Long March 3B/E

ChinaSat 1D | Long March 3B/E

Lift Off Time
(Subject to change)
November 26th 2021 – 16:40:04 UTC
November 27th 2021 – 00:40:04 BJT
Mission Name
ChinaSat 1D
Launch Provider
(What rocket company is launching it?)
China Aerospace Science and Technology Corporation (CASC)
(Who’s paying for this?)
China Satellite Communications
Long March 3B/E
Launch Location
LC-2, Xichang Satellite Launch Center, People’s Republic of China
Payload mass
Up to 5,500 kg (12,100 lb)
Where is the satellite going?
Geostationary Transfer Orbit (GTO)
Will they be attempting to recover the first stage?
No, this is not a capability of the Long March 3B/E rocket
Where will the first stage land?
It will crash back over land in China
Will they be attempting to recover the fairings?

No, this is not a capability of the Long March 3B/E rocket
Are these fairings new?
How’s the weather looking?
This will be the:
– 121st orbital launch attempt of 2021
– 139th launch of a Long March 3 rocket
– 81st launch of Long March 3B rocket
Where to watch
If available, an official livestream will be listed here

What Does All This mean?

CASC is preparing to launch the ChinaSat 1D satellite for China Satellite Communications. The satellite will be launched atop a Long March 3B/E rocket from the Xichang Satellite Launch Center in China. The satellite will initially be deployed into a geostationary transfer orbit (GTO), after which it will gradually raise its orbit to a geostationary orbit (GEO).

ChinaSat 6D

ChinaSat 1D is a Chinese communications satellite based on the DFH-4 (Dong Fang Hong 4) third generation communications satellite bus. Due to the nature of the satellite, not much is known about the technical details, but it is expected to have a 15 year lifespan.

Dong Fang Hong 4 (DFH-4), satellite bus
Dong Fang Hong 4 (DFH-4) satellite bus (Credit: China Space Report)

Long March 3B/E

The Long March 3B/E is an expandable three stage medium-lift rocket, with an optional fourth stage. It is a member of the Long March 3 rocket family, and is the enhanced version of the Long March 3B, having larger side boosters and a larger first stage, allowing for a greater Geostationary Transfer Orbit (GTO) payload capacity. While the 3B was first launched in 1996, the 3B/E variant was introduced in 2007.


The 3B/E has four side boosters, 16.1 m in height, which each have a single YF-25 engine. The engines are powered by Unsymmetrical Di-Methyl Hydrazine (UDMH) and Nitrogen Tetroxide (N2O4). Each of the boosters produce 740 kN of thrust at lift-off, burn for 140 seconds and have a specific impulse (ISP) of 260 seconds.

First Stage

The 3B/E’s first stage is 3.35 m in diameter and 24.76 m in height. It uses four YF-21C engines, which also burn UDMH and N2O4 propellant. The stage has an ISP of 260 seconds and produces 2,960 kN of thrust at sea level.

Second Stage

The second stage is 3.35 m in diameter and 12.9 m tall, and is powered by a YF-24 engine module, which contains a main YF-22E engine, and a single YF-23 Vernier engine to provide attitude control. Similarl to the side boosters and the first stage, the engine runs on UDMH and N2O4. This stage produces 742 kN of thrust and will burn for approximately 185 seconds during flight.

Third Stage

The 3B/E third stage is 12.4 m (40.7 ft) long and is powered by two YF-75 engines. Unlike the other stages, this stage is powered by liquid hydrogen (LH2) and liquid oxygen (LOx). The engines only produces 157 kN of thrust in vacuum, but has an ISP of around 440 s.

Optional Fourth Stage

It is unclear whether this stage was used to launch ChinaSat 1D, but this stage has a single YF-50D engine, which again runs on UDMH and N2O4. The stage produces 6.5 kN of thrust and has an ISP of 315 s.

Long March 3B/E, launch
Long March 3B/E launch with APStar-9 (Credit: ChinaNews.com)

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