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)

Filter by
Sorted by
Tagged with
0 votes
1 answer
73 views

Landing Zones 1 and 2 in Cape Canaveral and yet launching from KSC?

On Google Earth, I saw Cape Canaveral and Kennedy Space Center (KSC) are separate sites. However, I do not understand why SpaceX lands it's boosters on LZ 1 and 2 at Cape Canaveral but launches them ...
Lawn Hollander Lawn's user avatar
22 votes
5 answers
8k views

What is SpaceX doing differently with their Falcon 9 so that it doesn't cost as much as the Space Shuttle?

SpaceX has been launching and reusing their Falcon 9 for very cheaply quite often. Even though it is quite revolutionary, it is isn't the first time a rocket has been reused. The Space Shuttle side ...
User1's user avatar
  • 351
9 votes
2 answers
2k views

Why does the Falcon 9 first stage perform a burn at 60 km altitude?

When falling back to Earth, why does the Falcon 9 first stage perform a burn at about 60 km (37 mi) altitude during re-entry instead of performing a longer burn closer to the drone ship? Would it have ...
Old Man John's user avatar
6 votes
3 answers
1k views

Sonic Boom Location

If I'm understanding right#sonic boom it's the first stage rocket that is creating the Sonic boom we hear after a Falcon 9 has been launched from Vandenberg AFB. I am approximately 100 miles south ...
Diane's user avatar
  • 61
7 votes
1 answer
192 views

Does SpaceX clean the outside of Dragon between flights?

We see that for the first stage, Falcon 9 boosters, SpaceX barely cleans the soot off. (Generally the soot comes from flying through the engine exhaust of boostback, reentry, and landing burns.) The ...
geoffc's user avatar
  • 79.6k
7 votes
1 answer
275 views

Is the Falcon 9 or Falcon Heavy allowed to launch nuclear material?

Certain missions, like the various NASA Mars Rovers (Curiosity, Perseverance, Opportunity, etc.) contained either RTGs for power generation or RTHs for heating purposes, and these contain nuclear ...
Dragongeek's user avatar
  • 18.8k
2 votes
1 answer
151 views

How does SpaceX get its boosters from the ASDS to SLC-40?

Getting a freshly-landed booster from a drone ship to pad 39A seems straightforward: there's a deepwater channel from Port Canaveral to a dock next to the VAB. Sail the ASDS up, lift the booster off ...
Mark's user avatar
  • 15.3k
1 vote
0 answers
92 views

How to approximate the force generated by Falcon 9 grid fins?

I'm interested in approximating the force generated by the grid fins on a Falcon 9 rocket during its descent phase. However, I currently lack specific data and equations for this calculation. Can ...
IsolatedSushi's user avatar
0 votes
0 answers
90 views

How do you approximately calculate the center of pressure during flight? [duplicate]

I'm working on a simulator for landing the falcon 9 booster rocket. I'm aiming to incorporate aspects like the effects of restorative torque. However, I've been trying to figure out how to determine ...
IsolatedSushi's user avatar
0 votes
0 answers
127 views

How to Model the Aerodynamics of Landing a Falcon 9

I'm currently working on a landing simulation for the Falcon 9. One of my primary tasks is to model both the environment and the rocket. In a previous rough simulation, aerodynamics were mostly ...
IsolatedSushi's user avatar
3 votes
0 answers
231 views

What advantages will Rocket Lab's Neutron have over the Falcon 9?

With Neutron's debut coming up next year, are there any advantages of Rocket Labs design over SpaceX's Falcon 9 FT? The most obvious I can see are the attached fairings, but certainly with all the ...
David's user avatar
  • 1,001
1 vote
2 answers
377 views

Why can’t we send people to the moon in a falcon 9? Why do we need falcon heavy or starship instead when falcon 9 is capable of traveling very far?

NASA’s DART mission flew on a falcon 9, but it flew 7 million miles. That’s a lot further away than the moon is, so why would falcon heavy or starship ever be necessary to go there? Why can’t people ...
Paul Schiltz's user avatar
4 votes
1 answer
223 views

Why did SpaceX change Falcon 9’s engine configuration?

Why did the Falcon 9 go from a 3x3 configuration to a ring of 8 around a central engine? Was there some sort of aerodynamical advantage to be found or something? https://en.wikipedia.org/wiki/...
Blue Skin and Glowing Red Eyes's user avatar
3 votes
2 answers
264 views

SpaceX Falcon Reusable First Stage Innovations

What are the top five innovations that SpaceX was able to accomplish that allows the first stage to land vertically and be reused? I am sure the Apollo program would have liked to reuse their first ...
still_learning's user avatar
4 votes
3 answers
2k views

Could Falcon 9 push the second stage a little longer after MECO and before separation?

When watching Starlink launches I noticed the MECO/stage separation usually occurs at about 2m30s with the speed of about 8000 km/h and altitude about 65 km. After the separation the first stage with ...
Endrju's user avatar
  • 159
9 votes
4 answers
4k views

Why don't SpaceX boosters belly flop?

The first F9 booster landing attempts failed because the booster broke up. After that, they began lighting the engines in the upper atmosphere to slow the booster. It seems to me that their problem ...
Abdullah is not an Amalekite's user avatar
0 votes
1 answer
141 views

What caused the falcon booster landing failure during the CRS-16 mission?

On December 5, 2018 the Falcon 9 booster started spinning during the landing burn, and promptly appears to have soft landed on the ocean. While SpaceX stated that the booster could be reused it never ...
Starship - On Strike's user avatar
5 votes
1 answer
270 views

Why did the June 2016 SpaceX launch run out of propellant?

In other words, what caused SpaceX to miscalculate the amount of propellant required to safely land the booster. They had landed successfully on the drone ship in April. So what went wrong here? What ...
Starship - On Strike's user avatar
4 votes
1 answer
283 views

Does a RTLS (Return To Launch Site) landing deposit more soot on the booster than a drone ship landing?

First, it performs an extra burn (the boostback burn). Does this burn make a credible source of extra soot? Second, sometimes it appears to have flown through the second stage's exhaust plume. Does ...
Starship - On Strike's user avatar
3 votes
1 answer
247 views

How can you find out how many times a SpaceX fairing has been reused?

For the past few years, SpaceX has been reusing there fairings. While on some SpaceX webcasts they tell you, others they dont. Is there a way to find out how many times judging from how they appear? ...
Starship - On Strike's user avatar
2 votes
1 answer
263 views

Why do the Falcon 9 fairings have soot on them?

On nearly every SpaceX webcast since 2020 they explain that the Falcon 9 booster has soot on it because, during the entry burn, it flies through its own exhaust plume very quickly depositing the ...
Starship - On Strike's user avatar
1 vote
1 answer
780 views

What guidance algorithm does Falcon 9 use during powered descent and landing?

The SpaceX Falcon 9 does a powered touchdown with a rocket thrust higher than mass, so is not able to establish a low altitude hover and final descent as used by the Apollo lander. Instead it needs to ...
GremlinWranger's user avatar
2 votes
2 answers
475 views

How are Falcon 9 Grid Fins' rapid movements calculated and controlled?

Similar Question: What computer and software is used by the Falcon 9? What would the formula (function) calculating the changes in angle of attack of the Grid Fins (Falcon 9) before landing look like? ...
TheMatrix Equation-balance's user avatar
0 votes
0 answers
49 views

What's inside the white round elevated container next to the Falcon 9 starting base? [duplicate]

On images of the Falcon 9 start you see a kind of round elevated container (on the left hand side of the picture). What does it contain and why is it elevated?
elzell's user avatar
  • 101
3 votes
0 answers
66 views

Recent GPS III Launch Intended or Unplanned Venting?

Between 14:01 and 14:14 in the following video, there is a significant gas vent happening behind the engine bell: Is this working as intended, or does that appear to ...
HumanJHawkins's user avatar
2 votes
0 answers
252 views

What does "pogo bleed" entail?

At around T-3:00 on every Falcon 9 countdown, we hear the following: Stage 1 pogo bleed verification I assume they are referring to pogo oscillation, but what exactly does "pogo bleed" ...
quinnkenri's user avatar
  • 1,130
3 votes
1 answer
118 views

Can the Virgin Galactic's feathered rentry system be used for first stage recovery?

The stage seperation for Falcon 9's heaviest launch on 28 August 2022 was at approx 75km altitude and at a speed of 8000km/h. Virgin Galactic's Spaceship two has a max speed of 4000km/h and a max ...
RocketMan's user avatar
2 votes
0 answers
135 views

What would happen to a human in ordinary winter clothes who is tied to the Falcon 9 first stage during its ascent? [closed]

If there was an average-health-human tied to the Falcon 9's first stage during an ascent of the rocket into space, what would happen to them over the course of the flight in case they wore ordinary ...
Nullnummer's user avatar
2 votes
0 answers
108 views

Is it possible for fuselages to have a negative lift coefficient at positive angle of attacks?

Recently I was interested in the descent phase of the first stage of the falcon 9 launch vehicle. I assumed a long cylinder to represent the first stage. using DATCOM to predict aerodynamics ...
جامکلو حسن's user avatar
2 votes
2 answers
472 views

Why doesn’t SpaceX use Falcon Heavy to launch Starlink satellites?

In this chart that I found here (https://i.stack.imgur.com/f8wOR.jpg) It shows that the price of 1 kg to LEO is cheaper on the Falcon Heavy than the Falcon 9. Also the Falcon Heavy can carry more ...
The Rocket fan's user avatar
21 votes
1 answer
3k views

Why was there only a single Falcon 9 landing on ground-pad in 2021?

According to Wikipedia, there was only one Falcon 9 booster landing on ground-pad in 2021, all other 30 launches at least attempted to land on a drone-ship. Comparatively, 2020 and (so far) 2022 both ...
Speedphoenix's user avatar
  • 5,324
2 votes
1 answer
306 views

Is the first stage LOX tank on the Falcon 9 monocoque or semi-monocoque?

In the Falcon 9 user guide manual it is noted that the first and second stage LOX tanks are monocoque. That means the tank is made of a single cylindrical shell. Is that possible? How can the first ...
جامکلو حسن's user avatar
0 votes
0 answers
127 views

Is it possible to estimate the angle of attack or flight path angle of a launch vehicle from mission web casts?

The altitude and speed is shown in the web casts of Falcon 9 missions. Is it possible to estimate the angle of attack or flight path angle?
جامکلو حسن's user avatar
1 vote
1 answer
519 views

Why does the Falcon 9 come back to the launch pad despite having considerable speed after boost back burn after separation?

After separation, the first stage of a Falcon 9 makes a boost back burn. When watching the webcast of the NROL 108 mission, after boost back it has a speed of 830 km/h at an altitutde of 148 km, then ...
جامکلو حسن's user avatar
5 votes
0 answers
129 views

How large is the AoA during the ascent and descent of a Falcon 9?

If we divide the mission into ascent, descent before reentry burn, and descent after that, how large is the AoA (Angle of Attack) in each of these three phases? Is there any difference between the ...
جامکلو حسن's user avatar
7 votes
2 answers
4k views

Why does the Falcon 9 first stage continue to decelerate after its reentry engine burnout?

As you know, Space X streams its missions and the speed and altitude data of the vehicle is shown. After stage separation, stage one gains speed and accelerates in its decent trajectory till reentry ...
جامکلو حسن's user avatar
7 votes
1 answer
10k views

How long can the SpaceX Starlink satellites survive before they deorbit?

Like most Low Earth Orbits (LEOs), the Starlink satellites will eventually have their orbits decay and burn up in the Earth's atmosphere. How long, on average, will this take? I am assuming that there ...
Starship - On Strike's user avatar
3 votes
1 answer
247 views

What would happen during an inflight abort in a Falcon 9 if the booster engines did not shut down?

During the SpaceX'S Crew Dragon In Flight Abort Test on a Falcon 9 Launch System, as soon as the abort system was triggered Falcon 9 booster engines was shut down and crew dragon's super dracos ...
Ashvin's user avatar
  • 2,644
0 votes
1 answer
836 views

How many times has SpaceX reused Falcon 9 first stage until 20th May 2022? [closed]

How many times has SpaceX reused Falcon 9 first stage until now? Not about the possibility. I want to know the current progress with the Falcon 9 first stage.
Won's user avatar
  • 17
11 votes
1 answer
1k views

Does the Merlin vacuum engine on SpaceX's Falcon 9 gimbal?

SpaceX uses the Merlin Vacuum engine on the second stage of the Falcon 9 launch vehicle. Does the merlin vacuum engine gimbal or does the second stage uses only nitrogen cold gas thrusters for ...
Ashvin's user avatar
  • 2,644
0 votes
0 answers
73 views

What is the purpose of having a planned hold during a countdown for a rocket launch? [duplicate]

NASA had many with the space shuttle, ULA always had a planned hold at T-4 minutes, and yet other launch providers like SpaceX don't. What is the purpose of a planned hold, and why do some launchers ...
Starship - On Strike's user avatar
0 votes
0 answers
102 views

Why can't the Falcon 9 first stage touch the water? [duplicate]

SpaceX is spending considerable effort to catch the Falcon 9 first stage onto a giant drone ship. I am aware that salt water ruins almost everything in the long run, but the first stage is a composite ...
Starship - On Strike's user avatar
1 vote
1 answer
157 views

Could Falcon 9 be Caught by the Orbital Launch Tower?

Would it be possible to catch Falcon 9 with the orbital launch tower by its current grid fins or load points that could be added? If they can do this and then remove the landing legs, would mass ...
Duck's user avatar
  • 327
0 votes
0 answers
933 views

What is the reliability of the Merlin engine?

I know that Merlin is extremely reliable, at least over 99%. I do know of one time when one failed, on Falcon 9's fourth launch. SpaceX had used hundreds, if not thousands, of them. I assume there is ...
Starship - On Strike's user avatar
0 votes
0 answers
103 views

What would happen if a rocket was shot? [duplicate]

After the pre-launch explosion in 2016 of their Falcon 9 rocket, SpaceX seriously considered sabotage, going as far as to see how easy it would be to shoot the Falcon 9 rocket from the ULA building. ...
Starship - On Strike's user avatar
5 votes
1 answer
127 views

What is the current turnaround time for Vandenberg SLC-4E?

Is there public knowledge for the turnaround time for this Falcon 9 B5 pad?
RonaldObserves's user avatar
2 votes
1 answer
131 views

How did this upper stage end up on a collision course with the moon?

The upper stage of the Falcon 9 rocket that launched the DSCOVR spacecraft is expected to accidentally crash into the moon soon. How did it get into this position? I found answers here that say it was,...
Fred Larson's user avatar
5 votes
1 answer
191 views

Has Falcon 9 block 5's design stopped evolving?

Spacex famously iteratively improves the design when developing rockets, with each unit being slightly (or not-so-slightly) better than the previous. These days Spacex seems to be focusing most of ...
Speedphoenix's user avatar
  • 5,324
3 votes
2 answers
156 views

Why not first stage rocket recovery at launching site after one orbit?

Rockets first stage recovery at launch site needs a significant amount of fuel for going back. This is why SpaceX most often uses sea platform and booster back burn for re-entry. As we see on Falcon9 ...
the world is not flat's user avatar
3 votes
0 answers
72 views

Is SpaceX on the way to a reliability record? [duplicate]

One of the most striking phenomena of Falcon 9 launches is how smoothly they go, at least for the outside spectator. SpaceX launches a lot. Apparently, they have now had 109 successful missions in a ...
Peter - Reinstate Monica's user avatar

1
2 3 4 5
13