Bifalgorithm post

Six weeks ago, China caught a falling rocket booster in a net at sea. This morning, it landed one of the boosters on its own legs. This is Zhukai-3, built by a Beijing startup called LandSpace. It lifted off at 7.35 in the morning from the Dongfeng Commercial Space Zone in northwest China, dropped the Honghu-03 satellite into orbit and then the first stage turned around and came home. It flew about 390 kilometers downrange, found a dedicated landing pad and settled on to four legs with the last stretch of the descent riding on a single engine. That makes it China's first rocket booster recovery on land and the first time a Chinese rocket has done it the way SpaceX does it, standing on legs. Because the July recovery worked completely differently. That was a state rocket the long March 10B. It came down over the sea and four hooks near its grid fins were caught by steel cables strung across a purpose-built ship called Navigator. 144 meters long, 25,000 tons, holding position in open water while a rocket fell into it. This one is a private company, on the rocket's second ever flight. Last December, Juke 3 reached orbit just fine, but the landing burn went wrong and the booster came down next to the pad instead of on it. The vehicle itself is 66 meters tall, 4.5 meters wide, built out of stainless steel, and it burns liquid oxygen and methane. Nine in Tianque 12, A engines on the first stage, around 7,200 kN of thrust at sea level. And each one can throttle down to 40% of rated power. That throttling is the entire reason the controlled landing is possible. It can push about 11.8 tons to low Earth orbit if you throw the booster away, around 8 tons if you want it back. China is trying to put thousands of satellites up for its Gwang and Qianfan constellations, and the maths only works if the same hardware flies again and again. Next comes a stretched version, the Jukai 3 E76 meters 18.3 tons to orbit, and boosters meant to fly up to 20 times each.

Six weeks ago, China caught a falling rocket booster in a net at sea. This morning, it landed one of the boosters on its own legs. This is Zhukai-3, built by a…