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Comment by tyingq | Hacker News Reader

I'm curious what the emergency landing options are for this thing. It looks like there would be limited places it could land with that wingspan and landing gear spread.

Edit: Curious, not critical. Maybe it can land in a lot of places, just reacting to the size.

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Since its purpose is to launch rockets, I assume it lands where it takes off, and might never stray far away.

That's the sort of thing I'm interested in. Like, for example...how far away are you once you get this huge thing high enough to launch.

I'm not trying to criticize it, I'm just curious how dangerous a typical mission will be.

It only reaches 35,000 feet.

You can make occasional turns to keep close to the airport while climbing higher. I don’t know if that’s what they’ll do, but this problem has some easy solutions at least.

> Like, for example...how far away are you once you get this huge thing high enough to launch.

It can climb in a circle so that it's never far from its base.

It doesn't have to fly in one direction, it can do s-turns while climbing, or circle.

I think clearly payload launch is the risky part. What are the kinds of launch failures? Rocket engine failure can be uncontained and spectacular.

They're going to move it all over the world (or at least, over the latitude range) in order to get into the most optimal launch position.

Me too. I have serious questions in regards to maximum landing weight, will or won't the payload have to be jettisoned, and whether there will be propellant restrictions.

Imagine an emergency scenario where a high payload of hydrazine/NTO/UDMH/MMH has to be dumped at low altitude to recover the plane "safely".

With a traditional vehicle you at least will never have an incentive to take your launch vehicle anywhere where down range includes a low altitude intersect with a population center.

This on the other hand... Oof. This brings an entirely new dimension to Range Safety. I can see the lesson having to be relearned the hard way if we aren't careful. Not saying it isn't worth it, but man, those postmortem would not be fun.

Would be a hell of a thing to see go off without a hitch though.

With an option to jettison the payload I would imagine it can land relatively short. The majority of stopping distance is related to having enough rubber on pavement and keeping brakes cool enough. Stopping energy required changes dramatically as weight is reduced as it’s less energy required to stop and a slower touchdown speed.

I’m not sure how the dimensions of the aircraft affect its ability to use other airports though and exiting a shorter runway after repair can also present a major challenge.

Was there for this flight yesterday, and with someone who worked on the project.

Most runways are too narrow for both the wingspan and wheel span. It is quite limited in areas it can land and take off.

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