Thursday, April 13, 2023

China Practicing Landing "Boosters"

CAS Space, a spinoff from the state-owned Chinese Academy of Sciences (CAS), has begun testing a small vehicle doing vertical takeoffs and landings on ships in the sea off the coast of Haiyang in eastern China's Shandong Province.  

When they say "small vehicle," well, it's not quite 7 feet tall.  It's 2.1 meters or 6 foot 10.7 inches tall and 93 kilograms or just under 205-pounds.  We specify vehicle because it's not a rocket.  It's powered by twin jet engines each with a thrust of 550 newtons.

CAS has been running these tests since the first of the year and there's a video of one of these tests at the linked article.  The little vehicle takes off from land, moves to a vessel offshore, lands, then lifts off again from that barge and rises to 1000 meters (they report).  They say the test flight was 10 minutes long while the video is 1:14 so the vast majority of the flight is deleted.

CAS Space aims to launch its own reusable orbital rockets in the future, as well as a suborbital rocket for space tourism, in a similar fashion to U.S. firm Blue Origin and its New Shepard.

A CAS Space engineer told Chinese state media outlet Global Times that the firm may hold a first test flight of a near-space scientific experiment platform as early as the end of 2023.

CAS is not alone in aiming to develop reusable rockets in China.  The main, state-operated company in China, CASC, is working on a reusable version of the Long March family, called Long March 8.  Other private firms both inside and outside of China are working toward a similar goal.  The article mentions Landspace and iSpace and we've heard that the European Space Agency is also working on reusable rockets.  Reusability changes everything.



11 comments:

  1. That is roughly what McDonnell Douglas was doing with their Douglas Clipper (DC-X) in 1991, although MacDac was using a rocket engine instead of jets.

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    1. Hydrogen peroxide-oxygen engine wasn't it they used?
      Had a friend back in teenage years who ran a drag go kart at Epping NH had a mil-surp Hydrogenoeroxide and dry oxygen rocket on it. The raceway liked to have him do drmonstration runs, because the ricket exhaust would sweep all the tire and car bits off the track.
      When he would light the engine it looked like he was a paperclip being shot by a rubber-band. Ine second he was stationary next doing "150mph", that was the towns regulation for thrust driven race vehicles, so they would announce 150 thru the trap and right it in the book as such, but Gary said he was regularly breaking 200 plus. It must of been incredible perception of speed, sitting with his butt 2inches off the pavement. He said it was crazy fast. We both raced karts on closed road courses, using McCollogh Racing Kart 92B spec engines, with gearing set up you could do a buck 20 on end of some straights before you pitched into the corners, and that was like insane speed sensation.

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    2. Talk about "road rash" if one's steering was only slightly off!

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    3. Oh its dirt simple steering mechanism, rod and lever style, use aerospace grade rod ends, chome mloy rods and safety wire the fasteners. And you only use the brakes to kick the rear around, slow down by scrubbing speed using sideways drift, and run the gas pedal for steering, while basicaly maintaining your steering angle failry steady. Its a real gas driving one. Boring as hell to watch, but there is nothing close to the fun except motircycle road course, hanging off and steering with the tgrottle and back tire, with your elbow an inch or two off the pavement looking along the your bikes course.

      But yeah, when you crash on a kart its pretty violent, do the flying W. But what is called high siding is really violent, soecially on a bike, cause theres 3-4 gyros on a bike, two wheels, a crank, and if you have a heavy clutch system like on a Buel or a Ducati, a 4th gryo, i know raced both. Twins got a real long dwell between cylinder fires, so they give you a long time relative terms for your tire to break loisecand hook back up, verses the 4cylinder bikes, with have basically no hook up time, firing order is so close together, but the ideal is using your rear tire for steering, its subtle but highly effective because your always accelerating and thats the name of the game, he who is on the gas longer goes fastest. Anyways say your leaned over, kart of bike same difference, and your back wheel steering, you loose just a bit too much control, tire(s) gets too loose too long, tire gets real hot real fast around in one spot, its wicked greasy cause oil are always coming loose from the tire compound, greasy is the term too, well then your back end gets away from you, and self preservation kicks in, and if you back off too much on the throttle, the tite cools too quick and its like super glue for traction. Remember there's three - four gyros spining like crazy, tires hook up, machine suddenly stops moving one direction, but the gyros are still wanting to keep going in their direction, what happens is that energy translates into the chassis, and its real fast, if its "voilently" fast, the only loose part on the kart or bike is the driver, and you get glicked like a booger off the machine and the machine does crazy arse things the moment all that mass is ejected, like change 90 degrees faster than you can blink. Bad things happen real freakin, fast. You can be spit 30 feet in the air, like a super bucking bronco flips a cowboy, but everything metal not soft muscle your riding. Only high sided once, seen it lots of times, literally the most violent viscious thing imaginable. So violent there's no analog in life, i think from having it happen. But the thrill of riding that ragged edge, and doing against another racer is incredible highs. Nothing much like it but real close combat or physical fight where your winning. But racing i think its more control sustained linger under more controlled and known conditions, so theres the mindset and focus thing you refine and perfect. Though its deadly, racing kills you just as dead as a boolit if you screw up.

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    4. The DC-X used four RL-10A rockets, the DC-33 was going to use a bunch of them - it would be the full-sized SSTO designed to carry people or freight. Boeing got the contract for building the SSTO and never got it built, I strongly suspect chicanery as well as bribery when the contract was awarded. The McD had a working prototype, Boeing had pipe dreams and it showed.
      I wonder if some of the project engineers went to work for SpaceX or were Consultants...

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    5. SSTO had negative mass for payload. THAT is why it was not built.

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  2. Not really certain what they are learning, here. Almost all the difficulty of landing is in engine control, and I wouldn't think that understanding the jet engines is going to help them much with rockets.

    Gimbal control to balance a pogo stick is a first-year exercise in control theory, so they can't be trying to figure that out, can they?

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    1. I was thinking of how the Falcon 9 can't hover and they time firing the engine so that it reaches zero velocity when the booster calculates to be at zero height. Sometimes an ocean swell has the deck higher than they expect and it hits going too fast, other times the swell has the deck too low when the stage hits zero and then starts in free fall again.

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    2. And, either way the landing gear sucks up the impact!

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  3. Thats definately Asain mentality, they live tiny things neatly packaged, its kind of cuktural engineering art. Total opposite of American, where if course we build big stuff and crash it till it works kind of thing.

    After racing karts got into road racing motircycles, got one of those Yamaha RZ 259 twin 2stroke crate bikes from Japan. Was down in Daytina to qualify for the 200, and the motircycle institute across from the track invited all us 2stroke GP guys over to use their dynos, very gracious of them, it was a great time. I watched something just intriguing that was utterly an Asain engineering thing. Yamaha factory teams, and priviteers not like me, i was totally semi pro, no sponsors, when you contract for a top GP bike, you dont buy the bikes, you buy soares, lots of spares, pistons kast one race cycle, rings one qualifier etc, and along with bike and spares comes two factory engineer/mechanics, well they are like army ants over those bikes all the time, perfecting everything constantly. I was next up on a dyno, factiry team in the dyno was tuning for top end WOT, which is like 1minute 32 seconds average, and near a minute going diwn the back straight, its fast, not a fast as Poconos NASCAR back straight, but clise, anyways you bakance your crank rids and pistons so you can get to the RPM limit, but fuel tuning is the problem, at those sustained rpms, and its a crap shoot, like pulling a pin on a grenade, not if but when your engine will blow up. Its a game of finite tiny margins. Lije difference in 50rpms at 16 grand doing a buck 65-70 wide open throttle, you can actually loom over and watch the other guys tach sometimes. But what these two engineers did was awesome, watched them for over an hour. They would run the bike at full WTO till they could see on the graph and just hear the pistons start to swell and start to sieze against the cylinder wall and shut the bike down instantly, pull the cylinders off, pull the wrist pins, and with high power loops look at the scuff marks on the piston skirts, grap 600 grit conundrum wet or dry sand paper and hand sand those little scuff points, put it back together with new rings, inly one ring on these race engines for reducing drag, run it again WOT, reprat till they got 2 minutes and no siezing, pull it apart, a new set of rings slap it back together and good to go.
    And I'll bet you dollars to donuts its a similar engineering style/thing they are doing with that cute little VTOL rocket above, run it to the brink and fix the problem, run it again etc till the software and flight controls are to their satisfaction. All done. Only need to scale up and adjust for basic parameters of mass and thrust change, things like wind effects on a larger rocket body etc. But they got the base lines oackaged nice and tidy in Asain style.

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  4. SpaceX received its FAA launch license just before 5 PM CDT on the 14th. They anticipate launching on Monday, 17 April between 07:00 and 09:50.

    It is on! -- my blog

    UPCOMING STARSHIP FLIGHT TEST -- SpaceX website

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