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  ARM Give a man a fire and he's warm for a day, but set fire to him and he's warm for the rest of his life (Terry Pratchett, Jingo)

Watch SpaceX's Starship SN4 prototype accidentally self-destruct in a rocket test burn

(2020/05/30)


Video In yet another setback for Elon Musk's beloved steel spaceship, a SpaceX Starship prototype has exploded on the pad during a rocket test burn.

Starship SN4 – designed to ferry astronauts to the Moon and Mars – was undergoing a static engine fire test on Friday when, in scientific terminology, it blew the hell up. Footage of the explosive experiment, captured by news site NASASpaceFlight and embedded below, appears to show the prototype's rocket venting fuel, or some other material, shortly before a "major anomaly" occurred in which the craft rapidly scattered itself across the Boca Chica testing facility in Texas.

[1]Youtube Video

Fortunately, nobody appears to have been hurt, other than some feelings at SpaceX. And maybe possibly the US Federal Communications Commission, which this week [2]reportedly granted permission for suborbital Starship test flights.

"It looked to me like the lower tank began leaking after a static fire, probably caused a loss of pressure that then resulted in the tank being crushed by the mass in the upper tank," [3]surmised Scott Manley, an Apple software engineer and amateur astronomer.

"The failure of both tanks lead to ignition and RUD." That's rocket-speak for Rapid Unscheduled Disassembly, a term Elon Musk has used in a [4]Pythonesque way before.

Nevertheless, the explosion was large enough to be picked up by the radar systems of local weather stations in the US state.

The smoke plume from [5]#SpaceX ’s SN4 explosion could be seen from the Brownsville, Texas Doppler radar site!

Although it may appear green on reflectivity (like the nearby rain showers) we can use Dual-Pol products to determine this was indeed smoke. [6]#wx [7]#sn4 [8]#weather [9]#space [10]#txwx [11]pic.twitter.com/JYDuuFFI7k — Nash from Nashville (@NashWX) [12]May 29, 2020

SpaceX could not immediately be reached for comment on the destruction of its prototype. Founder Elon was also absent any sort of statement; both have opted instead to focus on this weekend's manned Dragon [13]launch .

It should be emphasized that the SN4 prototype that detonated on Friday is not the same as the SpaceX Dragon crew capsule and Falcon rocket set to take off from Florida on Saturday with American 'nauts onboard heading to the International Space Station. That combo, the Falcon 9 rocket and its Dragon capsule, has proven itself over several flights to be significantly less prone to fits of rapid unscheduled disassembly.

The crewed Dragon pod was slated to take off from Cape Canaveral on May 27, but had to be [14]scrubbed due to bad weather. Saturday's launch also faces the possibility of being called off by the weather.

The Starship craft, by comparison, is still in its prototype phase and undergoing early tests. These sort of blow-ups are not unheard of with craft this early in development: new rockets are hard at first, as you can see below.

[15]Youtube Video

The Falcon-lifted Dragon spacecraft are meant to be SpaceX's commercial bread and butter, delivering crew to the orbiting space station using American-owned and launched rockets without having to go cap in hand to the Russians. Boeing, too, is taking a shot at the market, although its project is behind schedule.

Starship is seen as a more ambitious long-term effort to create a vessel capable of not only heavy lifts, but also flights to the Moon and Mars. When you're dealing with rocketry on that scale, mistakes are going to happen – that's why you make them on the ground first.

Still, this is not going to be something SpaceX will want to see less than 24 hours before the most significant launch in its history is scheduled to go off. Test or not, a rocket exploding on the pad is a bad look for many.

As for Saturday's mission – an all American crew in an all American craft lifting off from American soil for the first time since 2011 – the forecast is changeable, so another scrub is possible. We'll be watching and keeping you updating as it happens. ®



[1] https://www.youtube.com/watch?v=7RPyDPpmDAk

[2] https://www.reportdoor.com/spacex-gets-faa-permission-to-fly-its-starship-spacecraft-prototype-report-door/

[3] https://twitter.com/DJSnM/status/1266447522676891649

[4] https://www.theregister.co.uk/2017/09/14/spacex_video_of_rocket_failures/

[5] https://twitter.com/hashtag/SpaceX?src=hash&ref_src=twsrc%5Etfw

[6] https://twitter.com/hashtag/wx?src=hash&ref_src=twsrc%5Etfw

[7] https://twitter.com/hashtag/sn4?src=hash&ref_src=twsrc%5Etfw

[8] https://twitter.com/hashtag/weather?src=hash&ref_src=twsrc%5Etfw

[9] https://twitter.com/hashtag/space?src=hash&ref_src=twsrc%5Etfw

[10] https://twitter.com/hashtag/txwx?src=hash&ref_src=twsrc%5Etfw

[11] https://t.co/JYDuuFFI7k

[12] https://twitter.com/NashWX/status/1266474051352002561?ref_src=twsrc%5Etfw

[13] https://www.theregister.co.uk/2020/05/27/nasa_spacex_launch_postponed_weather/

[14] https://www.theregister.co.uk/2020/05/27/nasa_spacex_launch_postponed_weather/

[15] https://www.youtube.com/watch?v=Z9EnUQltR9A

Sad

HildyJ

But with the MK1, SN1, SN3, and SN4 all blowing up (SN2 was a stripped down version for pressure testing) the Mars colony dreams seem to be sinking into the ruddy sunset.

The video doesn't show the full story...

squirrelboy

The video starts too late. If you look at other videos, you will see the full chain of events. The test fire for just a few seonds, then stops. The upper and lower tanks vent for about 40 seconds then stop. Nearly a minute later the upper tank starts venting and a couple of seonds later cryogenic fluid suddenly comes pouring out of the bottom of SN4, creating the white cloud around the base (this is where the linked video starts).This happens for nearly 30 seconds before the explosion, and is clearly an massive uncontrolled leak. Shortly after the masive leak, the upper tank starts emergency venting with a second outlet. SN4 doesn't deform or collapse, so I think Scott Manly is incorrect about the weight of the upper tank crushing the lower tank. SN4 is fully intact, and doesn't deform until the explosion shockwave hits it. Looking at varous videos frame by frame, it appears the igntion point of the explosion is external to SN4: for a few frames, the wavefront apears to defom around SN4 (which was fully intact), and only after then SN4 experiences RUD.

My guess is that the lower tank ruptured and an external ignition source triggered the explosion.

Still I'm sure valuable information was found. This is why they do testing.

Decade Blending:
In clothing: the indiscriminate combination of two or more
items from various decades to create a personal mood: Sheila =
Mary Quant earrings (1960s) + cork wedgie platform shows (1970s) +
black leather jacket (1950s and 1980s).
-- Douglas Coupland, "Generation X: Tales for an Accelerated
Culture"