This is so mind boggling. They appear to be using modified building cement for high performance heat protection. This has to be really low cost if they can use cement for heat protection.
I too have been waiting for news from 凌空天行 and am intrigued by their approach to spacecraft design and engineering. But there are a few red flags that came to mind after my initial exuberance died down.
Firstly, the tone of the ads and how it reminded me of venture capitalist firms (especially those pursuing military or government contracts) in other countries. It is just so easy to stir nationalist passions and use that as a pretext to get people to believe in your brand, invest large sums, or perhaps ignore shortcomings, and that makes me wonder how viable the product is in fact. Maybe its just my cynical attitude toward corporate tactics and messaging in general, but I really got the vibe from that video like they were intending to manipulate their audience in some way.
Secondly, really loud alarms started to go off when I read about using "industrial standard" off the shelf components instead of more expensive parts that met aerospace standards. I mean, there is a reason for standards bodies to exist, and it isn't to be put on a shelf to look pretty. I could also save money by hiring a back-alley surgeon, but probably shouldn't.
Thirdly, and this is the most subjective red flag, their designs are just too good looking. Generally, highly engineered peices of equipment are made by teams of engineers who couldn't care less about appearance, and often have horrible taste. But 凌空天行's engines and spacecraft designs look like they were made by artists. Hats off to them if they have actually managed to marry form and function, but my gut tells me the ratio of showmanship to craftsmanship may be off.
It's too early to tell though, so I will just wait and see. Incidentally, foamed ceramics (not cement) have been put forth for heat sheilding since the early 70's but proved too brittle. I think Lingkong got their inspiration by just going down a checklist of every expensive part that goes into a product and refusing to accept the status quo. That's actually a really good approach, but I am really curious to see how the shielding holds up once more data is made public.