Wednesday, November 9, 2022

China Changes Future Moon Rocket to Reusable

In the middle of the twenty-teens, China started looking to send their astronauts to the moon.  By 2016, China's state-owned developer, the China Academy of Launch Vehicle Technology, began work on an addition to their Long March family of rockets, called Long March 9.  In what must be a truly "cosmic coincidence," the rocket bears a resemblance to NASA's Space Launch System or SLS with the (not yet developed) Exploration Upper Stage.  It has a single large core stage and add-on solid rocket boosters.  The major differences relate to using technologies they have more confidence in, such as using kerosene instead of liquid hydrogen (don't get me started), but the big picture was the same.  China would use a one-time use, disposable rocket for each moon mission.  Their first mission was planned to land on the moon by 2030.  

Original design for the Long March 9.  Getty Images.

A funny thing happened on the way to Long March 9: Falcon 9.  SpaceX has demonstrated the reusability of kerosene-fueled first stages and gotten deep into developing its fully reusable Starship rocket. In various presentations, Chinese officials have discussed the possibility of incorporating reusable elements into the Long March 9 design. 

Now, according to Space News, China has made that direction official. The publication cited an interview that Liu Bing, director of the general design department at the China Academy of Launch Vehicle Technology, gave to China Central Television this week. He confirmed that plans for a fully expendable Long March 9 have been dropped.

Rather, the current design features grid fins on the first stage and no side boosters. The goal, Liu said, is to develop a large rocket with a reusable first stage capable of delivering 150 metric tons to low Earth orbit and up to 50 metric tons to the Moon. Liu said the design process remains fluid, with several technical challenges yet to address.

Gee.  Grid fins and no strap-on SRBs.  That doesn't sound as much like SLS anymore. 

Eric Berger at Ars Technica (top link) points out an interesting implication.  The story begins that the South China Morning Post (SCMP) reported on November 6th that the China Aerospace Science and Technology Corporation had successfully tested an engine destined for the Long March 9.  It's called the YF-130, and it's among the most powerful kerosene/LOX engines ever developed at 1 million pounds of thrust.  The SCMP noted the engine can enable China to fly to Mars, but any vehicle/engine combination that can fly to the moon can reach Mars, it's just a matter of the payload size it can bring there.

Eric notes that the Falcon 9 uses just one of its considerably smaller Merlin 1D engines for landing and 3 of 9 for the entry burn higher up in the atmosphere.  The one engine used for landing is still too powerful for the Falcon 9 to hover so the onboard computer needs to adjust the amount of fuel to burn in order to reach the deck of the drone ship when vertical velocity reaches zero.  An empty F9 booster figures to weigh much less than an empty LM9, and that YF-130 is providing much more thrust than and the Merlin 1D (165,000 lbs).  Does the thrust:weight ratio work out that the LM9 can land while throttling down?  

Or maybe the LM9 will need to go to large numbers of smaller engines, like the Starship/Super Heavy? 

Just something to keep an ear open for. 


It looks at the moment as though (now) Hurricane Nicole will be at its closest to us around 4AM tomorrow. There's always the chance we'll lose power and be offline, but we didn't during Ian and this is looking to be in the same strength category as Ian, which was a tropical storm here.



11 comments:

  1. The only way that the Reds can build anything is to copy it.

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    1. Yes, they are very good at military and commercial espionage, and unashamedly copy everything they get their hands on.

      Don't get me started.

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  2. What LL said. The last 'original' Chinese man-rated rocket was sumdood in a wicker chair with fireworks strapped to it. I'm sure parts of him hit the Karman Line...

    I wonder how SpaceX/Musk are handling ChiCom espionage? I wonder if we're ever going to find out? Would make an excellent story or documentary.

    Which, come to think of it, with all the open access that SpaceX has given people, you have to wonder where the documentary films/tv shows are? Yes, there have been some but they tend to touch on Virgin Galactic and Blue Origin more than SpaceX.

    I'd love to see a 1-2 hour professional treatment on the development of Falcon 9 from first dream all the way up to Falcon 9. Just a straight-up history treatment of it. It's not like there's not a dearth of exciting video out there.

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    1. The only SpaceX documentary I know of is in book format, by Eric Berger at Ars Technica. It's called Liftoff. While I'm sure Eric would like to see it made into a documentary, that would have to get some other people excited about it, too.

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  3. I hope the storm treated you well, the 1000 update shows it north of us here in Clearwater.

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    1. Aside from some water running under one door that got pounded by rain for hours, nothing bad happened at all. And that was a 15 minute cleanup.

      The electric clocks we have that are the most sensitive to power glitches are both still set, so we didn't have any glitches longer than a few milliseconds. I haven't done a complete walk around the house only about 2/3 of it but now that the rain is done, I think it's time.

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  4. Yep, even the Chinese can see the truth: SLS is the "launch system of the future", and it ALWAYS WILL BE. In fact, SpaceX and their approach is the future.

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    1. Your sarcasm is lost on me. Want to rephrase that? Typo? Dropped word?

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    2. Feel free to clarify, Backwoods Engineer, but I read that "launch system of the future", and it ALWAYS WILL BE as meaning it will never be operational - it will always be out there in the future and never working.

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    3. Like the Linear Aerospike engine. Cool idea, no need for gimbals or hydraulics but never made it to a real rocket..

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  5. Asking a single engine to deliver 150 tonnes to LEO and 50 tonnes to the moon and still achieve the limited thrust for vertical landing seems to be a bit much. IOW, I'll be looking forward to the fireballs, aka Unplanned Ralid Disassembly.

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