Long March 2
Langer Marsch 2 , LM-2 for short ( Chinese 長征 二號 / 长征 二号 , Pinyin Chángzhēng Èrhào , CZ-2 for short ) refers to a family of launchers from the Langer Marsch series of the People's Republic of China , with the individual versions partly differing from one another distinguished.
history
| 2 | 2C | 2D | 2E | 2F |
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Long march 2 / 2A / 2C
The development of the Langer Marsch 2 (abbreviated as CZ-2 from here on) was largely carried out by the Chinese Academy for Launch Vehicle Technology. The CZ-2 (referred to without the addition point or as a CZ-2A) is the basic model of the Long March 2 rocket family and was isolated from the ICBM DF-5 derived. Development work began in 1970, with the missile intended as a carrier for the FSW-1 return satellites. The rocket's first (and only) launch was on November 5, 1974, but it was a failure. The missile was then modified and renamed the CZ-2C (2B did not exist). The first launch of this variant took place on November 29, 1975. It was available in some sub-variants. The rockets for launching Motorola’s Iridium satellites were called the CZ-2C / SD. Another variant with three-axis stabilized upper stage was used for the Double Star program of the ESA and the KOMPSat program of South Korea . The CZ-2C was the second most frequently used rocket of the Langer Marsch family with 55 launches, of which only one failed (on August 18, 2011). Only the CZ-3B was used more often at this time with 69 starts (four of which were failures).
Long March 2D / E / F / G / H
The CZ-2D was developed by the Shanghai Space Agency (since March 1993 Shanghai Academy of Space Technology ) and had its first launch on August 9, 1992. Despite its name, it is not a variant of the CZ-2, but a two-stage derivative of the Langer Marsch 4A . As of June 2020, the CZ-2D is almost as frequently used with 48 launches as the CZ-2C and is also very reliable. Only on December 28, 2016, the rocket reached a lower orbit than intended.
The CZ-2E is a further development of the CZ-2D by the China Academy of Launch Vehicle Technology , whose development began in 1986. It was equipped with four additional boosters, which use the same engine as the second stage. The first launch took place on July 16, 1990. The history of this rocket is overshadowed by two false starts, which can be traced back to the same, unresolved bug. On both occasions the software used was unable to cope with the sudden change in wind conditions when leaving the basin of the Xichang Cosmodrome . In the first accident on December 21, 1992, gusts of wind and the missile control measures triggered by it, the load was so high that the payload fairing was destroyed and thrown off. The rocket nevertheless reached its intended orbit and deployed the (albeit completely destroyed) satellite there. In the second accident on January 25, 1995, the rocket got completely out of control in the same situation and fell a few kilometers from the launch site in a village, officially killing 21 people. Western observers, however, assume around 120 deaths. In total, the rocket was used seven times (last launch on December 28, 1995). A further development "CZ-2E (A)" with longer boosters was announced in 2000, but never realized.
The development of Langer Marsch 2F began in 1992 based on the CZ-2E. Since it was intended for manned missions, extensive measures were implemented to increase reliability. Redundant systems were introduced and the second stage was structurally reinforced. The unmanned first take-off took place on November 19, 1999 from the launch site (as with all other take-offs of the CZ-2F) from Jiuquan (see also Shenzhou 1 ) . After three more unmanned test flights, Shenzhou 5 was the first manned flight. The rocket is so far the most reliable model in the Langer Marsch 2 family.
After Shenzhou 7 took off , the Chinese government announced that this was the last flight of a Long March 2F for the time being. The rocket is to be replaced from 2011 (for Shenzhou 8 ) by a more powerful version, which can bring over 11 t into low earth orbit. This version for unmanned missions is called Long March 2G.
Specifications
Long march 2F
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Booster (4 *)
- Total mass: 41,000 kg
- Empty weight: 3,200 kg
- Vacuum thrust : 4 × 814 kN
- Isp: 291 seconds (2.9 kN s / kg)
- Burn time: 128 seconds
- Diameter: 2.3 m
- Span: 8.0 m
- Length: 15.3 m
- Fuels: Dinitrogen Tetroxide / UDMH
- Engines: one YF-20B per booster (so a total of 4)
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1st stage
- Total mass: 196,500 kg
- Empty weight: 9,500 kg
- Vacuum thrust: 3,256 kN
- Isp: 289 seconds (2.8 kN s / kg)
- Burn time: 166 seconds
- Diameter: 3.4 m
- Length: 23.7 m
- Fuels: Dinitrogen Tetroxide / UDMH
- Engine: 4 × YF-20B
- Stage: 2nd stage
Specifications for older versions
| model | stages | Length (m) | Max. Diameter (m) | Takeoff mass (t) | Starting thrust (kN) | Payload (LEO, kg) |
|---|---|---|---|---|---|---|
| Long march 2 / 2A | 2 | 31,170 | 3.35 | 190 | 2786 | 1800 |
| Long march 2C | 2 | 35.15 | 3.35 | 192 | 2786 | 2400 |
| Long March 2D | 2 | 33,667 (without shield) |
3.35 | 237 | 2961 | 3100 |
| Long march 2E | 2 (plus booster) | 49.686 | 11.45 | 462 | 5923 | 9200 |
See also
Web links
- Encyclopedia Astronautica : CZ-2A , CZ-2C , CZ-2D , CZ-2E , CZ-2F (English)
- Bernd Leitenberger: Chinese launch vehicles
Individual evidence
- ↑ 八 院 简介. In: sast.spacechina.com. Retrieved October 12, 2019 (Chinese).
- ↑ Eugen Reichl, Das Raketypenbuch, ISBN 978-3-613-02788-6 , 1st edition 2007
