# Tag Info

43

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 ...

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 ...

38

Because it's required by law (51 USC Ch. 509: Commercial Space Launch Activities) and by FAA regulations (14 CFR Chapter III - Commercial Space Launch Activities, Federal Aviation Administration, Department of Transportation) that implement those laws. Even amateur rockets are subject to some FAA regulations. A rocket going up 10 km is subject to quite a few ...

26

To expand a bit on David Hammen's answer, the reasons for the regulations requiring FAA permits for rocket launches are related to public safety (or sometimes the egos of bureaucrats, but mostly public safety.) There are a couple of particular areas that these fall under: Range Safety Obviously, rockets carry a lot of fuel and often very toxic materials (e.g....

19

Unlikely to be plausible. During belly flop descent the forces placed on the horizontal Starship are distributed over the windward side very evenly. The cylinder walls represent the majority of the frontal area and the flaps are fluttered back taking less than their full potential drag - and their mounts are still naturally broad and spread the additional ...

19

The angular resolution of the Hubble and James Webb telescopes are about the same - both are around $0.05$ to $0.1$ arc seconds or about $4 \times 10^{-7}$ radians. If we express the angle $\theta$ in radians then the distance subtended by that angle at a distance $r$ is just $r\theta$. Starman is about fifty million kilometres away, and at that range \$4 \...

17

Notice how it came down quite a bit askew apart from not halting the main rotation of the flip: they need two engines for roll control during the maneuver (you can see the engines gimbaling independently to control roll during SN8's flip). Even if this wasn't so, during the flip they have reduced drag slowing their descent: a slower flip means more downward ...

16

Though many say that success directly reflects how hard one works or how motivated one is, there is a huge amount of random "luck" involved; being in the right place at the right time, meeting just the right people who may be helpful later, etc. This leads to the following advice. Choose a path that has you doing things that you really enjoy doing: ...

16

Hubble is one of the few telescopes that could possibly image Starman, as a dot. James Webb will have far more sensitivity. It's a really small space rock in a really big space. You can take a look at https://www.whereisroadster.com/ which has information on how big of a telescope it would take to see it, and to resolve it, updated in realtime. The answer ...

12

In addition to the other very valid answers, at the moment we see Starship flying alone and can easily visualize adding wings, but in orbital mode it will be stacked atop the superheavy booster. Adding large wings to the top of a rocket makes it very unstable, akin to making a dart fly backwards source, and would need to be stacked at an odd angle to zeroise ...

12

Wings are heavy. Surprisingly so. As Jorg pointed out there is no air on the Moon, and Mars's atmosphere is pretty thin. In fact, Starships payload to the Moon is surprisingly low, because it has to carry all the fuel to land entirely propulsively. Cheating by using air resistance is important.

11

The SpaceX Starship is a very ambitious design still in its very early stages of development. The SN8 and SN9 both had about 7 seconds between completing the flip and landing. G forces decelerating from around 7 meters/second to 0 in 7 seconds work out to a very survivable 3 Gs. However, it must be pointed out, sans atmosphere on the moon, and very little ...

8

I can't tell you a specific job, but I can help you narrow it down quite a bit. The best way to start answering this question is to go look at the job openings that Space-X currently has listed, and what the requirements are for those jobs. https://www.spacex.com/careers/ You can also go to third party websites like indeed.com that list the same jobs, but ...

8

I think we can safely rule out a live rat at second-stage altitudes. The most likely explanation is that the "rat" is a lightweight piece of debris (possibly from the stage separation event), or a collection of ice chips, caught against the crescent-shaped manifold wrapped around the upper part of the nozzle. Under the acceleration of the rocket, ...

8

In addition to the answers to this near-duplicate question, you should note that a solid rocket casing is much sturdier than a liquid fueled stage. The shuttle SRBs were deformed by the force of the water impact and had to be re-rounded as part of their refurbishment; a Falcon 9 first stage would be completely crushed in a similar parachute landing, not to ...

8

On Earth, you need only build a suitable runway. Have a look at the Fly Back Booster concept from the 1990s. Gliding can lower rate of descent even better than parachuting, and at high landing speeds not a lot of wing is needed. One can only imagine a time traveler going back to the 1970s and meeting von Braun. We might have some idea what the NASA SLS ...

5

The problem wasn't the ignition mechanism - that's done with a sparking system. The problem (appeared) to be the fuel supply to the engine. You could see it was attempting to relight (and successfully lit a few times), but appeared to not be getting the stable fuel supply to maintain the flame. A can can't help with that. The biggest problem with spinning ...

5

Everything that goes above FL 180, about 18'000 feet needs a flight plan, which has to be filed with the FAA that can approve or not

5

No, they can't, for two reasons: When SpaceX recently test-fired the vacuum-optimized Raptor engine, they had to carefully manage the thrust and install additional bracing on the nozzle in order for it to not disintegrate. And you can still see the nozzle shaking and flexing quite a bit, even with the additional structural reinforcements. The vacuum-...

5

I'm surprised that nobody mentioned yet that another likely cause is that the thrust to weight ratio is too high to allow for an efficient flip "too high up above the ground". Let's take as a basic assumption that Starship requires 2 Raptor engines to land (others have mentioned roll control as one reason why this would be needed). Going off public ...

5

As an employee of SpaceX for many years, I can tell you that military experience is not something that goes very far in who they hire. Also, I can't think of anyone I knew there who had an electrical engineering degree. Your best shot at landing an engineering role at SpaceX is to get a mechanical engineering degree and have a strong interest in rocket ...

4

If I were you, I would do anything to do with repairing stuff. Airplane mechanic, ordinance technician, etc. There's a huge amount of demand for that kind of person. If that isn't your thing, you could try to work at one of the various command centers, such as the C-SPOC (Space Track). Just take a look at the Air Force careers website, start picking ...

3

A better question to ask might be: why do planes not land vertically, and instead require a long runway? The answer is that the engine (or more precisely the propellor or fan stage it drives) lacks sufficient thrust to overcome gravity, and therefore the plane relies on air passing at speed under its (large) wings to maintain lift. Rockets have enormous ...

3

It all depends on the initial conditions. If you need to create a large volume for the accumulation of resources in the shortest time, then this is ideal. For example, as accumulators of oxygen produced from regolith. For residential premises, it makes sense to deliver from Earth ready-made modules to the surface and bury them in trenches. It will be safer ...

3

Frankly, until 3d printing gets significantly better (as in print circuit boards and complex electronics better than printers print thermoplastics today), "open source hardware" doesn't really make sense because it doesn't have the key advantages that open source software does: Accessibility: Anyone with an internet-capable device can download an ...

3

The reason for the multiple inlets is to ensure that the header tank can be filled from the main tank when the tank level is low and the rocket is leaning to one side, whichever side that might be.

2

I think their preferred term is "Hover slam" not suicide burn. This is somewhat answered in a different question:Boostback, reentry, and landing burn times and it is about 32 seconds. We saw on the NRO mission, where they asked SpaceX not to show fairing deploy or any video from the second stage (Spooks, whatcha gonna do?) that they played the ...

2

You would need to bring along more rocket engines. If the thrust axis does not go through the center of mass of the craft the craft will rotate and landing while rotating is a crash. The Starship has all it's engines at the rear--incapable of pointing through the center of mass unless they're pointed virtually straight down.

2

Yes, reopening the fins mid-flip would of course increase drag and help to stop the flip. I'll guess that SN9 didn't do that because the increasing weirdly turbulent drag during reopening is much harder to model than the force exerted by the gimbaling engine. Less predictable response demands bigger safety margins: more fuel, faster gimbals, faster throttle ...

1

That is a complex question that depends on what the company's goals are among many other things. If the intention is to create a rocket with the highest specific impulse then hydrogen is the way to go. Although why that of itself would be the goal is unclear. Hydrolox engines have a potential performance advantage in upper stages. However the benefits are ...

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