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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.

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Where is the TEA-TEB stored for the Merlin engines onboard Falcon 9?

The Merlin 1D engines can restart up to four times, they use the pyrophoric mixture of TEA-TEB (Triethylaluminum-Triethylborane) to ignite the engines. My question is where is this stored in the ...
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Has SpaceX ever done a hot restart of a 2nd stage?

Another question highlighted this Space X commentary for the GRACE-FO launch: Now in order to fly an efficient trajectory for both of the payloads, we’re actually now running the second stage ...
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Purpose of side holes on SuperDraco pods of DM-1 flight Dragon 2 capsule

I've watched the launch video for DM-1 today, and one thing caught my attention. On SuperDraco pods, below the plugged SuperDraco engine openings, there are two more plugged holes. I've marked them on ...
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581 views

Roughly how many self-viewing cameras are present in a Falcon 9 LEO mission?

Watch any of last year's SpaceX LEO satellite deployment missions's broadcasts in YouTube, and you can see views from at least several different cameras. At least two on the 2nd stage nozzle, at least ...
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Why is SpaceX's Raptor's design so simple in comparison to SSME?

What is especially striking to me is how simple Raptor is in configuration compared to SSME. The Raptor doesn't have an LP fuel or oxygen pump. What's even more surprising, if we are to compare the ...
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173 views

Onboard recording of trans-Mars injection

Is there any video recording of the Falcon Heavy trans-Mars injection burn from onboard cameras? The live feed of the Tesla Roadster and Starman orbiting Earth cycled through multiple cameras ...
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327 views

What caused this shadow on Falcon 9 stage 2 w/Jason-3 before circularization burn?

While the image appears bright, the light is just reflected sunlight (from the earth, per the webcast). The circularization burn doesn't start until about T+ 00:55:16 per the SpaceX webcast. But at ...
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What is “OBJECT BS”?

I checked 2018-099 in Celestrak's satcat again for the question Where can I find the TLE of ExseedSat 1, India's first ever private LEO satellite? and noticed that ...
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203 views

How is Mr Steven piloted when catching a fairing?

Mr Steven is the ocean-going vessel used by SpaceX in its attempts to catch re-entrant Falcon 9 fairings for possible reuse. How is this ship controlled during fairing catch attempts? Is she* manned ...
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527 views

Progress of the raptor engine

I have seen that Space X has tested a scaled down version of the raptor, but that was about a year ago. Does anyone know the current progress? Do they have a full scale model? Have they hot fired a ...
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149 views

What accounts for the signal delay from cameras on the Falcon 9?

On the last few webcasts, SpaceX has shown video from both ground tracking cameras and the on-board camera side-by-side, and there's a noticable delay between the two, with the on-board camera being ...
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113 views

Did SpaceX use TDRSS or USAF ground station to track Falcon 9 stage 2?

Which system did spacex rely to? Falcon, not dragon
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What upgrades does the Merlin 1D need to increase its time between overhauls to 1000 hours?

This is a question I've been pondering for the last few weeks after I back-calculated the details of the Merlin 1D engine. Just as a thought exercise, I wanted to see what upgrades the Merlin 1D would ...
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What are these four “debris” objects along with the Starlink satellites?

Celestrak has an updated system of categories for retrieving lists of current TLEs, and there's already one for Starlink, yay! Currently https://www.celestrak.com/NORAD/elements/starlink.txt contains ...
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76 views

How similar to a crewed flight will SpaceX Demo Mission 1 be?

With the upcoming premiere of the Dragon 2 in SpaceX's DM1 launch, I was wondering how similar it will be to a mission with actual astronauts. What I mean by this is things like: Will the launch ...
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92 views

Purging process of a rocket engine

Does spacex purge Falcon 9 engines after landing ? If so, which gas is used for purging?
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171 views

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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Does the downrange position of an ASDS vary, depending on payload mass?

SpaceX in its recovery attempts can either do a Return To Launch Site (RTLS) or land downrange on an ASDS landing barge. The Telesat 19V and 18V payloads were some of the heaviest payloads on the ...
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Nature of “the silky black 'highly flame-resistant felt'” on Block 5 Falcon 9's, and its intended functions?

The Teslarati article SpaceX Falcon 9 Block 5 rocket’s drone ship return captured in stunning detail [gallery] and accompanying photo spread shows many interesting details of "SpaceX’s first West ...
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What is the droplet size that is desirable for pintle injectors?

The pintle injectors tend to generate droplets after impingement of the fuel and the oxidiser stream and I understand that the droplets will be premixed. In such a case, even a larger premixed ...
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Potential improvement to BFR or New Glenn if equipped with aerospike exhaust on their engines?

Aerospikes basically tackle the issue of the variability in required expansion ratio for a rocket engine to be efficient at a given altitude. A recent example though mired in legal issues is a small ...
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167 views

SpaceX CRS-11 landing pad debris identification

After sending CRS-11 into orbit to rendezvous with the space station, the first stage of the SpaceX rocket Dragon landed on Landing Zone one. In the video released subsequently you can see two pieces ...
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Books on Vertical-Landing Vertical-Takeoff (VTVL) of Rockets? or Rocket Design in General?

I am working on a rocket control system design and I am trying to understand the the fundamental principles and concepts to design an efficient controller for recovering and landing the rocket, ...
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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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What is SpaceX's parachute problem that NASA is concerned about in the NASA ASAP report?

The Washington Post's NASA to launch safety review of SpaceX and Boeing after video of Elon Musk smoking pot rankled agency leaders says: Earlier this year, Boeing had a propellant leak during a ...
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Fuel carried by current Crew Dragon

How much fuel weight will the current Crew Dragon carry? Will it be just enough for launch abort, or the full load (over 3000 lbs) needed for propulsive landing as a back-up to the parachutes? I ...
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What was the ambient air density was there when/were Starman/Roadster first started playing Bowie's “Life on Mars”

When the Falcon Heavy test flight 2nd stage fairing opened at about 115 km, David Bowie started singing "Life on Mars". Okay, the Tesla Roadster's stereo started playing "Life on Mars", or at least ...
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What could be used to associate these fairing halves with their launches?

Eric Ralph's Teslarati article SpaceX’s BFR factory in LA spied with four Falcon 9 fairing halves shows several panoramic photos of the site for the future rocket factory. In it, the author says: ...
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Is there any flutter analysis available regarding Falcon's grid fins?

I have never come across any papers which talks about flutter analysis of gridded fins in general, does it not under go flutter behavior or is it technically incorrect to talk about flutter for ...
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How long does it take SpaceX to mount a stage on the McGrgeor test stand, run the test, and dismount it?

Gwynne Shotwell at SmallSat 2016 in Utah mentioned that SpaceX would be using the JCSAT-14 recovered first stage as a fleet leader in wear and tear. That they would be mounting it on the McGregor, TX ...
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531 views

Falcon 9 v1.1 Full Thrust Specifications

Does anyone know what the dry mass and mass ratio of the Falcon 9v1.1 Full Thrust Stage 1 is? The best info I've been able to find was by taking the specified burn time and multiplying it by the mass ...
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Atmospherics for 'next generation' manned space flight / Exploratory Class Missions

Decompression sickness is a significant risk to both current and future astronauts and currently significant time is lost in preparation for extra-vehicular activity on the ISS [including airlock ...
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How much do SpaceX's titanium grid fin geometrical parameters measure?

Does anyone know approximately what is the width, length, thickness and depth of the titanium grid fins used in the Falcon9 v1.1? I'm trying to make a 3D model on solidworks but can't find the ...
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Is there video from the Falcon second stage of the Dragon solar panels deploying?

We get video from the second stage of the Dragon leaving the second stage. And we get video from the Dragon of its solar panels deploying. But a cool view would be of the Dragon's solar panels ...
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Falcon 9 Landing Speed

I wanted to know what the fastest speed is that a Falcon 9 can land at and thus the max force the landing legs can withstand. I assumed the mass when landed is 26,000 kg (I once heard that somewhere). ...
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157 views

Have the Starlink precursor Tintin satellites been talking to each other? If so, how?

Tintin A and B are the first two exploratory and testing spacecraft for SpaceX's Starlink program. It looks like they are in very similar orbits in both space and time, and are probably that way so ...
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Pre-launch TLEs for NASA launches

I was curious if the United States is on the verge of launching maned flights to the ISS, will anyone release Pre-Launch TLE data like was done back when the shuttle was flying.
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How much noise would the BFR make at launch?

In addition to multi-planetary travel, SpaceX has plans to use the BFR for intercontinental travel. However, would the sound generated by the BFR's launch disrupt local communities and therefore make ...
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What are the chances that the ISS transits the moon as seen from your house (or headquarters)?

In this answer I tried to do a simple probablistic estimate on the distribution of the ISS's ground track passes over Earth's equator. Recently there is a photo of the ISS passing over SpaceX ...
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What caused these strange lights around the Falcon 9 grid fins (Starlink launch)?

Early in the video of the launch of the first sixty SpaceX Starlink satellites we can see that after stage separation the first stage grid fins open. Around that time there are some phenomena I don't ...
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Could the BFR Tanker be used as an artificial gravity counterweight for interplanetary travel?

An alternative storyline to the Mars transport architecture: Tankers refuel starship, last Tanker gets mounted on the Starship for the Mars orbital injection burn, once on a Martian trajectory tanker ...
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Space-X Canaveral launch question

In the past, I could see space shuttle launches from my front door on the gulf coast of Pinellas County by looking due east on a clear day or night. I have tried to catch Space-X launches a couple ...
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96 views

How does a turbopump work

I am a kid pursuing a career in propulsion, and I was wondering, "how does a turbopump work?" I would really appreciate a detailed explanation. Thanks!
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154 views

Does the 90 million cost for the Falcon Heavy include everything?

SpaceX says that it costs them 90 million each time to launch a Falcon Heavy, does this include fuel? If I where to purchase a Falcon Heavy launch, how much would it cost me to launch it, buying my ...
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Falcon fairing half - between separation and parachutes deployment

How does Falcon fairing half behaves in atmosphere before parachutes deployment? What is its free fall attitude in atmosphere? Is the fairing's attitude stable (with some wobbling, but without ...
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77 views

Time For SpaceX to Plot Landing Course

How much time would it take for the SpaceX engineers/astrophysicist/other employees to plot the landing course for the reusable first stage rocket to land exactly on a 214 by 170 meter landing pad (or ...
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What kind of power is referred to in “the…most powerful all-electric propulsion communications satellite ever produced”

The Florida Today article On second flight, SpaceX Falcon 9 rocket to launch 'brute' of a satellite from Cape describes the upcoming SpaceX launch of SES-12. Next to this tiny image of (presumably) ...
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What's up with Star Man's Roadster's suspension?

On Earth, a vehicle's weight compresses the suspension, and the wheel rims are generally designed to closely fit the contour of the tires with only a small gap between. Take away that weight, the ...
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142 views

For a cubesat mission piggybacking on a Red Dragon, what are the tradeoffs for launch early and late in the launch window?

SpaceX will be launching two Red Dragons in 2020, one at the beginning of the launch window (July) and one at the end (September). For a CubeSat mission that would have to piggyback on one of the two ...
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227 views

How much helium and nitrogen are used in SpaceX's Falcon 9?

How much helium and nitrogen are used on SpaceX's Falcon 9?