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Questions tagged [falcon-9]

Questions regarding the Falcon launch vehicle developed by SpaceX for medium payloads (15,000 lbs) to LEO and GEO (via GTO, second stage cannot inject into GEO direct)

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2answers
1k views

Does SpaceX plan to repair SLC-40?

SpaceX just used 39A for CRS-10. Do they have any plans to repair SLC-40 from the September anomaly? The Boca Chica launch center should be ready in 2018, so will they solely use 39A and Boca Chica?
7
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1answer
820 views

What is this debris on the CRS-10 reentry at T6:30?

There are two pieces visible in the video. Are these some sort of fairing or abalator?
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3answers
498 views

When I see the SpaceX reentry vidos I see no flaming ionizaton

When I see the SpaceX reentry videos I see no flaming ionization from the time the reentry starts. I realize things must be getting hot at some point but its not the ball of fire I imagined . Where ...
10
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2answers
768 views

Do 'size of a bus' sized F9 fairings ever float after impact? Are they navigation hazards?

This and this answer describe the Falcon 9 fairings as being quite large, with the payload volume being roughly "the size of a bus" or simply REALLY REALLY big. 13 meters by 4.6 meters and being ...
26
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3answers
10k 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 ...
21
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2answers
2k views

What are the two bright objects separating from the Falcon 9?

On the recent Iridium 1 launch the separation of the first and second stages can be seen at T+3:50. In the following screenshot we see the second stage burning at the lower left of the frame and the ...
2
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2answers
443 views

How much fuel can Falcon 9's upper stage bring to orbit, without any other payload?

I wonder how useful SpaceX' second stage would be as a propulsion stage docking in LEO or so with separately launched payload. It seems to carry 92 tons of propellant on the launch pad. How much could ...
7
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1answer
504 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 ...
5
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1answer
757 views

How were the 10 Iridium NEXT satellites deployed by SpaceX?

Can someone explain (in general or specific terms) how SpaceX deployed these 10 satellites? I'm trying to imagine the mechanisms and process of launching these objects with the required precision. Is ...
9
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2answers
584 views

Final conclusion/description of the cause of the SpaceX Sept. 1, 2016 anomaly?

I've just read the phys.org new item which summarizes the conclusions by SpaceX about the cause of the September 1st 2016 anomaly. I'm citing quotes in the news item which come from a SpaceX ...
11
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2answers
1k views

Is SpaceX grid fin material flammable?

I was looking at the Thaicom 8 falcon 9 launch and landing, trying to get a bit more info about the trajectory the first stage takes. The camera is however damaged and we miss most of the atmospheric ...
9
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4answers
2k views

Could the solid boosters of SLS be replaced by reusable Falcon 9 first stages?

Is it feasible to redesign the Space Launch System to use a pair of reusable Falcon 9 first stages instead of the five-segment solid boosters now being developed? The reason would be to lower launch ...
12
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2answers
3k views

Why use Kerosene?

According to SpaceX's website, the Falcon 9 uses kerosene as fuel. According to Wikipedia, diesel fuel beats kerosene in energy density in terms mass by 2.8 MJ/Kg and in volume by 5.6MJ/L, so why ...
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0answers
95 views

What is the sequence of the main spacecraft and CubeSats separation during Falcon 9 launch?

I'm curious about timeline and the procedures related to the spacecraft separation during Falcon 9 (and perhaps other rockets if such information is available) launch. Let's assume a mission with one ...
7
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2answers
394 views

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 ...
0
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1answer
502 views

Is the “cryogenic helium” system in recent discussions actually LHe for cryopumping?

I am wondering if the "cryogenic helium" system discussed in articles about the 1-Sept-2016 SpaceX Falcon 9 anomaly (see this answer for a good summary to date) is not actually related to the high ...
6
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1answer
593 views

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 ...
4
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2answers
2k views

Problems compressing the helium tanks inside the F9 2nd stage LOX tank at the last minute?

A recent "Anomaly Update" dated September 23, 1:00pm EDT by SpaceX, includes the sentence: "At this stage of the investigation, preliminary review of the data ...
18
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1answer
1k views

Why is the F9-029 Amos 6 case more complex than the F9-020 CRS-7 explosion?

In the F9-029 Amos 6 mission failure at the launch pad, a "fast fire" happened near the 2nd stage of Falcon 9 FT. In F9-020 CRS-7 mission, an explosion happened in flight (again in the 2nd stage) a ...
6
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1answer
232 views

Can Falcon 9's fuel be ignited by static discharge?

Reading Twitter comments about the recent Falcon 9 pad explosion, some postulated the problem was that a static discharge ignited the fuel as it was being loaded. Since TEA-TEB is required to ignite ...
2
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1answer
230 views

What was the cause of the second explosion in SpaceX's pad “Fast Fire”?

This is well after the first and second stage were gone, so I suspect it was something about the pad itself that resulted in the second explosion event. Any ideas?
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3answers
1k views

GSLV MK2 vs Falcon 9 - Reasons for Huge performance difference

Yesterday ISRO operated the GSLV MK2 launch vehicle, which is a medium lift launch vehicle with a capability to lift 5 tonnes to LEO. I just compared Falcon 9 with GSLV MK2. Falcon 9 capability to ...
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0answers
45 views

Why was the payload placed on the rocket for a test? [duplicate]

The payload for the Falcon 9, the Amos 6 satellite, was placed on top of the rocket during the static fire test. Why was this done?
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0answers
355 views

What could be wrong in the ground support equipment to cause the Falcon 9 AMOS on pad explosion? [closed]

The AMOS-6 mission Falcon 9 had a RUD (Rapid Unscheduled Disassembly) event on the pad, and it is initially postulated that it was related to fueling the second stage. We know that SpaceX revamped ...
11
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1answer
332 views

When is the Dragon V2 abort system armed?

Or more specifically, had a Dragon V2 (uncrewed) been atop the AMOS-6 mission stage that blew up during propellant loading before a test fire would the Dragon abort system been armed and thus been ...
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3answers
4k views

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? ...
27
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1answer
3k views

Was Amos 6 insured for pre-launch operations?

The Falcon 9 rocket, complete with the Amos 6 payload, just blew up (Or RUDed) on the launch pad. I believe the standard language for most launch insurances is that it is only covered after "...
-1
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2answers
965 views

Falcon 9 fuel use [closed]

How much fuel does a Falcon 9 rocket used by SpaceX use, for a trip to the International Space Station? Any possibility of Teslas batteries being used in the future?
30
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3answers
12k 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 ...
13
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2answers
3k views

Why does the video feed always fail during Falcon 9 landings?

I'm in love with SpaceX and Falcon 9, I watch every live stream and the most special, most amazing, most thrilling part of each launch is the 1st stage landing. Seeing the smoke (or vapor) clear and ...
3
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2answers
594 views

SpaceX second stage altitude decrease?

I was watching SpaceX's launch of the Japanese satellite JCSAT-16 yesterday, and the second stage at a point seemed to decrease in altitude (from 171km to 165km) at about T+00:07:00 in this video. Is ...
3
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1answer
409 views

When this F9 2nd stage engine suddenly moves upon shutdown, is it moving along the rocket's axis?

The GIFs are made from frames of the live broadcast of SpaceX JCSat-16 2nd stage around the time of the second engine cut-off (SECO-2). It looks like the engine moves outward axially as the thrust ...
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0answers
280 views

What is the weird dual-tone pattern on the 2nd stage nozzle SpaceX JCSat-16?

I think it may be related to the sun, but I don't understand the "tooth" shape in the GIF - is this a shadow of something? Is the spacecraft already spinning for the satellite deployment? What are ...
4
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0answers
89 views

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 ...
10
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1answer
319 views

How does ITAR affect SpaceX's display of the Orbcomm first stage outside their headquarters?

There was a time, where people touring the SLC-40 facility were not allowed to take pictures of the engine end of the first stage for ITAR reasons. It appears that has relaxed since I have seen lots ...
4
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1answer
432 views

What is this 'engine plume interaction'?

SpaceX just released this high-speed footage, writing in the comments: Missions in order of appearance: May JCSAT-14; July CRS-9 launch, stage separation, engine plume interaction, and re-entry ...
4
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2answers
2k views

Can Falcon 9 first stage landing final burn using one, two, and three engines? Tradeoffs?

This question is about the final burn in the landing sequence of the Falcon 9 first stage return to Earth tests. If I understand correctly, there is usually far more thrust than there is weight at ...
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4answers
4k views

How does a simple construction keep a firing rocket on the ground?

Today I have seen this report of a SpaceX Falcon 9 rocket test firing. The force of a burning rocket is tremendous, and in the video we see an apparently simple construction keeping the rocket (or ...
7
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0answers
457 views

How is retropropulsion by the Falcon 9 first stage being used to design retropropulsion entry on Mars?

Much has been made of how the reentry burns of Falcon 9 first stages occur at an altitude where the atmosphere is similar in density to the atmosphere of Mars, and so they demonstrate that supersonic ...
2
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3answers
505 views

Could a Falcon 9 booster “abort” a landing, then land shortly thereafter, or somewhere nearby?

This comment below this question has me somewhat convinced that it would be hard for a Falcon 9 booster to abort a landing at the last minute (say within the last 100 meters or something like that) ...
4
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1answer
320 views

What happened to Formosat-4 and Formosat-6?

Formosat-5 (see also Gunters) is expected to be deployed along with Sherpa later this year. I noticed that before 5 comes 3, and after 5 comes 7. In that part of the world the number 4 is like a ...
6
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1answer
368 views

How does the flight trajectory of a GEO vs LEO mission vary for a Falcon 9 first stage?

How does the trajectory vary between the two types of missions? Specifically, how does the speed and velocity vary for the booster for a Falcon 9 mission?
8
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4answers
1k views

Recent Falcon 9 flights - 'topped off' with propellants, or just a margin over what's needed to land?

A simplified version of the landing choices might be - if there's going to be sufficient propellant, the plan is for the F9 first stage to u-turn and go all the way back to the launch area to land. ...
1
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1answer
108 views

What kind of maneuver Falcon9 & Dragon follows after separation

I was taking long-exposure shots of tonight's SpaceX launch and noticed these swirling like maneuvers when I zoomed-in: Are both stages making a roll or something? Separation Stage-1 Stage-2
3
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2answers
451 views

What is behind Dragon's Guidance, Navigation and Control bay door?

The timeline in the press kit for the upcoming CRS-9 SpaceX launch says at about 11 minutes after launch, "Dragon's solar arrays deploy", and at 2 hours 19 minutes, "Dragon's Guidance, Navigation and ...
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1answer
3k views

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 ...
9
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1answer
385 views

What definition of “LEO” does SpaceX use when specifying payload capability?

Please forgive me if I am asking a dumb question. I am a little curious about the orbital parameters of "LEO" used by SpaceX on many occasions specifically those related to payload capability. ...
9
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3answers
716 views

What difficulties will be faced modifying the Falcon 9 FT, so to have better and easier landings of the 1st stage from a GTO mission?

What difficulties will be faced making modifications for the Falcon 9 FT rocket, so in this way to make smoother, better and easier landings of the first stage from a GTO mission? For example ...
10
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1answer
429 views

How does a Falcon 9 booster know how far away the ground is?

In the latest landing video, it seems the Falcon 9 just hovered for a moment above the ship. That being said, it begs the question, how does the booster know where the ground is? Does it purely work ...
3
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2answers
205 views

How is engine thrust monitored during flight?

The failure of the Falcon 9 first stage landing during the Eutelsat/ABS mission was attributed to: thrust was low on 1 of 3 landing engines which indicate that engine thrusts are part of the ...