Yuanzheng-1
| Manufacturer | CALT |
|---|---|
| Country of origin | China |
| Used on | Long March 3B & Long March 3C fourth stage[1] |
| Associated stages | |
| Comparable | Fregat |
| Launch history | |
| Status | Active |
| Total launches | 3 |
| Successes (stage only) |
3 |
| Failed | 0 |
| Lower stage failed |
0 |
| First flight | 2015-03-30 BDS I1-S Mission |
| Engine details | |
| Engines | 1 YF-50D[1][2] |
| Thrust | 6.5 kN (1,500 lbf)[1] |
| Specific impulse | 315.5 seconds[1] |
| Fuel | N2O4/UDMH[1] |
The Yuanzheng-1 (AKA YZ-1) is an upper stage developed by CALT to enable the Long March 3B and Long March 3C to deploy directly to high energy orbits like MEO and GSO. Since the third stage of these rocket can not restart, it can not circularize orbit from a GTO transfer. Not only the restart capabilities are required, but the upper stage had the remain operational during the time to reach the orbit apogee to execute the circularization burn. For a standard GTO transfer, this is of around 6 hours. The YZ-1 was developed to meet these requirements and enabled the deployment of satellite pairs for BeiDou directly to their orbits or communications satellite directly to GSO. This way, the spacecraft do not need an LAE or APK.[3]
It has a thrust of 6.5 kN (1,500 lbf) with an isp of 315.5 seconds. It uses the storable propellant N2O4/UDMH can perform at least two burn within its rated life of 6.5 hours.[4]
Contents
History
Little is known at the time regarding this stage. Besides the basic characteristics, it is known that there will be a second version specifically designed for the Long March 5 called Yuanzheng-2. It was presented in a 2013 paper.[3] And had its first flight on
| Date (UTC) | Carrier Rocket | Stage Model | Launch site | Mission | Result |
|---|---|---|---|---|---|
| 2015-03-30 13:52 |
Long March 3C | YZ-1 | Xichang | BDS I1-S | Success |
| 2015-07-25 12:29 |
Long March 3B | YZ-1 | Xichang | BDS M1-S / BDS M2-S | Success |
| 2016-02-01 07:29 |
Long March 3C | YZ-1 | Xichang | BDS M3-S | Success |
Versions
Currently, there is known to be two versions:
- Yuanzheng-1 (AKA YZ-1): Initial version used with the Long March 3.
- Yuanzheng-2 (AKA YZ-2): New version used with the Long March 5.
