dfh4/
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*Topic: Encyclopedia › Technology and the built world › Transport and spaceflight › Spaceflight › Satellites › Satellites by country, orbit, and bus › Soviet/Russian and other non-Western bus families*
*Initially written Sep 17, 2026 · Reviewed: Sep 19, 2026; Sep 30, 2026 · Edited: Sep 19, 2026; Sep 30, 2026; Oct 11, 2026; Oct 15, 2026 · Last review: Sep 30, 2026*
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