SpaceX launches

The NASASpaceflight livestream was pretty funny, they're all holding their breath waiting for the landing and then just a loud boom followed by debris falling through the fog lol.

Once the fog clears and the roads are reopened it'll be interesting if there is a crater or not.

In reply to adam525i (Forum Supporter) :

Yeah, the feed looks like an ignition, then boom lighting up the fog, followed by a LOT of debris raining down outside of the landing area.

 

Keith Tanner said:

Zut alors, I was thinking this one would make it. It's like rocket science is hard.

I believe we're due some rocket science jokes to lighten the mood after the colossal explosion (hesitate to say "failure" at this stage):

Keith Tanner said:

Yeah, something went very wrong. I don't think it got as far as the landing, there was debris raining from the sky. I've seen speculation that it was terminated on command because it was off course, the debris was a fair way from the pad and it certainly didn't get low enough to get into the final landing phase. Timing says it would have been about the time of the bellyflop. We'll find out more.

Zut alors, I was thinking this one would make it. It's like rocket science is hard.

I was giving it a 50% chance, based on the fact this is the old SN model that apparently they found enough inherent flaws with to scrap the subsequent 12-14 versions and jump to the next model.  Still... I was hoping it would go better.

Very interesting post over at Ars Technica, which explains why SpaceX didn't replace an engine last week. They pulled #46, took it away and brought it back. Fingers crossed that the new Raptors will be more tolerant on relights. 

A significant problem that SpaceX seemed to have with SN11 is that they almost ran out of functional Raptor engines compatible with the SN8-14 design iteration. Quite some time ago now, in SpaceX time, they transitioned Raptor production to a design step that requires the SN15-class thrust dome, and that limited their engine allocation options for SN10 and 11. 

SN15 and Super Heavy open up the flight test program to accept newer and significantly improved Raptor engines that have been waiting for their opportunity to fly. That will be a critical time to assess progress on the propulsion challenges for Starship, whereas SN11 was really the dregs of a design iteration that was cut short for good reason.

In reply to Keith Tanner :

I found that interesting as well, since some of our development programs are doing the same thing with version hopping at the moment.  Look Ma! I'm just like SpaceX!

Here's how I see it.

SN8 - which did far better than anyone expected - highlighted a fuel delivery problem during the very dynamic flip maneuver. It was too late to make significant changes to the next few SNs are they were too far into production, so they finished those and tried some bandaids. The bandaids sorta worked but not completely. But in the meantime, SpaceX learned a bunch about pad procedures, flight dynamics, production techniques and landing pad repair :) They realized that the single engine relight was too risky so they changed how the flip was performed. All valuable, and far more educational than simply scrapping those obsolete prototypes.

SN15 is the second generation prototype and incorporates what was learned from SN8. Had SpaceX not been building these things as fast as possible, it would have been the second one built after SN8. But that's not how they roll!

Someone has been sleeping on this!  (yes, I was not paying attention either):

The Federal Aviation Administration has issued flight restriction notices for pilots in the area that from Friday through Sunday (April 30-May 2) in case SpaceX opts to try for a weekend flight. 

They scrubbed the flight of SN15 for today, but look out for an attempt this weekend.

This site is saying Monday:

https://www.rocketlaunch.live/?filter=spacex

I believe there are difficulties in closing the beach on weekends, so they only fly during the week. Prove me wrong, SpaceX!

We had a successful rocket launch in the park a couple weeks ago:

https://photos.app.goo.gl/dEiw4t5zzYRLgZTq9

A-series in the first stage, B-series in the 2nd (practice runs on a small field to check separation worked OK).  We've got a B/C combo if we decide we never want to see it again.  

They are now guessing tomorrow (Tuesday).

SpaceX really wants this one to work - SN9-11 were "it might land but it might not because we know they have a fundamental problem but let's see what happens", but SN15 is the next generation. Note that they did use 9-11 to experiment with different aerodynamic modes, engine control and angles of attack, so they weren't just fireworks.

Here's what killed SN11:

"Ascent phase, transition to horizontal & control during free fall were good. A (relatively) small CH4 leak led to fire on engine 2 & fried part of avionics, causing hard start attempting landing burn in CH4 turbopump. This is getting fixed 6 ways to Sunday."

Hard start is a euphemism for a bit of a bang :)

It's looking good for tomorrow. Fingers crossed! I can't wait for them to launch one of these with some real engine power, they've got the Raptors throttled back about as far as they can go to avoid going supersonic.

NASAspaceflight is showing a launch window of 12 pm to  8 pm central today on their livestream now, hopefully they have nice clear weather and can get this thing off the ground this afternoon.

Just checked.  Looks like they are scrubbing for today (Tuesday).

Scrubbed today, maybe tomorrow?

Things are looking better today but still early in the launch window. They are still doing final preps to SN15 and the pad/village have not been cleared yet.

Quick update:   Pad is cleared, looking pretty good for today?  Maybe?

Update:  Less than an hour, if all goes well.

Looking better, things are starting to happen. NASAspaceflight is predicting under an hour if things go well so around 6 pm EST?

Edit: It's looking like 5:45 pm EST so tune in soon for live views of the launch

SpaceX stream. This will go live about 5 minutes before launch and has the best quality video because, well, they can put cameras wherever they want instead of miles away :)

Should we be taking bets on when it blows up?

Vehicle wasn't compromised, I think we're good. Legs look fine. 
 

Wooooo!

Yep, looks like they were able to get things vented safely before things went boom. Awesome.

So what do they do with an intact landed SN15? SN16 is pretty close to be ready.

The SpaceX feed showed that it looked to land very close to the edge of the pad, maybe under a few feet?

Too bad for the overcast, but it was still interesting to see it blast through the clouds.

They did it! The crazy bastards, they did it!

Maybe they parked SN15 close to the edge to leave room for SN16 to land :)

I expect Tankzilla will swing by to drop SN15 on the centipede. There was some crazy gimbaling going on with the engines during landing, they might have a little work to do on the steering algorithms for Starship. The Falcon 9 landing yesterday was right in the 10 ring.