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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3
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0answers
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Altitude at which Falcon boosters go subsonic during reentry

Is there a distinct altitude at which Falcon boosters goes subsonic during reentry? If so, which is it? Is it +/- the same altitude for every flight?
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Why does the government still fund SLS while SpaceX is cheaper and has the same capabilities if not better?

Due to SpaceX's recent advancements in now proven rocket tech, why does the government still fund (what some would argue to be bloated) cost-plus contracts with Boeing and Lockheed? Am I missing ...
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1answer
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Falcon 9 second stage roll control: fins or dracos?

Unlike the first stage, the second stage has just one gimballed engine, meaning it can counter pitch and yaw perturbations, but not roll perturbations. Fins are effective for roll control, but at 50 ...
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How will the recovery of the first crewed Crew Dragon water recover differ from previous recoveries of Crew and Cargo flavors?

The NASA video Expedition 63 Inflight with New York Times, Fox News, and USA Today - July 7, 2020 includes an interview with Fox News reporter Bill Hemmer, who asks: I am most interested in your ...
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1answer
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Why would the Falcon 9 Block 5 carbon fiber thermal protection material need to be hydrophobic?

This answer to Nature of “the silky black 'highly flame-resistant felt'” on Block 5 Falcon 9's, and its intended functions? contains the following: This came into Falcon 9 design with Block 5 ...
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1answer
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Can SpaceX Starship Be laid on it’s side?

SpaceX is building Starships at a good tempo and may finally build them faster then they scrap them. The Falcon 9s have always been stored horizontally and erected at the launch pad. I’ve never seen a ...
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1answer
265 views

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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how much force can a falcon 9 landing leg handle

According to spacex, the falcon 9 landing legs are made of carbon fiber with aluminum in a honeycomb shape. How much force would be needed to break that?
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1answer
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Do the ASDS barges have mission specific equipment?

End of June 2020, there was a planned Starlink (L9) mission on Jun 26, and OCISLY (Of Course I Still Love You, name of the vessel, really! Not making that up!) went out catch the stage. Then a few ...
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4answers
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Can't astronauts use the ball point pens in space?

Is it true that astronauts can't use ball point pens in space? The mechanical contact of a ball point with the paper should make the pen write but I am not sure if it's true. Any clarification will be ...
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What goes in the bottom of the Dragon structural dome?

The Dragon has a structural dome shaped like a truncated cone (A below) on a stubby cylinder (B). Q: Is the crew section entirely in the truncated cone, or is it split in two stories with the second ...
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1answer
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Can the Valsalva maneuver or nose-scratching be done inside a SpaceX suit helmet?

Sometimes you gotta scratch your nose. Or you need to perform the Valsalva maneuver (close your nose and mouth, then blow hard) to help make your ears "pop". If you can flip your helmet ...
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Space-X Falcon-9 and Falcon Heavy fuel consumed for landing

The question is, how much fuel is used by each of above rockets for landing (in % of whole fuel of the rocket) as a function of three following components - payload, orbit and descend trajectory (land/...
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Where are Falcon 9 1st stage GN2 tanks located?

Is nitrogen propellant for the two cold gas thrusters pods contained in the interstage? The view we have from the B5-B1050 recovery shows several small COPV(s) pic1 Here you can see where the cold gas ...
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2answers
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SpaceX Body Flaps - Why so Much Power Required

I don't doubt the credibility of this particular source, but why would control surfaces, even at hypersonic speed (in rarefied air, mind you), and even with substantial windward surface, require 1.5 ...
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Can the Indian government ask SpaceX to pay for bandwidth usage in its airspace?

Any telecom operator who wants to launch their services in India has to pay billions of USD to the Indian government. My query is if I'm using SpaceX Starlink based data, can the Indian government ...
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1answer
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Which are good resources to learn more about the components of a rocket engine?

A detailed and annotated image of a SpaceX raptor engine (found on a SpaceX website) illustrates that in addition to the major components (e.g. pumps, inlets, combustion chamber, nozzle), there are ...
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1answer
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How do Falcon 9 grid fins deploy?

Is it aerodynamic drag that flaps the grid fins open? Or is there a controlled mechanism for it? Pictures show the grid fins connect through a small link to something inside the rotating trunnion arm--...
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Why is SpaceX deploying Starlink satellites without inter-satellite communication capability?

According to this answer, which cites Wikipedia, the current batch of Starlink satellites that are being deployed don't have the ability to talk to each other. That will come later, according to ...
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1answer
106 views

What factors do (or are expected to) limit reuse of a Falcon 9 block 5 first stage?

SpaceX have claimed (reported here) that the Falcon 9 Block 5 first stage should be reusable up to 10 times without significant refurbishment, and up to 100 times in total. What factors are expected ...
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1answer
735 views

Starlink's autonomous collision avoidance

On their website, SpaceX claims that Starlink satellites are able to conduct autonomous collision avoidance manoeuvres using alerts from the US Department of Defence. This seems very reasonable, given ...
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1answer
648 views

Effects On ISS Orbital Mechanics Resulting From Added Mass Of Dragon Capsule Visit

Does the ISS require any type of orbital mechanics management once the Dragon capsule was confirmed with a positive airlock seal, and the mass of the spacecraft, 2 additional astronauts, and supplies ...
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1answer
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What is this propeller-like object on top of the SpaceX Hopper?

In the spirit of Why does this rocket have a nose cone “cozy”? I'd like to ask why the SpaceX Hopper has a propellor on top, or at least something that looks reminiscent of Beany's propeller. What is ...
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What are these cartridges with holes on the Dragon trunk?

You can see them on the rim in a hexagonal pattern in the picture below. Also present in the latest version of the Dragon trunk, but less clearly than here. They alternate in color from nickel to ...
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Relative elevations of the bases for Falcon and Starship pad at LC-39A

The NASA environmental report of August 2019 (https://netspublic.grc.nasa.gov/main/20190801_Final_DRAFT_EA_SpaceX_Starship.pdf) provides a 2D view of of the planned changes to 39A for Starship. A ...
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1answer
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SpaceX Dragon 2 (Crew Dragon) Standalone Mission Duration

Wikipedia's Dragon 2 page states a one week free flight limit. However, by following their source, the only information available is mission duration from one week to two years. This book also states ...
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Why will Superheavy/Starship have a landing pad so close to the launch pad?

According to this image (taken from this answer) The landing zone is situated right next to the Starship pad. In contrast, the Falcon 9 landing pads are much much further at 28°29′09″N 80°32′40″W on ...
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2answers
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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 ...
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3answers
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How does SpaceX Falcon 9 keep balance while it is near to the landing site?

As we know, flight vehicles can't keep balance easily if they cannot propel enough air through their blades or wings. We can also see the Falcon 9 at a steeper angle a while before touching down on ...
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4answers
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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?
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1answer
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From what material and how are the Merlin engines and nozzles of it (sea level) manufactured?

I am specifically interested in the alloy used to build the engine, also about the nozzle: Is it just in one piece or welded using different sections. If they are welded then which welding techniques ...
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Starship Flame trench

During static fires of the Starship engines the exhaust goes everywhere creating a dust cloud, hitting everything with sand. Why does Spacex in Boca Chica not have a flame trench at the Starship test ...
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1answer
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Crew dragon falcon 9 first stage shut down

Crew dragon falcon 9 first stage shut down around 6700 km/hr and starlink shut down around 7900 km/hr, but around the same time. Is this because the crew dragon weighs more?
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1answer
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Is the Falcon 9 second stage engine throttled down to limit maximum acceleration

Is the Falcon 9 second stage Merlin vacuum engine throttled down during its burn to limit the maximum acceleration experienced by the Dragon or Crew Dragon capsule? As the second stage consumes ...
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0answers
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What is the speed of crew Dragon upon splashdown?

After reentry, what is the speed of the Dragon 2 capsule right before splashdown? What g-force is received upon splashdown? At the time of writing, this answer gives such information for many other ...
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3answers
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Is Crew Dragon flawed? Is it just an improvisation with no future?

I know that, Crew Dragon was initially designed for vertical landing on solid surfaces, as a reusable spacecraft, and then some changes were made to make it capable of landing in water using ...
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What became of slowing down and recovering the falcon 9 upper stage using large balloons

On 16 April 2018, Elon Musk posted on twitter This is gonna sound crazy, but … SpaceX will try to bring rocket upper stage back from orbital velocity using a giant party balloon And then land on a ...
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2answers
232 views

What are the challenges in recovering Falcon 9's second stage this way?

The Falcon 9's second stage is currently disposed of each flight. I know there have been some concepts by SpaceX on making it reusable, but evidently they have not yet done so. From my understanding, ...
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1answer
152 views

Were Crew Dragon's touch screens tested under 3-5 G on Earth in a centrifuge?

To use a touch screen wearing a pressurized suit with gloves may be not as easy as without space suit and gloves. But what about tests done under more than Earth's gravity?
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Will SpaceX paint over the NASA Worm on booster 1058 for its next flight?

For the Dragon Crew mission SpaceX flew a brand new booster (how declasse) B1058 and painted it with the old style NASA Worm logo. SpaceX owns the booster and is most likely to fly it many more times ...
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1answer
223 views

Purpose of foil on Merlin Vacuum Engines of SpaceX

I want to know what is the purpose of this silvery foil situated above the bell in Merlin Vacuum Engines, and what purpose does it fulfill exactly?
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3answers
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Falcon 9 launch process - perception of launch speed

One of the things that drew attention from my local group of rocket-watchers with the Falcon 9/Crew Dragon launch is the perceived speed of the actual launch process. We have been conditioned for ...
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1answer
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What is the specified procedure to follow if there is a fail to create an airtight seal during hard dock?

I was watching the docking process of Dragon to the ISS including both the "soft dock" process, which was then followed by the hard dock involving 2 sets of 6 locking mechanisms. I believe I'm ...
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1answer
3k views

Why would spacecraft docking to the ISS have a different atmospheric pressure?

In the SpaceX Demo 2 Crew Dragon livestream, they had to equalize pressure between the ISS and the Dragon spacecraft. The voice on the stream said that they were bringing it to levels that match Earth'...
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Why do the SpaceX suits require “drying” during the mission?

In the period when the Crew Dragon Demo-2 mission was initially docking with the ISS, before the hatches were open, one of the tasks was to "dry the suits". They reported on the status later, ...
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1answer
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How do Starlink trains spread into separate orbits with equidistant orbital slots?

Starlink satellites are launched in batches of 60. They are released from the launch vehicle, and then have to spread out – not only into equidistant slots along a single orbit ring, but now ...
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1answer
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How does re-usable boosters by SpaceX return back and land on the deck 'Of Course I still Love You'? [duplicate]

The idea was to bring back the rockets/boosters safely and re-use them for next time. How SpaceX was able to achieve this? Intuitively there have to be multiple sensors recording and computer ...
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4answers
331 views

How do Space Ships dock themselves so flawlessly to the ISS?

Use of sensors and lasers seems obvious, but what all goes into the system that achieves this? What does the process entail? Example includes SpaceX's recent autonomous docking to ISS of Crew Dragon.
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1answer
407 views

Are SpaceX new space suits inferior to existing ones in terms of usability?

There is an article in Russian "Why do the American space suits look so different from Russian ones?" which claims that the new SpaceX suits are designed for looks, and have several issues, which, ...
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How was Demo-2's Falcon 9 booster different from any other F9?

According to The Sum Of All Knowledge, the Falcon 9 has only twice (including the 2016 ground fire destroying the payload) failed to put the primary payload in orbit. Thus, the May 30 2020 Demo-2 ...

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