So does the shuttle have a bailout option for the early stages of launch? I assume jetissoning the SRB's would put a put of force on the ET and cause it to disintegrate, like on STS-51L. I know that when the SRB's are gone and the shuttle is below subsonic speed, the astronaut's can escape, at least from what I've heard.
Anyone know?
Yes, I know. And no, the Shuttle does not have such options. You can theoretically jettison the SRBs pretty early, the separation system is designed for this, but practically, the exhaust with its up to 5 cm large white-glowing slag balls, would badly damage your orbiter.
It is also impossible to simply jettison the ET any time. When the ET still contains too much fuel, the CoG of it is too high and it would likely hit the orbiter with its tumbling motion. Separating the ET with a lot of fuel in it is only possible with a very tough maneuver that is done during the RTLS maneuver.
The earliest abort options after SRB ignitions are always RTLS type aborts. You jettison the SRBs and fly a higher trajectory for gaining potential energy, aiming for the right moment to turn around, so the ET is almost dry when you can drop it and glide home. If you are too far away for returning to KSC, you can aim this RTLS at another runway at the US east coast, this is a East-Coast Abort Landing (ECAL).
When all three engines fail, or you are at a point where you can't get the energy for reaching a runway, you do an contingency abort: You simply reach a stable gliding flight, and when you are low and slow enough, a small explosive charge punches a hole into the cabin wall for quickly reducing pressure in the cabin, a second one is triggered to blow away the mid deck hatch, and a long curved pole is extended for bailing out below the large low wing of the orbiter.
There are no longer ejection seats on the Shuttle, these had only been available for the first flight and had been disabled and later removed for the others.
Still, the shuttle is, in terms of abort modes, only slightly worse than other manned spacecraft. While you can't simply abort in the first 85 seconds of flight (that is the soonest time for a secure SRB separation), it has more options for the rest of the ascent. There are many things that can go wrong inside the Shuttle, but the 69 million Euro for each SSME come for a good reason: Contrary to the simpler engines used on other launchers, the SSME has a very good health management, that usually reacts too soon, than too late, even being capable to detect small errors in fluid flow or a slightly different turbine vibration sound.
It is for example doubtful, a soyuz launcher would survive a STS-51L like rapid disintegration of the launcher right below the capsule, even though it has the better abort system in general.