WEBVTT - More Space Planes 0:00:04.120 --> 0:00:07.160 Get in touch with technology with tech Stuff from how 0:00:07.200 --> 0:00:13.960 stuff works dot com. Hey there, and welcome to tech Stuff. 0:00:13.960 --> 0:00:17.400 I'm your host, Jonathan Strickland. I'm an executive producer with 0:00:17.400 --> 0:00:21.240 how Stuff Works in love all Things tech and tech Stuff. 0:00:21.280 --> 0:00:23.919 Listener Ivan had asked me in the last episode to 0:00:23.960 --> 0:00:26.079 do a show about space planes. As it turns out, 0:00:26.079 --> 0:00:29.160 there was a bit more to talk about to fill 0:00:29.240 --> 0:00:32.120 up just a single episode. So here is the part 0:00:32.280 --> 0:00:35.400 two to this. UH. In that last episode, I covered 0:00:35.440 --> 0:00:38.400 what a space plane is in general and gave a 0:00:38.600 --> 0:00:41.760 history of some of the important developments and aviation that 0:00:41.880 --> 0:00:45.120 led to the deployment of the Space Shuttle, which was 0:00:45.159 --> 0:00:50.040 the first practical implementation of space plane technology. UH. There 0:00:50.040 --> 0:00:52.920 were space planes before the Space Shuttle, to be clear, 0:00:53.200 --> 0:00:57.000 but all of those were meant as test vehicles, experimental 0:00:57.080 --> 0:01:00.960 prototype vehicles that were meant to expand our understanding of 0:01:01.000 --> 0:01:04.479 engineering and strategies in order to create a working space 0:01:04.520 --> 0:01:08.200 plane that would have applications beyond just research and development 0:01:08.200 --> 0:01:12.480 and aviation, as in, uh, deploying satellites, for example, or 0:01:12.600 --> 0:01:16.160 taking crew to and from outer space. And so now 0:01:16.200 --> 0:01:18.800 we're going to pick up in the early nineteen eighties 0:01:18.840 --> 0:01:23.760 after the space Shuttle program had UH launched, and talk 0:01:23.840 --> 0:01:27.160 about some of the other space planes that have either 0:01:27.280 --> 0:01:29.399 been developed or proposed. And there's gonna be a lot 0:01:29.400 --> 0:01:32.360 of jumping around in time on this, because, as I've 0:01:32.400 --> 0:01:37.559 mentioned in previous episodes, the way space exploration and space 0:01:37.600 --> 0:01:43.120 programs have evolved over time is messy. It's not a 0:01:43.200 --> 0:01:48.320 simple in you know, in year X it started, and 0:01:48.360 --> 0:01:51.040 then that went on for ten years, and then this 0:01:51.080 --> 0:01:54.800 other project started. You have a lot of overlapping timelines. 0:01:55.160 --> 0:01:57.960 And so sometimes that means that if you were to 0:01:58.000 --> 0:02:02.640 just look at launches, like when a test vehicle launched 0:02:02.680 --> 0:02:05.600 for the first time, it would look like a more 0:02:05.720 --> 0:02:07.960 linear approach, But in fact a lot of these things 0:02:08.000 --> 0:02:11.799 were in development at around the same time. So with 0:02:11.840 --> 0:02:15.919 that said, in nineteen eighty two, the then Soviet Union 0:02:16.360 --> 0:02:19.840 began test flights of a new space plane design, an 0:02:19.919 --> 0:02:23.920 unmanned space plane called the Bore four, the b O 0:02:24.280 --> 0:02:27.280 R four. That b O R stands for something in 0:02:27.360 --> 0:02:29.400 Russian that is so complicated. I'm not going to try 0:02:29.400 --> 0:02:31.560 and say it because I will dislocate my jaw. I 0:02:31.639 --> 0:02:37.280 am that bad at all languages, including English. Anyway. This 0:02:37.360 --> 0:02:40.119 was the culmination of nearly a decade of work. When 0:02:40.120 --> 0:02:44.160 the Soviet space program really began serious research and development 0:02:44.160 --> 0:02:47.600 on space plane design in the nineteen seventies. The ultimate 0:02:47.639 --> 0:02:50.720 goal was to create a space plane called the Spiral 0:02:50.880 --> 0:02:53.760 fifty fifty, and that was a project that actually dated 0:02:53.800 --> 0:02:57.240 back even further in the Soviet space program. It first 0:02:57.320 --> 0:03:01.720 got started in the nineteen sixties. These two concepts are 0:03:01.800 --> 0:03:06.000 closely tied together, uh the Boar four and the Spiral 0:03:06.080 --> 0:03:10.040 fifty fifty. So let's start with Spiral fifty because that's 0:03:10.080 --> 0:03:14.240 what would ultimately give way to the Boar four. And 0:03:14.280 --> 0:03:17.240 while the spiral was a concept, the Boar four was 0:03:17.480 --> 0:03:23.959 actually constructed, So the spiral fifty concept was incredibly ambitious. 0:03:24.360 --> 0:03:26.440 The goal was to create an aircraft that could take 0:03:26.440 --> 0:03:29.560 off like a conventional jet, So in other words, it 0:03:29.560 --> 0:03:33.200 would launch from a horizontal position off some sort of 0:03:33.240 --> 0:03:37.800 takeoff surface like a runway. Then it would travel up 0:03:37.840 --> 0:03:43.800 into air and continue to ascend until it reached outer space. 0:03:44.680 --> 0:03:48.200 Not just above the carm online at a hundred kilometers 0:03:48.240 --> 0:03:51.040 that's the dividing line between the Earth's atmosphere and what 0:03:51.080 --> 0:03:54.440 we considered to be space, but even beyond that, all 0:03:54.480 --> 0:03:58.320 the way out into orbit. This vehicle was intended to 0:03:58.400 --> 0:04:02.240 bring supplies and crew two from space station's orbiting Earth, 0:04:02.680 --> 0:04:05.000 and then it would return to Earth at the end 0:04:05.040 --> 0:04:08.600 of its mission and land again like a conventional aircraft. 0:04:08.800 --> 0:04:11.680 And as you can imagine, this would mean creating a 0:04:11.760 --> 0:04:15.560 truly innovative system because the stuff that lets you fly 0:04:15.640 --> 0:04:19.040 around in Earth's atmosphere doesn't work so great in outer space. 0:04:20.080 --> 0:04:23.400 The concept included a pair of expendable rocket stages which 0:04:23.400 --> 0:04:25.919 would be necessary to push the vehicle out into space 0:04:25.920 --> 0:04:29.600 beyond the atmosphere. But within the atmosphere there would be 0:04:29.640 --> 0:04:33.560 an air breathing hypersonic booster that would provide the propulsion 0:04:34.279 --> 0:04:36.760 to get the aircraft to those very high altitudes before 0:04:37.120 --> 0:04:42.200 having to depend upon other rocket engines. This is a 0:04:42.200 --> 0:04:44.760 good moment to talk about why you would want or 0:04:45.080 --> 0:04:48.400 need an air breathing rocket in the first place, because 0:04:49.480 --> 0:04:52.479 we have a long history of using rockets that have 0:04:53.040 --> 0:04:55.279 oxidizers attached to them. Why would you go with a 0:04:55.279 --> 0:04:59.600 different design. Well, first of all, let's talk about oxidizers 0:04:59.600 --> 0:05:01.720 in the first pace. For combustion to happen, you have 0:05:01.839 --> 0:05:04.840 to have three things. These are the the three things 0:05:04.839 --> 0:05:07.240 that make up the triangle for fire. You have to 0:05:07.279 --> 0:05:10.120 have heat, you have to have fuel something to burn, 0:05:10.279 --> 0:05:14.120 and you have to have an oxidizer. Not surprisingly due 0:05:14.200 --> 0:05:18.400 to the names oxygen is an oxidizer a very common 0:05:18.440 --> 0:05:21.200 one here on Earth. Stuff can burn on Earth because 0:05:21.240 --> 0:05:25.440 we have oxygen that facilitates that process. But in space 0:05:26.040 --> 0:05:30.280 there's a distinct shortage of oxygen, so without an oxidizer, 0:05:30.680 --> 0:05:34.080 flames would die out and combustion would stop. Is the 0:05:34.120 --> 0:05:35.920 same thing as if you were to light a candle 0:05:36.400 --> 0:05:39.880 and then cover that candle with a clear glass bowl. 0:05:40.600 --> 0:05:42.680 You would see that the candle's flame would start to 0:05:42.760 --> 0:05:45.400 flicker as it was using up all the oxygen, and 0:05:45.400 --> 0:05:47.920 then it would ultimately sputter out. The same thing would 0:05:47.960 --> 0:05:52.320 happen with rocket engines unless we carried an oxidizer in 0:05:52.360 --> 0:05:55.440 addition to the fuel we plan on burning. But we 0:05:55.520 --> 0:05:58.800 also know that getting into space requires a very careful 0:05:58.839 --> 0:06:03.320 management of weight versus thrust. You want to minimize the 0:06:03.360 --> 0:06:06.560 weight as much as you can to make efficient use 0:06:06.560 --> 0:06:10.040 of fuel. The heavier the weight of the payload, whatever 0:06:10.080 --> 0:06:12.760 it is you're sending out into space, the more fuel 0:06:12.839 --> 0:06:15.040 you're going to need, and the more oxidizer you're going 0:06:15.080 --> 0:06:17.760 to need in order to generate the thrust necessary to 0:06:17.839 --> 0:06:21.599 put that mass into orbit, and it turns out that 0:06:21.680 --> 0:06:26.560 the oxidizer component in rocket engines weighs a lot. This 0:06:26.680 --> 0:06:30.120 is easily shown through an example. So we're gonna look 0:06:30.160 --> 0:06:33.800 at the Space Shuttle to explain what we're talking about here. 0:06:33.960 --> 0:06:37.560 If you have an empty Space Shuttle, it's the spacecraft, 0:06:37.600 --> 0:06:39.920 it doesn't have any payload in it. It would weigh 0:06:39.920 --> 0:06:43.039 in at a hundred sixty five thousand pounds or about 0:06:43.080 --> 0:06:48.040 seventy five thousand kilograms. The two solid fuel booster rockets 0:06:48.080 --> 0:06:50.080 that are would be on either side of the Space 0:06:50.080 --> 0:06:52.599 Shuttle when it was on the launch pad would each 0:06:52.640 --> 0:06:57.520 way one eighty five thousand pounds or eighty four thousand kilograms. 0:06:58.200 --> 0:07:01.880 The giant external fuel tank if it were completely empty 0:07:01.880 --> 0:07:05.080 of fuel, just the fuel tank by itself, that's the 0:07:05.240 --> 0:07:07.720 part that's in the center between those two big booster 0:07:07.839 --> 0:07:12.280 rockets that weighed seventy eight thousand, one hundred pounds or 0:07:12.320 --> 0:07:16.320 about thirty five thousand kilograms. So collectively, all of those 0:07:16.360 --> 0:07:21.400 components empty space shuttle, empty fuel tank, two solid fuel 0:07:21.560 --> 0:07:26.360 rocket boosters weighed six hundred thousand pounds. That's two d 0:07:26.520 --> 0:07:31.080 seventy eight thousand kilograms that's without fuel and without oxidizer. 0:07:31.680 --> 0:07:34.840 The oxidizer, which for the Space Shuttle was a hundred 0:07:34.920 --> 0:07:39.240 forty three thousand gallons or five hundred forty one thousand 0:07:39.400 --> 0:07:45.440 liters of liquid oxygen, weighed in at a staggering one 0:07:45.560 --> 0:07:50.080 point three five nine million pounds or six hundred sixteen 0:07:50.080 --> 0:07:54.920 thousand kilograms, So, in other words, the oxidizer weighed more 0:07:55.000 --> 0:07:59.560 than twice as much as the Space Shuttle, the rocket boosters, 0:08:00.000 --> 0:08:04.120 and the external tank combined. So the most most of 0:08:04.160 --> 0:08:08.040 your weight is coming not from the materials, but from 0:08:08.080 --> 0:08:12.640 the fuel and the oxidizer that makes up the vast 0:08:12.720 --> 0:08:14.960 majority of the weight that you're trying to send up there. 0:08:15.440 --> 0:08:19.080 A hypersonic air breathing rocket would use the oxygen in 0:08:19.120 --> 0:08:23.080 the atmosphere as the oxidizer, which means again it would 0:08:23.080 --> 0:08:25.080 only work as long as there were enough oxygen in 0:08:25.080 --> 0:08:28.600 the environment to feed the rocket. However, it would remove 0:08:28.760 --> 0:08:32.840 the necessity to carry so much fuel and oxidizer on board, 0:08:33.240 --> 0:08:37.080 drastically reducing the weight and by extension, the cost of 0:08:37.120 --> 0:08:39.920 the launch vehicle. Because if you don't have to put 0:08:39.960 --> 0:08:41.640 in as much fuel an oxidizer, you don't have to 0:08:41.640 --> 0:08:45.720 spend as much money per launch. So it was a 0:08:45.760 --> 0:08:51.960 way of making the flight more efficient, less costly, less difficult, 0:08:52.040 --> 0:08:54.760 less challenging in the long run, if you're talking about 0:08:54.880 --> 0:08:58.480 just figuring out how much thrust you need to uh 0:08:58.520 --> 0:09:02.240 to propel that much weight into the into space. An 0:09:02.280 --> 0:09:05.160 air breathing rocket also known as a rocket based combined 0:09:05.360 --> 0:09:09.319 cycle engine, works on a principle not that different from 0:09:09.360 --> 0:09:12.760 a conventional jet engine, which means now I get to 0:09:12.800 --> 0:09:15.640 talk about how jet engines work. This is how I 0:09:15.679 --> 0:09:18.920 sneak eighty different tech topics into a single episode. An 0:09:18.960 --> 0:09:22.120 I a stinker. Okay, So a jet engine is a 0:09:22.120 --> 0:09:26.200 type of gas turbine engine. Gas turbine engines have a 0:09:26.320 --> 0:09:30.760 rotating component called the turbine, which you should be familiar with. 0:09:30.800 --> 0:09:33.040 This is the same sort of component used in various 0:09:33.080 --> 0:09:37.280 power facilities, like a steam turbine or a wind turbine, 0:09:37.480 --> 0:09:41.240 and like those turbines, the gas turbine engine turbines are 0:09:41.360 --> 0:09:44.920 spun by a fluid. Right, for steam turbines, you have 0:09:45.320 --> 0:09:50.520 steam passing through this this fan blade turbine system which 0:09:50.559 --> 0:09:54.240 causes the rotation, but in this case the fluid is 0:09:54.240 --> 0:09:58.880 pressurized gas that's created by burning fuel, which then causes 0:09:58.920 --> 0:10:03.600 air to expand rapidly and then forcing that expanding air 0:10:03.760 --> 0:10:07.960 through the turbine. The turbines will spend at incredible speeds, 0:10:08.440 --> 0:10:11.600 which generates a lot of heat in the process. That 0:10:11.679 --> 0:10:15.360 actually is a limiting factor. You cannot have a regular 0:10:15.440 --> 0:10:19.080 jet engine operate beyond a certain point before you get 0:10:19.120 --> 0:10:23.080 into a dangerous situation because it's generating so much heat 0:10:23.120 --> 0:10:25.840 that components will either start to melt or they'll start 0:10:25.880 --> 0:10:29.960 to break down just from the incredible stress, the mechanical 0:10:30.040 --> 0:10:32.920 stress that it's under. Now, there are three main parts 0:10:33.360 --> 0:10:36.880 of your conventional jet engine. You have a compressor, which, 0:10:36.920 --> 0:10:40.280 as the name suggests, compresses air to increase the pressure. 0:10:40.600 --> 0:10:44.000 This usually comes in the form of sort of this UH, 0:10:44.080 --> 0:10:49.240 this bladed design and UH. It is typically powered by 0:10:49.280 --> 0:10:52.400 the spinning of the turbine itself. There's a chamber called 0:10:52.440 --> 0:10:56.160 the combustion area, which, as the name would suggest, is 0:10:56.200 --> 0:11:00.400 where fuel gets added to the incoming compressed air and 0:11:00.440 --> 0:11:04.520 then is burned. It's ignited, which causes that compressed air 0:11:04.559 --> 0:11:08.000 to expand and become a high velocity gas. And then 0:11:08.040 --> 0:11:11.280 you have the turbine which extracts that energy coming out 0:11:11.320 --> 0:11:13.679 of that gas, allowing the gas to flow through the 0:11:13.679 --> 0:11:18.640 turbine spinning it and UH that's where you generate your 0:11:18.679 --> 0:11:21.360 your energy or your generate your power, I should say. 0:11:21.640 --> 0:11:25.240 Jet engine turbines use that energy to help drive the 0:11:25.280 --> 0:11:29.000 compressor and intake fans. And in a jet engine, the 0:11:29.080 --> 0:11:32.720 hot air from the combustion area will combine with cold 0:11:32.760 --> 0:11:35.520 air that actually flows around the core of the engine. 0:11:35.960 --> 0:11:39.000 So you have an engine design where air can flow 0:11:39.679 --> 0:11:42.920 around the core as well as going into the core. 0:11:43.200 --> 0:11:45.160 The air that goes into the core is the air 0:11:45.200 --> 0:11:51.000 that gets compressed and then is UH in that combustion chamber. 0:11:51.080 --> 0:11:53.480 The air going around it stays at a lower temperature. 0:11:53.760 --> 0:11:57.079 The two will combine at the nozzle and escape through 0:11:57.120 --> 0:12:01.000 the back of the engine. Now, as we know, a 0:12:01.080 --> 0:12:05.640 reaction has an equal but opposite reaction, so that gas 0:12:05.679 --> 0:12:09.360 shooting out the back of the engine creates a forward 0:12:09.520 --> 0:12:13.160 thrust on that engine pushes the engine in the opposite direction. 0:12:13.679 --> 0:12:16.800 The amazing amount of velocity means that it's enough to 0:12:17.559 --> 0:12:21.000 push an entire massive vehicle like a jet plane, through 0:12:21.040 --> 0:12:24.280 the air. An air breathing rocket engine would work very 0:12:24.360 --> 0:12:27.360 much in the same way as your standard jet engine, 0:12:27.559 --> 0:12:31.359 but would need some simplification in order to avoid overheating. 0:12:31.520 --> 0:12:35.800 Simplification is being kind. I'm talking about removing some parts. 0:12:35.840 --> 0:12:40.160 So scram jets a k A supersonic combustion. Ram jets 0:12:40.679 --> 0:12:45.680 draw in air through an inlet, essentially an especially designed opening, 0:12:46.200 --> 0:12:49.839 rather than using an intake fan, and they don't need 0:12:50.000 --> 0:12:54.240 a rotating compressor to compress the air because the speed 0:12:54.320 --> 0:12:57.800 at which these jets are traveling is so great that 0:12:57.880 --> 0:13:00.920 the air gets compressed just by coming in through the inlet. 0:13:01.520 --> 0:13:04.240 And so you have this incoming air that's being compressed 0:13:04.240 --> 0:13:07.880 as it comes into this ramjet engine, and then fuel 0:13:07.880 --> 0:13:12.000 will get added to the combustion area and this supersonic 0:13:12.040 --> 0:13:16.040 airflow and fuel mixture gets ignited. That fuel tends to 0:13:16.040 --> 0:13:19.480 be stuffed, like liquid hydrogen for example, And the reduction 0:13:19.800 --> 0:13:21.880 of moving parts would allow this engine to operate and 0:13:21.960 --> 0:13:25.319 much higher speeds than conventional jet engines, which again would 0:13:25.480 --> 0:13:29.960 encounter those structural problems if they were to go way 0:13:30.000 --> 0:13:34.240 too fast. So theoretically a scram jet you would be 0:13:34.280 --> 0:13:37.880 able to hit like speeds of like mock fifteen I 0:13:37.920 --> 0:13:40.640 think the fastest. As I recall, I don't have it 0:13:40.640 --> 0:13:43.800 in my notes, but somewhere in the mock nine point 0:13:43.920 --> 0:13:46.920 six or nine point seven range. That's the fastest we've 0:13:46.960 --> 0:13:48.640 ever seen one go, but in theory they could go 0:13:48.720 --> 0:13:52.480 much faster. Because of the nature of these engines, they 0:13:52.520 --> 0:13:55.400 require a vehicle to already be going pretty fast before 0:13:55.440 --> 0:13:57.920 they kick in, So you need to combine those air 0:13:57.960 --> 0:14:01.559 breathing rockets with some other method that for the initial takeoff. 0:14:01.600 --> 0:14:04.840 They would not be sufficient to drive a vehicle so 0:14:04.880 --> 0:14:08.480 that they could take off from a horizontal surface, So 0:14:08.880 --> 0:14:11.880 you might need an expendable rocket, for example, like the 0:14:11.960 --> 0:14:14.840 kind that was proposed for the Spiral fifty. I'll talk 0:14:14.880 --> 0:14:17.040 more about the Spiral in a moment, and I'll explain 0:14:17.080 --> 0:14:20.280 what happened to that project, But first before I do that, 0:14:20.360 --> 0:14:30.640 let's take a quick break to thank our sponsor. All right, 0:14:30.720 --> 0:14:36.080 back to the Spiral. The project struggled throughout its relatively 0:14:36.320 --> 0:14:40.360 short life due to lack of funding, but elements of 0:14:40.400 --> 0:14:44.040 the project would continue even after the full Spiral fifty 0:14:44.120 --> 0:14:47.360 fifty got the acts, which it officially did sometime around 0:14:48.240 --> 0:14:50.760 although it had been canceled once before in nineteen sixty nine. 0:14:51.400 --> 0:14:54.720 One of those projects was the MiG one oh five, 0:14:55.040 --> 0:14:59.200 also known as the Experimental Passenger Orbital Aircraft. This big 0:14:59.240 --> 0:15:01.800 one oh five was ah jet that was designed to 0:15:01.800 --> 0:15:04.520 be a space plane. It never actually traveled all the 0:15:04.520 --> 0:15:07.240 way up into space. It was built and it was 0:15:07.280 --> 0:15:10.680 flown several times, but never all the way up to 0:15:10.720 --> 0:15:14.760 an altitude that would qualify space. It did have in 0:15:14.840 --> 0:15:19.800 its design a pilot capsule that was completely insulated from 0:15:19.880 --> 0:15:22.320 the rest of the aircraft and it was fully ejectable, 0:15:22.400 --> 0:15:25.560 So that was in order to us to to keep 0:15:25.600 --> 0:15:29.640 the pilot safe. The fear was that without this capsule 0:15:29.920 --> 0:15:32.800 and without that creatability, if something were to happen when 0:15:32.800 --> 0:15:38.360 the vehicle was traveling at fantastic speeds, the pilots, the 0:15:38.400 --> 0:15:41.760 pilot wouldn't have any options. The pilot would be a goner. 0:15:42.280 --> 0:15:44.600 The MAG one oh five could take off from a runway, 0:15:44.720 --> 0:15:48.760 or it could be dropped from a tuple of tow bomber. 0:15:49.520 --> 0:15:53.560 The project was initially canceled on June sixty nine, but 0:15:53.640 --> 0:15:57.120 the Soviets reinitiated the program in nineteen seventy four when 0:15:57.160 --> 0:16:00.600 they heard about the US space Shuttle program. The MiG 0:16:00.680 --> 0:16:03.800 one oh five was actually built and flew on eight 0:16:03.960 --> 0:16:08.040 test flights at least eight anyway from nineteen seventy to 0:16:08.120 --> 0:16:10.360 nineteen seventy eight. But again it never made it all 0:16:10.400 --> 0:16:12.520 the way up into space. The tests were to make 0:16:12.560 --> 0:16:16.040 certain the design principles were sound, but the project was 0:16:16.160 --> 0:16:18.600 ended in nineteen seventy eight after the pilot of the 0:16:18.640 --> 0:16:21.960 eighth test flight was forced to make a pretty hard landing, 0:16:22.600 --> 0:16:26.120 and ultimately the Soviet Union decided that the cost of 0:16:26.160 --> 0:16:29.000 that program didn't make much sense and they wanted to 0:16:29.040 --> 0:16:32.920 divert the funds to other projects. The Boer series b 0:16:33.040 --> 0:16:36.400 O R was another part of the design of this 0:16:36.600 --> 0:16:38.880 space plane, and it started off as part of the 0:16:38.920 --> 0:16:43.960 Spiral fifty fifty project. These were subscale test vehicles for 0:16:44.000 --> 0:16:48.600 this proposed spiral, so Bore one was a much smaller 0:16:48.840 --> 0:16:53.520 model Bore two boor three. They grew in size Bore four, 0:16:54.120 --> 0:16:57.520 the one that typically we we say qualifies as a 0:16:57.520 --> 0:17:02.200 space plane, was one half the scale of the proposed 0:17:02.280 --> 0:17:05.479 Spiral fifty fifty, but it was also an unmanned vehicle 0:17:06.080 --> 0:17:10.080 and it was primarily meant to test the design the 0:17:10.080 --> 0:17:14.600 physical design of the spiral, making sure that the quality 0:17:14.600 --> 0:17:18.000 the the calculations they had made for lift and gliding 0:17:18.080 --> 0:17:22.440 and maneuverability would all make sense. And one Spiral fifty 0:17:22.480 --> 0:17:25.960 fifty got the axe Bore four was able to continue, 0:17:26.440 --> 0:17:29.919 but had kind of transitioned from being a test vehicle 0:17:29.960 --> 0:17:33.120 for the spiral to being a test vehicle to try 0:17:33.280 --> 0:17:36.520 different heat shield materials that would be used for a 0:17:36.560 --> 0:17:39.240 different Soviet project that I'll talk about in just a second. 0:17:40.040 --> 0:17:43.359 UH So, in a way, you could think of the 0:17:43.400 --> 0:17:48.160 Boar four as being similar to a previous uh project 0:17:48.200 --> 0:17:50.680 over the United States, one called Asset, which I talked 0:17:50.720 --> 0:17:53.440 about in the last episode, that was intended to test 0:17:53.480 --> 0:17:57.919 out heat shield materials for the Dinah Sore Experimental Vehicle, 0:17:58.160 --> 0:18:01.480 which ended up getting the AXE. In the US, the 0:18:01.520 --> 0:18:04.160 so Union built at least a few Bore four vehicles, 0:18:04.800 --> 0:18:06.359 and as far as we know, there were at least 0:18:06.480 --> 0:18:11.120 four test flights that took place between two and nine four, 0:18:11.520 --> 0:18:14.119 and the Boar four was sent up to space on 0:18:14.160 --> 0:18:17.800 a launch vehicle. They used different launch vehicles for each 0:18:17.840 --> 0:18:21.600 of the tests, and then essentially it was allowed to 0:18:21.680 --> 0:18:24.359 drop back to Earth and it would parachute down to 0:18:24.480 --> 0:18:26.800 land in the ocean and the Soviet Navy would recover 0:18:27.000 --> 0:18:30.439 the vehicles. Uh. A reason why I use a lot 0:18:30.520 --> 0:18:33.840 of supposedly's and as far as we knows, it's because 0:18:34.480 --> 0:18:40.399 the SOI Union was notoriously secretive. They did not want 0:18:40.560 --> 0:18:42.680 the rest of the world to necessarily know what they 0:18:42.720 --> 0:18:46.040 were and were not capable of doing so. A lot 0:18:46.080 --> 0:18:49.200 of this information is stuff that came to light after 0:18:49.320 --> 0:18:53.160 the Soviet Union collapsed, but there's still tons of stuff 0:18:53.200 --> 0:18:56.040 we just don't know all the answers to Anyway. While 0:18:56.080 --> 0:18:58.639 the Boar four was originally part of Spiral, the lessons 0:18:58.680 --> 0:19:01.200 learned from that project but instead had informed the design 0:19:01.359 --> 0:19:05.240 of a different Soviet space plane called the Buron Uh. 0:19:05.240 --> 0:19:09.760 It was also the catalyst for a design of a 0:19:09.960 --> 0:19:13.000 US space plane, the Boar four that is, but more 0:19:13.040 --> 0:19:16.280 on that in a bit. So. Buron is a Russian 0:19:16.320 --> 0:19:19.360 word for blizzard or snowstorm, and one that I am 0:19:19.440 --> 0:19:22.679 sure I am mispronouncing, so my apologies. The Buron was 0:19:22.760 --> 0:19:26.399 essentially the Soviet Union's version of the Space Shuttle. It 0:19:26.400 --> 0:19:28.760 was originally intended to keep the Soviet Union in a 0:19:28.800 --> 0:19:31.800 competitive place with regard to the United States and space 0:19:31.840 --> 0:19:36.840 exploration and space exploitation. To be frank ironically, the cost 0:19:36.880 --> 0:19:39.480 of the program would actually help contribute to the collapse 0:19:39.600 --> 0:19:42.840 of the Soviet Union itself. So while it was meant 0:19:42.840 --> 0:19:46.080 to make sure the Soviet Union remained in a strong 0:19:46.119 --> 0:19:49.879 position worldwide. You could argue that it was one of 0:19:49.920 --> 0:19:53.720 the many factors that would lead to the Soviet Union 0:19:53.840 --> 0:19:56.920 dissolving in the nineteen seventies, While the United States was 0:19:56.960 --> 0:19:59.639 developing the space Shuttle program, the Soviet Union began to 0:19:59.680 --> 0:20:02.920 look into creating a similar program to maintain tactical parody 0:20:03.000 --> 0:20:06.080 with the US. There was a legitimate fear among Soviet 0:20:06.160 --> 0:20:08.359 leadership that the space Shuttle was going to be put 0:20:08.400 --> 0:20:11.960 to military use, which would put the Soviets at disadvantage, 0:20:12.119 --> 0:20:15.119 and the engineers in the Soviet space program studied the 0:20:15.160 --> 0:20:17.800 designs for the space Shuttle program, and they sort of 0:20:17.840 --> 0:20:20.520 began to pick and choose which components of the space 0:20:20.520 --> 0:20:24.400 Shuttle they thought were good in relation to the Soviet 0:20:24.480 --> 0:20:27.840 space program and which ones they should reject. So, for example, 0:20:28.000 --> 0:20:32.080 the Soviets had not developed a an enormous solid rocket 0:20:32.240 --> 0:20:35.240 booster that the Space Shuttle would be using. The in fact, 0:20:35.320 --> 0:20:38.000 Space Shell used two of them for liftoff, so the 0:20:38.000 --> 0:20:42.879 Buron space program would instead rely on liquid propellant boosters, 0:20:42.880 --> 0:20:47.040 not solid rocket fuel boosters. A Buran orbiter was launched 0:20:47.119 --> 0:20:52.840 on November. This was actually several years behind schedule, as 0:20:52.840 --> 0:20:56.640 the program was plagued with lots of problems, technological issues, 0:20:56.960 --> 0:21:00.840 funding problems, a lot of managements. That's a lot of 0:21:01.640 --> 0:21:05.280 Soviet politicians further up the chain who were arguing with 0:21:05.320 --> 0:21:09.600 one another as the years went by. This orbiter that 0:21:09.720 --> 0:21:12.560 launched had no crew aboard it. It was a completely 0:21:12.600 --> 0:21:18.400 autonomous flight. It flew to space, it returned, used automated systems, 0:21:18.600 --> 0:21:21.639 and actually landed under automatic control, making it the first 0:21:21.800 --> 0:21:26.520 space plane too go into space and return and land automatically. 0:21:26.920 --> 0:21:30.159 It was a successful test of this technology, but the 0:21:30.200 --> 0:21:34.359 cost of the program was incredible and the Soviet Union 0:21:34.440 --> 0:21:37.040 was crumbling, so after the collapse of the Soviet regime, 0:21:37.640 --> 0:21:40.679 the program languished. As far as I can tell, it 0:21:40.720 --> 0:21:44.840 was never officially canceled, largely because frankly, the government had 0:21:44.840 --> 0:21:48.959 bigger things to worry about having this this massive transition, 0:21:49.600 --> 0:21:54.480 but because there were no funds, the program essentially ceased 0:21:54.600 --> 0:21:58.520 to be without an official cancelation. Uh the orbiter was 0:21:58.720 --> 0:22:03.359 stored in a hangar, but that hangar would later collapse 0:22:03.560 --> 0:22:06.320 during a snowstorm and that would cause damage to the 0:22:06.359 --> 0:22:10.960 spacecraft inside. Meanwhile, as Buron was preparing to make history 0:22:11.040 --> 0:22:13.840 and its launch, there were engineers in the United Kingdom 0:22:14.080 --> 0:22:16.960 who were working on a different concept. This was a 0:22:17.000 --> 0:22:21.399 horizontal takeoff and landing vehicle called the Hotel h O 0:22:21.760 --> 0:22:27.240 t o L horizontal or take off landing. The rocket 0:22:27.280 --> 0:22:30.240 engine proposed for this vehicle was a special one called 0:22:30.280 --> 0:22:34.119 the Rolls Royce RB five four five air slash liquid 0:22:34.160 --> 0:22:39.240 hydrogen slash liquid oxygen rocket engine YEP. A Rolls Royce 0:22:39.280 --> 0:22:42.960 engine falls into the category of a single stage to 0:22:43.240 --> 0:22:47.080 orbit or s s O concept, so you would have 0:22:47.600 --> 0:22:50.359 this one instead of a multi stage rocket, you have 0:22:50.480 --> 0:22:55.520 this single stage method of getting this vehicle up into space. 0:22:56.160 --> 0:22:58.639 The concept placed the engine at the rear end of 0:22:58.640 --> 0:23:02.240 the vehicle, so think of like a a kind of 0:23:02.280 --> 0:23:05.880 a space shuttle looking design, and then blunt the back 0:23:06.040 --> 0:23:08.320 end and you know, you chopped the tail end of 0:23:08.320 --> 0:23:10.960 it off and you place an engine right there on 0:23:11.000 --> 0:23:14.240 the very back, and then the wings had to go 0:23:14.280 --> 0:23:16.199 in the back too, because that's where the engine was. 0:23:16.640 --> 0:23:19.639 And numerous calculations showed that they were going to have 0:23:19.680 --> 0:23:22.440 to make a lot of different adjustments because the way 0:23:22.480 --> 0:23:25.439 they had laid out the vehicle meant that its center 0:23:25.440 --> 0:23:27.919 of gravity was not where it needed to be in 0:23:28.040 --> 0:23:31.320 order for it to maintain efficient flight, so they had 0:23:31.320 --> 0:23:34.639 to keep making tweaks, which led to compromises when it 0:23:34.680 --> 0:23:37.040 came to the payload that the vehicle would be able 0:23:37.080 --> 0:23:39.560 to carry, and eventually that reached a point where it 0:23:39.600 --> 0:23:41.920 was clear that the concessions they were having to make 0:23:42.520 --> 0:23:46.280 would make this aircraft unfeasible for practical use because you 0:23:46.280 --> 0:23:48.800 wouldn't be able to carry enough stuff in it to 0:23:49.000 --> 0:23:52.040 make it worth the expense of launching it. So the 0:23:52.080 --> 0:23:56.320 project was ultimately defunded, but a company called Reaction Engines 0:23:56.520 --> 0:24:00.560 Limited resurrected that design to become the foundation for a 0:24:00.600 --> 0:24:06.000 new project called Skylawn. Skylawn is still in development, and 0:24:06.200 --> 0:24:09.160 assuming it ever becomes a reality, it will rely upon 0:24:09.160 --> 0:24:12.960 an air breathing rocket propulsion system called SABER, which stands 0:24:12.960 --> 0:24:16.879 for Synergetic air Breathing Rocket Engine. So I'll have to 0:24:16.880 --> 0:24:20.560 wait and see if that ever becomes a reality. There 0:24:20.600 --> 0:24:23.879 are people really working on it. The question is will 0:24:23.920 --> 0:24:29.359 there ever be a working aircraft before something else happens, 0:24:29.440 --> 0:24:32.440 like a project gets runs out of funding. In two 0:24:32.440 --> 0:24:35.440