Questions tagged [spacex]

Space Exploration Technologies Corporation, or SpaceX, is a private space exploration company. It was the world's first privately held company to successfully launch a cargo mission into space and a crewed mission into orbit. See wiki for related tags.

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Do Falcon 9 grid fins lock up during reentry?

Do Falcon 9 grid fins lock up when extended during reentry? Or do they rely on aerodynamic forces to keep them extended once they're deployed? Could the fins flail down during the reentry burn when ...
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Isn't Starship way too big?

The Shuttle was designed with a huge payload of 20 tons. This was supposed to not be a problem since the reusability would drive down costs until satellite operators dropped expensive space hardware ...
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SpaceX 2nd stage or tumbling satellite? WSW to NE over FL

Around 2040 EST We viewed an irregularly flashing object flying from WSW to NNE (roughly) from Jacksonville FL. Is the SpaceX 2nd stage still up there and if so, would it be tumbling and visible? Is ...
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Minimum reentry velocity ideal for a spacecraft returning to Earth

During the return trip from Mars or Moon, SpaceX starship can refuel it's propellant tanks before reentry. It can use these propellants for reverse thrust to bring the spacecraft velocity to near idle ...
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How big are the risks of Starship flipping during or after landing on the Moon?

Now that NASA has announced the selection of SpaceX to manufacture the Moon landing vehicle(s) for the Artemis program, I can't but notice how tall Starship is when compared to other concepts. Chances ...
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Evacuating the ISS but wait, there's only one Spacecraft?

I was doing some research regarding the Soyuz as I'm currently planning a summer project in which I would build a close replica of a Soyuz when the question popped into my mind, "What would ...
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How problematic is debris for Starship storage/depots?

So with the recent announcement that Starship has been selected as NASA's HLS (which is pretty radical), it's raised a question in me that been around for a while. For HLS; a Starship storage(depot) ...
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What is the cause of the blue light from LH2/LOX rocket engines?

Below are some screen shots from circa June 2016 launch (or re-launch) videos by Blue Origin (video link) and SpaceX (video link). The New Shepard burns $\text{H}_2$/$\text{O}_2$, while the Falcon 9 ...
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How does this fast-slewing SpaceX rocket-tracking dish track a moving spacecraft?

Elon Musk's recent tweet shows a video clip of a modest-sized dish on fairly fast-slewing mount located: At SpaceX Boca Chica launch site in Texas In the question Why is the reflector on this ...
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SN11 was launched in fog. Why not wait for better conditions?

The fog certainly frustrated the external observers, but it doesn't seem ideal from SpaceX perspective either. All the external observers were very distant from the launch/landing site and would be ...
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Should the SpaceX Starship static fire tests more closely match actual flight parameters?

Under the current 10 km flight program, all 3 Raptors are used at launch. During the ascent, they shut down one at a time. After a flop and free fall of several minutes, they are reignited, with the ...
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What is this “space ring”? Is it SHERPA or something new, or just “art”?

In the orbitalreflector.com website there is a picture of a ring that looks like it can deploy smallsats as part of a more complex launch. Reverse image search turns up another view, both shown below. ...
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What all is included in the contraption around Star Man?

In the streaming video, we can see a mannequin sitting in a car. It is fairly evident there is more to it than that, the cameras are clearly on some sort of supporting arms extending from the car, ...
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What's the atmospheric drag coefficient of a Falcon 9 at launch (sub-sonic, large fairing)

While I said just a few hours ago that "There's almost no such thing as a dumb question! this one just might sound like one. I'm making some slides about first principles thinking applied to ...
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Why have SpaceX skipped the SpaceX Starship SN12, SN13, and SN14?

Something has happened to the SpaceX Starship SN11. (For full details and answers regarding SN11, check out the question What happened to the SpaceX Starship SN11?) Elon Musk recently posted this ...
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What technology will SpaceX's StarLink satellites most likely use for sat-to-sat linking?

The question How does SpaceX plan to make money with StarLink Broadband? has got me thinking about how the satellites will link to each other. Wikipedia says it's something greater than 10,000 GHz and ...
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Is Starship planned to fly directly to the ISS without first stage? Is it even possible?

I'm having difficulty understanding how/if Starship and/or Super Heavy could be used to deliver crew to LEO. Is it expected to deliver astronauts to the ISS Crew-Dragon-style, but without the 2nd ...
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Methane or LOX tank at Boca Chica

As we can see on this picture from Mary "@bocachicagal" on NASASpaceFlight, there are two types of tank near the test stand. Some are black and others are white or bright and shiny metal, ...
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How will SpaceX Starship deploy its payload?

Most modern orbital launchers like the SpaceX Falcon9 have their payload at the front covered by a fairing which splits in half, ejecting the fairings and exposing the payload for deployment. With ...
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Are the engines present on the SpaceX Starship Sea level engines or Vacuum engines?

The SpaceX Starship will have engines that light up in space and propel the ship to Mars. Companies and organizations use vacuum engines in space. However, Starship has to land on Mars, travel back ...
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How much krypton is stored on a Starlink satellite?

How much krypton (fuel) is there for the krypton-powered ion thrusters on Starlink satellites and how long does it last?
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What happened to the SpaceX Starship SN11? Why did it crash?

What happened to the SpaceX Starship SN11? As per the live streams held on YouTube, I want to know what really happened to SpaceX Starship SN11 The live streams show a lot of smoke and others show ...
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Is Starlink VisorSat really dimmer?

Basically a repeat of Is Starlink 1130 (Darksat) really dimmer? but this time with Visorsat. What is the observed brightness of VisorSat(s) and is it dimmer than non-Visorsat Starlink satellites?
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Why SpaceX is keeping it's space industry policy transparent?

SpaceX has many global competitors, both private and government funded, in the space industry. But it is following a very transparent approach during the construction and testing phases. What possibly ...
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Why do SpaceX Starships look so “homemade”?

Maybe this is not possible to answer, but I was hoping there was some reliable information available on this. It seems to me that the SpaceX Starship rockets have sort of a homemade quality to them, ...
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How much does the SpaceX Starship flex during the Flop maneuver?

Poring over the woes (and sucesses) of Starship prototypes SN 5-11, I had read they were trying a thinner stainless steel skin in later iterations. The flop maneuver places the centers of drag at the ...
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Could another fuel be used in the SpaceX Starship header tank?

A memory of hexane and water in a separatory funnel brought to mind the issue of helium and LNG in the header tank while the Starship flips and does its powered landing. There was discussion of the ...
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Doesn't dirt get into critical Starship parts?

I guess that once Starship prototypes are complete they should be pretty weather- and dirt-proof. They should be perfectly sealed and stainless steel is well-suited to life outside (though sometimes I ...
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174 views

How does the economics of orbital refueling vs bigger rocket work?

SpaceX plans to refuel Starship in orbit for Moon and Mars missions. According to some other questions here, it seems like they would need 6 tanker Starships to send 1 Starship to Mars. At a glance, a ...
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468 views

Regulations preventing SpaceX from saying “no” if OneWeb asked them to launch their satellites?

The Forbes article With A Successful Launch, OneWeb Just Joined SpaceX And Others In The Satellite Internet Race says: This marks a turning point in a new generation of communications satellites, ...
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How did the SpaceX come up with such a disruptive design in the Falcon 9?

Because of the answers to Why has a rocket system like Starship never been proposed before? , now I need to ask something I'd always taken for granted. If Falcon 9 wasn't revolutionary for technical ...
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Can someone explain the SN10 landing failure in layperson's terms?

The things I can't understand from what Elon tweeted are: "engine was low on thrust due (probably) to partial helium ingestion" There are only tanks for liquid oxygen and CH4 - where did ...
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Is this explanation for the SpaceX 1-Sept-2016 anomaly plausible?

Question: Is this explanation for the SpaceX 1-Sept-2016 anomaly plausible? Or most of it at least (sans LHe)? In the recent New Atlas article SpaceX fingers helium as cause of Falcon 9 rocket ...
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Liquid Helium (4.2K) sealed, then raised to sub-LOX temperature (~70K) - what is the new pressure?

In this question there is discussion of the large differences in temperature between liquid helium-4, subcooled liquid oxygen (sub-LOX) and cold kerosene (RP-1). Approximate temperatures are 4.2K, ~...
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Why is heated Helium used for tank pressurisation in Falcon 1?

Here in Falcon 1 user guide, in table 2-1 in page 8, heated Helium is mentioned as used for tank pressurisation. What will be the temperature of such He and why is heated He used?
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How much helium and nitrogen are used in SpaceX's Falcon 9?

How much helium and nitrogen are used on SpaceX's Falcon 9?
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Why does the Falcon 9 require a helium pressurization system?

The Space Shuttle was designed in the seventies and did not require a helium pressurization system. Why does the Falcon 9 require one? What are the advantages/disadvantages?
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Does the Falcon Heavy also use a helium system?

The Falcon 9 uses a helium system to pressurize the tanks. Does the Heavy first stage also use helium? How big would the explosion be in case of a failure assuming the boosters would go too?
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Does SpaceX recover and reuse tank pressurization helium?

Given that SpaceX have successfully landed several Falcon 9 boosters and that these vehicles use helium pressure-fed engines, when these vehicles land, their propellant tanks will presumably be mostly ...
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Flying saucer shape rocket vs cylindrical shape rocket

Here's my hypothesis- Cylinder shaped large rocket is not suitable for vertical landing due to its high center of mass and bulky weight. However an equally weighing saucer shape rocket has more ...
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What secondary payloads, if any, are launching on the inaugural flight of Falcon Heavy?

Overshadowed by a silly, yet awesome primary payload — 'a cool colored cool electric sports car playing a cool track' on to a heliocentric orbit, are there other satellites/secondary payload Falcon ...
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How can NASA be prevented from becoming too dependent on one rocket company or vice versa?

Wouldn't it be an unhealthy situation if NASA were to become too dependent on one company, for instance the only one that could launch heavy rockets ? And also, if a private rocket company's existence ...
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SpaceX launch simulation software?

Say you're a SpaceX launch engineer. You have a mission design meeting where you'll talk about different mission scenarios. The meeting is in a few hours. Would you run a quick simulation in KSP to ...
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Design of starship fins

How much can the falling speed of starship approximately be reduced by the bellyflop fall with fins? Are we talking about numbers around 5% or 50% here? Wouldn't it make sense to put holes where the ...
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What is super heavy booster? What will it be used for?

Also called BN1, right? Please explain me what is booster and what will it be used for? Also feel free to give me additional insights other than included in my question about BN1.
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Static Fire Tests: How is the rocket prevented from flying?

In rockets like Starship, if 35 Raptors are firing at same time, then in a full-duration static fire test there would be enormous loads being exerted from 35 raptors, on the clamps holding the rocket. ...
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Why SpaceX want to land the rocket on the ground?

click for full size Won't it be easier and save a lot of money to just catch it or land it in a basket? So rocket coming down can open arm longer than the diameter of the high basket where it goes ...
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What will be “unique” about upcoming SES-9 GTO transfer profile by SpaceX?

In the SES-9 mission press kit, SpaceX mentions: "Given this mission’s unique GTO profile, a successful landing is not expected." What is considered "unique" about this transfer orbit's profile? ...
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How did SES-9 reach geostationary orbit from inclined transfer orbit (from F9 2nd stage)

The Spaceflight Now article Flight timeline for Falcon 9’s launch of SES 9 says near the end that the Falcon 9 2nd stage will leave SES-9 in an elliptical, inclined transfer orbit. And Falcon 9 rocket ...
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What is a static fire test?

I watched SN10 launching but not the static fire test. I am closely following SN11 launching, and read about a static fire test today. I don't know what it is. Can someone please explain "static ...

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