SpaceX News

[WLJ]

Some are speculation blasted concrete may have taken out some of the raptors

[WLJ]

Watch the splashes in the ocean

https://twitter.com/SpaceX/status/1649097087248891904

[WLJ]

Still got work to do Mr. Musk

[RocketMan]

That was some hit.  May have totaled the van.  Of course, it may be a curiosity now, and that could enhance its value.

[RocketMan]

As I was motoring around the yard today, cutting what I euphemistically call "grass", I was pondering Musk's choice to use 33 engines in that booster.  It seems like he's just increasing the odds of failure by doing that.  Many more moving parts and thousands more potential points of failure.
But then it occurred to me that, if he can get his Raptor 2 engines to demonstrate the same reliability as the Merlins used in his Falcon rockets, SpaceX can end up in a really good place.  The Raptor 2 engines are much simpler than the Raptor 1 units, and they are cheaper to build.  Simpler is generally better from a reliability standpoint.
Having 33 engines could instead provide some built-in redundancy, extra fault tolerance if you will.  The booster will be able to lose an engine or four* and still accomplish the mission.
Maybe that's what drove the design choice for so many engines.

* If the booster loses one engine, it really loses two as the opposite engine will likely have to be shut down for balance.  If the booster loses two engines, it then really loses four.

[dogmush]

* If the booster loses one engine, it really loses two as the opposite engine will likely have to be shut down for balance.  If the booster loses two engines, it then really loses four.

You would think, but that is not what happened today.  They lost several engines, but did not shut down opposite ones.  It seems like between gimballing and throttling, they can keep some thrust coming from the opposite engine.

[cordex]

Was the diagonal takeoff toward the ocean intentional to get the rocket away from the pad as soon as possible, or a product of the mismatched thrust?

[dogmush]

Was the diagonal takeoff toward the ocean intentional to get the rocket away from the pad as soon as possible, or a product of the mismatched thrust?

It seemed intentional, or at least they were using words like "nominal" on SpaceX's feed for the first min or so.  Beside, while my grasp of Orbital Mechanics isn't great, don't all rockets go kinda diagonal?  It's speed rather than altitude that most of that energy is needed for.  You gotta get moving sideways fast enough that when you fall, you miss the ground.

[RocketMan]

I think cordex is referring to the almost sideslip the rocket did as it lifted off.  I doubt that was intentional, instead due to thrust misalignment from losing engines at liftoff.
Rockets usually don't pitch over until they are well away from the pad, a few thousand feet up.

[AZRedhawk44]

I think cordex is referring to the almost sideslip the rocket did as it lifted off.  I doubt that was intentional, instead due to thrust misalignment from losing engines at liftoff.
Rockets usually don't pitch over until they are well away from the pad, a few thousand feet up.

I bet the lateral transition was intentional.  SpaceX's biggest hope with this test launch was to not cause too much damage to "stage zero," also known as the launch tower and mount and ground support equipment.

That thing was going REALLY slow when they got to stage separation.  There are times it was courting a TWR way too close to 1.0 with the engine failures.  A dismal 2000km/hr at stage separation.  Usually a Falcon 9 launch will stage at about 7500 or 8000 km/hr, at an altitude somewhere around 60-65km.  They called max Q at about 800 km/hr and an altitude of 9000 meters.  F9 hits max Q around 9000 meters also, but it is doing 1300+km/hr when doing so.  They called stage separation on this flight at about 30km altitude and velocity of 2000km/hr.  That's way too low and slow.

I don't think they got a real Max Q test.  This particular build of this vehicle (B24/SS7) hit Max Q for this flight, but it's nowhere near what Max Q is intended to be for this vehicle's designed flight plan.

So it looks like SpaceX isn't going to grab the crown of "first methane rocket engine to orbit."  Next up is United Launch Alliance, which is using a methane rocket that some guy named Jeff sold them.  Unless of course Tory Bruno finds more excuses to delay the maiden launch of Vulcan.

I don't see SpaceX launching another Starship stack until this fall at the earliest.

[WLJ]

Was the diagonal takeoff toward the ocean intentional to get the rocket away from the pad as soon as possible, or a product of the mismatched thrust?

Most of them do it to some extent to prevent the rocket from falling straight back down onto a very expensive and long to construct pad in case of engine failure. Now how much of that was intentional today is currently open to debate, it did seem a bit excessive. Thought it was going to do the Astra Slide for a moment.

[WLJ]

As I was motoring around the yard today, cutting what I euphemistically call "grass", I was pondering Musk's choice to use 33 engines in that booster.  It seems like he's just increasing the odds of failure by doing that.  Many more moving parts and thousands more potential points of failure.
But then it occurred to me that, if he can get his Raptor 2 engines to demonstrate the same reliability as the Merlins used in his Falcon rockets, SpaceX can end up in a really good place.  The Raptor 2 engines are much simpler than the Raptor 1 units, and they are cheaper to build.  Simpler is generally better from a reliability standpoint.
Having 33 engines could instead provide some built-in redundancy, extra fault tolerance if you will.  The booster will be able to lose an engine or four* and still accomplish the mission.
Maybe that's what drove the design choice for so many engines.

* If the booster loses one engine, it really loses two as the opposite engine will likely have to be shut down for balance.  If the booster loses two engines, it then really loses four.

Don't forget Falcon Heavy has 27 engines. 

[WLJ]

Someone suggest a while back they may have to steel plate the ground underneath the OLM or scrap the current OLM design and go for one with a proper flame diverter. Not sure if the water table there will allow the digging of one. 39A & 39B pad complexes are elevated I believe for this very reason. Technically so is the OLM but it needs something other than concrete underneath it and/or a diverter. I think Elon tried to keep the OLM too simple.

[WLJ]

[WLJ]

[RocketMan]

Don't forget Falcon Heavy has 27 engines.

I hadn't thought of that.  So 33 engines isn't much of a stretch then.

[RocketMan]

My money is on SpaceX and Musk eventually succeeding.  While it wouldn't surprise me to see one or two more RUDs in the test program, their Super Heavy booster and Starship will someday be flying safely and routinely.  I am looking forward to more exciting test launches from the Boca Chica Starbase.

[WLJ]

Noticed it appears they still haven't sent people to the launch area and that the OLM is still venting. Could be sign of a leak in the system.
Drone over flying the OLM at the moment

[RocketMan]

I see a flame trench addition to the OLM's future.  And the installation of the deluge system, finally.

[RocketMan]

Some are speculation blasted concrete may have taken out some of the raptors

That's entirely possible.  The video of chunks blasting the remote camera vehicle and chunks landing offshore lend a lot of credence to that idea.

[WLJ]

I see a flame trench addition to the OLM's future.  And the installation of the deluge system, finally.

Don't think they can go too deep there without water table issues. I'm thinking steel plating with a flame diverter. And a water deluge sys of course.

[RocketMan]

Don't think they can go too deep there without water table issues. I'm thinking steel plating with a flame diverter.

Maybe even increase the height of the OLM some amount in addition to the flame diverter and deluge system, if that's possible.

[WLJ]

And move the tanks further away if that's possible.

I note the NSF feed says road closed until 14:00 (CT  I assume). Still seeing venting from the OLM on LabPadre's feed.
Someone said in chat that one is the tank is leaking. Don't know if true.

[WLJ]

Looks like Hopper took some damage

https://twitter.com/WatchersTank/status/1649080855661277184

[WLJ]

Now for the million dollar question: Does this effect in anyway what the FAA thinks?