April 20, 2023

SpaceX Starship Launch: Success or Failure?

The April 20 launch of SpaceX's Starship was eagerly awaited and riveted viewers to their screens amid cheers from the launch team and spectators.

Some say the fact that the rocket blew up and the launch pad was torn up means that the mission was a failure. 

Not so! Elon Musk humorously refers to catastrophic destruction of his spacecraft as "rapid unscheduled disassembly," or "RUD," but SpaceX learns a tremendous amount from such failures. 

Hold that thought, and we'll first go through the four minutes of the launch and flight.

Watch the Video of the Launch!

At T-0, the engines lit and gradually built up thrust. The spacecraft very slowly cleared the pad and rocketed away. 

But the moment the thrust hit the ground, it broke up the cement underneath and dug a huge crater under the launch pad. Enormous clouds of dirt, cement and debris engulfed the rocket and damaged many nearby tanks and other infrastructure. It appears from videos that the force of the dust cloud might have pushed the rocket slightly. 

Due to the absence of a flame trench to safely divert the exhaust, and the absence of a water 'deluge' system to dampen sonic and shock waves, there were no means to limit the damage to the pad or damage to the rocket from flying debris. Virtually all other rocket launches use such systems.

It's possible this debris may have damaged some of the engines and other parts of the rocket.

However, the rocket roared to the heavens, reaching about 25 miles above earth. Along the way it passed a key hurdle, the "Max-Q" point of the maximum dynamic forces on the spacecraft. It continued unfazed.

Along the way, at least six engines failed, causing a loss of about 20% of its thrust. Several bright flashes were observed in the flame plume, possibly when engines or hydraulics failed.

At the point where the second stage was supposed to separate and fly to splash-down near Hawaii, the staging did not occur, and the complete rocket 'stack' was observed to rotate several times, perhaps due to an imbalance of remaining engines or loss of thrust vectoring. Then at the 4-minute mark, it was commanded to self-destruct via the autonomous self-destruct system, designed to prevent an out of control rocket from endangering others.

That's what everyone saw. Now let's look at what went RIGHT.

Elon Musk's low expectations for a completely untested rocket was just hoping it would at least clear the launch tower. Starship aced that!

The SuperHeavy booster flew for four minutes, in spite of several engines failing. The only test in advance had been a seven-second 'static fire' of the engines. 

By contrast, the Artemis SLS rocket core stage was fired for about two full minutes at NASA's Stennis Space Center's test stand, and tested again briefly at the Kennedy Space Center. 

The rocket held together for about three complete spins, experiencing high G-forces.

The autonomous self-destruct system did its job.

So what's that mean?

SpaceX now has terabytes of data to help discover what worked flawlessly or partially, and what failed. 

They learned the hard way that they need a flame trench and a water deluge system. Both at Boca Chica and at the Kennedy Space Center. There's a reason NASA designed launch pads 39-A&B to be as robust as they are.

NASA may over-test, and SpaceX may under-test--but learn via "RUDs." Each method can provide similar data. 'Build-fly-crash-build-fly-crash-build-fly-succeed' method can result in more rapid advancement, whereas the more risk-adverse NASA may take many years longer to arrive at the same eventual result. Because of the lessons learned from the few failed Falcon-9 launches at the beginning, that rocket system may have the best safety record of any launch system.

All this proves the aviation and space industry maxim, "why we test." And from failures come solutions.

'Success' for testing an entirely new spacecraft, that is more powerful than any other rocket in the world, isn't necessarily fully completing the intended flight to Hawaii. Just proving that the massive SuperHeavy booster could fly was a success.

Elon Musk offered the possibility of another launch in a few months. Due to the extent of the damage at the pad, that might be an optimistic estimate, but it's likely that one or two Starships will fly before the end of the year.

Musk congratulated the SpaceX team and declared the test launch a success.

Photo credit: SpaceX

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