How does the Russian 3M22 Zircon hypersonic missile compare to China’s Dongfeng DF-21?
俄罗斯3M22锆石高超音速导弹与中国东风DF-21相比如何？
I have an unpopular opinion as an engineer with lifelong interest for aviation.
作为一个对航空有终身兴趣的工程师，我的观点不受欢迎。
Scramjets are overated…
超燃冲压发动机过度老化…
They are not significantly more efficient than a good designed rocket engine. There are also a few problems with them.
它们的效率并不比设计良好的火箭发动机高出多少。它们也有一些问题。
1- Their very low thrust to weight ratio (around 2) means they can not function well in the lower atmosphere. They simply can’t defeat air resistance. Tsirkon will be a high flyer just like an anti-ship missile from 1950s.
它们的推重比很低（大约2），这意味着它们不能在低层大气中正常工作。他们根本无法战胜空气阻力。齐尔康将是一个高飞者，就像1950年代的反舰导弹一样。
2- They can’t go above the atmosphere which negates their efficiency advantage against rockets.
他们不能飞到大气层以上，这就否定了他们在对抗火箭时的效率优势。
These are probably why they never got much attention from the US navy or Air force. Despite multiple prototypes they were never deployed by the US military. Both China’s and the USA’s hypersonics programs are going after boosted gliders like DF-17 and DF-21D.
这可能就是为什么他们从来没有得到美国海军或空军的关注。尽管有多个原型，但美军从未部署过。中国和美国的高超音速飞行计划都在追求像DF-17和DF-21D这样的增强型滑翔机。
My vote goes to DF-21D. It has a much longer range, it seperates which makes it much more maneuverable and smaller during the final phase, it flies at a trajectory that all the US naval SAMs except the SM-3 are simply not capable of countering , and it carries a full fledged fighter-sized AESA radar.
我把票投给了DF-21D，它的射程更长，它的分离使得它在最后阶段的机动性更强，体积更小，它的飞行轨迹是除SM-3之外的所有美国海军SAM都无法对抗的，而且它携带了一个成熟的战斗机大小的AESA雷达。