Launch of worlds largest model rocket (Saturn V)

[cjolley]

Interesting points.

...
But that's beside the point...Shuttle wasn't designed with ejected cabin in mind, doing which is hard, and redesigning any craft for it even harder.
...

It was "in mind." It was rejected because of weight consideration, if I remember correctly.


PS It would certainly become unstable with the loss of an SRB though...

[Dr Mordrid]

Just so we have it all out there for the other forum readers;

Shuttle abort modes

1. Redundant Set Launch Sequencer (RSLS) Abort

The main engines are ignited roughly 6.6 seconds before liftoff. From that point to ignition of the Solid Rocket Boosters at T+0.00 seconds, the main engines can be shut down. This has happened five times: STS-41-D, STS-51-F, STS-51, STS-55 and STS-68.

This has always occurred under computer (not human) control after sensors uncover a problem before the SRB's ignite at T+0.00. The SRB's cannot be turned off once ignited and once they are the shuttle is committed to launch.

2. Inflight Crew Escape System

The crew would make the escape decision at an altitude of ~60,000 feet and make an input to the autopilot enabling this mode.

When the orbiter descends to ~30,000 feet its airspeed must be ~200 knots (230 mph) or it's a no-go. At ~25,000 feet a crew member in the middeck (the "jump master") pulls a T-handle which starts a controlled depressurization before the side hatch is jettisoned.

At ~25,000 feet the autopilot changes the orbiter's angle of attack to 15 degrees, which must remain nearly constant for approximately 3 minutes until the orbiter reaches ~2,000 feet. During this time the jump master deploys the escape pole and the crew exits.

This is an awful lot to go right in a presumably deteriorating situaton and presumes no damage to the orbiters flight systems or control surfaces and a successful tank separation, so its real-world effectiveness is IMO highly debateable.

3. Return To Launch Site (RTLS)

The Shuttle continues downrange until the solid rocket boosters are jettisoned. It pitches around with the SSME's retro-firing and the tank attached, which continues until downrange velocity is killed and the vehicle is headed back towards KSC. Then it jettisons the tank and glides to a landing on the Shuttle runway.

4. Transoceanic Abort Landing (TAL)

TAL is used between T+2:30 - T+ 8:30 (MECO - main engine cutoff) and involves landing at a location in Africa or western Europe (Portugual, Spain, Ireland, Iceland, the UK & a few others) about 30 minutes after launch. This occurs when velocity, altitude and distance downrange do not allow RTLS. It's also used when a less time-critical failure doesn't require the faster, but more stressful, RTLS abort.

5. Abort Once Around (AOA)

Abort Once Around (AOA) is used when the shuttle can't reach a stable orbit but has sufficient velocity to circle the earth once and land.

6. Abort to Orbit (ATO)

Abort to Orbit (ATO) is available when the intended orbit isn't attainable but a lower, stable orbit is possible. This actually happened on STS-51-F (Challenger).

[Nowhere]

...PS It would certainly become unstable with the loss of an SRB though...

Well, actually that is what happened to Challenger, sort of; but more of a massive structural failure kind, not in the same sense of losing an engine which I was thinking about - after all there's no way of shutting down an SRB even if you want to.

BTW Doc, I wonder - safe jettisoning of SRBs before time, when their trust lowers substantially, was deemed impossible, right?

PS. I believe there are also options for abort in New England / eastern coast of Canada during high inclination (ISS) launches?

[Dr Mordrid]

SRB's cannot be shut down, so an 'early' jettisoning is a rather dangerous affair since where they'll end up in an emergency situation is anyone's guess - their separation thrusters may fail, the control systems for the shaped charges on the struts may not work etc. etc.

No good options in that time frame at all, which is why I called it a death trap - once those things light the options are very limited in the absense of a launch abort system (LAS) for the crew capsule.

Orion and Dragon at least have LAS's for crew flights which can get the crew and ship out of Dodge on the triple-quick from before T=0 to long after, giving them more than a good chance in trade for some sore bones for a week or so; an 8+ G ride vs 3-4 G for a regular launch.

ECAL (east coast abort landing) sites

Eastern seaboard

1. Myrtle Beach, South Carolina (high inclination orbit only)
2. Marine Corps Air Station Cherry Point, North Carolina (high inclination orbit only)
3. Naval Air Station Oceana, Virginia Beach, Virginia (high inclination orbit only)
4. Dover Air Force Base, Delaware (high inclination orbit only)
5. Otis Air National Guard Base, Massachusetts (high inclination orbit only)
6. Pease Air National Guard Base, New Hampshire (high inclination orbit only)
7. Naval Air Station Bermuda (low or mid inclination orbit only

Canada (all high inclination orbit only)

1. Gander, Newfoundland
2. Goose Bay, Newfoundland
3. Halifax International Airport, Nova Scotia
4. St. John's, Newfoundland
5. Stephenville, Newfoundland

[WxDude]

ECAL (east coast abort landing) sites

Halifax International Airport, Nova Scotia

Ok,

Not saying I want it to happen, but how cool (and equally freaky) would it be to be waiting
at the airport for your flight and seeing the shuttle land on the runway?