SpaceX is testing a stainless steel heatshield for the BFR. https://www.teslarati.com/spacex-orbital-starship-heat-shield-tests/amp/ It's a 300 series alloy (kitchen equipment is often made from 316 series) and I'm really curious as to what the expected lifespan of the heatshield is supposed to be. I've worked with a lot of 300 series and it's pretty easy to fuck up if you get it too warm. And they're planning on letting it get pretty warm.
Everyday Astronaut has a great video and write-up about it here: https://everydayastronaut.com/stainless-steel-starship/ The TL;DR version is that while carbon composites are generally stronger and lighter than stainless steel, moving to steel solves a bunch of other issues. As one example, carbon composites have less strength at cryogenic temperatures while steel actually gets stronger at low temperatures. A fully fueled rocket leaping off the launchpad is also the point when it's both the coldest it will get and the heaviest so needing the most structural strength. Carbon composites would require the use of extra heat shielding, whereas stainless steel can put up with higher temperatures and can itself be the heat shield for the most part.
AFAIK typically ceramic would be used for heat shielding, so stainless would be a lot lighter than that, especially if they do something like what was done in the skin of the XB-70 by using a sandwiched waffle structure.
No, but the principle is the same. It helps with heat diffusion, too, because of the added surface area. I mean, yeah, they wouldn't be able to just use the same design as the XB-70's skin, but it makes me wonder what they came up with and how well it will work. As I said, typically ceramics are used for heat shields because of their high heat resistance, but as Columbia illustrated, it's very brittle on top of being very heavy, and doesn't have a very long life span even under ideal conditions.
It wasn't the ceramic tiles that failed on Columbia, it was the carbon component on the leading edge of the wing that shattered after being hit by falling foam.
Technically, a spacecraft must travel between solar systems to be classified as a starship. One that merely enters space is properly called a spaceship.
SpaceX to attempt triple rocket landing today. https://www.space.com/spacex-falcon-heavy-arabsat-6a-launch-landing-webcast.html
All three landed successfully, the text of the article appears to be copy and pasted from the first launch when it refers to the center core running out of fuel. This time around the center core landed on Of Course I Still Love You, the furthest out to sea of any landing they've done to date.
Shades of the Apollo 1 fire, the Dragon crew capsule SpaceX was testing appears to have exploded. https://www.digitaltrends.com/cool-tech/spacex-crew-dragon-testing-anomaly/
SpaceX admits that their Crew Dragon capsule exploded during testing but doesn’t yet know why. https://arstechnica.com/science/201...efore-the-firing-of-its-superdraco-thrusters/
The Hopper gets another test next week. https://www.dailymail.co.uk/science...untethered-hover-test-WEEK.html?ITO=applenews
It had a pretty nasty “burp” last night and it looks like the next test will have to be delayed. https://apple.news/Acy4_WSsQR_ekPA3mSmuFyQ
