The Black Arrow & Britain's Rocket Program

0:08 scott manley here 50 years ago in march 1970 Britain made its first successful flight of the black arrow rocket this was a sub-orbital test flight which would eventually lead to in the first and only orbital flight by a British built rocket Britain starts a development of large rockets in the 1950s they had nuclear warheads and they wanted a way to deliver them that didn't involve aircraft as much as I love the Avro Vulcan it was very clear that ballistic missiles were the future so there was a program called Blue Streak to develop an intermediate-range ballistic missile fueled by kerosene liquid oxygen running on rolls-royce built versions of s3d engines that's the same engine that powered the Thor PGM missiles this project proceeded for a few years they built up boosters they tested the engines on the Isle of Wight and in parallel they also ran a project called Black Knight where they used a smaller rocket to test re-entry vehicles and unfortunately the thing kind of ran over budget and eventually they decided to put it on ice and instead buy ICBMs from the USA and put British warheads on them but the project didn't die right away they tried to repurpose what they had they tried to take the booster and then use the Black Knight as the second stage this became known as Black Prince and if you're wondering about these names these are called rainbow cords there are in the format of a color followed by a known and they came into being after World War 2 because British intelligence realized that they'd been able to understand lots of information of its secret German projects just by looking at the codename and the example is a project called Wharton Wharton was a one-eyed God and somebody had the bright idea that this was a navigation system that used a single radio beam so black prince was seen as a way to reuse existing development work on something new that might have a use and yet was known as black prints but it was also known as the Blue Streak satellite launch vehicle and on paper it been able to put about 1 ton of spacecraft into low-earth orbit the first stage was the Blue Streak booster using kerosene and liquid oxygen as a fuel in those air rolls-royce engines the second in the third stages were based on the Black Knight and those were powered by the armstrong siddeley gamma engines sounds very British doesn't it those ran on high-test peroxide and kerosene and actually by the time that black prince was in the offing they had already flown 25 flights with this all successfully blue streak on the other hand hadn't flown up to that point so unfortunately black prints while it was seemed like a good idea nobody wants to actually support him and put money into it eventually what happened was Britain joined a European launch collaboration to create the Europa rocket and Blue Streak was assigned as the first stage of this with a French built second stage and a German built third stage and that was when we actually got some flights off the Blue Streak and it was far by far the most reliable part of that entire combination but Britain eventually you know lost patience got bored I don't know they moved on and the French then of course spearheaded the Ariane launch vehicle instead which went on to be quite successful and so we come to the black arrow program this was originally authorized in 1964 so it happened in parallel with Europa and one interesting decision in the design was that the first stage the dimensions were specified in metric because they considered that the first stage of the black arrow could be part of this European Launch System however the second and third stages they were still specified in imperial units compared to Blue Streak and black prints black here'll was a lot smaller a lot less ambitious it was gonna in theory bail to put something like a hundred kilograms into low-earth orbit the first stage was going to be powered by an eighth chamber version of the gamma the second stage was gonna have a to chamber version and the third stage was going to use a single spin stabilized Waxwing rocket solid rocket the whole stack was about 13 meters tall which makes it not much bigger than the Astro rocket that we were hoping would launch earlier this week in terms of launch mass it was about 18 tons as well so it's more or less about twice the mass of that Astro vehicle it's definitely a small sat launch vehicle so let's talk about that fuel choice high-test peroxide and kerosene not seen really outside of the british rocket program so what you do with this is you take the peroxide which is 80 sorry 85 percent hydrogen peroxide 15 percent water you pass it over a heated catalyst where it decomposes into water or steam and oxygen and then that oxygen reacts with the kerosene and you burn it so you end up with an exhaust which is mostly hot steam and a small amount of carbon dioxide relatively speaking now decomposing the peroxide and burning the kerosene produces a lot lower temperatures than you get from burning kerosene with liquid oxygen but the exhaust makeup has a lot more water in and if as you probably know the Lord the molecular mass of your exhaust the better use specific impulse you get so although it has lower temperature it also has lower specific air lor and molecular mass therefore the specific impulse isn't quite that bad in fact the specific impulse is about 278 whereas for comparison your typical kerosene liquid oxygen rocket will have maybe 300 320 even but this fuel combination is also very dense in terms of its volumetric impulse right that means the amount of thrust you're gonna get from a cubic meter or whatever specific volume of the propellant if you look at kerosene and liquid oxygen you have to have 2.3 times the amount of mass of oxygen compared to the kerosene kerosene is a lower density fuel its density is about point eight kilograms per liter whereas liquid oxygen has a density of about one point one four so having more liquid oxygen is good because that's dancer but with peroxide the density is one point four for so it's even denser than liquid oxygen and the oxidizer to fuel ratio is up about eight so you have eight times the mass of your propellant is in this peroxide which is denser and it turns out if you're looking for the impulse per unit volume then peroxide kerosene totally wins over you know kerosene and liquid oxygen so having a higher density is useful because it means you can actually build a smaller rocket and it also helps because if you've got a smaller rocket than your aerodynamic drag is lower so as all these factors are always a trade-off and of course hydrogen and oxygen is the rocket fuel which gives you the best specific impulse but it's obviously very very low density the other advantage of kerosene peroxide is that it is a room-temperature fuel it doesn't need any cryogenic storage or anything you don't need to worry about that that it does have the problem that peroxide does tend to decompose over time into water and oxygen and yeah if you spill it it can actually cause things to catch fire which can be really nasty but on the other hand it will eventually evaporate safely the propellant combination also offered a technical advantage to other engines of the time couldn't match so to power the turbo pumps most of the engines at the time used a gas generator so they would take a small part of their propellant and burn it off and exhaust that a little pressure so they lost a little bit of performance with the gamma engine they could actually take the peroxide run that over catalyst and use the steam generator to power the pumps and then the steam in the oxygen that came out could go through the engine Bale so they created a stage combustion cycle a closed cycle engine because they were able to run the pre burner by decomposing one of the propellants so while the performance of the fuel doesn't look that great to start with it actually turns out to be pretty great when you start to take all these advantages into account so the black arrow Rockets were manufactured in Britain and then they were transported to Australia to be tested and launched at the Woomer rocket range so they would launch the first stage again it was a meter-wide stage is six point nine meters long that would burn for a hundred and twenty seven seconds propelled by eight gamma engines the gamma engines would be arranged in four of gambling pairs they would have roll and pitch in your control then after that there would be a stage separation there would be some stage separation waters and the second stage would ignite now the second stage was an named foot six inches long and 4 feet six inches wide as I said different units for different stages that would burn for another two minutes getting them most of the way up to orbital velocity and for the final stage they would separate the upper stage and then it would spin up using small motors so that was spinning three times per second then the wax wings solid rock motor stage would burn and inject it into an orbit and that would take about 55 seconds to do that so the first test launch of black errol was in June of 1969 it was going to be a suborbital launch with a boiler plate at a spin would however there was some problems with the control system and the vehicle was already oscillating out of control even before it cleared the launch pad about a minute into flight its deviations went so far that the spacecraft was spinning out of control and was destroyed by range safety and as I said the first successful launch a suborbital test was 50 years ago pretty much today 4th of March in 1970 that was successful so they thought they moved on to an actual real payload this was gonna be the Arbour satellite which was scheduled for launch in September of 1970 however the spacecraft sprung a leak and they started to lose pressure in the second stage oxidizer system so the second stage cut out several seconds early and that meant that the final stage didn't deliver enough velocity to put the payload into orbit and re-entered you before it completed a single orbit the fourth launch would be in October of 1971 carrying the Prospero satellite this was a success of put the spacecraft into a and Prospero spacecraft is still in orbit as of today however that launch was occurred under the with the understanding that the project was actually being canceled already and so this was an interesting rare unique moment in rocket history because I think Britain is the only country to have actually developed and flown a rocket into orbit off its own design and then decided that they didn't want to do that anymore and you know if you ask me I think that was the wrong decision then again I am biased I really like rockets I may not be the best person to ask however 50 years on we might actually see a British built launch vehicle or maybe a Scottish built launch vehicle depending upon your particular national persuasion our backs is one example they're building a small Sat launcher called prime which should be able to put about a hundred and fifty kilograms into low-earth orbit and potentially do this from a Scottish spaceport in the north of Scotland and if they make that work that will be a major first because while there have been many European long rockets launched to orbit there has never been a European rocket launched from Europe to orbit I'm Scott Manley fly safe [Music]

Channel: Scott Manley

Views: 253,239

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Id: FKRkFwc9234

Length: 12min 47sec (767 seconds)

Published: Thu Mar 05 2020