news

한어Русский языкEnglishFrançaisIndonesianSanskrit日本語DeutschPortuguêsΕλληνικάespañolItalianoSuomalainenLatina

text/chen lan, columnist of observer.com

this september, just like the typhoons that are coming one after another, the commercial aerospace circle is also quite lively. just ten days later, we saw another heavyweight rocket recovery test flight.

at 13:40 on september 22, jiangsu deep blue aerospace co., ltd. conducted the first high-altitude vertical recovery flight test of nebula-1 at the "deep blue aerospace ejina banner spaceport" in inner mongolia. but unfortunately, the rocket fell short at the last moment, and an almost perfect flight unfortunately ended in tipping over and catching fire.

figure 1 nebula-1 recovery test arrow in flight (source: deep blue aerospace)

figure 2 the nebula-1 recovery test arrow caught fire and fell to the ground after landing (source: deep blue aerospace)

the official press release stated: the recyclable one-stage rocket body experienced an abnormality during the final landing stage of the flight test, and the test mission was not completely successful. according to the "nebula-1 first high-altitude vertical recovery flight test outline", there are a total of 11 major test verification tasks. in this flight test, 10 of them were successfully completed, and only one shutdown and landing was not completed.

figure 3 completion of the nebula-1 test rocket recovery mission (source: deep blue aerospace)

in fact, for many aerospace enthusiasts, this is an extremely familiar picture. we should all still remember the shocking scenes of huge rockets crashing down in flames in videos with different toppling positions and different shooting angles. however, that was many years ago, the location was on the other side of the earth, and the rocket was to be replaced by falcon 9.

figure 4 falcon 9 failed to land (source: spacex)

needless to say, falcon 9 is a model and reference for china’s recyclable rockets. the difference is that at that time, falcon 9 was alone and seeking defeat, but today in china, a hundred flowers are blooming, and many companies are advancing simultaneously.

what is gratifying is that although nebula-1 failed to land this time, it has received unanimous praise from the media and the public, including the most critical netizens. in the current internet ecosystem where trolls are rampant and trolls are everywhere, this is extremely rare.

this also shows that the trial-and-error iterative development model advocated and successfully practiced by musk in the aerospace field has been accepted by chinese astronauts, regulatory authorities, media and the public. we also have reason to believe that the new trial-and-error culture has taken root. it will complement the traditional return-to-zero system and help accelerate commercial aerospace.

musk can call the first flight of the starship, which was a complete failure by traditional definition, a success. so, it should not be overstated to define this test of deep blue aerospace as a success. moreover, the technical span and challenges of this flight are not ordinary.

compared with the nebula m, the previous recovery test rocket of deep blue aerospace, the diameter of the nebula-1 rocket has increased from less than one meter to 3.35 meters, the height has increased from 7 meters to about 21 meters, and the take-off thrust has been expanded from 5 tons to 3.35 meters. 60-ton class. this span is quite challenging. since the nebula m-kilometer recovery test more than two years ago, the eighth academy of aerospace science and technology and blue arrow aerospace have caught up. now, deep blue aerospace has not only returned to the top three, but has also surpassed it in many aspects.

nebula-1 is china's first high-altitude recovery test of a launch vehicle that can be put into orbit, and it is also the only recovery test rocket in the world that directly uses a sub-stage of a rocket that can be put into orbit. it is very similar to the f9r dev (formerly known as grasshopper v1.1) tested by spacex in 2014. the rocket body directly uses the first stage of the orbital rocket, equipped with foldable and release landing legs, and uses three engines to take off and one engine to land. in this test flight, it was the first time in the domestic recovery test that the engine was shut down in the air and turned into a single engine.

figure 5 spacex f9r dev recovery test arrow (source: spacex)

the nebula-1 sub-stage test rocket is equipped with three thunder-r liquid oxygen kerosene engines fully independently developed by deep blue aerospace. this is china's first reusable liquid rocket engine in which more than 90% of the main structure is integrally formed using high-temperature alloy 3d printing technology. this test is also the first flight test of an open cycle liquid oxygen kerosene needle bolt engine in china. as the best engineering practice to solve the problem of thrust adjustment of kerosene engines, pinbolt technology is one of the technological peaks of open cycle liquid engines. the center engine of this test performed thrust adjustment throughout the 179-second flight, ranging from 110% to 58%, with an accuracy better than 1%.

figure 6 thunder-r liquid oxygen kerosene engine (source: deep blue aerospace)

in terms of control technology, this test successfully verified the precise attitude control of the shaking state of the shallow tank with less than 1/5 of the propellant under high-altitude vertical recovery conditions. at the same time, the use of high-precision self-alignment technology based on a moving base and take-off roll-to-injection launch technology can meet the launch requirements in all directions without changing the upright installation state of the rocket. in the future, it can greatly simplify the preparation of different flight missions. workload and improve adaptability. in addition, the recovery trajectory optimization and meter-level precision guidance algorithm based on optimal control were preliminarily verified, and engineering verification was conducted for the subsequent orbit entry + recovery optimal control method.

deep blue aerospace said that the landing leg of nebula-1 is the first landing buffer device product in china that has entered engineering application. in order to meet the stringent weight requirements of the orbit-stage rocket, the mechanism is manufactured with an all-carbon fiber structure. at the expense of weighing no more than 1.2 tons and accounting for less than 10% of the empty weight of the rocket, the total weight of the rocket's first sub-stage with remaining propellant is no more than 15 tons, the speed is no more than 3 meters/second, and the attitude angle is no more than 5 ° case, a safe, reliable and soft landing.

as a rising private and commercial rocket company, the first full-scale arrow recovery test achieved more than 90% of the technical goals, and the degree of completion far exceeded the first flight of a starship. isn’t it a major achievement?

however, china’s rocket recovery race has entered a fever pitch. in addition to deep blue, blue arrow and the eighth academy, interstellar glory, aerospace science and industry, the first academy of aerospace science and technology, china aerospace science and technology, galaxy power, etc. are chasing closely. there are also tianbing technology, eastern space, aerospace engine, arrow technology and so on. they are also gearing up and will soon join the recycling pilot club.

in the history of the world's aerospace industry, there has never been a market competition of such a large scale, with high strategic significance and technical content. the space race between the united states and the soviet union during the cold war ran counter to commercial goals, and the asymmetric “race” between spacex and blue origin on the american continent had one-sided results. we have every reason to expect that china’s recyclable rocket race based on a perfectly competitive market will produce the world’s most cost-effective space launch vehicles.

in such a perfectly competitive market, efficient "trial and error iteration" will inevitably become a natural choice.

ten years ago, the images of falcon 9’s successive landing failures brought a huge visual impact to the world’s aerospace audiences. musk has brought a new idea to the increasingly conservative aerospace industry. the success of spacex proves that commercial aerospace can have different ways of playing, and innovation is indispensable.

spacex has affected the global aerospace process, but no one has had the greatest impact than china. while the internet is full of cynicism about musk, the seeds of commercial aerospace have already taken root in the hearts of some people. in 2015, the policy window that had been closed for decades was opened, and the entrepreneurial talents of chinese aerospace people were stimulated. china's commercial aerospace industry has since then begun to run wildly.

for decades, we have become adept at importing, digesting, assimilating, and then recreating. with the same ideals as musk, china's start-up aerospace entrepreneurs invariably learned the technical ideas of falcon 9 and quickly embraced the development model of frequent trial and error and rapid iteration derived from the it industry. standing on the shoulders of giants, we don’t have to reinvent the wheel.

however, the high efficiency of trial and error comes at the cost of high investment and requires taking great risks. due to accountability and historical inertia, the national team is unlikely to be the first to break the safe and reliable zeroing tradition. the trust of regulators and capital in startups also needs to be gradually established. through unremitting efforts in the early years, chinese commercial astronauts have proven their capabilities and value, and the trial-and-error model has gained regulatory and capital support. this is an important reason why rocket companies have accelerated their development in recent years, liquid rockets have emerged one after another, and the race for recyclable rockets has continued to heat up.

you may have noticed that there was only more than 2 months between the two recycling tests of blue arrow and deep blue aerospace in september and the "test run turned into test flight" accident of tianbing technology on june 30. this fully shows that china’s aerospace regulatory authorities not only accept and even encourage the development model of frequent trial and error and rapid iteration, but also continue to maintain a positive and open attitude towards commercial aerospace development, and they also have high work efficiency. this is welcome progress.

since this year, many rocket companies such as oriental space, interstellar glory, and china science and technology aerospace have received large amounts of financing. since may, deep blue aerospace has completed four new rounds of financing, b, b1, b2, and b3, within three months, locking in more than one billion yuan in capital. while the current venture capital market is at a low ebb and new start-ups are facing financing difficulties, leading rocket companies can still obtain capital support and unswervingly follow the path of trial and error iteration, giving us confidence in the future of china's commercial aerospace industry.

thanks to musk and spacex for years of “trial and error” education through frequent test flights and high-profile failures of falcon 9 and starship, our media and the public can naturally accept the trial and error of chinese aerospace enterprises. fail. we know from a young age that failure is the mother of success. but if every failure requires paying a considerable amount of real money, such as when rocket launches failed in the past, there will still be a lot of people running out to badmouth it. now, they have fewer and fewer responders.

the recovery of nebula-1 failed, and the response from all parties was quite positive, which may further increase the acceptance of the trial and error model. once trial and error becomes a culture, efficiency will be greatly improved, and the future will be even more worth looking forward to.

deep blue aerospace announced after this test that it will conduct a high-altitude vertical recovery mission again in november based on the summary of this test and the zeroing out of technical faults. only two months of iteration time, this is the efficiency of trial and error. we expect a flawless launch and recovery.

we are also looking forward to the first flight of nebula-1 into orbit next year. its biggest attraction is that it will be recovered immediately after its first flight. china's first orbital rocket first-stage recovery will most likely be achieved by nebula-1.

figure 7 some domestic privately owned recyclable rockets (not true scale) (source: author/related rocket companies)

nor should we underestimate the strength of other competitors. blue arrow’s suzaku 3, galaxy power’s pallas 1, and tianbing technology’s tianlong 3 are all designed to be first-level recyclable and will all make their first flight next year. although the first flight will not be recovered, this is an important step towards recovery. as for interstellar glory's hyperbolic 3, like nebula 1, it is planned to be recovered upon its first flight. if all goes well, it will be launched and recovered by the end of next year.

china’s race for recyclable rockets has actually just begun, and the exciting climax is yet to come. who can stand out and take the lead, and who can persevere to the end and be proud of the world, are still unknown. but one thing is certain, the realization and maturity of recyclable rockets will significantly reduce the long-standing high launch costs, and will greatly promote the promotion and popularization of various aerospace applications. our various dreams of looking up at the stars, from space tourism to mars colonization, from giant solar power stations to lunar bases, from asteroid mining to interstellar flight, will also be realized soon.

the high-altitude vertical recovery flight test of nebula-1 will be recorded as a "successful failure" in the history of china's commercial aerospace development. what future generations will remember will be its pioneering spirit and historical significance.