SpaceX Starship : First Flight : Starbase, TX : 20 April 2023 - DISCUSSION

[SpeakertoAnimals]

Please don’t overlook that the SpaceX presenters are engineers who design/build the product for day jobs. The presenter gig is part time/for fun. They are not professional media personalities, they are enthusiastic amateur presenters but professional rocket builders first.

I prefer the engineers, the media people frequently demonstrate that they have no idea what they are talking about.

[oiorionsbelt]

 Random thought about SpaceX's last maiden flight.
In June 2010 when F9 launched for the first time and did so successfully, Jim commented something along the lines of, "Now NASA has a replacement for the Delta II"  (Wish I could find the exact quote.)
 F9 went on to become so much more than Delta ll

How will Starship be viewed after it's first successful launch? Now NASA has a replacement for Saturn V ?
It's likely to become so much more than Saturn V.

[TheRadicalModerate]

...

At mars pressure lox and lch4 are subcooled.

Dropping pressure lowers the boiling point.  If you drop the pressure on a boiling liquid, it just boils faster.  You can raise the pressure and make it subcooled, though.

I think you and rs are using the term differently.

Yes, a liquid is subcooled when it is below its boiling temperature for its given pressure, but by that standard the LOX in a Falcon 1 tank was subcooled once the tanks were pressurized for flight.  SpaceX, when speaking of subcooled propellants, is of course saying that they are densified by being brought below their boiling point at Earth atmospheric pressure (since they are usually stored in bulk near atmospheric pressure, with their temperature maintained through boil-off).

Subcooling methane with respect to Mars atmospheric pressure will be difficult to do given its triple point of 90.69K/0.117bar, well above Mars's atmospheric pressure of 6mbar!  Instead, what I believe rs is saying is simply that the densified propellant temperatures that SpaceX calls subcooled on Earth will be that of boiling propellants in an only partially pressurized tank on Mars.

FYI, I posted a question over on the Raptor engineering thread about this.  Somebody over there is going to know the answer and save us from wandering off into the thermodynamic weeds.

[DigitalMan]

Please don’t overlook that the SpaceX presenters are engineers who design/build the product for day jobs. The presenter gig is part time/for fun. They are not professional media personalities, they are enthusiastic amateur presenters but professional rocket builders first.

When StevenOBrien posted about SpaceXer PhotonEmpress wanting feedback, I tried to make a positive contribution. (point was don't just joke about something, explain the detail).

Obviously, feedback is feedback, I tried to limit mine to things those individuals could do to improve.

[alugobi]

Considering the bodies they threw at the booster and qd since the scrub, seems as though there was a lot more than a HE valve they were having to fix.

[clongton]

Jay Apt once told me that big liquid-fuel rockets produce a more basso-profundo roar than big solid-fuel rockets.  Don't ask me to explain the underlying physics.  

Pretty good explanation here:

[Echo_Jex]

Considering the bodies they threw at the booster and qd since the scrub, seems as though there was a lot more than a HE valve they were having to fix.

I really don't know if I'm adding anything here. I was startled on the fleet size sent out too. when airplanes are trying to take off, the pilot can have a priority 1 grounding problem, and then there can be 2 pages of priority 2 non mission critical discrepancies that can get worked while waiting for parts and labor to wrap up.

[Glorin]

Not sure if that been noted, but for anyone planning on being on-site at Isla Blanca, the park opens at 5AM.

[intrepidpursuit]

Cross post from the viewing thread. I need help or I'll be sleeping on a bench at the airport tonight.

I need help. I need a ride from Valley International Airport at midnight tonight to South Padre Island.
I'm flying back into Valley International Airport at midnight tonight and my Turo rental car just cancelled. Turo has no more cars, the rental car companies will be closed, Uber and Lyft show that they are unavailable, the taxis are booked.
I have an incredible condo rental on South Padre Island that can see the launch mount. It had parking passes and an extra bed. I was actually hoping to post an invite to join me anyway, so company would be welcome.

Please message me if you are willing to save my trip. I would be in your debt.

[Chris Bergin]

I've removed the embarrassing posts (and they are truly embarrassing) to save the members posting them from looking like idiots muttering about SpaceX commentators to 1000s of people reading them. I'm furious as one of them was a racist comment. That person is gone.

DO not post here unless you have something useful to add.

In fact, I'll start a new thread and I'm just going to stop a bunch of people (I don't care if you're L2 or not) from posting if I have to come back here again to a set of report to mod alerts that even the mods are throwing their hands up at (and having read them, I see exactly why). It's only a handful of people, but I'm seeing the same names, and sadly they are long-time members. They will not be allowed to lower the tone of this forum into some Reddit food fight.

Thread 2:
https://forum.nasaspaceflight.com/index.php?topic=58671.0