Serial Number 5 was Alive!

In case you missed it, after many, many aborts, Starship (test vehicle) s/n 5 finally launched on a 150 meter "test hop", lifting off from a very basic test stand to a few hundred feet of altitude, traversing horizontally a few hundred feet, and landing again on a very simple flat concrete pad.

It appears to my admittedly ignorant eyes that having virtually no exhaust management or flame diversion / suppression on the launch stand resulted in the fire in the external engine space that we can see in the video. I am confident we will only see that once. ;)

For those who haven't been following every little detail of SpaceX's new rocket design, please keep in mind one fact when looking at this vehicle: this section is meant to be somewhat close to the upper stage, which will have the crew / cargo section attached on top... but there will be a whole other rocket - a whacking great booster called Super Heavy - which goes under this thing!

The last I heard, the Starship upper stage will have six Raptor engines on board: three atmospheric engines and three vacuum engines.  Only three will operate at one time.

But Super Heavy will have thirty-six, no wait, thirty, no wait, twenty-seven... um, once they finish increasing the performance of the Raptor and figure out how many they are actually going to use (ahem), there will be, er, a whole bunch of them on the tail end of the big booster that will sit under this Starship upper stage.  Super Heavy will be a BEAST, developing about twice the thrust (and noise / vibration) of a Saturn-V launch!  If you aren't aware, that is a lot; until Blue Origin's big rocket goes live, Starship + SuperHeavy will be the most powerful rocket, with the greatest lifting capacity, in history.

Note: the main difference between the atmospheric and vacuum versions of an engine

are the size of the exhaust bell (commonly called the 'nozzle', but it's important to

recognize that this most-visible portion is only one third of the three parts of a

rocket engine nozzle).  The purpose of the exhaust bell is to capture and contain

the rapidly-expanding gasses as they leave the combustion chamber, preventing

them from expanding sideways, and redirecting that expanding pressure to the rear

where it can do some good, like pushing the vehicle forward. Gasses that go sideways

don't push the vehicle forward.

When the vehicle leaves the atmosphere behind and begins to travel in regions of low

pressure and finally the vacuum of space, it becomes much easier for the expanding 

gasses to go sideways instead of backward, so a much bigger and longer bell is 

required to redirect those gasses to go straight back.

 It is also important to understand that this test vehicle is not a good representation of what the final Starship upper stage will look like; this is little more than a test article intended only to prove the functionality of the basic parts of the rocket's systems: the fuel tanks, the structure, the engine and Thrust Vector Control system, the Reaction Control System, and some basic navigation / orientation.

 There will be several more test hops until the basic launch sequence is thoroughly characterized and understood, bugs in Raptor's performance and stability are worked out, and possibly some facility upgrades (cough, exhaust management, cough) are accomplished.  One thing is certain: they sure as hell aren't ready to test 30 Raptors firing at once, yet!  That will be a sight to see.