Zhuque-2E soars for its first mission! [Zhuque-2E Y1]
LandSpace has successfully conducted its first launch using the upgraded Zhuque-2E vehicle.
On November 27th at 10:00 am China Standard Time, or 02:00 am Universal Coordinated Time, LandSpace’s improved Zhuque-2E launch vehicle lifted off from Launch Area 96A at the Jiuquan Satellite Launch Center. The vehicle flew as planned for eight and a half minutes to enter its 300 by 500 kilometer low Earth orbit, with a fifty-degree inclination, to deploy its two payloads.
The two payloads onboard Zhuque-2E for its debut flight were Guangchuan 01 (光传01) and Guangchuan 02 (光传02). Not much is known about the satellites but their name literally means ‘Light Transmission’ in English, possibly highlighting testing for inter-satellite optical laser links for communications. This technology is useful for large satellite constellations, with LandSpace working on one in partnership with Hongqing Technology.
Despite carrying customer payloads, this mission was a test flight of the improved second-stage propelled by a new engine. The improved second-stage uses a common bulkhead design to save weight and has switched to using a single TQ-15A engine, replacing the TQ-12 engine and four TQ-11 vernier thrusters. LandSpace has a lot of data for the TQ-15A during ground testing, with Zhuque-2’s first-stage having flown all three of its flights as planned previously, giving the team strong confidence.
LandSpace’s switch to using a TQ-15A engine will allow the second-stage to reignite, opening up a wider range of missions not previously possible and strengthening the company’s market position. Post-launch comments from LandSpace emphasize this too with the company stating:
“The improved Zhuque-2 launch vehicle is independently developed by LandSpace” — “It fully inherits the mature technology of the Zhuque-2 medium-sized liquid oxygen methane launch vehicle that has achieved continuous launch success, and is comprehensively optimized and improved on this basis, and has now formally entered into the stage of commercial operation and is now ready to be delivered to the market in batches. With a carrying capacity of up to 4 tons in a 500-km sun-synchronous orbit, the improved Zhuque-2 will become a mainstay of the commercial satellite launch market in the future with its highly competitive cost advantage, delivery guarantee capabilities, and stable launch reliability verification”
If there are any problems with this translation please reach out and correct me.
After payload deployment, two additional burns of the TQ-15A are reported to have taken place successfully, demonstrating relight capability for future missions.
With the successful mission, LandSpace also highlighted what they believe are a series of firsts achieved for China’s space sector with this launch, and are as follows (simplified explanations after):
China’s first dual cryogenic liquid launch vehicle with full subcooling refueling. Adopting liquid oxygen and liquid methane parallel full-subcooling refueling program can make the refueling process more concise, efficient, safe and economical, and can realize the rapid refueling of propellant within 1.5 hours with full-subcooling, which greatly simplifies the pre-launch process of the launch vehicle. The low temperature of the subcooled propellant can effectively increase the propellant density, enhance the rocket's carrying capacity, improve the engine performance and further optimize the stability and reliability of the rocket flight.
The first domestic liquid launch vehicle dual low-temperature single-layer common-bottom storage tank. The rocket's secondary tank adopts a common-bottom structure, which reduces the number of tank bottoms and inter-tank sections, and uses the pressure difference between the upper and lower tanks to offset the internal pressure load, further reducing the mass of the common-bottom structure; used for the first time in China The structural form of a single-layer common bottom + single-layer tunnel tube is reduced, which reduces the complexity of the common bottom and tunnel tube structures. The tunnel tube is inside the tank, which reduces the structural protrusions on the outer surface of the rocket and further optimizes the aerodynamic shape of the rocket.
China's first large-size high-precision niobium alloy nozzle processing and manufacturing technology. The TQ-15A engine uses a large-size niobium alloy nozzle extension, which can effectively reduce the weight of the engine structure, increase the engine's specific impulse and thrust-to-weight ratio, and enhance the rocket's carrying capacity. All the key technologies in the nozzle production process are self-researched by the company, such as the double-curvature sheet metal forming technology of niobium alloy, high-precision machining and assembling technology of large-size double-curvature thin-walled parts, air-environmental laser welding and anti-oxidation technology of niobium alloy, and coating preparation and sintering technology of large-size niobium alloy products, which realizes a breakthrough in the research and development of high-thrust and high-performance second-stage liquid rocket engines.
For the first time, a domestic launch vehicle adopts a probability-based flight load calculation method in high wind regions. Ballistic wind correction technology was applied during the design stage to reduce the angle of attack in the windy area of the low-altitude section of the rocket's flight. Based on the simulation of large-volume target flight, data analysis and probability statistics, the flight load in the high wind area is optimized, which solves the load envelope problem of the traditional statistical wind field design, and makes the process more concise and the method more scientific.
For the first time, a domestic launch vehicle adopts an inter-stage cold separation scheme that eliminates the need for forward thrust rockets. The rocket follows the interstage cold separation program, which cancels the original two-stage positive thrust rocket, so that the two-stage maintains a short-time weightless gliding state before ignition. This measure effectively reduces the complexity of the system and the weight and cost of the rocket body of the second stage on the premise of ensuring the safety of inter-stage separation and the startup of the second stage.
For the first time, a domestic launch vehicle adopts the intermittent sinking scheme of propellant in the taxiing section. The second taxiing section of the second sub-stage adopts the intermittent sinking propellant management program, where the engine used for sinking works intermittently instead of continuously. Compared with the continuous forward thrust method, this scheme can reasonably select the thrust size and optimize the thrust action time and interval time, thereby reducing the amount of propellant and improving the carrying capacity. It is suitable for long-term taxiing and multiple restarts.
If there are any problems with these translations please reach out and correct me.
And now in simplified not-as-technical language, point one is about propellant loading ahead of launch, with it taking an hour and a half. Point two is referring to the new common dome tank design for the second-stage, which saves mass and coincidentally shortens the stage. Point three highlights the niobium alloy nozzle material used by the TQ-15A engine, this nozzle improves engine efficiency for in-space burns. Point four explains improvements to the rocket’s guidance system and how it uses its limited resources more efficiently. Point five is explaining the new stage separation system and how it uses cold gas thrusters instead of small solid motors to separate the stages, which of course saves mass, simplifies production, and reduces risk both in flight and on the ground. Lastly, point six is referring to the second-stages propellant settling system and how it can be used to help ignite the TQ-15A engine multiple times in space.
Wrapping up its post-launch blog post, LandSpace stated that both the Zhuque-2 and Zhuque-3 launch vehicle series’ would enter regular flight operations within two years to support the deployment of China’s mega-constellations, while propelling LandSpace forward as a key space company.
A few days ahead of launch, Zhuque-2E’s customer user guide was leaked online, with details differing from some of LandSpace’s prelaunch material. The first thing I noticed is that Zhuque-2E is planned to be 55 meters tall and have a 4.2-meter diameter payload fairing, today’s launch quite obviously did not use that fairing while the vehicle stood at 47.3 meters tall. Another detail is that the vehicle’s weight ahead of launch would be 264,000 kilograms with four TQ-12A’s generating 327 tons of thrust to liftoff. This increase in weight would likely have to be from more propellant being onboard. Four TQ-12 engines were also powering today's launch instead of the TQ-12A’s, as stated by LandSpace’s own materials.
The possible reason LandSpace opted to have four TQ-12 engines powering the flight along with not stretching the vehicle is due to an overproduction of older engines and first-stages due to previous plans to fly more this year. Back in March, and reiterated in April, LandSpace was planning to fly Zhuque-2 four times in 2024, likely in the previous Zhuque-2 configuration. Since then the company has evidently had a change in plans and has an excess of older known-good first-stages and TQ-12 engines in storage that can be used while new hardware is manufactured and tested. It is unknown when Zhuque-2E will fly as described in its users guide.
As mentioned earlier, this was the 1st flight of Zhuque-2E, it was also the 4th flight of LandSpace’s Zhuque-2 series. Along with these, this was the 58th launch from China in 2024.
Liftoff Videos
Videos via LandSpace, China航天, and Vony7 on Weibo.
Check out more from LandSpace
What is Zhuque-2E?
This section is for those less familiar with China's various commercial launch vehicles.
Zhuque-2E is LandSpace’s privately-developed commercial launch vehicle, and is largely based on the company’s Zhuque-2 vehicle. The vehicle consists of two stages both burning liquid methane and liquid oxygen.
The payload capacity of the launch vehicle is currently as follows:
6,000 kilograms to low Earth orbit
4,000 kilograms to a 500-kilometer sun-synchronous orbit
Four TQ-12 engines power the first stage to generate 282 tons of thrust while burning liquid methane and liquid oxygen. The second-stage is powered by a single TQ-15A engine, also burning liquid methane and liquid oxygen, to generate 85 tons of thrust.
On the launch pad, Zhuque-2E is 47.3 meters tall and weighs 219,000 kilograms when fully fuelled. The first-stage, second-stage, and fairing have a diameter of 3.35 meters.
Once again, further upgrades are planned for Zhuque-2E to increase the first-stage thrust to 327 tons via the introduction of the TQ-12A engine, with an increased liftoff weight of 264,000 kilograms too. These upgrades will also likely introduce the change to a 4.2-meter diameter fairing and an increase in vehicle length to 55 meters.