Re: SpaceX News
Posted: Fri Jan 04, 2019 7:13 pm
So how does the need to spend weight on more shielding affect the weight savings?
Editpaperburn1 wrote:Or maybe a totally different problem is being fixed by the SS
https://www.wired.com/story/a-spacex-de ... g-the-iss/
I don't think that NASA has anything to do with it. Elon Musk himself said that it was because it was the better solution. My guess is that SpaceX has developed a new stainless steel alloy that is maintaining enough strength at high temperatures that it can be used without any TPS. Without a TPS, a stainless steel version might actually end up being lighter than the carbon composite version. Even if were to be slightly heavier, it would still have the operational benefit of not needing a TPS that potentially needs a lot of service between flights. Given the proposed uses for the Starship (including going to the Moon and Mars and regular intercontinental passenger flights), this by itself is very important.paperburn1 wrote:Editpaperburn1 wrote:Or maybe a totally different problem is being fixed by the SS
https://www.wired.com/story/a-spacex-de ... g-the-iss/
but the more I read and think about it Nasa might be clipping wings on this new bird. I just read the bracket report and I thing they are so resistant to risk they will not support carbon fiber until a large amount of testing is done. Spacex spent a huge amount on tooling to suddenly change directions so quickly. Just a point to ponder. any other thought out there?
It goes on to provide a good summary of what we've learned from his recent tweets:But above all these things, Musk is a geek at heart, in the sense that geek means a "knowledgeable and obsessive enthusiast."
He is knowledgeable about rockets and obsessed with their details. In sharing all of these tidbits about Starship, Musk is telling the world that he is really (really) freaking excited about Starship.
* The vehicle's exterior will be made from a stainless-steel alloy that will not buckle and will remain stable on the launchpad even when unpressurized. The strength and weight of "full hard stainless" at cold temperatures is slightly better than carbon fiber, at room temperature it is worse, and at high temperature it is vastly better.
* The metallic skin of Starship will get too hot for paint, so it will have a stainless mirror finish. It will need much less shielding as a result, and areas that take the brunt of atmospheric entry heating will be activity cooled with residual liquid methane. As a result, "Starship will look like liquid silver."
* A "radically redesigned" Raptor engine will be ready for test firing early this year. This is the engine that will power both the first stage "Super Heavy" as well as the Starship. For the test hopper, there will be three Raptor engines (there will be seven on the full Starship). Engines currently on the vehicle are essentially mock-ups. The first engine for hopper test flights "is almost finished assembly in California."
* SpaceX developed a "superalloy" to withstand the incredible pressures inside the Raptor engine and its hot, oxygen-rich gas. "Our superalloy foundry is now almost fully operational. This allows rapid iteration on Raptor."
* Musk expects the first hopper tests to occur in March or April of this year, sooner than expected. "I will do a full technical presentation of Starship after the test vehicle we're building in Texas flies."
* Musk believes a single-stage-to-orbit launch from Earth is "pointless." A large booster is needed to escape Earth's gravity well if one wants a decent-sized payload. But the single-stage Starship alone is great for launching from Mars and the moons of the Solar System.
As any seasoned farmer can confirm, regularly pruning a tree keeps it healthy and spurs fresh growth in the remaining branches.choff wrote:Saw a report SpaceX is laying off 10% of the workforce.
So that certainly clarifies that NASA wasn't the reason behind this decision. But while it's hard to knock his track record, this kind of statement makes me worried that he knows just enough to be dangerous. I think I would have felt better if this is something that had bubbled up from ongoing design work at a lower level.I was contemplating this for a while. And this is somewhat counterintuitive. It took me quite a bit of effort to convince the team to go in this direction. But now I believe they are convinced—well, they are convinced.
But Musk also at one point claimed that installing a solar roof would cost less than putting on a standard roof. Anxious to see numbers that support this.The thing that’s counterintuitive about the stainless steel is, it’s obviously cheap, it’s obviously fast—but it’s not obviously the lightest. But it is actually the lightest.
Only the "fairing" part of it. The part with the tanks and "legerons" is fine. The rest was built in a few days. So it should be an easy repair.Maui wrote:The Starship hopper was destroyed last night by a storm
https://forum.nasaspaceflight.com/index ... msg1904371