Hacker News Reader

Comment by krisoft | Hacker News Reader

All of those you said are very true. It's also worth mentioning that that very 'safe' engine has already killed three people, and injured three others during a cold-flow test. Very tragic.

see for details: http://www.knightsarrow.com/rockets/scaled-composites-accide...

or the "Test program accident" at the wiki: http://en.wikipedia.org/wiki/RocketMotorTwo

View on HN

How do you even manage to kill not one but three people with shrapnel during a pressure test? Proper safety procedure demands that anything potentially shrapnel-producing is contained within an enclosure and that engineers are outside the area while testing takes place.

The whole incident indicates a lax safety culture.

Precisely. An absence of proper safety procedures is how.

You are right. Hybrid engines are not looking like the safe & reliable middle-ground between solid & liquid engines that they were made out to be.

"The best of both worlds" has an often overlooked twin sibling.. "The worst of both worlds"

Or as it's sometimes formulated, "the sports car-slash-dump truck problem."

In other words, you can build a great sports car, or a great dump truck. But there's no way to build a great sports car that is also a great dump truck.

Maybe not, but you can always pivot[1]!

http://spectrum.ieee.org/view-from-the-valley/transportation...

all the performance of solids with all the complexities of liquids!

"The only thing in the middle of the road is yellow lines and dead armadillos."

Yeah, "rocket" + "safe enough to carry tourists regularly" just seems like a difficult combination.

Many years ago, trying to combine "flying in the air" with "safe enough to carry tourists regularly" would be seen in a similar light.

It took 54 years to go from the Wright Brothers first flight to the Boeing 707.

It took 53 years to go from Yuri Gagarin's first flight (one orbit) to this suborbital flight test.

It only took 8 / 9 years between Gagarin's flight and landing men on the Moon. That's remarkable.

It's depressing to think how much closer we'd be to humans on Mars if we had focussed all the Afghan and Iraq war money on space research.

Or simply to reduce the national debt.

It only took 8 / 9 years between Gagarin's flight and landing test pilots on the Moon. Which is still remarkable.

Since this sub-thread has invoked tourists and the implied safety and convenience of a commercial operation that carries passengers and other payload. Tourists are payload, test pilots are ... test pilots.

Fair point, but the failure modes of flying seem to be more addressable than those of rockets. Like if the airplane engine is essential, add enough that you can tolerate a failure. If control surfaces are essential, add redundant systems. Whereas the failure mode of rockets tends to be exploding, and that's pretty hard to mitigate.

The failure modes of rocket engines could be explosions but nobody says you can't have multiple redundant engines on a single rocket. In fact, in 2012 Falcon 9 demonstrated exactly that: one of their 9 Merlin engines blew up but the rest redistributed the load and the rocket successfully delivered the payload to the ISS[1].

[1] http://blogs.discovermagazine.com/badastronomy/2012/10/08/sp...

According to the article you are quoting the engine didn't explode; it's just failed. I'd be very impressed if a rocket survived an explosion of one of its engines (they are much closer together than jet engines on a passenger plane and even i such planes an explosion of one engines can damage others due to shrapnel).

Reply on news.ycombinator.com