Look, if you're going to hop in the ITS and make a propulsive landing on another heavenly body then you are already trusting your life to a system without a dedicated abort system. At that point you might as well take the ride out of Earth's atmosphere too.
I don't know if I think ITS should have an abort capability or not, but:The idea that abort on Mars would be pointless is a dumb myth that needs to die. There's no reason that need necessarily be true, and there are several strategies to ensuring survival for those who abort.Down-range placement of supplies or rover.Survival equipment on the capsule.Mars aircraft sent for pickup or supply delivery.Small orbital caches sent to the surface.Suborbital hoppers.Backup ITS used to rescue stranded survivors.Fast rovers.Escape capsule maneuvering.A combination of the above concepts.Seriously, you might think it's not worth it. I haven't decided myself. But to say aborting crew would necessarily be toast is incredibly small-minded.
Quote from: Robotbeat on 07/25/2017 03:10 amI don't know if I think ITS should have an abort capability or not, but:The idea that abort on Mars would be pointless is a dumb myth that needs to die. There's no reason that need necessarily be true, and there are several strategies to ensuring survival for those who abort.Down-range placement of supplies or rover.Survival equipment on the capsule.Mars aircraft sent for pickup or supply delivery.Small orbital caches sent to the surface.Suborbital hoppers.Backup ITS used to rescue stranded survivors.Fast rovers.Escape capsule maneuvering.A combination of the above concepts.Seriously, you might think it's not worth it. I haven't decided myself. But to say aborting crew would necessarily be toast is incredibly small-minded.You just might be right on some of those options. Every effort to save a crew is worth while. We certainly try very hard to save people here on Earth. Even great efforts are spent too save animals that are trapped, hurt whatever. Many fire units are even equipped with mask to save a dog or cat. I applued all of that. Life is very precious.You had valid points that I was not aware of as options. But your rebuttal would have been just as evective if delivered without harshness, meant that way or not.I have generally found honey first, then the vinager has a higher success rate with people.No offense meant with my reply. I have usually read your posts a little closer.Sent from my XT1565 using Tapatalk
Quote from: stcks on 07/25/2017 02:33 amLook, if you're going to hop in the ITS and make a propulsive landing on another heavenly body then you are already trusting your life to a system without a dedicated abort system. At that point you might as well take the ride out of Earth's atmosphere too.Not really. Earth orbital launch is completely different than a martian orbital launch. The delta V and atmosphere make for two different vehicles. Martian orbital launch launch vehicle is a small SSTO. Earth orbital launch will be a large multistage vehicle.
Two ways to solve it you either make the systems able to handle multiple failures during launch and able to make an emergency landing if needed like an airliner or you launch it uncrewed and then once it's on orbit have a vehicle that is inherently safer such as a capsule,small space plane or even a HOTOL like Skylon carry up the crew and passingers.Dealing with T+ 0 failures is lot easier for a HOTOL as like an airliner they don't fall back on the pad if thrust to weight drops below 1 to 1 which is why I suggest it as a solution.Plus having ITS launch uncrewed removes some of the time constraints to get it refueled and not having 50 to 100 people and all their luggage on board would save a lot of mass on the hardest leg of the trip.
If you loose all propulsion in an airliner you will most likely die.
I look on it as if you were trying to make an launch abort system for a small airliner carrying say 100 people. Some way of getting everyone to safety if it fails in flight.And I cannot think of a way of doing that...
It just seems odd to me to ferry passengers to LEO on a separate ship when their lives will depend entirely on the integrity of the interplanetary ship anyway.
Elon Musk has mentioned the possibility to launch the passengers late into the refuelled vehicle. It would be quite inefficient to use a full ITS for that purpose. Take a tanker and cut off the nose. Replace it with an abort capsule. For 100 passengers it may have a weight of 60t and would not reduce the tanker capacity too much. The capsule would be crammed but it would only be for a few hours.