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 , cargo to the ISS (International Space Station), land and reuse a booster, and a crewed mission into orbit. See the wiki for related tags.

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What computer and software is used by the Falcon 9?

I don't know if this would be public, but what CPU / Microcontrollers are used and what software do they run on the Falcon 9? Do they use an OS or is it just bare metal programming? I found some ...
neelsg's user avatar
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97 votes
3 answers
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What happens to the Falcon 9 second stage after payload separation?

In a Falcon 9 launch, the second stage looks like it achieves orbit along with the payload. But is that impression accurate? Does SpaceX need to do anything to deorbit the stage? I can see a few ...
Hobbes's user avatar
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77 votes
6 answers
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Is the SpaceX Falcon Heavy payload (a Tesla car) space junk?

Yesterday SpaceX succeeded in the first Falcon Heavy launch, but the payload, a Tesla car has no real useful purpose (except for company prestige). Thus, can it be considered as space junk ? How long ...
Covich's user avatar
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74 votes
5 answers
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Difference between BlueOrigin and SpaceX rocket landings?

So, SpaceX has finally landed their booster back to the land. BlueOrigin has achieved the same thing in a recent past, but I have read so many people commenting and criticizing the comparison of ...
Riley Willow's user avatar
71 votes
10 answers
55k views

Why is SpaceX considering Methane as fuel for their next engine, the Raptor?

Currently, SpaceX has developed the Merlin 1 family (1B (Falcon 1), 1C (Falcon 9 v1.0), 1D (Falcon 9 v1.1/F9-R/Falcon Heavy), vacuum versions and sealevel versions) which are LOX/RP1 based. (75-...
geoffc's user avatar
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71 votes
5 answers
20k views

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, ...
PhilippNagel's user avatar
67 votes
8 answers
39k views

Why would SpaceX not use parachutes for the final descent of the first stage?

According to what I've read, SpaceX tried to use parachutes to recover the first stage of the Falcon 9, but it did not survive reentry. Now they plan to use 2 separate rocket burns to land: Reentry ...
neelsg's user avatar
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66 votes
6 answers
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Can I drive Elon Musk's Tesla after it's been in space for 100 Years?

We know that the the payload of the maiden Falcon Heavy flight will be... Elon Musks's Tesla Which will be placed in "Mars Orbit" Assuming it is serviced and road ready when launched with the keys in ...
James Jenkins's user avatar
62 votes
6 answers
20k views

Why does the SpaceX reusable launcher use vertical rather than horizontal landing?

As alternatives to vertical retro-engines landing: horizontal landing using wings, already discussed in Why is it preferable for SpaceX to land their booster vertically rather than fly it down with ...
mins's user avatar
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60 votes
5 answers
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What are the towers around the SpaceX launch pad used for?

I noticed four(?) towers around the SpaceX launch pad during yesterday's aborted launch Image credit NBC News What are the towers used for? Tracking? Radio communications?
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57 votes
2 answers
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How does the Falcon 9 first stage avoid burning up on re-entry?

Now that a Falcon 9 first stage has successfully landed after a launch mission, I want to know how the first stage can avoid burning up when coming back down to earth. There doesn't appear to be any ...
Rickest Rick's user avatar
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56 votes
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Why doesn't the Falcon-9 first stage use three legs to land?

The immediate thought that would probably come into your mind would be "Because 4 legs is more stable than 3." However that is not always true. 3 legs offer the same or in some cases more stability as ...
Star Man's user avatar
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55 votes
4 answers
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What was the fate of the main core of the first Falcon Heavy launch?

February 6th 2018 saw the first test launch of SpaceX's Falcon 9 Heavy rocket. During the main core's landing on the marine landing pad, the connection was lost. As such it is not immediately clear ...
JAD's user avatar
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51 votes
1 answer
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In Starman's roadster, where's the Towel?

Did Starman forget his towel? A towel is the essential thing every explorer needs to carry, right? Can't get very far without it.
Jake J's user avatar
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50 votes
2 answers
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How does the SpaceX Falcon 9 first-stage straighten for landing?

I just saw this video of supposed "SpaceX Rocket Camera Landing Footage Fakery" with over a million views. The narrator repeatedly says it's complete garbage because he doesn't understand ...
Hugo's user avatar
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3 answers
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Why would NOAA restrict the ability of SpaceX to live stream the second stage?

I was watching the live stream of the Iridium-5 launch and they mentioned that NOAA had restricted their ability to live stream the second stage and that SpaceX was working to remove this restriction. ...
Machavity's user avatar
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48 votes
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Is Starman wearing a seatbelt?

While staring at the live feed of a crash dummy in a convertible in outer space, I was wondering: Is this crash dummy following safety conventions and wearing a seat belt? I somehow doubt that it ...
Mithical's user avatar
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43 votes
4 answers
11k views

Why can't Falcon 9 fairings touch the water?

SpaceX is spending considerable effort to catch Falcon 9 fairings into a giant net on a ship. I am aware that salt water ruins almost everything in the long run, but the fairings are a composite ...
filo's user avatar
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43 votes
3 answers
10k views

Is a SpaceX launch completely automated?

Once the engines are ignited and liftoff occurs, are any operators/controllers on the ground making any manual changes to the flight? Or are they simply monitoring the entire event until the boosters ...
v15's user avatar
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43 votes
2 answers
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What is that haze on Starman's windshield?

There is a haze on the top half of Starman's windshield? It was not there in the first day o fthe launch and the video feed. It looks like fogged window, but assume it cannot be that. What is it and ...
kdobrev's user avatar
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42 votes
3 answers
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SpaceX merlin engine failure

On SpaceX's website, they make a claim that their rockets are the safest and most reliable in the industry. This is because apparently it can complete its mission even if up-to two of its engines fail ...
Urvish Ramaiya's user avatar
41 votes
5 answers
15k views

Why did the SpaceX Starship SN10 explode?

Much to everyone's relief. The SpaceX Starship SN10 successfully completed its flight and landed..... But, sometime later, It exploded! Why? And did it have anything to do with the fire near the ...
Đαrkraι's user avatar
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40 votes
4 answers
13k views

Before we build a Mars colony, why don't we build a 100% self-sustainable test colony in the Antarctic?

Before we go to Mars, why don't we build a sealed dome self sustaining colony in the Antarctic? One that can heat itself, recycle all materials, water and waste. Grow enough plants to produce oxygen ...
Bretton Ferguson's user avatar
38 votes
6 answers
9k views

Why did it take so long for methane to be used as a rocket propellant?

SpaceX have put methane on the map as a rocket fuel, but they weren't the first to consider its use. The first experiments in building a rocket engine that uses methane date back to 2007. Now methane ...
Hobbes's user avatar
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38 votes
4 answers
6k views

After the Crew Dragon's success, does Boeing's Starliner still offer value?

Boeing's Starliner is more expensive than Crew Dragon and seems not to offer any significant advantages. Is there still value to NASA or other parties in the future to having a choice between the two?
Anixx's user avatar
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37 votes
4 answers
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Why did Starhopper's exhaust plume become brighter just before landing?

In 2019 Aug 27's test flight, during the final 8 seconds before landing (T+00:45), Starhopper's plume was suddenly much brighter. Why? The Raptor's thrust can't ...
Camille Goudeseune's user avatar
36 votes
1 answer
5k views

What are these shiny wrist plates worn by astronauts in the SpaceX crew capsule

What are these shiny wrist plates worn by astronauts in the SpaceX crew capsule? screen shot from the NASA YouTube video Watch NASA's SpaceX Crew-1 Mission Arrive at the International Space Station
Bel Chavarria's user avatar
35 votes
3 answers
8k views

What is the primary reason for SpaceX motion to have astronauts board Dragon before fueling up the rocket?

News piece: NASA supports SpaceX plan to fuel rockets with astronauts on board. The move is criticized by many as unnecessarily dangerous. From what I understand though, it shouldn't be necessary - ...
SF.'s user avatar
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35 votes
2 answers
5k views

SpaceX and propulsive landing on Mars -- what just happened? (and why?)

There is some news that I've just read about in the Pod Bay SE chat room: Wired: SpaceX's Mars Plan Hits a Pothole. Up Next: The Moon? Ars Technica: Elon Musk’s Mars rocket may be about to lose half ...
uhoh's user avatar
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Why was AMOS-6 mounted on the rocket for a test fire?

I understand that the static test is a general test of pre-launch procedures, but risking a multi-million dollar payload for a test seems remarkable. Couldn't they use a mass simulator or something? ...
Abacus Lever's user avatar
35 votes
1 answer
10k views

Why does the Falcon 9 consume hydraulic fluid?

According to many news articles, the crash of the Falcon 9 during landing on 1/10/2015 was due to running out of hydraulic fluid for the steerable hypersonic grid fins. This was seemingly confirmed ...
pbristow's user avatar
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34 votes
8 answers
9k views

Why not land SpaceX's Starship like a plane?

I get the reasoning behind designing Starship to land upright. It doesn't require landing gear and the turnaround is expected to be much faster. But I'm beginning to question that logic. I think the ...
loweryjk's user avatar
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34 votes
6 answers
21k views

Why did SpaceX attempt to land the booster on a barge instead of somewhere on land?

I understand the benefits of reusability for the rocket booster. But I don't understand why they're landing it on a barge. I've read tons of articles about this but not one has even hinted at an ...
user avatar
33 votes
2 answers
10k views

What holds SpaceX’s rocket in place in this launch?

On a recent launch video, the gantry is at an angle and only loose tethers are attached as the rocket is prepared for launch. What is keeping it upright and in place at this point? The engines haven'...
MarsJarsGuitars-n-Chars's user avatar
33 votes
3 answers
7k views

Why is there any launch window at all for the Falcon Heavy test flight?

Why is the window only ~3 hours long, why not 2? why not 5? why not "until it launches"? I'm guessing range safety, they could only get a TFR that long?
Sam's user avatar
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33 votes
4 answers
6k views

Will the Falcon Heavy be far enough in 12 seconds to not cause damage?

Elon Musk has stated that he will consider it a success if the Falcon Heavy gets far enough away from the launch pad to not cause damage if it blows up. The Falcon Heavy underwent a 12 second static ...
PearsonArtPhoto's user avatar
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32 votes
3 answers
15k views

Why does the SpaceX Falcon 9 rocket do a 180 flip for reentry?

I am very new to the rockets and this can be a very dumb question, just that I am not sure if my understanding here is right? All of the rockets engines are at bottom which help it take off and ...
KP.'s user avatar
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32 votes
4 answers
7k views

Is it possible to track an object as small as the Tesla Roadster around the Solar System

I have heard that we will soon lose track of the Tesla Roadster launched with the Falcon Heavy test launch. Yet, we know where Voyager is out beyond the Solar System and we followed other satellites ...
Dan Sorensen's user avatar
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31 votes
6 answers
7k views

Why is SpaceX not also working on a smaller version of Starship?

SpaceX is planning to retire Falcon 9, which would leave it with only Starship. While a Starship launch is expected to be cheaper than a Falcon 9 one, a downscaled Starship launch would be cheaper ...
Stephane Bersier's user avatar
30 votes
3 answers
5k views

Could a Falcon Heavy test flight be responsible for these observations?

We observed a bright, slow moving (in our view for several minutes) large object that eventually left large bright contrails. This was over Northern New Mexico at around 7:29 PM MST. The object was ...
MT Hensley's user avatar
30 votes
3 answers
7k views

Why won't they recover the Falcon 9 from CRS-14?

According to the upcoming livestream of SpaceX CRS-14 (resupply of ISS): SpaceX will not attempt to recover Falcon 9’s first stage after launch. Why not? Wasn't that the whole point of (among ...
Mast's user avatar
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30 votes
2 answers
17k views

What is a thrust puck on Starship?

Elon Musk recently mentioned a Thrust Puck on Twitter, "We’re stripping SN2 to bare minimum to test the thrust puck to dome weld under pressure, first with water, then at cryo." He also mentioned ...
PearsonArtPhoto's user avatar
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29 votes
6 answers
12k views

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 ...
Abdullah is not an Amalekite's user avatar
29 votes
4 answers
2k views

What started the explosion on the crashed Jason-3 stage landing on the barge?

If you watch the truly awesome video of the Jason-3 first stage landing on the ASDS Barge Just Read The Instructions, it is pretty clear that for one thing, they landed it. Then the leg gave out, ...
geoffc's user avatar
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29 votes
2 answers
5k views

Why do Crew Dragon astronauts need to climb up one level using the stairs before ingress?

While watching the launch of SpaceX Crew Dragon, I noticed that, once the astronauts came out of the elevator in the fixed service structure, they had to 'climb up' one level using the stairs, before ...
Vishnu's user avatar
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28 votes
4 answers
8k views

Why does the Falcon 9 have 9 engines?

What are the reasons for using 9 engines in the first stage of the Falcon 9? Why not 8 or 10? Looking at the Raptor engine, they seem to be looking at 9 engines again. Is there some specific advantage ...
neelsg's user avatar
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28 votes
3 answers
10k views

Does launching a device into orbit change earth's orbit?

Does launching a space shuttle or rocket change the earth's orbit? After all, to get momentum in space you need to throw something out.
Manish Sain's user avatar
28 votes
3 answers
11k views

What makes 21st century fairings so valuable that they'd potentially be recovered and re-used?

I've read in @geoff's answer that SpaceX is doing some experimentation that may lead to fairing recovery capability. In fact I remember hearing Elon Musk mentioning a few years ago that it was being ...
uhoh's user avatar
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28 votes
4 answers
19k views

Is the SLS irrelevant if the Falcon Heavy launch is successful this year?

My take is that, like so many bad, and good, NASA ideas, the SLS will get the axe after spending billions on the NASA subcontractor(s). Regardless if the SLS comes to full life cycle, NASA will not ...
CDS's user avatar
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28 votes
1 answer
4k views

Why the soot pattern on the nosecone of Falcon Heavy side booster?

When a SpaceX booster is landed, we are used to seeing soot deposited all over it, usually in a specific pattern. You can read more about that in this question: Why the strange bands of soot of the ...
geoffc's user avatar
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