# SpaceX Falcon 9 historic landing thread (1st landing attempt & most recent missions)

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#### manixFan

##### Not a rocket scientist
...snipped for brevity....
I'm not "down" on the project. But the problems they have had for being zero and three now for intact vehicles, is a setback even for a development program like this.
...snipped for brevity....
I disagree that it is a setback. They landed successfully, which was the goal of the flight. If it was a setback then we could expect to see a big delay and rework before the next flight, which we won't. As much as possible what was learned from this flight will be incorporated into SN11, and the rest into SN12 and beyond. I guarantee that if you asked any of the SpaceX folks if this was a setback, they would probably laugh and instead breathe a sigh of relief. Whatever caused it to exlplode at the end is just likely a plumbing issue considered trivial in the scheme of things.

When you consider that it only took three flights to nail what is arguably an incredibly complex flight profile using the first ever (production) full-flow staged combustion engine powered rocket, it's hard to call that a setback.

Tony

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#### georgegassaway

I am always wishing them success. Sometimes it doesn't go to plan. I thought it would have been good to have SN10 in a museum display if it had not exploded.
Maybe a museum display after its' 10th flight. They've got to get out of this "kaboom" ("ha-ha-ha-ha") rut and into the "lots of reflights of the same vehicle" thing. I didn't expect 10 out of SN-10, but always expect more than one.

Saw this posted on a SpaceX group. It is supposed to be a tweet from Elon Musk referring to the cause for the hard landing. They did not link to it, and I do not slavishly follow anyone on Twit-erville so I'm not going to search. But it's probably a real tweet since it was a group moderator that posted it:

"Elon tweet:
Thrust was low despite being commanded high for reasons unknown at present, hence hard touchdown. We’ve never seen this before.
Next time, min two engines all the way to the ground & restart engine 3 if engine 1 or 2 have issues.
"

.

#### mach7

##### Well-Known Member
One important thing to consider,

This is flight test. Not just flight test, but flight test of a whole new flight profile and system.
This is just a proof of concept vehicle.
Flight test can be ugly at times, and it is usually not this public. Blue Origin?

Things to ponder.

They are improving/learning.
Many times in flight test you don't know what you don't know.
The SN's are highly instrumented so much data are being gathered. (Proper english?)
No people were injured.
SpaceX has proven that they are very capable of making adjustments.
This is just so Freaking COOL!

#### Peartree

##### Cyborg Rocketeer
Staff member
Global Mod
I think that it's like rocketry (and motor sports) in general. We wish for success. And we know that successes are amazing, incredible, impressive, and many other superlatives. But we cannot deny that the failures in these endeavors can be truly spectacular.

#### georgegassaway

Couple of other videos. Slo-mo of landing, and then explosion. Note that it was tilted on landing due to the angled offset of the three engine cluster with the thrustline thru the CG. So if the engine is offset by let's say 3 degrees, the main body has to be tilted by 3 degrees for a vertical landing.

Different view of the landing. Things being "not quite right" in the tail section once the second engine shut down, is a bit more obvious here.

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#### OverTheTop

##### Well-Known Member
TRF Supporter
There is a little bounce on landing visible in various footage also. Something that big bouncing is not likely an expected behaviour.

#### RocketGeekInFL

##### Well-Known Member
This proposed site plan seems kind of condensed for a rocket port don't you think?

#### OverTheTop

##### Well-Known Member
TRF Supporter
I guess it will do for now. They are putting their faith in the accuracy of their landings and not having too much of a boom if things go wrong. Not much collateral damage so far.

Thinking about their idea of having an entire city there, where Boca Chica is currently. It would be convenient for workers, but wouldn't be too practical if they have to evacuate everyone whenever there is a launch.

#### Mushtang

TRF Supporter
I didn't expect 10 out of SN-10, but always expect more than one.
Why would you expect more than one if more than one was never part of their design? Are you just looking for reasons not to give SpaceX their due props now that they've let you down a few times?

#### Cape Byron

##### The BAR formerly known as Skippy-2
TRF Supporter
Thinking about their idea of having an entire city there, where Boca Chica is currently. It would be convenient for workers, but wouldn't be too practical if they have to evacuate everyone whenever there is a launch.
To be fair, they'd prolly only have to evacuate the city for landings...

#### OverTheTop

##### Well-Known Member
TRF Supporter
To be fair, they'd prolly only have to evacuate the city for landings...
Given the size of blast waves that can be generated by full-sized fully-fueled rockets I think you would find launches would be included as well. The blast zone pressure wave, and even the acoustic effects of a regular launch, can be detrimental.

As the rockets get bigger the clearance zone gets bigger and the bunkhouses get lower and more streamlined, based on the amount of energy available for the blast.

There is an observation area near LC39 I have seen that has a small earth tunnel. They found that the acoustics from a launch (shuttle in this case I think) can trash a diesel generator even at over a kilometer away. The generator is now protected by an earthen shield. The observation area was/is used for remote cameras during launches.

#### Cape Byron

##### The BAR formerly known as Skippy-2
TRF Supporter
Given the size of blast waves that can be generated by full-sized fully-fueled rockets I think you would find launches would be included as well. The blast zone pressure wave, and even the acoustic effects of a regular launch, can be detrimental.
See what happens when I forget to put a smiley in my post? People start taking me seriously. Which can be a bad thing.

#### Sooner Boomer

##### Well-Known Member
See what happens when I forget to put a smiley in my post? People start taking me seriously. Which can be a bad thing.
We ALWAYS take you seriously

#### Cape Byron

##### The BAR formerly known as Skippy-2
TRF Supporter
We ALWAYS take you seriously
That just proves you don't know me very well...

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#### CalebJ

##### Well-Known Member
TRF Supporter
It was definitely mentioned during the live broadcast that this was not going to be reused.

#### boatgeek

##### Well-Known Member
I got the impression (and I don't know where) that SN8-11 were basically one-use pieces to test the landing maneuver. The idea was that SN8-11 were an older design with the older alloy, so they weren't all that good for much other than the landing test. I assumed they would re-use the Raptors though. SN15 was then intended to take over re-use testing because it had the new alloy, better landing legs, and maybe some other good stuff too.

Sort of along these lines, do we know why SN8-10 used flip-down landing legs instead of just having them bolted in place in the extended position? The rocket wasn't going to fly fast enough for aerodynamics to be an issue, so it seemed like it added another failure point without really testing long term flight hardware.

#### Marc_G

##### Well-Known Member
10 m/s? Really? I'm shocked it was still moving that fast. Sure it was still moving and bounced but wow!

#### manixFan

##### Not a rocket scientist
Nice short video of SN10 highlights, except for the Big Bang:

Tony

#### Sooner Boomer

##### Well-Known Member
Yet another Falcon launch. Yet another batch of satellites in orbit. Yet another booster fly back and recovery. Yet another recovery of fairing halves.

They're kinda getting good at this stuff!

I wonder if Starlink wasn't actually the result of a solution looking for a problem...

#### davel

##### Well-Known Member
Beware complacency.

#### OverTheTop

##### Well-Known Member
TRF Supporter
I wonder if Starlink wasn't actually the result of a solution looking for a problem...
No. Probably the fact that they had this great reuseable launch system for getting things to orbit and the "ramp to volume" was a bit slow because it really was a paradigm-shift in rocket operations, and the rest of the world is still trying to wrap their heads around what this enables. That opened up the business opportunity to provide internet for the world, like many other providers were already talking about and attempting, but failing with the launch costs. So it is the technology that enabled the outcome, but that doesn't make it a solution looking for a problem. Lasers are another prime example of this. As the technology progressed and matured they found many new applications that were never possible before, but people needed to figure out what those applications were and then research and refine them.

In the case of SpaceX I don't know how any other space-based internet providers with low-latency LEO satellites would be viable. The reuseability and the fact that SpaceX and Starlink are companies owned by the same group of people make this possible, getting the launches at "transfer" pricing (I am guessing this) and not retail/wholesale rates. That makes it easier for them to maintain high launch cadence to expand the constellation and replace satellites that fall out due to the low orbit. How many other companies are around that particular combination of constraints and circumstances? Not many. Other companies would be more likely to go for higher orbits and longer satellite lifetimes. I am sure the short satellite lifetimes also allow some price reduction in the satellite production from the engineering side, and the quantity allows economies of scale in their production.

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#### Reinhard

##### Well-Known Member
TRF Supporter
I wonder if Starlink wasn't actually the result of a solution looking for a problem...
I'm under the impression, that this is mostly an attempt to get more money. Compared to changing energy usage on earth and getting to Mars, satellite internet didn't appear to be part Elons "mission" in the past (or I just didn't notice).

As a pure launch provider, SpaceX is limited to maybe $1-2B yearly revenue for now. Last year, they had 25 flights for usually$60M (except a few manned, heavy or national security launches, which are more expensive). I'd expect that market to grow, but not dramatically so. If your ambition is to establish a city on Mars, $2B per year is a pittance. The telecommunications market is much bigger than the launch market - the bigger players in the US alone exceed$100B per year. I don't know how much of that SpaceX can grab - Starlink is not well suited for population centers where many customers would have to share few satellites - but the potential is still significant.

If this works out, that could be quite synergistic. Mass launches of Starlink satellites would provide a commercial justification for Starship and the expected low cost of Starship would make it hard for other companies to build a competitive constellation. We'll see.

Reinhard

#### Winston

##### Lorenzo von Matterhorn
How Amateur Radio Fans Decoded SpaceX's Telemetry & Engineering Video
15 Mar 2021

MONITOR SPACEX ROCKET LAUNCHES WITH SOFTWARE-DEFINED RADIO
11 Mar 2021

#### georgegassaway

Well, there is a possibility SN-11 will fly Friday. There was a static test earlier in the week. They swapped out an engine after that.

Another static firing is planned for Friday. It looks like if that static test is done early, and goes well, they may fly Friday.

#### Marc_G

##### Well-Known Member
Any updates? I see the window remains open until 8:30 I think.

#### Reinhard

##### Well-Known Member
TRF Supporter
Any updates? I see the window remains open until 8:30 I think.
They had a static fire earlier today. Right now, it looks like they are arming the FTS, which probably means they will attempt a launch within the next hours.

Edit: The Everyday Astronaut stream came just online which estimates the launch to happen in about 2 hours.

Reinhard

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#### Marc_G

##### Well-Known Member
Scrubbed for today.