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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44
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4answers
10k 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 ...
9
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1answer
470 views

What makes it so hard to precisely land a fairing?

SpaceX currently tries to land their fairing halves on a boat with a net attached to it. So far they had no success but landed nearby, although quadrupling the net area. They first tried with this ...
8
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1answer
260 views

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 ...
6
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1answer
949 views

What is the minimal TWR of Falcon 9 booster right before touchdown?

A big point about Falcon 9 booster landing is that they need to stick the landing on the first try; they can't just hover and adjust position because even fully throttled single Merlin engine provides ...
20
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2answers
3k views

Will SpaceX delay launches, if the landing site weather is unacceptable?

With the initial landing attempts, it was not a big deal, twas all an experiment and they only reused Block 1-4 boosters once at best. So holding a launch because of weather at the landing site ...
5
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1answer
571 views

How do rockets “blow” smoke rings? Did “smashing through Max-Q” really do this?

The Teslarati article SpaceX delivers largest commercial satellite in kick off of Falcon 9 marathon includes several beautiful photos, of the Telstar 19V launch, including the one below. It shows ...
5
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0answers
969 views

Dragon 2 in-flight abort test - what will happen to the booster?

SpaceX is planning to do an in-flight abort test of the Dragon 2. I imagine that at max-Q the Dragon will start its own motors to fly slightly faster than the booster (and move sideways). Suddenly ...
34
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2answers
7k 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'...
5
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3answers
783 views

Why are these Falcon 9 1st stage bodies (apparently) wrapped in black plastic for transport?

The Teslarati article SpaceX’s third Block 5 rocket heads to Texas test site as launch marathon nears includes the image and caption below. Is this an unused rocket body being transported for launch, ...
22
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4answers
7k views

Why does the Falcon 9 use RP-1/LOx and not LH2/LOx?

Why does SpaceX use RP-1 in the first and second stages of their rockets? In my view at least the second stage could use hydrogen as it currently is not being reused. I am aware that you have higher ...
13
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1answer
1k views

Why does the 2nd stage of Falcon 9 need compressed He tanks?

It is well known that the rapid disassembly of Falcon 9 static testing started with the rupture of the composite fibres of the copv He tanks. But what is the need to have the composite tanks ...
7
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3answers
2k views

Will reusable rockets be financially viable?

While the vertical landing of rockets by SpaceX is certainly a significant achievement, there seem to be many who say that reusability is not actually financially viable. Apparently, it is far too ...
4
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1answer
130 views

How far apart do both SpaceX half fairings splash down?

Inspired by this question: How far apart from each other (both in space and time) do the two halves of a Falcon fairing land? I'd also be curious to know what's the error margin they have on this. ...
9
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1answer
385 views

What are these tiles inside the Falcon 9 fairing?

The three photos in SpaceX's recent tweet about attempting to recover the GRACE-FO/Iridium-6 fairing halves included a close-up of the inside of the fairing: [] What do those black tiles with the ...
7
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2answers
1k views

How does SpaceX decide which half of the Falcon 9 fairing to catch?

Question: How does SpaceX decide which half of the Falcon 9 fairing to catch if they are only going to catch one half? Is one half more expensive and/or well instrumented than the other? Images from ...
6
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1answer
3k views

How much does a current F9 fairing-half weigh?

Question: How much does a current F9 fairing-half weigh? Is this resting on something, or is it really floating this high in the water? Images from this SpaceX tweet: Falcon 9 fairing halves ...
17
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2answers
2k views

Why is the first stage from the Falcon 9 SES-12 mission not recovered?

Youtube video here At 4:13 minutes into the Iridium-6/GRACE-FO NASA Launch, the commentator mentions: The first stage is not going to be recovered, so there won't be any views from the drone ship ...
7
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3answers
490 views

What are these circular structures around the rocket?

Youtube video of the Iridium-6/GRACE-FO NASA Launch (Falcon 9 SES-12). Edit 31 May: Too bad they have changed the content of the video (and still call it 'live'), so that you can no longer see the ...
5
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1answer
206 views

Should SpaceX have 2 versions of the Falcon 9 rocket (cargo-only and human-only)?

I am learning that having a human rated Falcon 9 rocket is very difficult. Would it be better to have 2 versions of the Falcon 9 rocket? I figure a human-only version would be easier to design with ...
6
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2answers
604 views

Do Falcon 9/Heavy Block 5 boosters need landing legs? Or can they land back on their launch mounts?

At 2017's International Astronautical Congress, Elon Musk claimed that SpaceX could master propulsive landing without landing legs. The assertion was that Falcon 9's ...
3
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1answer
144 views

Will Falcon 9 block 5 successful launch speed up production of BFR?

I was just wondering that as Spacex has just launched it's final variant of Falcon 9 block 5 successfully, so now will it speed up the process of building BFR rocket ?
1
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0answers
31 views

Non-axial thrust during Falcon 9 Block 5 launch? [duplicate]

Looking at video of the Block 5 launch today (2018 May 11) I noticed that from the ground tracking views, the vehicle roll axis and the exhaust plume appeared not to be collinear. When they cut to the ...
5
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1answer
360 views

What caused launch abort on SpaceX's Bangabandhu-1 launch

On Thursday, May 10th, 2018, SpaceX attempted a launch of the first Falcon 9 block V rocket carrying Bangabandhu-1 however the countdown was stopped at t-58 seconds and the launch was scrubbed for 24 ...
10
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1answer
506 views

What improvements does SpaceX Falcon 9 Block 5 have over prior version?

Does SpaceX disclose what improvements their Falcon 9 Block 5 will have over the Block 4 model? If so, what improved features will it have? I have heard general comments about it in the news, but I ...
12
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2answers
3k views

Can SpaceX Falcon 1st stage hover during landing?

I came across with this video in which the Falcon Heavy boosters' landing burn seems to deaccelerate the 1st stage until a point their speed is constant right before touchdown. ...
18
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1answer
6k views

Why is Falcon 9's fairing so big?

The Falcon 9 fairing costs millions of dollars. It is 5.2 meters wide while the rocket itself is only 3.7 meters wide. There is no aerodynamic reason that the fairing has to be so big, since Dragon ...
3
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1answer
555 views

Is it feasible to launch NASA's InSight mission Mars using a Falcon 9, instead of an Atlas V rocket?

The Insight mission is launching the spacecraft to Mars on May 5th aboard the Atlas V rocket by ULA. Would it have been possible to launch this mission using a SpaceX Falcon 9 Block 3/4/5 (expendable ...
30
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3answers
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 ...
3
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1answer
161 views

Is a soot covered flight proven Falcon 9 lighter or heavier than a new falcon 9?

Since SpaceX now does not repaint or clean off the sides of the first stage booster prior to reuse, does this make the soot covered stage heavier or lighter? And is this difference in weight ...
51
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3answers
16k views

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. ...
16
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1answer
3k views

Was SpaceX's launch of Formosat-5 more vertical than normal for any particular reason?

Reading both the abstract and the plain language summary of the recent paper published in the journal Space Weather Gigantic Circular Shock Acoustic Waves in the Ionosphere Triggered by the Launch of ...
10
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1answer
324 views

What's happening in this photo?

This is a 30 second exposure of the Falcon 9 launch on March 6th. The trail is from right to left; the photo was taken north of the launch site, about 3 or 4 minutes into the flight. I think I ...
7
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1answer
1k views

How did SpaceX achieve such a high Thrust to Weight ratio with the Merlin engine?

Were there specific breakthroughs which allowed SpaceX to get such an incredible thrust to weight ratio? The next closest American engine was almost twice as heavy (199 vs 82), and the next closest ...
5
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1answer
253 views

Can (or will) Block5 Falcon 9s be used on the Falcon Heavy?

With the Block5 version of Falcon 9 booster soon to be flying, will they be used for the Falcon Heavy, or will they remain a stand alone thing?
4
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1answer
490 views

Why is there a coasting phase between the second stage engine cutoff and payload deployment?

[basing this question on the Falcon 9, Paz satellite launch on 22 Feb] Hi, this is probably a silly question, but there is an approx 3 minute time difference between second stage engine cutoff and ...
10
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3answers
2k views

Pressure inside a launch fairing - falcon 9

This article indicates that a faclon 9 launch is being delayed due to an issue with the "payload fairing pressurization system". Are launch fairings pressurized to 1 atmosphere for the benefit of the ...
7
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1answer
300 views

Falcon 9 fairings stability on reentry

On the descent of the fairings into the atmosphere how is stability provided? Why does it not start to rotate in a uncontrollable fall but reenter gently without apparently damage on the interior ...
4
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2answers
1k views

What is that thing spraying during a Falcon 9 launch? [duplicate]

What are those things spraying something at the pad during the beginning of a Falcon 9 launch?
16
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1answer
669 views

What is this jet of material spraying out from Stage 2 during the SpaceX PAZ mission?

This spray seemed to be there throughout the entirety of the Stage 2 burn but was especially visible once Stage 2 cutoff had happened. As that nozzle uses radiant cooling, it can't be cooling fluid, ...
11
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3answers
2k views

How do Falcon 9 fairings survive the reentry?

SpaceX recently tried to recover fairings from falcon 9, which landed intact in the ocean. How come do these not burn up during reentry?
4
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1answer
344 views

Which engine failed during CRS-1?

During SpaceX's CRS-1 mission, "engine 1" failed, but the booster still completed its primary mission due to a plentiful thrust and fuel margin. Clearly, an outboard engine failure is more critical ...
1
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1answer
330 views

Starman and Tesla temperatures [duplicate]

As The Tesla car and Starman continue to orbit the earth, How does the paint on the car survive the extremes of temperature? As I understand it, they are both exposed to temperatures between 120C and -...
15
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2answers
3k views

What is the cause of this Falcon 9 first stage “dance” after landing?

Recently I watched a video on YouTube by Scott Manley: How To Do A Hoverslam - Things Kerbal Space Program Doesn't Teach. It deals about landing burns of Falcon 9 first stages. It features short clips ...
21
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3answers
5k views

How many SpaceX Starlink Internet-service satellites could be deployed in a single Falcon 9 launch? Falcon Heavy? BFR?

The mass of the two test satellites being launched this month is 400 kg, but I don't believe that includes the antennae and the structure to hold and release them. Is total mass the only constraint or ...
3
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1answer
169 views

What is pictured in the back of Falcon 9's 2015 launch photo?

Wikipedia (actually Wikimedia) has an image of Falcon 9's 2015 launch during its night flight (16th flight in total) that took place on Sunday, March 1, 2015 at 10:50pm ET: I was wondering what is ...
44
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3answers
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 ...
7
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4answers
4k views

Why is fuel cheap compared to rocket?

The fuel for a Falcon 9 (SpaceX) costs around \$200,000 per launch, while the launch itself costs \$62,000,000. Safety precautions, rocket shell and rocket engines cost a lot. But why not fuel?
10
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2answers
2k views

Why is BFR replacing the Falcon 9?

Not every payload (or even batch of payloads) needs super-heavy launch capacity, but that seems to be what SpaceX is doing. https://www.space.com/38323-spacex-phasing-out-rockets-for-mars-bfr-...
4
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1answer
341 views

Can Falcon Heavy side boosters/center core be reused as Falcon 9s?

Since the Falcon Heavy is just essentially 3 Falcon 9s strapped together, would it be possible to reuse them as Falcon 9s with some modification?
12
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3answers
2k views

If the SpaceX drone ship's camera feed gets disrupted every landing, why cant they throw the antennae off the ship on a buoy for better reception?

They mentioned on the live stream that this is because of the shaking antennae. It has also been discussed on here before why this happens: Why does the video feed always fail during Falcon 9 ...

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