Virgin Galactic: The Myth of Informed Consent

boy did it straighten back out quickly pretty stable huh again uh High dihedral just that made the ship difficult to fly throughout the entire program [Music] there's only one place that the entire propulsion system complete it has just one valve which goes open over and closed and it operates at room temperature and I'll tell you you don't even need to go to Stanford to be able to design a good valve to do this people working on a rocket meant for a Virgin Galactic spacecraft died in 2007 after it exploded at the Mojave Spaceport [Music] send anybody up especially my children since they're going in their first flight you know we will have tested this space rocket many many many many times and we want to be absolutely sure that anybody flying on Virgin Galactic gets a return ticket that's what we're here for today is to investigate the loss of the reusable launch vehicle and the fatality and injury that occurred as a result of that according to an FAA spokesman the unity space vessel did not follow the flight plan previously agreed on the agency barring Branson space tourism company from flying its spaceship Unity 2 rocket during the investigation [Music] every time you get in a vehicle you are in effect rolling a dice roller one and you won't come home at the end of the day for your car that dice has about 5 million sides for a commercial airliner it has about 11 million in the case of the Space Shuttle the dice had only about 65 sides every time we make a safe journey in a vehicle however most sides are added to the dice we can never be a hundred percent certain how many it has but the more safe trips we take the more confident we can be that the dice has an increasingly higher number of sides of course fatal incidents dramatically slashed the number if and when they occur Virgin Galactic operate a commercial launch system for four hundred thousand dollars you can roll their dice however in this video I'm going to argue that no one is able to estimate the number of sides on Virgin galactic's dice foreign this is a topic I wanted to talk about for years it's also a tricky one space tourism is a popular topic for discussion at the moment there's been growing talk in recent months about exactly how safe virgin galactic's experience is unfortunately many of these discussions focus on aspects such as the company's funding its enigmatic figurehead and other somewhat irrelevant factors I'd instead like to collect everything known so far about the company's safety philosophy design choices and working procedures so we're going to head into this presentation with the following conditions I'm not an aeronautical engineer even if I was I wouldn't be able to entirely critique the design of Virgin galactic's launch system as much of it is not disclosed to the public so please consider this a presentation on the dangers of not understanding and properly communicating risk there are many comparisons between the recent Ocean Gate incident and Virgin Galactic some are superficial some are difficult to brush off we must note that Virgin Galactic have expended much much more effort into safety due to the inherent dangers of space flight that does not necessarily make their system safer than ocean Gates however they may indeed be doing nothing wrong at all it's just that there may be no demonstrable way to do what they're doing as Virgin Galactic are a publicly traded company almost all of their technical assessments take place behind closed doors therefore it's impossible to obtain detailed design documents everything discussed here is based on publicly available information where none is available that will be noted and contribute to our final conclusions as we'll see shortly the majority of space flight is orbital Virgin Galactic performs suborbital flights only as such will not be directly comparing their system to orbital space flight systems some will get a mention but only to discuss relevant historical incidents this presentation was originally to cover Virgin Galactic and blue origin blue origin face similar issues due to the lack of safety transparency however they've gone through a more comprehensive test program and have a number of more visible and conventional safety provisions so while I decided to make this presentation solely about Virgin Galactic do not take it as an endorsement for blue origin I would still not fly on their system even if offered it for free most of the organizations discussed here have let's say problematic figureheads this video is not a billionaire Showdown we will focus on system design legislation and communication only I can explain the differences between suborbital and orbital space flight in the time it takes Virgin Galactic to get you to space and back so let's fire up a real-time animation and go for it to begin let's make sure we understand the vast golf between suborbital and orbital space flight the two are often lumped together in pop science writing but as the saying goes getting to space is easy staying there is hard suborbital flight involves taking a ride on a rocket usually pretty much straight upwards for a few minutes with a sufficient amount of energy and a low enough Mass a relatively small rocket can get a crew high enough to be considered in space please note we're not going to get bogged down in the definition of exactly where space starts it's arbitrary and that includes the common line by the way which is neither fixed nor unambiguously defined for the purpose of this video Let's just call it about 80 kilometers upwards and leave it there anyway once you're up there you get a few minutes of weightlessness as you round the top of a ballistic Arc and then fall back down to earth it's not an easy task by any means to get there but a world away from orbital flight if you want to stay in space you're going to need to go higher and a lot faster spaceship 2 manages about 90 kilometers of altitude on a good day before falling back to Earth at the point of apogee and assuming a dry mass of about five tons that's roughly 4.5 gigatoult of gravitational potential energy so 4.5 gigajoules must be provided to the craft from its fuel and the fuel on the carrier craft in the case of spaceship 2. to get the same five tons orbiting at the height of the International Space Station would need about 20 gigajoules of gravitational potential and wait for it 145 gigajoules of kinetic energy that's 37 times the energy when compared to a suborbital flight for the same mass and that's a huge simplification to once we factor in the need to accelerate the fuel itself and the associated structures as we go along the energy requirements grow even more and then consider the other end of the trip all that energy is about the same that is output by a typical gas-fired Power Station working at full capacity for a couple of minutes when we re-enter the atmosphere that energy needs to go somewhere and that somewhere is into heat again we're not going to get bogged down in terminology Ram heating adiabatic compression friction whatever you want to call it a re-entering orbital spacecraft and its surroundings are subject to comparable heating to the output of an entire power station for a few minutes that requires a heat shield and advanced fluid mechanical considerations to ensure the craft doesn't burn up on re-entry spaceship 2's maximum speed is about 4 000 kilometers per hour it's fast enough for skin heating to be a concern and it requires material and design considerations but nothing compared to an orbital spacecraft so it is all on the same page it's clear why getting six humans to orbit requires something that looks like this but just getting them to space only requires this from a research perspective the gulf between suborbital and orbital space flight has very clearly been worth Crossing only a tiny minority of cruise space flights have been suborbital though it is often said the mesosphere that's the layer above the stratosphere is the least well understood part of our atmosphere as we have no way of staying there however there's never been much of a demand for crude flights to this region for scientific study there's very little a crew can do in a three minute window and this is why we must seriously begin to question The Innovation value of any private suborbital operation let's begin to get a sense of how safe Virgin Galactic system could be we're going to almost exclusively focus on the main vehicle spaceship 2 and not White Knight 2 which is the carrier vehicle both were largely designed by Bert Rattan a figure will repeatedly refer back to begin we're going to discuss where it sits in comparison to every other crude suborbital vehicle and to be honest there aren't very many of them I've broadly split them up into three categories so let's work chronologically and see where each system fits the first crude suborbital launch system was Mercury Redstone it was in essence a modified ballistic missile with a crew capsule strapped on top and that puts it in our first category vertically launched systems Mercury Redstone had a total of just two crew flights to space before being retired it went to space an additional three times on crude though somewhat anemic compared to its successes I personally think it's the best looking rocket ever built I even have a tattoo of it on my leg actually anyway two years later the U.S Air Force asked the question what is the smallest amount of plane that can be added onto a rocket engine and still have it fly subsequently this gave birth to the X-15 the fastest aircraft ever flown and this allows us to add in our second category space planes the X-15 went to space 13 times before being retired in 1968. a 36-year Hiatus Then followed for crude suborbital flight this was ended with the creation of spaceship 1. and this vehicle falls into my fuzzier third category of modern systems and putting anything post Space Race into this category the reason is the Advent of advanced computational fluid dynamics finite element analysis composite materials and many other Technologies make anything post 99 is almost impossible to directly compare with systems from the 1960s spaceship one was a space plane so it fits into that category too and to be absolutely clear spaceship 1 was the direct predecessor of Virgin Galactic spaceship 2 and shares much of the design philosophy it made three crude flights to space the next system to make it spaced is so without a crew blue Origins uh somewhat suggestive new Shepard system it first made it to space in 2015 and carried out a total of 16 uncrewed flights between then and now two of those didn't make it to space since 2021 new Shepherds taken Crews to space successfully six times it's a conventional vertically launched rocket with a crew capsule and that brings us to spaceship too spaceship 2 cannot be flown uncrewed and has flown to space with a crew six times that figure is of course subject to change in the near future and that's also the case for new Shepard so through all of history there's been a total of just 27 crude suborbital flights like I said the vast majority of cruise space flight is orbital this number's way too low for any kind of meaningful statistical analysis however let's add all the major incidents to our diagram are all the known ones anyway working chronologically again we're going to and I want you to listen extremely carefully it's my wording here before you jump in the comments we're going to include major safety incidents for flights that either reached space or were intended to reach space okay Mercury Redstone I intentionally missed out a flight if you can call it that the first time the system flew on an uncrewed test flight it made it a total of four inches off the launch pad before terminating miraculously it didn't explode and what followed was one of the most comical engineering incidents of all time I don't have time to discuss it here but we'll add it as an uncrewed near Miss the second and final crude flight was also problematic with Gus Grissom very nearly drowning on Splashdown so we'll call that a crude major incident the X-15 its final space flight was unfortunately also its fact the final flight for pilot Michael J Adams the craft broke up on rear end re-entering the Earth's lower atmosphere as an aside I'd be pretty surprised if the other 12 suborbital flights went off without anything major happening I just can't find anything publicly disclosed spaceship one is an interesting case his second flight was widely reported as a success thanks to it being the first of two flights that would bag it the Ansari X prize however it's less widely remembered that the craft ended an uncontrolled role during the ascent there is a clip in the intro to this video and it's pretty alarming the exact reasons have never been fully publicly disclosed but it seems to be a combination of loss of cockpit instrumentation and the craft itself having low inherent role stability these factors in conjunction with the interesting Control Systems which we'll get to later led to the craft rolling 29 times uncontrolled on its ascent during the incident a NASA Observer on the ground Was Heard to say that is a dead man however the pilot was able to recover and this major incident is largely forgotten in the public eye new Shepard has never had a publicly disclosed major incident during crude flight however his last uncrewed flight at the time of recording failed but the capsule was successfully recovered thanks to a crew escape system I'm not sure how to include that on our diagram let's call it a survivable major uncrewed incident and finally we get to spaceship 2. none of its six flights to space have seen major publicly disclosed incidents however a 2019 test flight to space was later found to encounter issues that in any other Aviation Circle would be considered major safety critical a seal on a horizontal stabilizer was incorrectly installed leading to it debonding during the ascent the loss of the stabilizer during Ascent would almost certainly have led to a loss of control Todd Erickson a former VP for safety and test pilot for Virgin Galactic went on to say quote I don't know how we didn't lose the vehicle and kill three people end quote the 2021 flight with Branson aboard did result in a temporary loss of their FAA certification due to straying outside their pre-assigned flight path however there is no reason to be sure this compromise crew safety so I'm going to be charitable and leave it out comparing spaceship 2 to Prior launch systems is tricky if we exclude spaceship 1 since it was descended from it it's tempting to compare to the X15 since it's a space plane but the two were built in entirely different eras and for entirely different purposes it's contemporary new Shepherd is a separate design altogether however of 21 crude flights in history one resulted in a fatality and three resulted in near misses that is about a 15 probability of the crew being in significant danger based on historical data it's also worth noting there have been major incidents in all three of my categories of spacecraft I'm not sure many observers would consider this as acceptably safe if spaceship 2 is indeed acceptably safe it must incorporate truly revolutionary safety measures to bring this percentage down significantly going forward let's try to ascertain whether this is indeed the case in any other recent historical setting spaceship 2 would be classified as an experimental vehicle and one with very few test flights at that we're going to get into why it's not required to legally operate as such later for now let's look in detail at its test flight history then we'll move on to its design site and safety systems I've skirt around the elephant in the room for long enough now spaceship 2 had a fatal incident in 2014. I'm not going to dwell on it since the details are well covered elsewhere in short the pneumatic feather system was activated too early in the flight leading to a premature deployment and breaking up of The Craft amazingly the pilot Peter siebold was thrown clear of the wreckage and was able to parachute to Earth albeit with major injuries the co-pilot Mike Aylesbury did not make it we'll come back to this incident again but I want to be clear that although every flight to space has brought the crew back alive not every flight of spaceship 2 has done the same a prior test flight in 2011 also led to a serious incident very nearly resulting in the loss of craft crew and probably Virgin Galactic as a whole the intention was to release spaceship 2 from its carrier aircraft and perform a Glide test for reasons that are not entirely clear spaceship 2 rapidly entered a spin I personally did spin recovery training in a light aircraft 12 years ago and I still remember the procedure despite not flying for more than a decade it's something absolutely drilled into you in this case pilot Mark Stuckey followed the recovery procedures to no avail he then tried some ad hoc remediation learned from his extensive experience still to no avail as a last ditch with the craft falling out of the sky he deployed the feather system now the feather system is a variable configuration tail boom system and we'll discuss it further later it was not in the written procedures and not something that had been practiced before but it worked allowing the craft to be brought to a precarious Landing stuck his astonishingly unconventional thinking saved the lives of three people the incident was kept under wraps and only became widely known publicly a few years ago another major incident occurred in 2013 during a rocket Fireflight test the rocket was fired for 16 seconds and the craft flew on a limited ballistic trajectory in the stratosphere to simulate a space flight the feather was deployed in the thicker air of the stratosphere this caused it to begin raising above its rated in atmosphere speed something of a precursor to the 2014 breakup little else is known about this incident because unsurprisingly Virgin Galactic haven't publicly disclosed anything and we've already discussed the near loss of a horizontal stabilizer in 2019 in a rare case of self-reflection Virgin Galactic had a retired Boeing executive to conduct a safety review following this incident however the resulting 40-page report has never been made public or even shared with Virgin galactic's Flight test director so it will be the case throughout this video we do not know whether sufficient remedial action was taken following this incident in fact we wouldn't even know about the incident had it not been publicly revealed by a combination of embedded journalists and former Virgin Galactic employees speaking out Virgin Galactic have done everything in their power to keep it quiet so as to avoid spooking future customers I suspect a major contributor to the somewhat sketchy test history of spaceship 2 lies with its predecessor spaceship 1 and the motive for its design spaceship one was constructed to win the Ansari X prize 10 million dollar prize for the first privately funded craft to take a crew to space twice within two weeks I remember this well I was 15 years old at the time NASA had effectively hobbled themselves with the expensive death trap that was the shuttle there was much media hype at the time and it was collectively decided that the moment was pivotal enough to Warrant the retirement of spaceship 1 allowing for its permanent preservation in the National Air and Space Museum in Washington DC which is a fantastic museum museum by the way if you have a chance to go do Bert ruten stated that no governments are required for space flight and arrogantly declared NASA or naysay is he rather cringily kept calling them were quaking in their boots what actually followed was a 17-year Hiatus until the next crude private suborbital flight much as was the case with government agencies it soon became apparent that orbit is where the real prize is and led by SpaceX the vast majority of private investment was directed at orbital space flight it's difficult to ignore the fact that the X prize may have actually set back space flight had spaceship ones fledgling space flights not been so publicized and sensationalized the craft would have almost certainly been flown many more times to better understand its aerodynamic and control characteristics I imagine it would have been iterated upon and Scaled Composites would have gained a comprehensive understanding of SuperSonic and suborbital flight systems a hypothetical example of what I consider to actually be innovation instead they were almost immediately contracted by their new partner Virgin Galactic to design a passenger carrying model and this led to the initially Hasty development of spaceship 2. essentially a scaled up version of spaceship 1. in an Ideal World we'd have seen dozens of space flights from spaceship 2 before taking paying customers up again that would broaden virgin galactics and The Wider worlds knowledge of space plane mechanics but unfortunately the need to make a relatively rapid return on investment appears to have precluded what I would call true innovation and let's be crystal clear here I am not saying private investment always hinders Innovation look to spacex's Falcon rocket Labs electron Ariane spaces launches orbital science corporations Pegasus and others and that includes blue origin's upcoming orbital offerings these companies either chose to or were Bound by appropriate regulations which forced them to embark on a comprehensive test and certification program before launching highly Innovative systems commercially so I think it's time we discuss why Virgin Galactic have faced no such obligations spaceship 2 is licensed for commercial space Transportation by the Federal Aviation Authority or the FAA Virgin Galactic were happy to make a great Fanfare about that when they obtained it in 2018 and subsequently re-obtained it in 2022 however I'd argue that that statement is extremely misleading in the US if you pay to take a flight in an aircraft that aircraft must be certified by the FAA the airworthiness certificate is a third party verification that the aircraft is considered safe by FAA standards FAA inspectors oversee design production and continued airworthiness certification for all registered commercial aircraft in the US as I've discussed in previous videos this is expensive but essential I'm not an aeronautical engineer but when I get on a Delta Airlines flight for example I know the aeronautical Engineers have performed relevant safety checks on the design and maintenance of that aircraft so I can be confident that it's safe to fly spaceship 2 does not have an airworthiness certificate and neither does a new Shepherd for that matter nor do they have any other third-party certification or disclosed adherence to standards by relevant bodies such as NASA so what is the nature of this FAA license then it exists solely to quote protect the public health and safety safety of property and National Security and foreign policy interests of the United States end quote in other words the FAA only attempt to minimize the risk of individuals and property on the ground being hit by a falling spacecraft they provide no checks or assurances regarding the safety of passengers in the craft itself spaceship 2 is not certified as safe for travel by any third party I believe along with new Shepard this is unique in commercial flight in the US I think it's a fair assumption that in general a spacecraft is inherently more risky to travel in than a standard passenger aircraft so how on Earth did this situation come about where an inherently riskier mode of Transport requires no safety certification to carry passengers The Superficial answer is removing regulations to promote innovation the more directly worded answer is political lobbying following the success of spaceship one Burt routen publicly stated he would go on to certify future craft with the FAA for passenger flight now I'm not here to critique rutan's engineering prowess much the man is one of the greatest aircraft designers of all time but his public opinions of Regulation uh let's say a bit libertarian he clearly stated on multiple occasions that his desire to certify passenger carrying systems was to prevent legal action in the case of an incident but this didn't last long anyway later in 2014 enthralled by the prospect of a burgeoning private space tourism industry followed by heavy backing from the industry itself Congress passed the commercial space bill included in this bill was an eight-year moratorium on FAA regulations for passenger safety on human space flight systems that moratorium has since been extended to October 2023 and I'll be surprised if it's not extended again a couple of months after I release this video the intention of the moratorium is to allow the fledgling industry to develop without restrictions or regulation comparisons were made with the early aviation industry which was also unregulated I don't have time to go into full details now but these comparisons are superficial at best passenger Aviation accidents in the 1920s was so common that the industry voluntarily persuaded Congress to require FAA regulation to improve safety as a whole I'll leave more details in the sources removal of regulation for testing is one thing removing it while allowing operators to carry fair paying passengers is another so how are passengers to assess where the spaceship 2 or any other space fairing system is acceptably safe this is where we finally get to the video title informed consent let's go to Virgin galactic's annual report and let them explain informed content in their own words quote under U.S federal law and the commercial space launch act that's csla operators of space flights are required to obtain informed consent from both participants and members of the crew for any commercial human space flight end quote they go on to detail how the relevant federal laws also protect them from Financial liability in case of an incident though that is a common topic of discussion I do not care about operators being sued or not the focus of this video is on safety of the system itself and how effectively that level of safety or lack thereof is communicated to customers and while we're here I do wish Virgin Galactic would stop referring to their prospective customers as astronauts it's yeah anyway in plain English all customers of Virgin Galactic must sign a waiver declaring that they consent to flying on what as we have already discussed is essentially an experimental spacecraft that is informed consent I argue that we can quite reliably drop the word informed I think I've already made pretty clear that there is no amount of money you could pay me to fly in spaceship too and that is because I have no idea how safe it is due to the lack of flight history no one knows how safe it is however knowing the following would go some way to informing my choice full details of every test flight with flight envelope findings conclusions and subsequent actions full details of rocket motor tests has the motor ever catastrophically failed on a test stand how is its Integrity insured prior to enduring a firing full maintenance and inspection records for all flight critical systems and materials full records of pilot training including hours flown in Simulator the craft itself and the White Knight 2 mock-up if I had this information and no doubt much more I'd still be nowhere near knowledgeable enough to make a judgment based off it if I could afford to and actually wanted to fly on spaceship 2 I would hire a relevant team of Engineers and technicians with expertise in the above to collate this information and provide a safety assessment the astute amongst you will know I have just described an audit process really just a step to certification anyway even if I wanted to do this I could not some of this information is not publicly available as it constitutes a commercial secret for Virgin Galactic and they do not wish to make it public in fact Virgin Galactic do not have a single published patent which was another obstacle to researching this video the rest can't be publiched due to International arms trafficking regulations so we have an uncertified space flight system with a total of six prior space flights with one fatal test incident at least one near fatal test incident and at least one safety critical flight incident and through corporate secrecy an arms trafficking regulations we cannot access any meaningful technical information or test data to make an engineering-based risk assessment I think it is quite clear that no customer can be informed when giving consent to fly on spaceship 2. I'd now like to take a close look at spaceship 2 itself I can only carry out a limited engineering risk assessment due to the lack of available information previously discussed however there's still plenty we can cover and in the interests of balance I'd like to discuss some of the systems that I believe make Virgin Galactic spaceship 2 safer to Flying than it would otherwise be first of all the motor spaceship 2 uses a class of rocket motor that's rarely used for crude space flight let's quickly discuss the three families of rocket engine all rocket engines require fuel to be burnt and exhaust ejected through a nozzle at high speed to ensure a vigorous and complete burn the fuel must be mixed with oxidizer in the combustion chamber achieving this safely and reliably is something we're still a long way from solid rocket Motors are something we're all familiar with if you've ever launched a firework you've launched a solid rocket mower here the fuel and oxidizer are both solid and combined together in a single contiguous Mass if that sounds alarmingly similar to heavy Ordnance that's because it is solid Rockets are seldom used in isolation for crude flight AS once they're lit they cannot be put out just to give some context to that statement Mike Mullane in his book riding Rockets made very clear that once the shuttle solid rocket boosters were lit that thing was leaving the launch pad regardless of whether the hold down bolts released and even if the bolts have the strength to hold the shuttle in place the exhaust from the boosters was not hot enough to melt the steel hold down structure it was hot enough to boil it at the other end of the complex a controllability spectrum a liquid-fueled engines every crude space flight with the exception of spaceship 1 and spaceship 2 has used liquid field engines as the primary means of getting to space they're throttleable and can be shut down at any point during a flight however this comes with the drawback of complexity liquid fuel requires complex plumbing and turbo pump assemblies and the fuel itself is far from benign a fuel leak carries high probability of fire and if the fuel and oxidizer somehow make unwanted contact an explosion as we've seen many times in the past had spaceship 2 used a liquid-fueled engine Peter siebold would not be with us now hybrid Motors on paper offer improved safety over both types with less complexity than liquid engines they combine a solid fuel with a liquid oxidizer in fact I have one right here I built this a couple of years ago but I've never got around to firing it this video is already long enough without my personal project so we'll test fire it in another video but let's quickly see how it works mimo uses 3D printed fuel it's just pla plastic is benign so it poses no significant flammability risk for the oxidizer it uses nitrous oxide in this little cylinder and yes that's why one of those appeared in the previous video using a remote igniter I can create a flame here and then drop a weight here to puncture the cylinder the nitrous oxide breaks down to nitrogen and oxygen in the flame thus creating an oxygen-rich environment here the field Burns vigorously in this environment creating a high velocity exhaust through the nozzle spaceship 2's motor is that largest hybrid ever used for crude flight it's honestly not too far in design for my little rocket motor it too uses nitrous oxide to burn a solid fuel in this case the fuel is still plastic but it's HTTP rather than pla I think Virgin Galactic should be on the whole commended for using a hybrid design due to its inherent safety over other systems scaling up the motor from that used in spaceship 1 has proved significantly more difficult than expected however but sticking with a hybrid design does mitigate fears of volatile fuel handling and lack of throttle ability we should note that the choice to use a hybrid motor is almost certainly the reason spaceship 2 requires a carrier aircraft nitrous oxide and solid fuel Motors just don't have the specific impulse achievable by liquid engines are in more colloquial terms no one's yet been able to design a hybrid motor that can burn long and strong enough to get a crew all the way to space however with a carrier craft spaceship 2 can begin its rocket booster descent from 18 of the way to space with about a quarter of the required speed in addition it's released above about 90 of the Earth's atmosphere so has to contend with much less atmospheric drag as we see here reaching space without the carrier vehicle would require significantly more fuel than oxidizer leading to a craft more akin to new Shepherd I do however have a few safety concerns with spaceship 2's motor as is the case with every aspect here I cannot quantify the extent of the risk these are just additional unknown factors that prospective customers face when trying to give informed consent first of all the motor does actually use some liquid fuel the NTSB report from the 2014 crash shows two fuel tanks in addition to a helium header tank no details are provided but the fuel tanks likely contain methane I believe which could be fed in during ignition to reduce the chance of a hard start hybrids are susceptible to hard starts which can cause catastrophic failure and a flow of liquid fuel on ignition can help mitigate this risk however the additional plumbing and presence of a volatile fuel source may also partially diminish some of the safety advantages of a hybrid motor additionally prior to the development of rocket motor 2 nitrous oxide was almost universally viewed as a stable and relatively safe substance this changed in 2007 when a tank of nitrous oxide exploded during a cold test at Scaled Composites resulting in three fatalities the likely cause was a thermal decomposition reaction caused by a malfunctioning electrical pump in the nitrous line normally this reaction will be self-quenching but due to a number of factors that are still not fully understood the reaction propagated back into the main tank causing an explosion although the final OSHA report on the incident placed blame on scale Composites I'm actually inclined to grant them some leniency the mechanism which created the explosion was sparsely understood at the time nitrous oxide is present in almost every dentist office and operating theater worldwide though please do know third-party experts were much more scathing than me in their assessment placing the blame squarely with scale composites nevertheless spaceship 2 carries four and a half tons of nitrous per flight in a tank of unknown composition it is unknown due to the previously mentioned arms trafficking restrictions so once again another risk of unknown magnitude the second system for which I believe scale Composites and subsequently Virgin Galactic deserve praise is the feather system let's go back to the X-15 crash we mentioned near the start of the video for suborbital flight the X-15 would climb above the vast majority of Earth's atmosphere and then re-enter on a ballistic trajectory when I say ballistic trajectory what I really mean is it comes screaming back into the thicker stratospheric Air at Mach 5. with only a primitive flyby wire system available back in the 1960s this meant the pilot had to hold a specific nose of attitude manually while the craft bled off this extra energy and I don't think it requires a Degree in Aeronautical Engineering to Guess that the X-15 was not a particularly stable aircraft just look at it the 1967 incident and breakup of The Craft was caused by the pilot slightly deviating from the required attitude possibly due to an electrical failure leading to an unrecoverable spin during that incident Michael J Adams was actually a personal friend of Bert rattan and Bill acknowledges that the crash was the inspiration for spaceship one's most Innovative feature the feather the vessel's tail boom sat on a hinge which could be raised prior to re-entry as long as the feather was deployed the craft was passively stable always falling back to Earth in a safe orientation spaceship 2 uses exactly the same design principle hinged tail booms which guarantee a stable descent from the upper atmosphere considering the feather design in isolation and not the ancillary systems which interfaced with it I believe Virgin Galactic should be commended for following a design philosophy which effectively removes one of the major threats to the crew during a trip to space though this is not a billionaire Showdown and we're focusing on safety here a very quick digression is appropriate while we're discussing positive aspects safety and ethical considerations are intimately linked and I think it's important to give credit where it's due Virgin Galactic were pursuing funding to the tune of one billion dollars from the Saudi Arabian royal family in 2017. however Branson refused the offer following the assassination of Jamal khashoggi in 2018. in a world where we're often led to believe morals keep you poor I have nothing but admiration for this Elon Musk did not do the same when searching for co-invests to fund his purchase of Twitter a few years afterwards there are two highly visible design choices present in spaceship 2 that give me great concern the first is quite Broad and has played a part in three of the major flight testing incidents I've discussed prior it's the control system and it's lack of automation retana has historically chosen to avoid working with systems he does not understand with the apparent exception of nitrous oxide he revolutionized the use of composite materials in aircraft design but most of his designs rely on surprisingly unequated control systems Julian Guthrie provides a lot more insight into rattan's propensity to cut back on systems he considered non-essential in his excellent book how to build a spaceship I won't go into details here but this leave out the non-essentials just make sure you have really good Pilots approach he's not one seen anywhere else in commercial Aviation I extensively discussed how non-essentials can quickly become Essentials in my previous two videos let's discuss reversible controls if you grab a control surface on a light aircraft to move it the joystick will move in unison that's because the two are physically linked by a cable there have been a total of three supersonic aircraft in history with reversible controls the first was the Bell X1 the first supersonic aircraft ever built which flew in 1947. the other two were spaceship 1 and spaceship 2. I spent a couple of days verifying this and it absolutely appears to be true the Bell X2 the X15 the F-100 mig-19 all had a hydraulic system between the stick and the control surfaces equally surprisingly White Knight 2 also has reversible controls in fact I'm not even able to find info on whether it has electrical actuators I think the entire aircraft might be flowing entirely by stick and rudder I want to drive the point home how unusual this is to do that let's look at a great paper from the US Air Force flight Dynamics laboratory from 1968. why am I choosing such an old presentation because flyby wire in supersonic aircraft was already the norm back then and also older papers tend to be a bit easier to understand and communicate so we start with Snoopy flying a World War One era biplane and asserting that security is a mechanical flight control system I think now in 2023 that is still a common misconception for the uninitiated a physical link between the pilot and the control surfaces feels reassuring however if we step back into the real world it's readily apparent that this is a fallacy and the author does a great job pointing this out this paper focuses on electrical actuators to assist the pilot however since it was written almost every large and or supersonic aircraft also has a hydraulic system between the pilot and the control surfaces this acts as a force multiplier and allows the pilot to actuate the surfaces with much reduced physical effort anyway in contradiction to established design spaceship 2 does not have a hydraulic system focusing on electrical actuation only the author goes on to detail the various redundancies and measures that must be taken to ensure control can be maintained in the case of fly-by-wire system failures he discusses quadruple redundancy two fail still operate systems entirely independent power and sensor systems and how failovers can be automatically and manually initiated by the pilot our paper ends with Charlie Brown asserting that security is a fly-by-wire control system and the subsequent 45 years have proved incorrect since this paper was written two civilian supersonic airliners flew extensively the Concord and the Tuple of tu144 but the less said about that one the better neither had a crash due to a fly-by-wire failure similarly every supersonic jet built since was had hydraulically actuated controls and some kind of flyby wire whoa okay correction from Alex a few hours before the videos published I don't know why I kept mentioning Hydraulics here yeah lots of large airliners require hydraulic actuators to move the control surfaces but plenty of aircraft particularly smaller ones use electric actuators that is one of the purposes of electronic flyby wire to get rid of all those hydraulic lines spaceship 2 has electrical actuators for supersonic trim in fact the speculation they may have been repurposed somewhat recently and used with a computer to perform some kind of stability augmentation but the controls are still directly connected so those tabs those electronically actuator Tabs are not part of a full flyby wire they only have limited Control Authority and this augmentation system if it exists is most certainly not externally certified and it's been to space a maximum of five times at the time of recording okay back to two weeks ago Alex there have been incidents due to Modern Control Systems being implemented incorrectly but reversible controls in anything other than light aircraft are something that largely belong in the distant past the aforementioned X-15 crash was caused by a partial failure of the flyby wire system however subsequent study of the failure points makes it clear that the system was improperly implemented by modern standards the x-15s flyby wire used unqualified components suffered from a lack of risk assessment and per human factors considerations flyby wire systems were in the infancy back in 1967. we have nearly 50 years of learnings to draw on and current systems avoid these shortcomings most light aircraft are inherently stable for most flight scenarios when I say inherently stable I mean if you let go of the controls the aircraft will either stay in its current orientation or in some scenarios actually return to level flight so in these cases reversible controls are fine for supersonic aircraft however Things become weird once we start to get near and Beyond the sound barrier airflow backs up ahead of the aircraft and can change the behavior of the control surfaces control inputs that would normally move the aircraft in a linear manner often result in unpredictable non-linear Behavior due to the change in pressure and flow regime at supersonic speed look at spaceship one it had a high Wing format with a dihedral excellent for role stability at subsonic speed but when flying supersonic highly unstable in the roll axis to build an aircraft that is reasonably stable in both subsonic and supersonic flight we usually need to physically change the configuration of the aircraft itself when going supersonic or use a flight computer to artificially maintain stability by augmenting human inputs at a faster speed than a human is physically capable of doing spaceship 2 achieves the former and it does so via electric actuators which are just the position of trim tabs on the control surfaces the shape of the surfaces is changed by the pilot entering trim inputs once the vehicle has gone supersonic so although the controls are reversible there is at least some kind of secondary system to adjust the flight characteristics when flying supersonic the Bell X1 had a similar system raising the horizontal stabilizers to bring them out of the high pressure airflow at supersonic speed I can't however find any information on whether this Electric System assists the pilot in maintaining stability via a flight computer as it is stated there is no fly-by-wire on spaceship 2 my assumption is that it does not the pilot accounts in Nicholas schmindle's book test gods are to be believed there is no reason to believe they're fabricated but I haven't used this book as a single source as it may be biased supersonic flights of spaceship 2 are mentally taxing with Pilots constantly fighting to hold a given orientation particularly against unwanted role this requires significant physical strength due to the absence of hydraulic control actuation with no flight computer and flyby wire the entire workload is placed on the pilot to hold the aircraft in a stable position and if the aircraft ends up losing stability which can happen extremely quickly and in an unpredictable manner when flying supersonic it is entirely up to the pilot to restore it no computer assistance available cannot stress enough this is unique in currently operational supersonic aircraft this highly unusual rudimentary control system and The Wider lack of automation as a whole has been the direct cause in at least three incidents and regulation breaches experienced by spaceship 2 so far remember how the 2014 breakup was due to the feather system being deployed early the co-pilot had a window of several seconds during the transition to supersonic flight to flip a switch to unlock the system this would ensure it's functional and would fully deploy for re-entry if no unlock confirmation was received the motor will be shut down and the craft glide back to the runway on the surface this is a good safety measure a function check to ensure the craft Will Survive re-entry in reality what would be a relatively simple task for a computer or to be honest an extremely simple task for a computer increased task loading on a pilot during one of the most stressful phases if not the most stressful phase of the flight in 2014 that switch was thrown early deploying the feather at high speed in a relatively thick atmosphere destroying the vehicle the Virgin Galactic eventually brushed this off as pilot error which is technically true for decades engineers in all sectors have done everything possible to design the operator out of crude systems we know operator error is extremely common so we try to reduce the chances of it happening in the first place through appropriate design this is known as human factors design put another way would you be happy as a passenger in a plane that contained a one touch please make the plane explode button in the cockpit during a portion of the flight though Virgin Galactic State they've designed out that particular procedure spaceship 2 is very much still a manually flown low automation spacecraft and they're so therefore subject to the relatively common curse of human error in fact Virgin Galactic are proud to show that off in their sales brochure we know spaceship one wasn't particularly stable in Flight spaceship 2 has had past stability issues and let's be honest it doesn't look stable but Rattan is one of the best airframe designers in history so I'm not going to go there regardless of its inherent stability we do have to question whether the 2011 control loss incident would have even been possible given the presence of a proper flight computer and fly-by-wire system as we see in every other operational supersonic vehicle in operation today were the minor aerodynamic changes made to the craft since 2011 sufficient to prevent a repeat incident happening could that incident happen at a lower altitude where the feather wouldn't be able to save the crew I don't know I'm assuming you don't either the other highly visible design choice that unsettles me is a natural consequence of choosing a space plane design in fact this consideration May preclude space planes from being truly considered as safe well into the future is the lack of a launch Escape system or less spaceship 1 and spaceship 2 are the only suborbital spacecraft ever built that are unable to eject or boost the crew compartment free in the case of structural failure broadly speaking there are two phases during any space flight where a catastrophic failure is relatively likely the Boost phase and the re-entry phase we've already discussed how Virgin Galactic have essentially designed in inherent safety during re-entry due to the unpredictable nature and necessary low safety margins required for Rocket design catastrophic failures of both the engine and vehicle structure are relatively common during the Boost phase for space-faring vehicles historically as a result most space launch systems are equipped with a crew escape system the only three systems that have not been thusly equipped that's orbital and suborbital are the shuttle Les would likely have saved the lives of the Challenger crew spaceship one and spaceship 2. we've discussed the 2014 breakup incident already but again a Les would likely have brought both Pilots home the surviving pilot did have an automatically deploying parachute kind of rudimentary less I suppose and that is one factor in the unlikely chain of events that allowed him to survive no crew fatalities have ever occurred on the upward leg of a flight to space in a less equipped system in fact they've saved the lives of Cruz on two occasions both on soyuz launches in 1983 and again in 2018 in addition the most recent uncrewed launch of new Shepard suffered an engine failure triggering the Les and returning the capsule with its scientific payload to Earth safely unlike the pilots of most high altitude aircraft neither the pilots nor the passengers in spaceship to wear pressure suits so a loss of cabin pressure would expert all occupants to the vacuum of space but in the only commercial launch to date crew are shown donning parachutes but this is a far cry from the full-blown Escape systems we see elsewhere or even from the ejector seat of the X-15 which sounds like an absolute nightmare to design yet was still deemed necessary to improve crew safety for The Craft of course Allah is far from a silver bullet but given the historical failure rate of space launchers and The Proven record of well-implemented Escape systems I find it absolutely astonishing that any sufficiently informed participant would be happy to take a flight in a vehicle where a significant portion of the flight guarantees their death in the event of a historically common failure keep reiterating but what is the chance of a catastrophic structural failure on spaceship 2. say it with me we don't know I'd like to conclude by challenging a more qualitative argument for the safety of Virgin Galactic as a whole Branson flew in it so it's likely to be safe or sometimes the pilots wouldn't fly it if it was unsafe I don't actually need to tackle this argument head on because it's one I have direct experience with back in 2012 when I regularly flew as a helicopter passenger to offshore oil Platforms in the North Sea there were a couple of major incidents that very much directly affected me within the space of five months two Eurocopter ec225 helicopters were forced to ditch in the North Sea in both cases All crew and passengers survived and the issue was found to be due to fatigue cracking in the main gearbox much like an explosive rocket motor failure basically guarantees the loss of a spacecraft a gearbox failure guarantees the loss of a helicopter engine failures can be dealt with helicopters can be Auto rotated to a landing gearbox failures mean the rotors stopped turning and you fall out of the sky in both ditching incidents the pilots responded to a warning light before the gearbox actually failed and were able to ditch safely in time only c225s were grounded for a couple of years while the root cause was investigated various remedial actions were taken but it was not deemed necessary to make major material or structural changes to the gearboxes themselves themselves although the main shaft was redesigned the type was returned to service in 2014. in retrospect somewhat amazingly the main argument I was given by my superiors was if it wasn't safe the pilots wouldn't fly it looking back this is just a more refined version of well he does do it why don't you followed by flapping arms and making chicken noises and I don't want to take credit here at the time I was far less versed in Risk Management I was happy to accept that argument back then I think we can all see where this is going it took just a couple of years in 2016 an ec225 which had been returned to service and was flying in the Norwegian sector had a main road a Detachment shortly after takeoff there were no survivors the cause of failure fatigue cracking in the main gearbox shortly after this video is published four passengers are scheduled to roll the dice with Virgin Galactic one of them currently studies at Aberdeen University barely a stone's throw from where I live I wish her and her fellow passengers the best of luck though I have no idea how much of it they need thank you very much for watching

Channel: Alexander the ok

Views: 22,844

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Id: R5XEZfzoxvY

Length: 64min 33sec (3873 seconds)

Published: Wed Aug 09 2023