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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
410 views

How does SpaceX handle rearranging flight order?

In this question: How does SpaceX manage parallel processing at the LC-40 Complex? I asked how SpaceX handles two cores at the HIF building at LC-40 at the same time. Based on available data it looks ...
7
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2answers
598 views

Was there a barge landing attempt on Launch 16 (EUTELSAT 115 / ABS 3A) March 1st

I've been reading here (SX) and SpaceX website and other sites and can see no reference to any attempt to try the barge landing of the first stage booster on the recent Falcon-9 launch on March 1st. ...
6
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1answer
1k views

What auxiliary engines do the Falcon 9 first stage have?

Looking at the launches and animations for the Falcon 9, you can clearly see some rockets firing at the top/side of the stage to maneuver it clear of the second stage and orient it correctly for ...
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2answers
22k views

What is the cost breakdown for a Falcon 9 launch?

I don't know if this was already asked, but I'm very curious about the cost breakdown of a Falcon 9 launch.
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0answers
82 views

Why is there only a small difference between Falcon 9 and Falcon Heavy launch prices? [duplicate]

SpaceX's website says that a Falcon 9 launch costs 61 million while a Falcon Heavy launch 85 million. Considering that the Falcon Heavy is almost three times bigger than the Falcon 9, I don't ...
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0answers
81 views

What view of the Falcon 9 does this screenshot show? [duplicate]

Watching SpaceX webcasts, I've noticed this particular view during the Falcon 9's flights. No one I've asked has any idea what's shown here. (Though one person commented that it looked like a ...
9
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1answer
714 views

Optimum velocity for first stage separation in a two-stage launcher

Looking at the numbers that are given, for example, at the SpaceX launches, it seems that the velocities at first stage separation are a bit above 2 km/s. The second stage does all the rest of the ...
2
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2answers
687 views

Why has no TLE been published for the DSCOVR satellite and the Falcon 9 R/B?

So, usually a few days after every launch, I go out and check out the published TLE data for each satellite, made public courtesy of CelesTrak. It generally includes all the orbital parameters for ...
8
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1answer
1k views

Could a rocket booster be refueled in space?

The F9R is planning to safely land on platforms, using propulsive landing, which requires that the rocket has extra fuel leftover from the primary launch mission, to be able to have a propulsive ...
3
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1answer
126 views

Which Falcon 9 (1.0 or 1.1) core has fuel cycled the most?

This question is related to reuse possibilities. One of the things that affects reuse is thermal cycling of the fuel tanks. (Consider how microfractures in the X-33 composite tank killed that project. ...
7
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1answer
2k views

How long does it take to recover the first stage of the Falcon 9?

When SpaceX recovers the Falcon 9 first stage at sea, roughly how much time passes between lift-off and soft touchdown on the barge?
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2answers
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Why would a mission to Sun-Earth L1 have an instantaneous launch window?

I was watching the webcast for Falcon 9 Flight 15 (launching DSCOVR) when they scrubbed their first launch attempt due to some issues during the terminal countdown. Before the scrub, the narrator ...
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3answers
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How can the reusable Falcon 9 succeed when the reusable Space Shuttle failed?

Space Shuttle was designed to be partially reusable but was later shut down because it turned out to be very expensive to run compared to disposable spacecraft. Now Falcon 9 is suddenly reusable to a ...
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6answers
8k views

Why can the Falcon 9 be reused while the SLS cannot?

In reading about SLS, I learned that the reason they won't reuse their rocket is that the weight of the parachutes to enable recovery is too much of a sacrifice. How is the weight of the hardware and ...
6
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1answer
3k views

What is changing between the Merlin 1D engine and the uprated Merlin 1D+ engine?

SpaceX is apparently uprating the thrust of the Merlin 1D engine used on the Falcon 9, by about 15-20%. What are they changing (in the engine, in the fuel) to achieve this new thrust level? It has ...
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5answers
3k views

Mathematics used for SpaceX first stage re-entry burn guidance?

I thought it would be fun to make a basic simulation of a first-stage fly-back of SpaceX's Falcon 9, but was wondering what mathematics is used to perform something like this. Looking at this page: ...
9
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1answer
371 views

Falcon 9 second stage impact on first stage trajectory

In this video, you can see the Falcon 9 first stage flying through the second stage's plume post-separation. I would assume that this would alter the first stage's trajectory -- potentially causing a ...
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3answers
1k views

SpaceX Landing Platform video: why is the rocket moving so fast?

This is the video of the Falcon 9 first stage attempting a landing on SpaceX's barge. Why is the rocket moving so fast at impact?
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3answers
658 views

How can Falcon 9 first stage land vertical in a strong wind?

As I see it, Falcon 9 has to land on the barge in a vertical orientation and with no horizontal drift. It has fins that are ineffective at low speed. It has a rocket motor that can probably vector ...
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4answers
7k views

Why does the Falcon 9 have 9 engines?

What are the reasons for using 9 engines in the first stage of the Falcon 9? Why not 8 or 10? Looking at the Raptor engine, they seem to be looking at 9 engines again. Is there some specific advantage ...
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3answers
50k views

What happens to the Falcon 9 second stage after payload separation?

In a Falcon 9 launch, the second stage looks like it achieves orbit along with the payload. But is that impression accurate? Does SpaceX need to do anything to deorbit the stage? I can see a few ...
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3answers
2k views

How will Dragon v2's solar panels be protected during launch on top of Falcon 9?

When Elon Musk unveiled Dragon v2 last year, we got our first truly good look at what SpaceX's crew vehicle is like. Apart from the ability to propulsively land, one of the big changes was the lack of ...
32
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1answer
9k views

Why does the Falcon 9 consume hydraulic fluid?

According to many news articles, the crash of the Falcon 9 during landing on 1/10/2015 was due to running out of hydraulic fluid for the steerable hypersonic grid fins. This was seemingly confirmed ...
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6answers
18k views

Why did SpaceX attempt to land the booster on a barge instead of somewhere on land?

I understand the benefits of reusability for the rocket booster. But I don't understand why they're landing it on a barge. I've read tons of articles about this but not one has even hinted at an ...
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2answers
1k views

Would it not be easier for SpaceX to make their first stage only partly reusable?

Very excited about the upcoming test to land the first stage of the next Falcon 9 on an ocean platform. Elon Musk & Co. make it sound incredibly difficult though. I'm assuming that the first ...
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8answers
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Why would SpaceX not use parachutes for the final descent of the first stage?

According to what I've read, SpaceX tried to use parachutes to recover the first stage of the Falcon 9, but it did not survive reentry. Now they plan to use 2 separate rocket burns to land: Reentry ...
8
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1answer
572 views

Where will SpaceX take CRS-5 after it lands?

If SpaceX's plan to land the CRS-5 first stage on their Autonomous Spaceport Drone Ship goes perfectly, there will be a 50 (ish) meter rocket on a barge in the Atlantic. Leaving aside the interesting ...
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2answers
3k views

How much fuel can SpaceX save by landing the Falcon 9 booster on a barge?

It sounds from the text of this tweet like Elon Musk plans to continue to do barge landings over the long term: "Base is 300 ft by 100 ft, with wings that extend width to 170 ft. Will allow refuel &...
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2answers
648 views

Through what mechanisms would SpaceX test and examine the returned CRS-5 first stage?

A significant minority of the users over at the /r/SpaceX Reddit community seem to be of the opinion that SpaceX will attempt to reuse the Falcon 9 CRS-5 first stage provided it lands on the downrange ...
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3answers
8k views

Why is there so little price difference between the Falcon 9 and the Falcon Heavy?

A Falcon 9 costs 61.2M dollars. A Falcon Heavy (1 Falcon 9 + 2 boosters) costs 85M dollars. That means 1 booster of the Falcon Heavy costs only 11.9M dollars. So, why does a Falcon 9 (9 Merlin 1D + ...
4
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1answer
527 views

How can I calculate the Characteristic Energy to Sun-Earth L1?

Alternatively, does anyone know it? I'm asking in regards to the upcoming DSCOVR (Deep Space Climate Observatory) mission scheduled to launch aboard a Falcon 9 v1.1 rocket in January 2015. DSCOVR is ...
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1answer
19k views

What are the droplets/particles falling off rockets at launch?

In this picture from the AsiaSat 6 launch by Falcon 9 on 8th September 2014, the part of the rocket between the fairing and the engine appears to be surrounded by dust, water droplets or debris: And ...
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1answer
544 views

How does SpaceX manage parallel processing at the LC-40 Complex?

After the SpaceX CRS-4 launch of Dragon on F9, Hans Koenigsmann, SpaceX head of launch operations is quoted as saying: Koenigsmann said that shorter gaps between launches should become more routine ...
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4answers
2k views

Other than then N-1 (30 engines) has there been a single stage of a rocket with more engines than a Falcon 9?

The Saturn V had 5 engines (F-1) on the first stage, five engines on the second stage (J-2). The N-1 had 30 engines on its first stage (NK-15). The Falcon 9 (1.0 and 1.1) have 9 Merlin 1 engines on ...
14
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1answer
813 views

What is the value of the cross-track angle between the two designated CRS-4 first stage recovery zones?

For the SpaceX Falcon 9 launch on its Dragon/CRS-4 cargo delivery mission to the International Space Station, according to Spaceflight 101, two downrange safety zones have been identified: The SpX-...
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1answer
2k views

Does the Falcon 9 v1.1 form a shock diamond when in flight?

How does the Falcon 9 v1.1 form this exhaust pattern with its nine Merlin 1D engines? Is it a bigger, rougher shock diamond? I am trying to learn more about how one could form with a cluster of ...
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3answers
2k views

How far downrange would a reusable Falcon 9 first stage land (without fly-back)?

Let's imagine a rocket like the Falcon 9 recovers its first stage via a soft landing, but doesn't attempt a return to the launchpad. For the sake of argument, let's imagine that there are no ...
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1answer
335 views

What went wrong during the OG2 Mission 1 launch attempt on June 20th 2014?

Yesterday (June 20, 2014), SpaceX intended to launch a Falcon 9 to bring 6 satellites of the Orbcomm OG2 satellite constellation into orbit. However, the launch was first postponed for an hour and ...
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5answers
6k views

How is SpaceX going to land their Falcon first stage?

SpaceX's attempt at a reusable first stage rocket sounds amazing, but how they're going to get it to land back on the launchpad is beyond me. Assuming that the first stage will separate with a speed ...
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0answers
212 views

SpaceX launch site - why all the cables are needed around top of the rocket [duplicate]

On the SpaceX launch site (slc-40 launch pad) there are lot of cables suspended around top of the rocket (between four white rods). What is the function of them? Why no such cables is used on other ...
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2answers
2k views

Are the Falcon 9 landing legs aerodynamic surfaces as well?

With the CRS-3 (SpaceX-3) launch of a Falcon 9 v1.1 with a Dragon capsule to the ISS the F-9 will launch with landing legs for the first time. Elon Musk Tweeted an image of the legs mounted on the ...
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3answers
6k views

What are the consequences of Vertical vs Horizontal integration for SpaceX?

One of the issues the Air Force has with using SpaceX as a launch provider is that their payloads are designed for vertical integration. That is, the booster stands on the pad upright, and the ...
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1answer
519 views

Does the proximity of engines in engine clusters cause interference?

One way to create a heavy launch vehicle is by clustering large numbers of small engines together in a stage. An example of this approach is the SpaceX Falcon 9: Now I've heard people arguing against ...
12
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1answer
569 views

What is the alternate hangar SpaceX has available at the Cape?

In the web cast for the Falcon 9 Flight 8 launch campaign they showed an alternate hangar where spacecraft can be prepared and fueled, before being brought to the SpaceX hangar on LC-40 for ...
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2answers
812 views

Is the LC-40 SpaceX Transport/Erector updated for Falcon Heavy already?

When I was watching the F-9 Flight 8 they showed some footage of the launcher on the pad. I grabbed this screen grab that looks like they might have added to the T/E as as shoulders for the F-H ...
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2answers
2k views

What is “downrange distance”?

On the SpaceX mission I hear periodic "Downrange distance: N kilometers" for various values of N (initially 1, then 3, then 383, 920, 1500...). What is the meaning of this value?
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1answer
2k views

On a Falcon9 launch at T-13 they poll all stations, what are all the stations they poll?

While listening to the webcast for flight 8 of Falcon 9 (Thiacom-8 mission), they did a poll of all controllers/stations at T-13:00. I could guess a number of them, but wondering what the full set ...
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2answers
615 views

What are the basic concepts of the SpaceX Falcon 9? [closed]

Is the Falcon 9 a launch vehicle or a spacecraft? What are the key design features and why did NASA decide to use it for cargo instead of its own spacecraft?
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1answer
131 views

Were there any extra objects in the latest Falcon 9 launch?

The previous launch of the Falcon 9 included a number of mysterious objects. Has there been any indication that the recent SES launch produced similar objects?
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1answer
726 views

Was any first stage recovery system tested on SpaceX Falcon 9 flight seven?

My son really was upset he missed the launch live, so we re-watched the video at breakfast and I noticed starting at 3:27 in the video a few seconds after MECO, and stage separation, you can see the ...