Starship Passenger Landing - Emergency?

[Spindog]

You know, watching Starship reentry, bellyflop, and flip and burn, I keep thinking that if there was a crew onboard in a safe (no burn-through) crew compartment (even right now), there would be plenty of opportunity for occupants to safely egress the vehicle during the bellyflop and descend under parachutes! Speeds during the bellyflop drops below 400 km/hr. I'm not saying that would be a good idea but it would seem to be perfectly possible and reasonably safe. I wonder if it would ever make sense to have that capability just in case there was some reason to think that the flip, burn, and catch had become too risky? Just a thought ....

[xvel]

But how to get out from starship safely when it goes down 50% faster than you want as a skydiver?

[Jim]

You know, watching Starship reentry, bellyflop, and flip and burn, I keep thinking that if there was a crew onboard in a safe (no burn-through) crew compartment (even right now), there would be plenty of opportunity for occupants to safely egress the vehicle during the bellyflop and descend under parachutes! Speeds during the bellyflop drops below 400 km/hr. I'm not saying that would be a good idea but it would seem to be perfectly possible and reasonably safe. I wonder if it would ever make sense to have that capability just in case there was some reason to think that the flip, burn, and catch had become too risky? Just a thought ....

Crew?  You mean passengers.  Do airliners have parachutes for passengers?  Parachutes on Mars?

[meekGee]

The narrow corridor of "Broken enough to jump out of, but not quite broken enough to prevent you from doing so".

I think it got instilled in us watching videos of B17s returning from Berlin....

That corridor became really narrow with the jet age, and practically non-existent for space travel.

That's if it were free.  But by the time you finish paying for it, in mass, complexity, etc - the added risk shuts it down completely.

There is such a thing as a doomed ship, just like there is such a thing as a doomed aircraft, and that's part of travel by anything other than a kick scooter.

[Eka]

There is such a thing as a doomed ship, just like there is such a thing as a doomed aircraft, and that's part of travel by anything other than a kick scooter.

I would argue there is even a doomed kick scooter. Especially for those sold in the 1960s... As a kid, my parents would not buy me one because they were death traps. Brakes were added and it still didn't stop the deaths.

The chance of death is always there from misadventure. At a certain point it is no longer feasible to try to engineer out all possible misadventures, faults, failure modes, etc. As said, it may be impossible due to mass constraints. Until we have a breakthrough in high power rocket engine ISP, we have to live within the constraints of the tyranny of the rocket equation.

I know investigations of accidents will happen. I don't think Starships will be grounded once flights to Mars are going on due to the twin issues of Starships already in flight with no other way to end their trip, and transfer windows only being open a short time every 26 months.

[meekGee]

There is such a thing as a doomed ship, just like there is such a thing as a doomed aircraft, and that's part of travel by anything other than a kick scooter.

I would argue there is even a doomed kick scooter. Especially for those sold in the 1960s... As a kid, my parents would not buy me one because they were death traps. Brakes were added and it still didn't stop the deaths.

The chance of death is always there from misadventure. At a certain point it is no longer feasible to try to engineer out all possible misadventures, faults, failure modes, etc. As said, it may be impossible due to mass constraints. Until we have a breakthrough in high power rocket engine ISP, we have to live within the constraints of the tyranny of the rocket equation.

I know investigations of accidents will happen. I don't think Starships will be grounded once flights to Mars are going on due to the twin issues of Starships already in flight with no other way to end their trip, and transfer windows only being open a short time every 26 months.

I only meant that it's the most jump-off-able vehicle I can think of.

[Oersted]

For the first test flights with a couple of steely-eyed test pilots, sure, why not pack a parachute. They had ejector seats on the first Shuttle flights too. But when Starship starts scheduled operations with big crews it obviously won't be feasible any longer.

[Jim]

For the first test flights with a couple of steely-eyed test pilots,

What test pilots?  11 test flights have flown without pilots.

[darkenfast]

People thinking of ejection seats or escape capsules need to be aware of the actual positions necessary to ride a Starship. For the launch, the seats need to be reclining (think Dragon launches), in other words, they will be almost on their backs, with their feet towards the non-TPS side of the hull (because of the next bit). For re-entry, they will need to be upright relative to the deck (faces towards the non-TPS side), right up until the flip-and-burn landing, so that the g forces always come from about the same direction. I assume that during that maneuver they will need to recline at least partway, especially after long-duration flights.
 

[meekGee]

The only thing worth designing in is increased survivability in case of non-tower landing.

[jpo234]

But how to get out from starship safely when it goes down 50% faster than you want as a skydiver?

Pilots of fighter jets have ejected and survived at hypersonic speeds, so this seems a solvable problem.

In the early 1960s, deployment of rocket-powered ejection seats designed for use at supersonic speeds began in such planes as the Convair F-106 Delta Dart. Six pilots have ejected at speeds exceeding 700 knots (1,300 km/h; 810 mph). The highest altitude at which a Martin-Baker seat was deployed was 57,000 ft (17,400 m) (from a Canberra bomber in 1958). Following an accident on 30 July 1966 in the attempted launch of a D-21 drone, two Lockheed M-21 crew members ejected at Mach 3.25 at an altitude of 80,000 ft (24,000 m). The pilot was recovered successfully, but the launch control officer drowned after a water landing. Despite these records, most ejections occur at fairly low speeds and altitudes, when the pilot can see that there is no hope of regaining aircraft control before impact with the ground.

[rfdesigner]

People thinking of ejection seats or escape capsules need to be aware of the actual positions necessary to ride a Starship. For the launch, the seats need to be reclining (think Dragon launches), in other words, they will be almost on their backs, with their feet towards the non-TPS side of the hull (because of the next bit). For re-entry, they will need to be upright relative to the deck (faces towards the non-TPS side), right up until the flip-and-burn landing, so that the g forces always come from about the same direction. I assume that during that maneuver they will need to recline at least partway, especially after long-duration flights.

I'm not sure I agree with you.

The acceleration vector will either be inline with the axis of the ship or there will be a vector from the TPS side during re-entry.  If you always have your feet pointed to the TPS side of the ship and back pointed at the rear of the ship, you're good.  The ship only pulls 2G max on re-entry (so far), so that can be done with "upright seat" position.

[J]

occupants [...] safely egress the vehicle during the bellyflop and descend under parachutes!

Yuri Gagarin approved! That's literally how
the first astronaut made his descent to earth.

[spacenut]

By the time the Starship flips, it is only going what about 200mph or about 440kph.  Ejection maybe with ejection seats.  But, as said, that adds a mass penalty of several kg per person. 

SpaceX has landed rocket boosters over 500 times without a problem.  That is a high percentage without a failure. 

Getting back through the atmosphere I think is going to be their biggest hurdle.  Once TPS is solved, it becomes routine.  I don't even think in space docking and fuel transfer is going to be that big a problem. 

Yeah, and a lot of space programs have capsules for abandoning a large starship, but that is si-fi.   

We would not have lost Challenger if they had listened to the solid booster manufacturer.  Columbia may not have been lost had they did a space walk to determine the tile damage and had another ship to come and get the crew or even paid for a couple of Soyuz launches to pick up the astronauts.  Lots of ifs and inches. 

[StraumliBlight]

[Garrett]

The only thing worth designing in is increased survivability in case of non-tower landing.

This is the only contingency I think about. Like when a plane can't land at an airport and has to ditch in a field, the sea or a (Hudson) river.
I have no idea what such a contigency would look like. Maybe a landing on the engine bells in such a way that it remains upright? Or if it can't remain upright, then cold gas thrusters that can cushion the blow as it lays down horizontally?

[TrevorMonty]

Hope cremation is in passengers will as that will be result of any SS failure. By some miracle it achieves soft landing still not safe until all liquid methane has been removed and been purged from tanks with inert gas, which isn't 5 minute job.

Shuttle had lot of fatal failure points but it aleast could glide back to soft landing  giving some probability of surviving a failure.

[Roy_H]

The only thing worth designing in is increased survivability in case of non-tower landing.

This is the only contingency I think about. Like when a plane can't land at an airport and has to ditch in a field, the sea or a (Hudson) river.
I have no idea what such a contigency would look like. Maybe a landing on the engine bells in such a way that it remains upright? Or if it can't remain upright, then cold gas thrusters that can cushion the blow as it lays down horizontally?

I think his last point is very reasonable. If a tower catch looks unlikely, land in the ocean nearby and use the cold gas thrusters to lay it down in the water without breaking up. It should float until rescued.

[meekGee]

The only thing worth designing in is increased survivability in case of non-tower landing.

This is the only contingency I think about. Like when a plane can't land at an airport and has to ditch in a field, the sea or a (Hudson) river.
I have no idea what such a contigency would look like. Maybe a landing on the engine bells in such a way that it remains upright? Or if it can't remain upright, then cold gas thrusters that can cushion the blow as it lays down horizontally?

There's two main parts to it IMO

For land landings:
Reinforce the skirt so the perimeter doesn't crush in (you want the base as wide as possible) and building redundant hardware for safing and inerting it.

For sea landings:
Ensuring it can bob and inert w/o exploding

The failure scenarios are propulsion under performance of any kind in either stage that don't allow RTLS.

[testguy]

Seams to me that landing legs on all Manned Starships would be the way to go. Legs are needed for the Moon and Mars any way. One attempt for a tower landing at some point is not going to work. Aircraft can go around or divert to another airport if required. Yes it will decrease payload, but for me it is worth the penalty to save lives.