SpaceX: Starship – SN8 – High-Altitude Flight Test | Hacker News Reader

SpaceX: Starship – SN8 – High-Altitude Flight Test

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That was the literal bomb. So awesome.

Not understanding yet why it was green at the end. Raptor shouldn't really use TEA-TEB.

Seems like an engine busted on the way up. Or maybe one of the nitrogen tanks in the skirt.

Scott Manley will do a rundown on all of these soon I would assume. Tim Dodd will do an interview with Elon.

Great community making content about this.

> Not understanding yet why it was green at the end

I think they call it engine rich exhaust; some of the copper from the engine being burned

Yes, Elon Musk explained what happened.

The pressure of the fuel was too low during landing, which had 2 effects:

1. the exhaust gases contained mostly oxygen, which burned the copper linings, giving a green flame

2. the decceleration was insufficient, causing the impact with the ground which resulted in an explosion

It also didn’t help that the legs didn’t deploy

Looks like a success! Almost nailed the landing as well!

May have ran out of fuel towards the end.. but amazing to watch.

Green flame might mean something copper burning that shouldn't be. Based on the size of the explosion it looks like there was still a decent amount of fuel.

Is it necessarily copper? There are other compounds that can produce green flames (like https://en.wikipedia.org/wiki/Triethylborane)

Edit: There are some other comments talking about "engine rich exhaust" that are burning parts of the engine. Still incredible they got it this far.

The inside of the nozzle uses copper for heat dissipation. There were previous cases of green flames with the Raptor, and Elon said it was copper. The big question is why it was low on methane - bad calculation in the planned consumption, too methane rich during the ascent?

> This suborbital flight is designed to test a number of objectives, from how the vehicle’s three Raptor engines perform, and the overall aerodynamic entry capabilities of the vehicle, including its body flaps, to how the vehicle manages propellant transition. SN8 will also attempt to perform a landing flip maneuver, which would be a first for a vehicle of this size.

> With a test such as this, success is not measured by completion of specific objectives but rather how much we can learn as a whole, which will inform and improve the probability of success in the future as SpaceX rapidly advances development of Starship.

That was spectacular! I'm completely blown away by how audacious and bold the Starship project is. Sending a rocket that massive into space and then attempting to land it back on earth, with the intention of using it to eventually send people to Mars and back. Just thinking about how much force those thrusters must have been exerting to propel the ship and pull off that flip maneuver gives me chills. I can't wait to see how fast they'll take to build and send up the next one. Props to the people at SpaceX for getting this far!

That flip at the end was fun to watch. Getting 15 stories of rocket back to vertical like it ain't no thing. An engine was out earlier in the flight (intentional or not?), so I wonder if more fuel was onboard than planned and came down heavier than expected? I am only speculating...their engineers are smarter than me.

They came down vertical, right where they wanted...just a little hot. The next Starship iterations are gonna be awesome.

Awesome! The landing was almost there but the test was most definitely a success. Great work SpaceX.

Task failed successfully :)

R2D2, watching on from the sidelines...

Delayed to 22:40 UTC / 4:40PM CST

Ka-boom! Spectacular fail!

It completed the high altitude flight test

Unfortunately people are going to focus on the explosive ending. But the high altitude test went well.

The belly cruise and the final flap too...

I know that. I watched the entire thing live: climb, stall, belly flop, tail stand, landing, rapid disassembly. I understand the significance.

Still a cool explosion though. :)

That was amazing. I don't normally watch SpaceX launches but I'm glad I watched this one. They did all their orientations perfectly. I've never seen a rocket take fall damage while vertical before. Thanks for the heads up, HN.

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