USA Space Programs & Discussions

[Radonsider]

And another delay (they will replace a grid fin actuator)

 

[Radonsider]

Some online think that the second test flight will be make or break. I disagree. A lot is hanging on the Starship. They will power through it and get at least 3-4 more.

Yeah, they need to reduce lower their bar for a bit

 

[Rodeo]

Some online think that the second test flight will be make or break. I disagree. A lot is hanging on the Starship. They will power through it and get at least 3-4 more.

Their production rate is so high that they could throw ten launches at it if necessary. They produce multiple raptor a day and test them till they break in McGregor facility. They could launch it and put the second stage into orbit very soon.

Orbital refueling and the catching mechanism of the booster(chopstick mechanism) is a question though. Then there's the issue of landing on the unprepared lunar and Martian soil. It would not be much of an issue if they had concrete landing pads but they won't be available for the first missions.

Edit: I totally forgot about the hot staging. How will the booster survive the direct heat and pressure from the second-stage raptors? The launch will be spectacular either way.

Note: SpaceX will not be attempting to recover the booster or the second stage. There won't be any orbital refueling in the near future. The goal of this launch is to reach the orbit.

 

[Rodeo]

Last 40mins till launch

The streams with commentary:

 

[Rodeo]

Official Live Stream

https://twitter.com/i/broadcasts/1dRKZEWQvrXxB

 

[Radonsider]

Props to SpaceX for managing 33/33

 

[Sanchez]

Unbelievable. Look at that! That was an awesome display of RUD.

 

[Rodeo]

The booster didn't survive the hot staging but the upper stage is powering through

 

[Sanchez]

The booster didn't survive the hot staging but the upper stage is powering through

And there she goes. Successful test all around.

 

[Rodeo]

https://twitter.com/i/web/status/1725865737577693400

 

[Rodeo]

This was surreal

https://twitter.com/i/web/status/1725863437887242515

 

[Afif]

The majesty of that spaceship is off the chart. all those 33 Raptor engine was burning to the perfection and look how clean it was. And of course we cannot ignore the starship itself.



Edit- The Last bit is straight from Sci-Fi. The future is here.

 

[Sanchez]

The Last bit is straight from Sci-Fi. The future is here.

Blurs the line between sci fi and reality. You could change the cars next to them to 50s and this photo would look from 50s. Change it to 80s, it looks 80s. Change it to flying cars and it's 2040s. Such interesting design cues.

 

[Rodeo]

The majesty of that spaceship is off the chart. all those 33 Raptor engine was burning to the perfection and look how clean it was. And of course we cannot ignore the starship itself.



Edit- The Last bit is straight from Sci-Fi. The future is here.

Why do the raptors(methane burning engines) burn pink(at 0:53)?

And how realistic do you think the chopstick catching mechanism for the gigantic booster?

@Nilgiri @Yasar

 

[Afif]

Why does the raptors(methane burning engines) burn pink(at 0:53)?

Because Methane burns much cleaner than Kerosene? I don't know why pink specifically though.

 

[Yasar_TR]

Why do the raptors(methane burning engines) burn pink(at 0:53)?

And how realistic do you think the chopstick catching mechanism for the gigantic booster?

@Nilgiri @Yasar

Ingenious system of catching used booster rocket. If it works why question it!

Methane burns blue. Higher the energy of a flame, the bluer it is. But as the flame leaves and cools/loses energy, it would gradually turn towards red spectrum.
below picture of raptor rocket testing shows the flame as blue at exit. Then more pink/reddish further away from nozzle.

 

[Nilgiri]

Why do the raptors(methane burning engines) burn pink(at 0:53)?

Like Yasar has explained, it depends on the temperature faced by the hydrocarbon (whatever it is, they are all C-H combos) in presence of oxygen.

If the stochiometric mix is perfect, you will only ever see a blue flame, like that you see of a bunsen burner (when you swivel the air duct)....and get the commensurate temperature and (higher) electron excitation in the C, H and O atoms involved to give a combined register of blue (specifically the conversion of C + O2 to CO2 directly, since I believe H + O2 -> H2O is largely colourless)

If the mix is instead fuel rich (and not stochiometrically balanced) as is the case with most rockets (given premium of the oxidizer compared to the fuel), you will instead see some amount of fuel expelled out the nozzle unburnt or only partially burned (C + O --> CO)....somewhat similar to a bunsen burner when you keep the air duct closed.

The CO + O2 ---> CO2 happens further down the (intense velocity) ejecta plume along with some further C + O---> CO. These combine to give a yellower flame given the lower electron excitations involved. As to why lower energy released by the electron shifts cause lower frequencies in the light emitted, needs a look into electron structure physics and chemistry and Planck's E=hf (and associated series of light emission in the atom w.r.t balmer series, which is the visible part our eyes are capable of picking up).

So pink is a transition colour depending on these dynamics of the plume and fuel-rich combustion (blue closer to the nozzle, and more red and yellow tinge further down added to give purples and pinks where there are both happening).

You see similar phenomena happen with afterburners too depending on flame temperature....since again its a hydrocarbon.

When you have only full hydrogen and oxygen combusting (say hydrolox rather than kerolox or metholox), water vapour does its own thing with opaque droplet refraction shielding the near-transparent combustion colour (as non visible light is activated mostly in the electron excitations here).

Camera filters can further add a skew to the colour too sometimes.

 

[Rodeo]

Another milestone

https://twitter.com/i/web/status/1738434850233938355

 

[Rodeo]

A single Falcon 9 booster has put 260 tons of payload into orbit in 3.5 years.

SpaceX has no competition.

https://twitter.com/i/web/status/1739458499334045809

 

[Rodeo]

https://twitter.com/i/web/status/1760063643583148365