Because it has an inherent intact abort capability over 99% of its flight envelope with an over 90% chance of success and decades of flight experience and data to back up that claim? Otherwise... No, not the reason.
With all respect, but if we are talking about a spaceship, any kind of abort capability is useful only on less than 1% of its "flight envelope".
Thanks but it's not that simple and it depends on the system and launch vehicle as well. Orion is aiming for 100% ascent coverage, (
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140011918.pdf) but as the video notes there are always going to be spots you can't abort from. Also as noted Starship can possible prove it's 'safe-enough' but that's not clear yet and won't until it has a actual (and much deeper) flight history. It's SpaceX's decision to make.
I was specifically addressing the idea that it's as "safe" as an modern aircraft with over 100 years of a VERY steep in spots learning curve on aircraft safety. Space travel is technically a bit over 50 years on but in reality it's not that more advanced than it was at the start and while the average 'safety' is pretty high the consequences of an 'failure' can be catastrophic very easily. Starship is NOT as huge a technical leap ahead as some think. It's a launch vehicle with two stage, lots of moving and complicated parts and failure IS an option. It's obviously NOT going to be as 'safe' as a 747 or C5 because it doesn't have the history and depth of those aircraft's safety systems and operations.
Space travel will present unique safety challenges specific to its' environment. Nonetheless, there is already an analog to it today. It operates in an unforgiving and lethal medium and yet does not rely on escape pods or a separable structure.
In the world of nuclear submarines, design seeks to drive failure to the lowest possible level backed up by protocols to operate and maintain equipment with a culture that eliminates slipshod or incompetent behavior. It seems to have worked for over 50 years now.
Something similar to the "subsafe" process for design, maintenance, and operation of spacecraft will be needed. For launch and re-entry, the kinetic and thermal energies are so extreme, abort opportunities are limited. Autonomous operation and putting sensors everywhere to constantly analyze system performance for signs of anomalous behavior is a given.
Unfortunately, it would be a miracle if no serious accident occurs over time. But mandating architectures which only governments could afford effectively shuts down any idea of meaningful expansion in space development.
The progression towards a safer system is pretty inherent in any transportation system as it evolves, but the evolution takes time and unfortunately quite often the learning curve can turn into a deadly cliff. SpaceX thinks they can balance the risk and benefits of not having an abort system and that's frankly their call. We'll see what happens but it's very likely it's going to go wrong at some point as the current level is still pretty early. As noted in the video you fix that by flying a LOT more, which I have no argument with
And even if some sort of 'abort' system is mandated it's not going to be something "only governments" can afford for pretty obvious reasons. If it's required designers and builders will find a way to do it and still make a profit, it's the nature of the process. Trying to excuse not having a safety system because you "can't afford it" is a really good way to get an even stricter set of regulations
In Starship's case there aren't a lot of "good" options because of the margins that will be inherent in the design much like the Shuttle and Buran. As the video noted if they ever get NASA or another government agency as a customer for people moving it's likely they will insist on something OR a pretty clear flight and safety history to base a risk assessment on. Quite obviously at this point Starship has neither and the possible failure modes are mostly assumptions from previous data from different vehicles.
One thing that bugged me about the video is he states that prior to SpaceX everyone thought propulsive landing was 'impossible' which is not at all true since it's been known to be possible since the beginning. Heck it was a primary demonstration goal of the DC-X program! The main issue was the need to restart rocket engines that early on weren't really conducive or easy to restart and the primary problem that holding propellant through the flight for that purpose will cost you payload and performance. There are also operational considerations since a lot depends on how you plan to land and what that entails. (Most assumed some ability to 'hover' and adjust the landing whereas, like New Sheppard, SpaceX thought outside the box and came up with the hover-slam. We're actually getting USED to it now and it will be used for Starship as well but THAT was what freaked most folks out the first couple of times
) That most LV's were expendable was also a major factor but it was seriously considered and studied several times on several different reusable systems.
Oddly it was found that propulsive landing with a rocket engine wasn't really as effective as one might think but that some type of 'airbreathing' engine was more efficient and reliable. The main issue there was the mass of the engine compared to the propellant load to run a rocket for landing and that itself tended to be variable and arguable either way. And it's not that you actually need an entire 'engine' since you can often just use a tip turbine 'fan' system with the turbine run on air/fuel or even monopropellant/RCS. The main hurdle is finding a way to incorporate it into the design, especially as a retrofit. I can't see SpaceX using one on Starship simply because they are aiming for multi-planetary use and the atmosphere on Mars is to thin. But for an Earth orbital transport system it would make a lot of sense in some ways. Adding a 'ring-fan' around the top of the booster stage (somewhat similar to the aerodynamic ring on New Sheppard for example) could work. But again it's not a choice SpaceX is likely to make given the way they are going.
Randy