Elon Musk Explains Updates to Starship and Tours Starbase

    >New grid fins on the newest boosters which have chines on the sides which will make re-entry performance better and allow Starship to come in at a lower entry velocity. And get a higher precision coming in for the tower catch. Slightly less cross-sectional area, but more pressure at the base. These are 'very primitive chines', our 1st attempt. They should get wider at the bottom. Why grid fins? They're more consistent than flaps/wings. At subsonic, the center of pressure shifts significantly (from supersonic to subsonic). The actuator power needed to turn a grid fin is much less to turn a flap/wing. We can definitely get away with 2, not more than 3.

    >>- When tiles get hot, they will expand and tighten the gap. The gaps you see here should get smaller as tiles heat up. You're not going to see a lot of heat going down through those gaps so shingling doesn't seem to be important. We want to minimize the peak heat load. This will determine if it will melt the tiles or not. You want to slow down as much as possible in the thin upper atmosphere to minimize peak heating. That's the goal.

    >>- We think we've learned what we needed to learn with the suborbital flights. So best to focus on getting to orbit.

    >>- The Starship orbital stack is going to come off the pad very fast. 1.5 thrust to weight. For a reusable vehicle you want a higher thrust to weight than an expendable vehicle. If it's below 1, it's not doing anything.

    >>- Cost per ton to orbit is the primary optimization. Any given technology is irrelevant to the degree that it produces cost per ton to orbit.

    >>- Right now the cost per useful landed ton to the surface of Mars is in excess of a billion dollars. This will have to improve to under $100k/ton in order to make life multi-planetary and have a self-sustaining city on Mars.

    >>- Starship is intended to be 10,000 times better than the current state of the art. Lot of orders of magnitude. It is possible to do that.

    >>- I think we need to move the forward flaps more toward the leeward side. Major internal debate. There's a massive amount of optimization that can be made with the forward flaps. They're the wrong size, in the wrong position, and wrong location. But they will work! I'm really not a fan of our forward flaps. Every time I look at them it drives me crazy because they're so sub-optimal. There's a potential scenario where we can delete the forward flaps entirely.

    >>- Megabay is about 4x the usable space than then Highbay. Many more positions for manufacturing the booster and the ship. A lot wider/deeper. Need many stations for high production.

    >>- Ground systems, especially inclusive of the tower, are as complicated as stage 1 and 2