Soyuz launches with the crew capsule under fairung and even stacked under the orbital module - it still has a LES[0], that pulls off the whole fairing away & then drops the capsule once clear of the rocket.
A bit complicated but was already used in emergency and worked.
> Can't they blow the fairing as part of launch abort?
I'm not a rocket scientist, so I don't really know the answer. But I have some questions:
* How reliable will the "blow the fairing" system be? If it's only used in emergencies (instead of the regular fairing separation mechanism) than it'll suffer from the same problem as emergency generators - they're rarely tested and fail very often when needed.
* How easy is it to get the fairing out of the way once it's opened? Normally, regular aerodynamic forces slough the fairing halves off, but an LES/LAS doesn't have time for that - it's escaping a potentially exploding rocket. And those fairings will act like sails - huge surface area:volume ratio means they're just not going to move fast.
* What happens if DreamChaser hits one of the fairings on the wing? Would it damage it enough that it'd have trouble landing? Is it enough to cause it to foul the escape trajectory? Or even put it in a spin?
It seems like a lot of work to get it to work with or without a fairing.
That's one more thing to go wrong. In a LES scenario something(s) has gone wrong in an unrecoverable way. Very few systems can be relied upon to exist let alone work correctly. A LES on a crewed capsule is supposed to be able to pull itself from the vehicle all under its own power. It can't assume explosive fasteners on the fairing are functional or actual all function correctly.
You don't want the LES to activate, seem to be working correctly, and then blast the crew into a fairing panel that did not fully separate. The crew doesn't have time to roll down the window and kick it loose.
