Take that CFD nerds From the Anderson hypersonics book

So, if I understand correctly, it sounds like GE has successfully tested a turbine-based combined-cycle engine that incorporates: 1) gas turbine; 2) rotating detonation engine; 3) ramjet; 4) scramjet 🤯

Could in theory go from 0 to Mach 10+

Demo at full scale planned for 2024 GE press release:

Some earlier reporting on the concept: geaerospace.com/press-release/…
aviationweek.com/shownews/paris…

As we approach what may be a historic Starship flight test, this Reuters report is really, really bad

No excuses: as arguably the number one launch provider *in the world* the safety culture at SpaceX has to be better. They should be setting the standard (in a good way)

If we are going to continue giving them billions annually in taxpayer dollars, they can’t keep treating workers like disposable meat puppets


And yes before you ask these numbers are much worse than industry averages

If you're ever frustrated by someone with a PhD acting like a know-it-all outside their niche field of study, just remember that Albert Einstein tried to design an airfoil but it performed so poorly during testing it's flight characteristics were compared to a "pregnant duck" HT to @milan_tomicc for reminding me of this the other day

Am I being unreasonable in thinking that "clearing the launch pad" (that everyone knew would be destroyed) is a bit of a low bar for arguably the most successful launch company *ever*?

Sorry for having higher expectations for SpaceX?

The whole thing feels half-baked and rushed

https://twitter.com/DrChrisCombs/status/1649444526170284033

I really want SpaceX to do well

We NEED SpaceX to do well

SpaceX has a great track record of success

There are tons of insanely smart, hard-working, talented people there

NASA needs Starship to put boots on the moon

So I expect more than what we got yesterday

WE DID IT!!!

MOO-K SEVEN

HEIFERSONIC I HAVE NO IDEA WHAT WE LEARNED BUT I'M EXCITED

The stans were so caught up in defining what is and isn’t an electric rocket that they totally missed the real issue: Newton’s Third Law

So gather round folks and let’s do a quick review… Backing up: let’s start with first law. This is straightforward. To make something move faster or slower (or to get it moving in the first place), you need to introduce a force. Object at rest stays at rest, object in motion stays in motion, unless acted upon.

Them: Elon is an innovator! Pushing the envelope! A once-in-a-generation engineering mind!

Elon: *should* be the nail in the coffin for the “Elon is brilliant” crowd but the stans are gonna stan

The point I've been repeatedly trying to make is that a purely stainless steel Starship construction would not survive reentry at orbital velocities fully intact & functional

You need something else (tiles, ablator, active cooling, etc.) to make that system survivable No idea why this is controversial

If safely returning from space was as simple as slapping together some stainless, they would have done it 70 years ago (trust me, that would have been preferred)

Good visualization for the “why are jet engines harder than rockets?” crowd. Those little blades deal with scorching temps and high pressure—consider too the J-79 here is an old one

There’s a reason more countries can make nukes than jet engines One issue w jet engines that makes them a unique challenge is their required durability

Jet engines must run reliably (carrying people!!) for thousands and thousands of hours with countless start/stop cycles

Even “reusable” rockets go for a few minutes ~10 times

Ok so at risk of staying the obvious it’s not supposed to do that… Coolant leak

https://twitter.com/Space_Station/status/1603222101040586752

*WARNING: GRAPHIC VIDEO, NSFW LANGUAGE*

Just terrible to see—devastating video of a P-63 King Cobra colliding mid-air with a B-17 Flying Fortress at the Wings over Dallas air show. Really sad

Developing story, not many details released yet fox4news.com/news/dallas-ex…

lol NASA's up next, I'm telling you it's been 16 hours and they haven't been suspended yet

that's an eternity on Twitter

if a SpaceX parody can last >16 hours, think of what else they'll miss

Interesting—this is the first time I’ve noticed this new Chinese hypersonic wind tunnel referenced specifically as a piston-driven tunnel (Stalker tube).

You get high-temp, high-speed flow but only for ~1ms and piston maintenance is touchy

amp.scmp.com/news/china/sci… The Mach 33 number has always seemed odd but this article also makes it seem more clear that there are Moon mission motivations (that’s ~moon return speed)—that makes more sense than some of the earlier defense-based rationale for the tunnel

That was fast

Imagine they will get scooped up by competitors in no time...hopefully they all land on their feet in greener pastures

https://twitter.com/verge/status/1537699941748965376

The "free speech absolutist" jokes are too easy to make. Elon is of course hypocritical in this regard

But it's his company and he can fire people if he wants. Your first amendment rights don't apply here, I get it.

HYPERSONIC PRESSURE-SENSITIVE PAINT

Recent images from our Mach 7 wind tunnel @UTSA showing tunnel “unstart” after a test of a simple finned rocket geometry

We paint the model with a mixture that responds to pressure changes!

So so so much happening in this video! Note that red = higher pressure and blue = lower pressure

Imaged at 20,000 frames per second

The reason so much is happening here is because this is taken from when the tunnel is *shutting down* and you have an unsteady shock system moving through the test section!

TOP GUN RAPID REAX

I feel the need…the need for a Top Gun: Maverick thread!!

(🚨Spoilers🚨) First, a disclaimer: I’m going to pick at some details here but I don’t want to get all Neil deGrasse-Tyson and be a party pooper

This movie is a fun, summer popcorn flick about AIRPLANES. It’s not a science textbook. So I can enjoy it even if they missed some things

Making a propeller on a lathe #AvGeek

From Culver_Props on IG instagram.com/reel/Cd6V8C4j2… They make some beautiful wooden props. That’s art folks #AvGeek

📷instagram.com/p/CW3Z7YiLZG0/…

DID WE JUST GET THUMBS UP/DOWN ON COMMENTS???

Elon: population decline is our greatest existential threat. We need more babies. Why aren’t you having more babies??

Also Elon: if you don’t spend 40+ hrs/wk in a physical office you’re a bum

Please tell me others see this contradiction… This is exactly what I’m talking about

A dude: “45 hrs/week is no problem, 50 hrs sometimes is fine too! No big deal”

Same dude: “oh yeah my wife is a stay at home mom”

I’m glad it works for them but it doesn’t work for everyone. Women shouldn’t have to chose family OR career

HYPERSONICS REALITY CHECK

I'm happy with how the CNN video turned out & it was great to show off the lab

The headline is a bit misleading though (I get it, this is how media works) & many commenting clearly just read the headline

So a quick thread...
cnn.com/videos/world/2… Okay, are Russia & China ahead of the US in hypersonic missile testing? It's complicated.

Let's start with Russia. TBH I am not concerned with Russia's hypersonic ground test infrastructure (wind tunnels). I do not see it as competitive in this sphere. But...