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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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Why did Falcon 9 boosters numbers skip B1027? What happened with it?

Looking at the list of Falcon 9 launches I noticed the booster numbers jump from B1026 to B1028. Anyone know what happened to B1027? Was it scrapped during manufacturing for some reason?
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1answer
636 views

Why is the development of the Falcon Heavy difficult, when two of three cores are reused?

Elon Musk said that the integration of the Falcon Heavy was "shockingly difficult". I can absolutely believe that. But at the same time, SpaceX is reusing two "flight proven" boosters for the Heavy. ...
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1answer
384 views

Falcon 9 - relief valves closing times

From what I understand, prior to the launch, the relief valves are open to allow some of the boiling LOX to evaporate and be replaced with fresh, cold one (we can see oxygen evaporating - and "...
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1answer
1k views

How many kilo's of nitrogen does Falcon 9 load for its first stage cold gas thrusters?

Watching the video of the 1 May NROL launch, I was surprised at the frequency and apparent size of the cold gas thruster firings. Does anyone know approximately how many kilograms of N2 are required ...
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SpaceX rocket strange velocity

In SpaceX launch on May 1st, 2017, we get to see the full flight path of the first stage rocket of the falcon 9 from launch to land: It accelerates to around 1685m/s ...
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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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How much fuel is necessary for 2nd stage of Falcon 9 rocket to land?

What is the fuel mass nedeed for the 2nd stage of Falcon 9 rocket to land, how much compared with its total fuel mass that it has? Or how much delta-v is necessary? Would it be able for Falcon 9 to ...
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2answers
280 views

Why is the Falcon 9 upper stage tumbling so much after separation? (SES-10)

Immediately after separation, the upper stage of Falcon 9 seems to head 30 or so degrees sideways. What causes that? Is it a problem or a feature? Separation occurs at 4:40 in this video of the ...
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2answers
750 views

How does Falcon 9 mitigate re-entry pressure?

I was reading this question about Falcon 9's re-entry Max Q, which states that the Falcon 9 has a re-entry pressure 3 times higher than during launch. I was shocked, because SpaceX takes precautions ...
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2answers
414 views

SpaceX NROL-76?

According to SpaceX's website, it does not announce a NROL-76 launch in mid-April. However according to other sources such as the NRO and spaceflightnow announce that a Falcon 9 will launch the ...
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1answer
2k views

Why does the CRS-8 Falcon 9 rocket appear to be swaying before launch?

I just saw the video from the YouTube channel SpaceX Edits titled SpaceX B1021: The First Rocket to Fly Twice (a supercut of highlights mentioned in the Pod Bay, and noticed the Falcon 9 for the CRS-8 ...
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527 views

SpaceX Falcon expected life span (how many reflights?)

When SpaceX first announced their plans to develop a re-useable first stage, what was the envisioned life span of an individual booster in total launches before retirement (expected typical and ...
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1answer
185 views

What support equipment is necessary to maintain a falcon 9 booster during transport after recovery?

This file photo shows a Falcon 9 first stage being transported by truck after landing. There is some equipment at the end of the truck, which includes dials, knobs, and an exhaust stack, which ...
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2answers
1k views

Do each of the fairing halves now use thrusters post-deployment? How does that work?

From Reddit Recap of the Elon Musk and Martin Halliwell press conference with lots of new info, March 31, 2017 (presumably not related to April fools day in some time zones?) Fairing and future ...
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1answer
522 views

Why not use a rotorcraft drone or quadcopter using GPS navigation to live stream SpaceX booster landings on the droneship?

In droneship landings of SpaceX boosters, many times in live streaming, the video has stopped because of vibration in the droneship caused by the 1st stage landing of a Falcon 9 rocket. Would it be ...
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2answers
1k views

What's behind the design of SpaceX grid fins?

These grid aerobrakes/drag control moving surfaces, have been used for a while on various aerodynamic designs, and presumably they provide a turbulent airflow, which in some way is more predictable ...
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2answers
251 views

Will the SES-10 booster have a secondary mission goal of landing?

SpaceX is slated to launch the SES-10 this coming Thursday from LC-39A at KSC. This is widely seen a pretty major milestone, as this will be the first time a re-used booster will be used to put a ...
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2answers
599 views

What is a “re-radiation system”?

In SpaceX's Echostar XXIII Hosted Webcast after T+ 00:03:50 they mentioned the "re-radiation system" as a part of the payload fairing that increased it's value and ...
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2answers
4k views

More efficient SpaceX landings?

Although the exact trajectory of a rocket is not known before launch, could SpaceX position its landing barge even further down range of the launch pad and eliminate the need for a boostback burn ...
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1answer
495 views

What does SpaceX do with all the engines?

SpaceX has had 8 successful launches in 2016 according to a wikipedia article. The launch manifest agrees with that, but leaves out the launch pad failure. According to another wikipedia article, ...
7
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1answer
407 views

Preflighting TVC actuators on Falcon 9

It is my understanding that the Falcon 9 thrust vector control (TVC) actuators use RP-1 as hydraulic fluid and use the fuel turbopump energy to drive the hydraulic pump for the TVC. How do you do a ...
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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?
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1answer
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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
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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 ...
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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 ...
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3answers
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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 ...
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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 ...
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2answers
476 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 ...
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1answer
536 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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1answer
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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 ...
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3answers
824 views

Final conclusion/description of the cause of the SpaceX Sept. 1, 2016 anomaly? What's a “buckle”?

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 ...
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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 ...
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4answers
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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 ...
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2answers
4k 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
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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 ...
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2answers
415 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 ...
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1answer
565 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 ...
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1answer
622 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 ...
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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 ...
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1answer
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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 ...
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1answer
235 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 ...
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1answer
269 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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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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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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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 ...
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1answer
339 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? ...
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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 "...
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2answers
1k 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?
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13k 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 ...