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China's Space Program News Thread
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supercat
Major
China space news from Aviation Week & Space Technology:
China’s Rapid-Response Rocket Prominent In 2018 Program
China will conduct five missions with Long March 11 solid-propellant launchers this year, confirming that the fast-response rocket is finally regarded as mature. One of the launches will be from a ship, says Li Hong, the head of China’s main space-launcher builder, Calt, confirming a previously disclosed plan.
In an extensive preview of the 2018 launch program, Li makes no mention of a flight by the new Long March 7. And Long March 5B, designed mainly to put a space station into orbit, is now scheduled to fly not this year, as previously planned, but in 2019. That is consistent with what looks like a general one-year slippage in the Long March 5 program arising from a launch failure last year. Development of the Long March 8, intended to be a low-cost launcher, also appears to have slipped by about a year.
The missions of the Long March 11 will be among 36 launches scheduled this year for various types of rockets that are all called Long March, all made by parts of state space industry group Casc, though they are not all interrelated. Most missions will be done with the Long March 3As and Long March 2Cs, members of China’s original series of hydrazine-fueled space launchers. Lofting Compass Navigation Satellites is a major task this year. Another is to send the Chang’e 4 probe to the far side of the Moon.
The first of the five Long March 11 missions was conducted on Jan. 19. Rockets of this type can place a 350-kg (770-lb.) payload in a 700-km (430-mi.) sun-synchronous orbit, Casc President Wu Yansheng said in June 2017. Calt is part of Casc.
Because it uses solid propellant, the Long March 11 can be stored for long periods and prepared for a mission very quickly. It can be fired after only hours of notice, rather than months, state media have reported. This is militarily valuable. Under the concept that the U.S. calls operationally responsive space, small satellites are hurled into orbit tactically, as and when forces need them—for example, for reconnaissance.
But the Long March 11’s entry into regular service has been slow. It first flew in September 2015, again in November 2016 and not at all in 2017, indicating that to some extent it remained developmental. The plan to use it five times this year means officials now regard it as reliable.
The sea-launch mission will use a converted freighter ship. “The critical technology has been mastered and the detail scheme for the launch has been worked out,” the Xinhua state news agency says, quoting Li. Sea launches have the advantage that a floating platform can be placed on or near the equator, giving a low-inclination satellite the greatest possible velocity boost from the Earth’s rotation. Sea launches can also avoid either the danger of sending a rocket over populated places or payload loss from having to maneuver around them.
Of this year’s 36 “Long March series” launches, 14 will use Long March 3As, Li says. Rockets of that type can loft 8.5 metric tons (18,700 lb.) to low Earth orbit or 2.4 metric tons to geostationary-transfer orbit. The continuing importance of this launcher, now 24 years old, is underscored by Li’s expectation that it will also be used 26 times in the following two years. The Long March 8, with much the same launch capacity, is evidently intended to replace it. Eight of this year’s Long March 3A launches will each place two satellites in orbit.
The Long March 2Cs, with low-orbit capacities of 3.85 metric tons, will be used for six launches in 2018. In one, this type of launcher will be mated for the first time with the Yuanzheng 1A restartable upper stage, a simplified version of the original Yuanzheng 1.
Another Casc unit, Sast, builds the hydrazine-fueled Long March 4 and new Long March 6, which, like the Long March 7, burns kerosene with liquid oxygen. In discussing the 2018 launch program, Li did not mention Long Marches 4 and 6, probably because he is not responsible for them. But they could be included in the total of 36 missions.
The Long March 7 program will advance in 2018 with higher “product reliability,” Li says. “The Long March 7 development team is also working on development and design of improved rockets [that is, versions] for satellite-launch and other types of missions.” The reference to greater reliability hints that the design of Long March 7 is being reviewed and perhaps changed to minimize the risk of failure.
Li says the Long March 8 is now due to fly in 2020. Lu Yu, director of Calt’s science and technology committee, said in June 2017 that a first flight in 2018 was possible but that probably two more years of development would be needed, implying entry into service in 2019.
The Long March 8 is intended to loft 7.6 metric tons to low Earth orbit or 4.5 metric tons to a 700-km sun-synchronous orbit. Calt is trying to develop it quickly and economically, using propulsion modules from earlier launchers
“Long March 8 has entered the development stage, and there has been preliminary progress in critical technologies for vertical takeoff and landing,” the China News Service, another state news agency, quotes Li as saying. This ambiguous quote raises the surprising possibility that Calt may be doing preliminary work on vertical landing for the Long March 8.
But the news agency does not make clear that the ability to land vertically, a recovery mode for reusability, is being developed for the Long March 8 in particular. Such a capability has not been previously mentioned in relation to this launcher, and including it would imply that provision for reusability is being engineered into the rocket, increasing challenges in a fast development program. Calt has previously described early work on vertical landing, but not in relation to any specific current launcher program.
Apart from low cost, the Long March 8 will have a brief launch preparation period and suitability for several launch sites, the China News Service says.
Among progress in various parts of the manned space program, “the Long March 5B transportation rocket is scheduled to make a first flight around June 2019,” says the news agency in a report citing the deputy director of the manned-flight program, Yang Liwei.
“Long March 5” is the name of China’s biggest launcher type and also its first version. The Long March 5B is the second version, designed to deliver bulky loads of up to 23 metric tons to low Earth orbit—specifically, each of the three modules of the space station. An enlarged fairing replaces the second stage of the original version.
Whether the first module of the space station will be risked on the first flight of the Long March 5B is not known. The political consequences of losing the module would be great, because the Chinese government exploits its space program heavily for nationalistic propaganda. For example, the second flight of the original version was preceded by extensive and detailed media coverage. When it failed, there was just a terse statement saying so and then a media blackout.
Before the failure of the first version on its second flight in July 2017, the Long March 5B was due to fly this year. The failure was caused by a manufacturing fault in a YF-77 hydrogen-burning engine of the first stage, according to a source close to the Chinese industry The manufacturer, Calt, says it has now definitely identified the problem.
The extent of the Long March 5 program delay became apparent in September 2017 when an official said the Chang’e 5 lunar mission, which only the big new rocket in its original version can launch, would be pushed back to late 2018, a year later than previously planned. That new timing of the Chang’e 5 mission notably was not repeated by Chinese space officials in several interviews they granted during the country’s annual parliament meeting this month.
“Assembly and fitting of the cabin of the space station’s core module will be completed this year,” the China New Service says. Also this year, “large-scale integrated testing on the module will be progressively conducted,” it reports. This work is presumably not proceeding very intensely, since the unavailability of the launcher has given the engineers and technicians making the station an extra year to get it ready.
supercat
Major
More from AW&ST:
Chinese Working On Giant Engine For Long March 9
Completing a demonstrator for a huge first-stage rocket engine, possibly this year, is among the technology acquisition projects being undertaken by China’s main space industry group in preparation for a go-ahead for manned Moon missions. Work on engines for second and third stages and on the structure for the giant launcher, informally called Long March 9 and due to go to the Moon around 2030, is also underway.
Long March 9’s targeted payload to low Earth orbit is 140 metric tons (310,000 lb.), of which 50 metric tons would be sent on a trajectory to the Moon. It would therefore have about six times the capability of China’s current largest rocket, Long March 5.
The first-stage engine would burn kerosene
Thrust is to be 480 metric tons
The engine technology demonstrator is part of research intended for an engine generating 480 metric tons of thrust. The organization developing the hardware, the Academy of Aerospace Propulsion Technology (AAPT), says the demonstrator, which it calls a prototype, will be a complete engine. But AAPT also says it lacks test facilities for engines of this size, raising the possibility that the hardware it is building will be a scaled-down engine. Work on a second-stage engine of about 200 metric tons thrust and one for the third stage, generating about 25 metric tons thrust, is also in progress, AAPT says.
The organization, part of state space industry group Casc, would strive to deliver the engines for the Moon rocket eight years after getting a go-ahead for their full-scale development, says the official newspaper of the Ministry of Science and Technology, in a report citing AAPT President Liu Zhirang.
For the big engine, which will burn kerosene, a turbopump has been built, says Li Hong, head of Calt, the Casc unit that leads overall development and production of most Chinese space launchers. It must be a huge pump, because the engine will generate four times the thrust of the largest Chinese rocket engine to date, AAPT’s 120-metric-ton-thrust YF-100.
Li, quoted by the China News Service state news agency, says the thrust of the planned engine is 480 metric tons. The ministry’s newspaper, Science and Technology Daily, says the engine is in the 500-metric-ton class. The F-1 engine that powered the U.S. Apollo program’s Saturn V rocket had a thrust of 680 metric tons.
“A complete prototype for the engine in the 500-metric-ton class can be built and assembled this year,” Science and Technology Daily says, quoting Liu. Despite the reference to a “prototype” in the Chinese-language report, the program, not yet fully launched, cannot be ready to build anything closer to the final hardware than a technology demonstrator.
“Because of the great parameter changes that come with rises in thrust, the current test and verification equipment cannot satisfy requirements” of the Moon rocket propulsion program, the paper cites Liu as saying. “We cannot always do 1:1 scale tests. As a result, only simulations and scaled-down tests can be done for some technology and hardware. This increases the degree of difficulty for the program.”
The three engines will variously use kerosene and hydrogen as fuel, Liu says. He does not identify which engine will burn which fuel, but the third-stage unit and probably the one for the second can be expected to use hydrogen—a conventional choice, because of the element’s high ratio of energy to mass when burned with oxygen.
The Moon rocket will have a diameter of 10 m (33 ft.), according to the China News Service, adding that a sample piece has been made. Fabricating the rocket structure will be a great challenge for the program, a senior space industry official in China tells Aviation Week.
Calt last year showed a concept design for Long March 9 with what appeared to be four engines, each with two thrust chambers, mounted in the core first stage and two in each of four boosters. If 12 such engines had 480 metric tons of thrust each, the total at liftoff would be an extraordinary 5,760 metric tons. Alternatively, if each booster had only one such engine, or if there were only two twin-engine boosters, the total would be 3,840 metric tons.
The senior official says the required thrust for Long March 9 is 3,500-4,000 metric tons and the mass at liftoff will be around 2,800 metric tons. This weight is less than that of earlier concepts and the same as Saturn V, which departed with 3,400 metric tons of thrust. The Chinese payload to low orbit is higher than Saturn V’s 118 metric tons, but AAPT no doubt expects to improve on the efficiency of the F-1. The sea-level specific impulse of the huge U.S. engine, comparing thrust with fuel flow, was 263 sec.; Chinese officials say the YF-100, using the staged-combustion process for driving its propellant pumps, has demonstrated 305 sec.
Although AAPT is working on huge solid-propellant boosters, Calt is very unlikely to use them if it settles on kerosene-burning engines for the first stage. Its published concepts have consistently used either kerosene and liquid oxygen or solid propellant at liftoff, for simplicity. The blueprints featuring solid-propellant boosters had hydrogen-burning engines for the core.
antiterror13
Brigadier
Just saw China's space station fly overhead for a few minutes.
How did you do that? please share
vesicles
Colonel
How did you do that? please share
I believe he’s referring to the Tian Gong-1 that lost control a few years ago and has been coming down to earth for the past couple weeks. Debris has been expected to cover a narrow band of area in the northern atmosphere. I think Michigan is the most likely place for the Tian Gong-1 to come down to. B.I.B. might have seen the debris in the sky.
It is still in orbit right now.I believe he’s referring to the Tian Gong-1 that lost control a few years ago and has been coming down to earth for the past couple weeks. Debris has been expected to cover a narrow band of area in the northern atmosphere. I think Michigan is the most likely place for the Tian Gong-1 to come down to. B.I.B. might have seen the debris in the sky.
or
Maybe B.I.B. has a telescope.
vesicles
Colonel
It is still in orbit right now.
or
Maybe B.I.B. has a telescope.
Oh! My bad. I thought it’s coming down now...
not yet, but very soon. April was the latest according to CASC's prediction.Oh! My bad. I thought it’s coming down now...
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