65

It seems to me that the SpaceX Starship rockets have sort of a homemade quality to them, like they were made in someone's garage with basic tools That is because they are! The "zeroth" prototype, Starhopper was built from November 2018 to March 2019 literally in a dirt field in Texas, in the open air. When Elon Musk announced in December 2018 that ...


57

There are many reasons. They include money, intellectual property, regulations, and Elon Musk. Money. Building open source software is relatively inexpensive, sometimes ridiculously inexpensive. No equipment is needed as most programmers have their own computers. There are many open source software projects where the developers do their work for free. ...


50

Starship alone is not capable of orbital flight, but it is capable of high suborbital flights sufficient for testing reentries. The booster's only use is as a first stage for Starship. It could only be put into use immediately if a Starship has been developed and built to stack on top of it. And it is expected to be much quicker and easier to develop than ...


48

Salt does all sorts of unpleasant things to just about every building material humans use. Hot salt spray, such as you'd get from a rocket launch, is even worse: spraying something with hot saltwater is one of the techniques used for corrosion testing. Build a launch pad over the ocean, and you'll need to clean it off after each launch to try to keep the ...


47

There are several compelling engineering and design reasons why a bigger spaceship makes sense and several reasons why making a mini-starship does not make sense for SpaceX specifically (and their vision). First and foremost, Elon Musk has made it clear that his goal for the company and the future isn't to provide cheap satellite launch capabilities, it's ...


46

So there are probably several things about which you are referring. They mostly stem from the same issue, which is using Stainless Steel for the hull of the vehicle. This has benefits that other questions have addressed. Why switch Starship from composite to Stainless? First off, they do not paint it, since stainless does not really need paint (Though they ...


45

There is not enough air on Mars. You would need absolutely humongous wings. There is no air at all on the Moon. Surely SpaceX can find a quick and easy way to get Starship vertical and in position for the next launch. Starship is not structurally capable of being in a horizontal position. It will simply crumple and/or break in half. Could you remove an ...


44

Musk is creating a Starship "production line", because obviously, he wants a lot of Starships. This aligns with the company's goal of "making humanity a multi-planetary species". As for "where is the market?": It doesn't exist yet. Currently, SpaceX's attitude towards space is "build it and they will come". Many large scale investment organizations ...


44

I wonder why nobody ever proposed a space launch system like Starship. What exactly do you mean by "like Starship"? Systems like Starship have been proposed before, although differing in the details, going back to Von Braun's mid-1950s Mars expedition concepts. Starship is ambitious in several ways, but it's more evolutionary than revolutionary. ...


41

Neither has much financial purpose without the other. A BFR cannot perform any useful function without an upper stage, and that is the BFS. Since the whole platform is a major investment in a new architecture, they are starting with the smaller piece - the BFS. Since it uses some of the same engines as the BFR, it can act as a testbed for both BFR and BFS ...


40

Sorry for the length of this, but it brings up some interesting facts and possibilities. The moons you mention, Titan, Europa, and Enceladus, are three very different places. Titan has a relatively large surface gravitational acceleration (as far as satellites go) and a very thick atmosphere; Europa has a relatively large surface gravitational acceleration ...


40

In my experience, I've noticed that SpaceX uses a lot of temporary components until such temporary components need to actually be tested. Since the legs of MK1, MK2, and most probably MK3 will never see uneven soils rather than concrete landing pads, they will most likely just have simple legs. After a few successes with MK3, we should start seeing much more ...


40

You're basically describing the Space Shuttle. The Space Shuttle wasn't even a good solution when it was designed. It had precisely one goal - to look like a plane for the image of the Air Force. As far as engineering goes, the Big Dumb Booster was already well proven, and is what every other solution to space has used. But in order to get Air Force ...


40

EDIT: Elon has revealed in multiple tweets (one, two, three, four) what went wrong, and although this doesn't tell us exactly what led to the explosion directly, it gives some insight to what went wrong. I will be updating this answer later... The proper answer to questions like, "What went wrong with SpaceX's [insert mission here]?" is: Unless ...


40

Fundamentally, it's because of economics. There simply wasn't any demand for a large rocket between today and the space race. Let's analyze what (I think) makes the Starship concept special: Size: Starship is one of the biggest (if not the biggest) rockets ever constructed. Reusability: One of Starship's core design goals is to be reusable comparable to ...


37

SpaceX plans to use autogenous pressurization for Starship. Autogenous pressurization means using the same consumable that is in the tank in its gaseous state to pressurize the tank. So, for the liquid methane tanks, you use gaseous methane for pressurization, etc. The landing failure of Starship SN8 was caused by low pressure in the methane header tank, ...


34

In the question you mention about why Falcon 9 uses four legs to land instead of three, there are multiple great answers. One of them by @David Hammen states that: "Another factor is that the Falcon has nine engines, one in the center and the other eight around it in an octagonal or square-like arrangement. The bottom part of the thruster reflects ...


34

This is some unsourced conjecture, since much of this simply comes from public observations of operations in Texas by the countless fans. They are running Boca Chica like a prototype Starship assembly line -- multiple test vehicles are under construction at all times. They roll sheet steel into rings, form bulkheads, stack the rings, etc in a multi week ...


32

Starship is a 9 meter wide vehicle. The first stage (Super Heavy) will be mounting 35 or 38 or some other number in that range of sea level engines. As you can imagine that will take at least three separate rings of engines. 6 in the center, then two more rings with the rest. The Starship is the same diameter as Super Heavy, and the inner ring will be ...


31

Elon Musk stated in a news conference after the Falcon Heavy launch that the BFS will be the focus because they think they understand designing booster rockets pretty well, and thus they decided to focus on the more difficult piece first. He answers this in response to a question that starts at 20 minutes 52 seconds here, and speaks specifically to starting ...


30

F9 can enter engine first because it isn't returning from orbital speeds. While fast, it's a fraction of the speeds something returning from orbit (or further) comes in at. So the engines are out as an entry surface, you need more protection. One way to achieve this is Dragon-style: put a heat shield on the bottom, and engines in the sidewalls. Great for ...


30

Anyone know what the story is? The main driver for the large number of engines on the BFR first stage is the desire to use a common engine design (albeit with different optimized nozzles) for both the booster stage and the interplanetary spacecraft stage. Building and maintaining only one type of engine makes things more efficient, and is a strategy that ...


29

Elon Musk posted a tweet on this topic: The Raptors were well below max thrust or the ship would have blown through the altitude limit. As we hit min throttle point, an engine would shut off. The issue was that three Raptors at full thrust would have gone too high, too fast. They needed to control speed and altitude to stay inside their allowed flight ...


29

SpaceX is doing two things in Boca Chica: Prototyping Starship and Superheavy Prototyping the factory for building Starship and Superheavy The second one is probably even more important than the first one: SpaceX wants to build a thousand Starships. And they want to do this as cheap as possible. They also want at some point to be able to do it on Mars, ...


27

This has been answered before, but I chose not to just mark it a duplicate because there is one new reason for the header tank unique to Starship. In a Reddit AMA in 2017 where Elon Musk answered questions about the original ITS design, he answered a question about the header tanks: Those are the header tanks that contain the landing propellant. They are ...


26

A couple days ago I watched this video which does a pretty good job of explaining the whole test. Basically: Take-off needed all three engines to reach enough altitude, so all three engines were initially fired up. As the ship was climbing up, higher altitude and lower weight due to fuel consumption meant less thrust was needed to reach the apogee and turn ...


26

It’s important to keep in mind what SpaceX is trying to achieve here and follow its logic. Their goal is to make humanity a multi-planet species and build a self sustaining city on Mars. And this is not just a sound bite as so many company goals are, this really is what SpaceX are about. To achieve this goal it must be practical, both in engineering and ...


25

I had the same question. Elon Musk confirmed the "engines did great!" There's also some discussion over here where the prevailing opinion is that the shutdowns were intentional. Just before the engine on the left of the screen goes out, you see all three of them gimbal. The one being shut down moved out of the way, and the others took up a ...


23

While this seems lightly ill conceived, it actually makes sense. Super Heavy is going to be very large, as these things go. 70m tall, 9m wide, and while not very dense, still quite heavy. Not very easy to move around. The plan is to land close by to make moving it back to the launch pad easier. Original plan was notionally to land back on the launch ...


23

Since the term "grain" is already in use in the solid rocket context, I'm favoring the term "cereal". Cereals contain about 66–76% carbohydrates -- mostly starch (55–70%) plus some sugars and cellulose. Cellulose combusted with gaseous oxygen yields surprisingly good specific impulse, up in the 240 sec range; sugars with potassium nitrate ...


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