Curiously, the Guardian says:
Hundreds of millions of dollars worth of equipment, ranging from “classified cryptographic” gear to school science experiments, was destroyed in a giant fireball on Tuesday evening after technicians detonated a self-destruct mechanism six seconds after launch because of a “catastrophic” equipment failure.
From which one would infer that the rocket’s human controllers played a role in its post-failure destruction…???
It’s deflagration up until the LOX tank ruptures on impact on the pad.
Then, it’s detonation. (-:
Not a complete knockoff:
Buran’s only flight - a single orbit - was an unmanned test flight. The Shuttle never made an unmanned test flight, because the Shuttle wasn’t capable of flying without a crew.
(Standard Soviet practice at that time was to control all spacecraft remotely from the ground, even manned craft.)
Also, as KarlS notes, the Buran orbiter had no main engines. All the launch engines were on the Energia booster, which could also be used as an unmanned heavy-lift cargo/satellite launcher.
(Energia only flew twice - once for the Buran test, and once for the unsuccessful Polyus satellite launch)
That is curious. There should have been some attribution for that in the Guardian article. Maybe it was in a later paragraph that got cut.
I found more on that here and here.
Frank Culbertson, Orbital’s executive vice president, said that after things “began to go wrong,” a safety officer sent a destruct command to the rocket. He could not say how much of the explosion was caused by the failure and how much was caused by the intended self-destruction.
Well, yeah, but I would have expected something more along the lines of “holy shitballs it exploded.” Presumably he had the presence of mind to take his finger off the transmit button first.
You haven’t bought the knowledge of how to use a search engine?
Look, this is not the time to be bragging about your sex life.
Spaceflight involves a large container filled with inflammables which is built as lightly as possible, because the weight margins are so tight. So it is always going to resemble flight by Zeppelin more than it resembles a trip in a 747. Which isn’t to say that a reasonable degree of safety isn’t possible, but it will never be routine or easy. Which is why I tend to look askance when anybody has some amazing drawing board fancy that will make it cheap, reliable and routine. It’s like those “1% mortgage” offers that we used to get. I don’t have to dive deeply into the fine print to figure out what the catch is, but I’m pretty sure that there is one.
This isn’t to say that it hard so we shouldn’t do it. Just as Kennedy said, “We do these things not because they are easy but because they are hard.” And we should be constantly looking to improve the safety and lower the cost. But falling in love with every half-thought out scheme that promises to make getting into orbit cheap and easy is, I think, a distraction. One that may prove fatal if people become so in love the the promise that they fail to account for the peril.
It is my understanding that it is standard practice to abort, with extreme prejudice, any launches that exhibit unplanned behavior outside of certain safety margins. A dramatic fireball, and lots of little bits flying around, is markedly less dangerous to bystanders than a mostly-intact-but-headed-in-the-wrong-direction-and-on-fire rocket zipping merrily off course and crashing into something.
They prefer, of course, for the failure to occur a bit further up, so that it doesn’t trash the launch pad quite as badly as this one did…
Except accelerate your zeppelin to several G’s and then let it float weightlessly, all the while burning the stuff in the zeppelin. Maybe a little like a rigid explosive water balloon, too.
Well of course an early Atlas with it’s pressure strengthened tanks and jettisoned engines resembles a blimp that you drop engines off, but the analogy is not a particularly close one.
Sorry I’m late. It was cloudy here last night so I didn’t look for the liftoff, and didn’t hear about the launch failure until about an hour ago.
The ISS is fine for supplies. They ran big loads of supplies up on the Dragon and Progress that were undocked over the weekend to free up parking space for the Cygnus that this Antares was supposed to deliver. So no worries there.
This launch was a new version of Antares, with a more powerful upper stage, so in that sense a new bird with no track record.
I can’t get too excited about an unmanned redundant resupply ship being lost, but it makes me sad that Deke Slayton still didn’t make it into space. And the loss of the Arkyd-3 - a 3D printed satellite intended to pave the way towards future asteroid mining - is pretty significant, and a big setback for Planetary Resources.
It was a deflagration all the way until the fire went out. There was a rapid chemical reaction going there, but at no point did the progress of the flame front exceed the speed of sound in the medium.
But, that’s a supercilious nitpick. It only matters if you are close to the center of the fire. If it’s a detonation, you are subjected to a much more intense, and sudden, pressure gradient, which does a lot more damage. With a deflagration, you simply burn up. If you are a mile or so away, both are just ‘explosions’.
Wow–guy had to tell the launch folks to stay where they were when the thing exploded. Heard one male voice say something just after the thing exploded and started coming back down, but nothing afterwards. That was strange. Gene Kranz woulda figured that shit out, pronto.
Heh. My thought exactly. )-:
Good for whatever quick thinker remembered his training and pushed the button, then. Far better for a damaged rocket to fall back and wreck a launchpad than go spiraling randomly across the countryside and land on someone’s house.
My first thought at reading that was to respond to the effect of, no, actually it’s the job of mission control to say what’s going on with their instruments/assemblies, since doing so might help alleviate further catastrophe. But then I wondered if they stop speaking because they’re obviously being recorded, and the readings they see might offer wildly inaccurate data, which could then be used by the much-feared insurance rep. Especially when it’s a “multi-billion dollar” policy that needs to be awarded.
You have the self-destruct feature on most rockets. As others said already, it’s better to get a rain of fragments and burning fuel to land somewhat predictably to a known-safe area, than to have the same load of combustibles moving intact in uncontrolled direction for possibly rather long distances.
I don’t know from top of the head how it is done with liquid propellant engines, but with the solid ones the self-destruct mechanism is a linear shaped charge along the length of the casing; on activation the explosive makes a metal “knife” that cuts the tube open and lets the pressure go outside sidewards and break the fuel grain, which leads to instant loss of thrust and appropriate visual effects. The two explosions visible at later phases of the Challenger mishap are the SRBs blown by the range safety officer; after the first fireball there are two smoke trails of the uncontrolled separated FRBs, that end with fireballs of their own at approximately the same moment - that’s it.
What @MarjaE noted with N1 engines didn’t mean much to me until I saw this in your second link:
Antares boosts on two AJ-26 engines, which are modified versions of the Russian NK-33 engines. Those engines were surplus left over from the Soviet N-1 moon rocket that was supposed to compete with the United States’ Saturn V. The N-1 was cancelled by the Soviet space agency after every single one of the boosters blew up in the first minutes of flight due to engine failures.
Was the second lowest bidder proposing to use refurbished early-70’s Protons?
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