China's Space Program News Thread

[SinoSoldier]

Actually, I think your translation is right. The issue I have with the Xinhua article is that should be more clear that the CASIC SRB will have diameter of greater than 4 meters.

Ignition verification should be proof of concept that the basic design of the SRB motor works (probably in a lab). Full verification should be firing a full SRB motor that can be installed into a functional space launch vehicle (presumably on an outdoors test rig/stand).

Speaking of the graphics, for the 70 ton payload variant, are they planning on putting in multiple SRB motors, or just one single, upscaled motor? I'm asking since the graphics suggest only a single nozzle.

The Xinhua article did say "greater than 4 meters"


This article says the exact diameter is 4.2 meters for KZ-21 and KZ-31.

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Ignition test is as you said, a proof of concept. It usually last a short time, shorter than burning a full tank of fuel, tens of seconds. Full verification test will burn the full tank, lasting however long time, the full working time of a typical launch.

As the "multiple SRB motors for 70 ton payload", I doubt it. The tank is 4.2 meters one piece, I don't think it works by adding two motors to one single tank. In liquid rocket it works, the fuel is fluid and can be relatively easily pressed to flow to multiple motors. But in solid rocket, I imagine it would be very complicated to do so, so complicated that it is easier to make one single big motor.

Thank you all for the information (and Merry Xmas!)

I guess the "ignition verification" will be similar to the short firing test of the 3-m diameter booster back in August 2016, while the "full verification" will be a complete firing of the booster with all of its intended segments installed (like the SRB tests in the Utah Desert)?

 

[taxiya]

Thank you all for the information (and Merry Xmas!)

I guess the "ignition verification" will be similar to the short firing test of the 3-m diameter booster back in August 2016, while the "full verification" will be a complete firing of the booster with all of its intended segments installed (like the SRB tests in the Utah Desert)?

Merry Xmas to you too!

I regard the August 2nd 2016 test as a full firing test of two-segment booster. It burnt all fuel in the two segments. The intended application can go up to three segments.

Ignition test last much shorter. As I recall of another test which was called by "ignition test", it lasted for around 10 seconds (much shorter time compared to above). To my understanding, the purpose of this kind of test is to see if the motor starts properly, the fuel flews properly, thrust increases, BUT not full burn, not lasting long enough for the thrust to reach max.

 

[Quickie]

Actually, I think your translation is right. The issue I have with the Xinhua article is that should be more clear that the CASIC SRB will have diameter of greater than 4 meters.

Ignition verification should be proof of concept that the basic design of the SRB motor works (probably in a lab). Full verification should be firing a full SRB motor that can be installed into a functional space launch vehicle (presumably on an outdoors test rig/stand).

Speaking of the graphics, for the 70 ton payload variant, are they planning on putting in multiple SRB motors, or just one single, upscaled motor? I'm asking since the graphics suggest only a single nozzle.

The Xinhua article did say "greater than 4 meters"


This article says the exact diameter is 4.2 meters for KZ-21 and KZ-31.

Please, Log in or Register to view URLs content!

Ignition test is as you said, a proof of concept. It usually last a short time, shorter than burning a full tank of fuel, tens of seconds. Full verification test will burn the full tank, lasting however long time, the full working time of a typical launch.

As the "multiple SRB motors for 70 ton payload", I doubt it. The tank is 4.2 meters one piece, I don't think it works by adding two motors to one single tank. In liquid rocket it works, the fuel is fluid and can be relatively easily pressed to flow to multiple motors. But in solid rocket, I imagine it would be very complicated to do so, so complicated that it is easier to make one single big motor.

Looks like the Kuai Zhou series of rockets are all multi-staged. According to this web-site the KZ-31 could have 3 solid fuel stages but I think it could have 4 stages with the last stage being liquid fueled, just like the KZ-1A since the fuel combination is more fuel efficient.

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Edit:

Looks like the KZ-11 is 3-staged.

From the link provided by Taxiya above.

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[SinoSoldier]

Merry Xmas to you too!

I regard the August 2nd 2016 test as a full firing test of two-segment booster. It burnt all fuel in the two segments. The intended application can go up to three segments.

Ignition test last much shorter. As I recall of another test which was called by "ignition test", it lasted for around 10 seconds (much shorter time compared to above). To my understanding, the purpose of this kind of test is to see if the motor starts properly, the fuel flews properly, thrust increases, BUT not full burn, not lasting long enough for the thrust to reach max.

The article mentions a maximum thrust of 1000 metric tons, comparable to that of the SSSRB, which leads me to believe that the full-sized booster (perhaps 4-5 segments) will be tested in the full verification test. The ignition test perhaps only involves the igniter portion of the booster.

 

[taxiya]

The article mentions a maximum thrust of 1000 metric tons, comparable to that of the SSSRB, which leads me to believe that the full-sized booster (perhaps 4-5 segments) will be tested in the full verification test. The ignition test perhaps only involves the igniter portion of the booster.

While SSSRB is a single stage booster, no matter how many segments it has, it is a one stage rocket, the whole thing burns to the end then dropped.

On the other hand, the KZ series are designed as multi-staged launch system, so the number of segments of any stage should be less than 4-5 (if that is the right number for the SSSRB sized equivalent). In fact, in case of KZ-31, there are three stages, so the total segments would be more than 5, but non of the stages would be more than 3 (my wild guess).

Another difference is that SSSRB was used in a two stage LEO launching system. Not a three stage GTO capable system. So it need more segments to give longer burn time (2 minutes).

The max thrust of 1000 tons is the liftoff thrust (I think), which is provided by the first stage only. So yes, the first stage engine is as powerful as SSSRB, but it should have less segments, therefor less fuel and shorter burn time. Less segments only limit the burn time, not the maximum thrust.

Of course, the stage could use 4-5 segments as you guessed. It is a matter of design choice of the launching system, whether to have the first stage to last longer to do partially the second stage's work in a different design.

However, there may or may not be a further full-burn test involving 3 segments after the August 2016 test (2 segments). It depends on how confident China is about the reliability of the design around segment (fuel passing, ignition of the next segment, maintaining thrust at the switch etc.)

 

[Hendrik_2000]

This Yaogan aka Naval surveillance satellite keep proliferating. This should be the 31st or Henri K got it wrong last month launched should be 39th. From Dafengcao
China launches trio of Yaogan-30 reconnaissance satellites from Xichang on Christmas Day
Yup this guy got it wrong I check NASA website they call last month launch 30th

 

[Dolcevita]

Third set of Yaogan -30 satellite successfully launched

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China launches remote sensing satellites
Source: Xinhua| 2017-12-26 08:24:48|Editor: Yang Yi

China launches remote sensing satellites on a Long March-2C carrier rocket from Xichang Satellite Launch Center in southwest China's Sichuan Province, Dec. 26, 2017. As the third batch of the Yaogan-30 project, the satellites will conduct electromagnetic environmental probes and other experiments. (Xinhua/Liang Keyan)

XICHANG, Sichuan, Dec. 26 (Xinhua) -- China launched remote sensing satellites at 3:44 a.m.(Beijing Time) Tuesday on a Long March-2C carrier rocket from Xichang Satellite Launch Center in southwest China's Sichuan Province.

The satellites have entered its preset orbit and the launch was proclaimed a success.

As the third batch of the Yaogan-30 project, the satellites will conduct electromagnetic environmental probes and other experiments.

The launch is the 260th mission of the Long March rocket family.

China launches remote sensing satellites on a Long March-2C carrier rocket from Xichang Satellite Launch Center in southwest China's Sichuan Province, Dec. 26, 2017. As the third batch of the Yaogan-30 project, the satellites will conduct electromagnetic environmental probes and other experiments. (Xinhua/Liang Keyan)

 

[SinoSoldier]

While SSSRB is a single stage booster, no matter how many segments it has, it is a one stage rocket, the whole thing burns to the end then dropped.

On the other hand, the KZ series are designed as multi-staged launch system, so the number of segments of any stage should be less than 4-5 (if that is the right number for the SSSRB sized equivalent). In fact, in case of KZ-31, there are three stages, so the total segments would be more than 5, but non of the stages would be more than 3 (my wild guess).

Another difference is that SSSRB was used in a two stage LEO launching system. Not a three stage GTO capable system. So it need more segments to give longer burn time (2 minutes).

The max thrust of 1000 tons is the liftoff thrust (I think), which is provided by the first stage only. So yes, the first stage engine is as powerful as SSSRB, but it should have less segments, therefor less fuel and shorter burn time. Less segments only limit the burn time, not the maximum thrust.

Of course, the stage could use 4-5 segments as you guessed. It is a matter of design choice of the launching system, whether to have the first stage to last longer to do partially the second stage's work in a different design.

However, there may or may not be a further full-burn test involving 3 segments after the August 2016 test (2 segments). It depends on how confident China is about the reliability of the design around segment (fuel passing, ignition of the next segment, maintaining thrust at the switch etc.)

I'm not using the SSSRB as a frame of reference; instead, I'm basing my figures and numbers on the Ares 1, which is essentially a launch vehicle version of the SSSRB with an additional segment. I can infer from the maximum thrust that the full verification will involve a complete first stage of the KZ-21/31 and should have roughly same number of segments (4-5), following what I can only suspect is a change in design of the KZ-21 (which was originally designed to have a 3 m diameter engine).

 

[taxiya]

I'm not using the SSSRB as a frame of reference; instead, I'm basing my figures and numbers on the Ares 1, which is essentially a launch vehicle version of the SSSRB with an additional segment. I can infer from the maximum thrust that the full verification will involve a complete first stage of the KZ-21/31 and should have roughly same number of segments (4-5), following what I can only suspect is a change in design of the KZ-21 (which was originally designed to have a 3 m diameter engine).

I see how you got the idea.

If I may guess "why Ares 1 SSSRB has 5 segments", I would say that is due to Ares 1 is a two staged LEO vehicle. The 2nd stage is LO/LH which works better in high altitude but worse in lower altitude (take off). The added 5th segment makes the first stage works longer (about 150 seconds) to push the 2nd stage up high in its optimal altitude.

KZ series are all three staged vehicle, and all stages are solid. There is no preference of which stage should have more segments, they all have the same performance. Instead of having more segments (5) in the 1st stage, it is better to have shorter (<=4) 1st stage and drop it to reduce the dead weight earlier.

It is the different design (Solid+LO/LH vs. all solid) for different purpose (LEO only vs. LEO+GTO) that made the difference.

 

[Hendrik_2000]

I am wrong I guess these are series of satellite So total 9 satellite under code name Yaogan 30
China launch yet another Yaogan 30-03 series satellite. The gauntlet is forming

Another trio of Yaogan military satellites launched by China

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A Long March 2C rocket lifted off from the Xichang space base at 1944 GMT (2:44 p.m. EST) Monday. Credit: Xinhua
Three more Yaogan satellites successfully lifted off Monday from the Xichang space center in southwestern China, joining two similar triplets launched earlier this year for the Chinese military.

The trio launched at 1944 GMT (2:44 p.m. EST) Monday aboard a Long March 2C rocket from the military-run Xichang rocket base in Sichuan province, according to China’s state-owned Xinhua news agency.

Liftoff occurred at 3:44 a.m. Beijing time Tuesday.

The two-stage Long March 2C booster flew east-southeast from Xichang and placed the three Yaogan satellites into an orbit around 370 miles (600 kilometers) above Earth at a tilt of 35 degrees to the equator.

China did not announce the launch in advance, keeping with the country’s usual policy of not disclosing the launch schedule for military satellites.

Xinhua reported the third batch of Yaogan 30 satellites will “conduct electromagnetic environmental probes and other experiments.”

The Yaogan 30-03 satellites launched Monday join two other triplets launched into the same type of orbit Sept. 29 and Nov. 24. The groups were built by the Chinese Academy of Sciences Institute of Micro-satellite Innovation.

The Yaogan series of satellites are believed to be operated by the Chinese military for intelligence-gathering purposes.

Some analysts suggested the nine Yaogan 30-01, 30-02 and 30-03 satellites launched over the last three months could be testing new electronic eavesdropping equipment or helping the Chinese military track U.S. and other foreign naval deployments.

China’s military has another satellite named Yaogan 30, but it is in polar orbit and believed to be a high-resolution imaging spacecraft.

Monday’s launch marked the 18th Chinese space launch attempt of the year. Seventeen of the missions successfully reached orbit.