The front lights are connected by an illuminated strip that stretches across the base of the radiator
Cruise Control (ACC) Lane Departure Warning (LDW) Intelligent High Beam Control (IHBC) Blindspot Information
of the topic, we have readers that got it confused with the stability control system instead.
The system can take over steering, braking and acceleration of the new Tiguan at speeds of between 0
Amidst the launch of the Honda Connect, Honda Malaysia has also said that the long-awaited Honda City
The only system in the class to offer Low-Speed Follow function Automatically follows the flow of traffic
Ahead of the 2020 Proton X50’s launch tomorrow, Proton has been sharing a number of videos showcasing
Let’s take a look at the model and see how it stacks up, courtesy of these photos from Autohome.The
the Driving Experience Control switch.
The full specs of the Malaysian-spec Hyundai Kona have leaked out, giving us a good idea of what Hyundai
featuring a new Plasma Yellow Pearl colour, a new front end, and new feature called e-Active Shift Control
encapsulating these features: Pre-Collision Braking (PCB) Pre-Collision Warning (PCW) Pedal Misoperation Control
Control Lane Departure Alert Lane Tracing Assist Automatic High BeamPre-collision System is Toyota&rsquo
Comfortable third-row seatsCons Not as efficient as expected Dated-looking infotainment system Lacks adaptive
for the course with a 1.6-litre turbocharged 4-cylinder petrol engine pushing out 167 PS and 240 Nm of
Perodua has just opened bookings for the highly-anticipated 2021 Perodua D55L.While full specifications of
First of all, what is traction control?
In this article, we will detail the pros and cons of buying the W205 Mercedes-Benz C-Class.Pros of buying
of the upcoming all-new 2021 Isuzu D-Max.Earlier, Isuzu Malaysia mentioned that the all-new D-Max will
detect whether the driver’s hands are gripping the wheel, so it can’t be fooled when the adaptive
Honda Malaysia today previewed the new Honda Civic ahead of its official launch later this year.As this
the Honda HR-V as well as the upcoming Hyundai Kona.Price and variantsThe prices for all 4 variants of
the most impressive safety features would have to be adaptive headlights.
The eighth-generation Toyota Camry 2.5V raised a lot of eyebrows.
Pros Good ADAS suiteDynamic Radar Cruise Control in action.Since the Triton and Ranger also have active
needed some essential features which were missing in my swift like a reverse cam, rear defogger/wiper, cruise
the Proton X70 get: 6 airbags Traction Control Stability Control Auto Brake Hold Hill Hold Assist Hill
model have surfaced since then, including potential powertrains and prices.More recently, another piece of
TC Subaru Sdn Bhd, the exclusive distributor of Subaru vehicles in Malaysia is offering buyers of the
If you didnt already know, the Ativa boasts a lot of car for not a lot of money.
The Benefits and Drawbacks of Adaptive Cruise Control
Yes, but with reservations. On the plus side, my car is swift, silent and sexy. I love the big control screen and the speed-changing Adaptive Cruise Control, and watching the steering wheel move back and forth as the car steers itself is totally cool, like The Invisible Man is my chauffeur. It’s so quiet, I can sneak up on dogs in it. As updated programming comes available, it is downloaded to my car through my house’s wi-fi. But like everything else, it has drawbacks. For me, two big ones are price and range. My Model S is effective and comfortable, but I could have bought a REALLY luxurious gasoline car for way less than what I paid for The Aluminum Falcon. In fact, the Tesla cost more than the total price of every car I’ve owned previously. As for range, it’s not really a problem, as the longest trip I take regularly is within the battery pack’s range. However, my experience has been that the range figures advertised by Tesla are very optimistic; my car is supposed to have a max range of just over 300 miles, but I’ve never gotten more than about 265 with the battery charged all the way to 100%. The range figures are usually calculated by driving a perfectly-configured car in a lab or on a special track, rather than on the open highway. And according to my car’s range chart, you have to keep the car at 50–55MPH to get the max range. Very few Tesla drivers do this. Would I buy a Tesla again? Yes, but probably not another Model S, not at the price I paid for my current one. Now that the lower-priced Model 3 and Model X are available, I’d more likely get one of those instead. On the other hand, Tesla recently announced a much less expensive version of the Model S will soon be available, perhaps due to increased competition from other EV manufacturers. So maybe another supercar is in my future after all.
One of the most important reasons during early use of large electric ,motors ,, powered by diesel electric ,generators ,was RPM propeller control and efficiency when connected to a fixed pitch propeller. The ability to control the revolutions per minute of large single screw 30,000 tonne freighters in confined harbors was also beneficial. The drawback of early models was durability in salty atmospheric environments. Fast forward to today, the advantages and quality have quadrupled depending on the type of ship. Single Source power reduces complexity Can be easily designed / adapted to be redundant (more than one generator). Fuel efficiency Full computer / digital control Long life / smaller diesel engine required (lower cost to maintain) Generators used for all ship power requirements, not just propulsion including all hydraulics (if required, many hydraulic systems have been replaced with electric motors!), cargo handling cranes, air conditioning, etc. Reduced ship weight For Cruise Ships, the benefits are more space for passengers and significantly less noise, odors and vibrations created by large diesel engines that burn bunker oil. It is true, some newer cruise ship power systems have not been as durable as was expected or required. Some were simply overloaded while others have had serious defects that nobody found during Sea Trials. But there can be no doubt, hybrid diesel-electric propulsion, for almost any class of ship is more efficient when designed properly. The largest container ships in the world use it and has sailed millions of miles using this design. The ones currently under construction capable of carrying over 23,000 TEU's (230,000 tonnes) will all be hybrid diesel-electric or turbine / electric.
I have owned a 2015 Ford F150 since new. It has the 2.7L ecoboost V6, full size cab, Edit: 3.31 rear end, 36 gallon fuel tank, and dark blue metallic paint with more chrome than most desire. I have had ZERO major issues with it over the 77k miles ive had it. I absolutely love this truck. The modability using opesosouce apps like forscan is a major plus too. 0-60 mph takes place in 6.9 seconds on premium gas and it takes 21 seconds from dead stop to reach top speed limiter of 102 mph. Yet I average about 21mpg in occasional heavy traffic, city 50% split with rural highways. I can get 32+ mpg if I baby it at the correct speeds. When not using boost from turbos this engine is shockingly efficient, at 55mph its 33mpg to maintain speed, but at 75 it takes 1-3psi of boost to maintain speed and only gets 23mpg real time. Even at 23 mpg with the 36 gallon tank it has over a 750 mile driving range. I have driven 670 miles on a tank, it had 40 miles of range remaining according to trip computer with an average of 21 mpg on that trip. The tank fit 33.4 gallons when I filled it that time. The small turbo motor has a few drawbacks that are somewhat accounted for. It has auto start stop, which I dont know anyone who likes this system, but it is very seamless. It takes only 400 ms (under 1/2 second) for engine to restart, the time it takes to release brake and press gas pedal it is moving. It has low ac for about 1 1/2 minutes (depending on outside temps), and low heat for about 2 1/2 minutes while engine off. It has a few things that are engineered better to use this system. An AGM deep cycle battery, 200 amp alternator, heavy duty starter, electric auxiliary water and oil pumps to keep coolant and oil flowing even when off, and an oversized cooling system that also water cools the turbos with dual electric radiator fans. Negatively it has a large amount of plastic in important places like the oil pan, oil drain plug, oil filter housing, and lots of outer engine parts that do not hold pressure. The important and expensive parts are made out of advanced alloys, the engine block is iron graphite alloy. Edit: a few other things pointed out to me that are negative is the sound of the motor, yes it doesnt sound good. In fact the EcoBoosts in general sounds so bad that they play fake engine sounds over the interior speakers (actually true look it up). I turned this off, it actually sounds like a unholy combination between a Cummins and a vacuum sucking up rocks. Also they are super complex and are expensive to repair. The only issues I have had are a check engine light for emissions system P2450, its a TSB that apparently only occurs when under high throttle and set cruise control without letting go of throttle pedal, this apparently prevents the exhaust gas recirculation valve from opening back up, throwing a code. I can still recreate this on demand. Fully releasing pedal for one second after full throttle prevents it. Also my a/c system was undercharged from the factory, took 30 minutes to cool off before in 95 degree weather, now takes 5-10 minutes. You cannot use a very high flow air filter with auto start stop (like a drop in k&n), as this can cause the engine to not shut down correctly requiring a manual restart. Swapping to OEM filter fixed this issue. Handling with the lightweight body and very light motor is remarkable for a pickup truck. With my upgraded bilstein shocks and Michelin all season tires this truck can outhandle many normal passenger cars out there. Not to mention the ride quality with these upgrades is quite impressive. The adaptive electric power steering and sport mode for transmission make it remarkably high performing on road and fun to drive. Its the best handling vehicle I have ever driven, better even than the 2 corollas ive been behind the wheel of. I also have upgraded led head lights, I use Sealight S3 Source fan cooled units that are 4500 lumen per bulb. I used forscan to enable all lights at same time, so low, high beams and fog lights, all led and can be on at same time. Sealight s3 provides same lighing pattern as halogens but much brighter, so they DO NOT blind oncoming drivers (except for highbeams) if aimed correctly. I did have to aim them slightly, but still able to see speed limit signs reflecting over 2 miles away. The darker metallic paint option on these trucks are gorgeous, although the styling is a little odd its better than the current chevys. The fit and finish is much better than chevys but worse than new rams. Functionality is also lost to ram. Practicality of using it for truck things is lost to chevy, fords are good at specific tasks depending on how its equipped, whereas most chevys will perform well at pretty much everything, but loses different areas to different equipped trucks. Another issue ive had is poor fuel economy when towing, and its also too light to tow anything in any wind or poor roads. I got 12 mpg with about 1–1.5 cord of firewood on a trailer (trailer was 2200lbs dry, probably total 5000-6500lbs), it dropped the suspension over 4 inches with 800 pounds of tongue weight, and performed adequately but barely controlling this weight in crosswind. Had more than enough power however, never needed to exceed 3k rpms with this weight. However 1/3 cord of wood in the bed it handled very well. I thought I had pics of the wood in bed and on trailer but I cant find it, I will update if I do. fuel economy reads about 0.6 mpg high Edit: added LED lights
EDITOR'S PICK|,19,634 views| Dec 19, 2017, 8:11 am The Toyota Prius C Has Outlived Its Usefulness Sam Abuelsamid,Senior Contributor Autos A lifetime in the car business, first engineering, now communicating 2018 Toyota Prius C, despite the black plastic wheel arch extensions and faux skid plate front fascia, this is no way a crossover SAM ABUELSAMID Timing, as they say, is everything. If the right product comes to market at the wrong time, no matter how good or appropriate it might be, it’s likely to be doomed to failure. About a decade ago, Toyota was riding high on the popularity of the Prius, gas prices in the U.S. were on the rise and appeared set to stay there, and American car buyers were taking a fresh look at small cars. Toyota decided to leverage the strength of the Prius brand as a symbol of efficiency to build a whole family of related models, including the more affordable and compact Prius C. The addition of a battery and electric propulsion to a conventional internal combustion engine means that hybrids will always cost more upfront than traditional propulsion systems. The Prius C was meant to provide a more affordable entry into the world of efficient hybrid driving. Unfortunately for Toyota, the confluence of several factors severely damaged the demand for this smallest of Priuses. Within a couple of years of its late-2011 launch, the price of oil plummeted to under $50 a barrel, and it is projected to stay relatively low for the foreseeable future. Gallery: 2018 Toyota Prius C 14 images View gallery At the same time, conventional powertrains have gotten more efficient, and consumers have abandoned small cars in favor of crossover utility vehicles. It was a perfect storm of bad introduction timing. In 2015, the Prius C got a mild styling update that added some pseudo-utility elements like black plastic wheel arch extensions and a front fascia with what looks vaguely like a faux skid plate at the bottom. Frankly, despite these features, the Prius C looks even less like a crossover than the Chevrolet Bolt that is actually marketed as one. It’s not that the Prius C looks bad — it’s fine, and in the tangerine paint that covered mine, it even looked kind of fun. 2018 Toyota Prius C SAM ABUELSAMID The problem is that there are so many better options available as we head into 2018. The C is more compact than most of the other smaller cars currently available in the U.S., and the interior is not a great place to spend time. The king of small car packaging, the Honda Fit, offers 96 cubic feet of passenger space, compared with a mere 87 in the Prius. The Fit starts at $4,500 less than the $20,630 starting MSRP of the Prius, and even the top-end Fit EX-L undercuts that by more than $100. The “loaded” Prius C Four that I drove came to more than $26,400 including delivery. At that price point, which by the way is $2,000 more than the nicely equipped Civic that I bought earlier this year, the Toyota doesn’t actually offer much in the way of amenities. There is a single zone automatic climate control, and the front seats feature heaters, but they are strictly on/off, with no adjustability. Driver assist functionality is limited to forward collision warning with automatic emergency braking and lane departure warning. No radar adaptive cruise control is offered. 2018 Toyota Prius C SAM ABUELSAMID The audio system is pretty basic with Bluetooth streaming support, and Toyota has made it clear it has no plans to support Android Auto or Apple CarPlay even on its newer models with its latest Entune 3 infotainment systems. The Prius is dominated by hard plastic surfaces, and the seats are covered in less-than-top-grade vinyl. I can fit my 5-foot-10-inch frame behind the front seat set for myself, but just barely. At this price point, you can definitely find a lot of much more enticing driving environments. The Prius C is fuel efficient, and even during the cold week I drove it, it averaged 41 mpg. Its overall acceleration performance is decidedly meh. It can more or less get up to speed when merging onto a highway, but it won’t get your blood boiling. Ride quality is fine, but it understeers pretty aggressively and doesn’t really provide any feedback of note through the steering. If you want a Toyota hybrid, the conventional Prius is actually a much better option, with a starting price just $2,800 more than than that of the C. However, if the looks of the current Prius don’t do it for you, there are other more enticing options that offer better fuel economy and more car than this Prius C. 2018 Toyota Prius C SAM ABUELSAMID Hyundai offers the Ioniq Hybrid in a Prius-like form factor but far more conventional styling, and even the mid-grade SEL version offers more amenities at a delivered price about $800 less than the Prius C that I drove. If you want more of a crossover look, Kia offers the mechanically identical Niro at similar pricing, and both offer substantially more interior space and better handling and fuel efficiency. Time has marched on. The Prius C was the right idea for Toyota at the time it was conceived, but it has outlived its usefulness in the lineup and should be retired. Car buyers can get far more value and a better experience elsewhere. The author is a principal analyst on the Transportation team at ,Navigant Research,and co-host of the ,Wheel Bearings, podcast Sam Abuelsamid,Senior Contributor I’ve spent my entire adult life working in and around the automotive industry. After earning a mechanical engineering degree from GMI I spent the next 17 years working on…Read More Loading ... Also on Forbes Autos Mitsubishi Heavy IndustriesBrandVoice: Power Providers Need To Fill The Gaps In Power Generation. Here's How Flexible Aero-Derivative Gas Turbines Can Help. ENERGY,#PowerUp Getting Rid Of This Vehicle Fuel Economy Standard Is Actually A Great Way To Combat Climate Change © 2019 Forbes Media LLC. All Rights Reserved. AdChoices Privacy Statement Terms and Conditions Contact Us Jobs At Forbes Reprints & Permissions Forbes Press Room Advertise
The plesiosaurs stand no chance This is a plesiosaur. It looks dangerous and scary but it's actually an animal that feeds on bottom dwellers so it's not actually adapted to fighting. Also that long neck is a drawback as the megalodon can easily bite it and it will be game over Here are the plesiosaurs sizes The largest plesiosaur here is pliosaurus. It weighs approximately 19.2 tons. That's a lot of weight but it really doesn't compare to this That megalodon mouth is maybe 1.5 or maybe even 2 humans tall. Imagine how big this creature was. Its basically an oversized great white. And we all know that great whites are powerful and successful predators And in case your still not convinced take a look at this Even the smallest individuals of megalodon are twice the length of a great white. I can easily see the smallest individuals of megalodon weighing much much more then a pliosaurus The best thing the pliosaur could do is run but the problem is that great whites have lots of muscle That is a great whites muscles. Imagine a megalodon muscle A shark has two types of muscles to ensure movement: the red muscle and white muscle. The red muscle is used for “cruise control” or slow-muscle action and the white muscle is used for fast sudden bursts of speed. I'm sure megalodon has white muscle so I can easily see the megalodon being much faster then a pliosaur So basically here's the pliosaurs fate. It's doomed
I have been using the “E-pedal” in my 2018 Leaf for three months now and I like it. It means that I almost never touch the brake pedal. All the regular city driving is done with just the accelerator pedal and on the highways I don’t use any pedal thanks to the adaptive cruise control. Say that the range of the accelerator pedal is 0–100. Normally you have acceleration through the whole range, but when you activate the “E-pedal” 0–20 gives you 40%-0% brake, 20 is coasting and then 20–100 is acceleration. You only need to push the brake pedal if you want more than 40% brake force. The only drawback I have noticed is that when you need more than 40% brake force, it seems like the car is coasting and when you start pushing the brake pedal nothing happens until you are halfway through - since the car is already braking. One big advantage compared to an old car is that as soon as you start letting go of the accelerator, the car will begin to brake. There is no delay since you don’t have to move your foot to the brake pedal and start pushing it.
At this particular time in the transition to full EVs the range and charging are the two biggest drawbacks. Until charging posts are as common as gas pumps it will remain so. I drive a plug in hybrid and it seems the most logical and economic way to go at this time. I can drive on all EV about 35 miles on a full charge and in my situation this means there are often 8 or 10 days in a row where the ICE never comes on and even a full charge only takes 5 or 6 hours at night in my garage on a 120 Volt circuit for about 50 cents. When my ice does come on, my particular car gets a solid 50 to 53 mpg in hybrid mode and is good for about another 585 to 600 miles. My particular vehicle with a 6 speed dual clutch automatic transmission also has a driving charge mode and I have the option to recharge my drive battery pack to a full charge in about 55 minutes which is 2.5 times faster than at a level 2 charger, so it does give me a lot of options that no Tesla has for any price. I recently returned from a 6500 miles round trip to California and my fuel cost was just over $300 Canadian funds. My average fuel consumption was 62.5 mpg including the miles on all electric which were all totally free. At one stretch I travelled from Salina, Utah to Carson City, Nevada on US 50 which is 541 miles and there are no charging stations of any kind on that particular 541 miles so obviously no Tesla could drive that route at present. Also when I drive to the west coast, I like to put in 8 to 900 miles the 1st day so when I reach scenic areas I can take more time to enjoy the drive for the next 2 or 3 days and I doubt that many Tesla drivers can do 800 plus miles comfortably in one day. I have driven my stepson’s Tesla and his seats are simply not as comfortable as mine so this could affect an 800 mile day as well. I have also never noticed a Tesla drafting as I do behind a 70 mph truck or motor home with my radar adaptive cruise control but I suspect it is not because they can’t but rather an ego thing. Most of them on the highway appear to feel they must pass everything on their way to the next charge station. Something along the line of Cadillacs in the past going by everyone quickly as they hurried to the next gas station. I look forward in the next couple of years to buying something all electric with perhaps a 300 mile range but at this time I don’t see myself ever not having at least a plug in hybrid as well just for the convenience and ability to drive anywhere without planning. Next year I would like to drive to Alaska and the Yukon and I don’t think that is yet possible on all EV. There are many stretches of roads in the U S and Canada that have more than 250 to 300 miles of remote spots without chargers so as I said, only a plug in hybrid will totally serve a traveller like myself. Other than the above, the Tesla is a fine, (although overly expensive) car that has truly brought the concept of electric driving to the public’s attention. Tesla is simply another vehicle and like any vehicle now or in the past, you buy what fits your budget and driving requirements.
It's extremely unlikely that we'd be able to intercept a North Korean ballistic missile in the boost phase, and almost certainly this would not come from a naval vessel in international waters. Prepare for everything you might want to know about glorious Juche ballistic missile launches and belligerent imperialist Yankee missile defense: we're going for a ride! Warning: We need to do a little math, but I promise I’ll hide the bitter taste in the sweet, sweet sugar of some pretty awesome charts and graphs. A ballistic missile has three major phases: boost, midcourse, and terminal. The earlier you can engage and defeat a missile, the wider of a geographic footprint you can protect. Each of these phases offers unique challenges and obstacles for Ballistic Missile Defense (BMD) to overcome; some in ways that are simply not feasible with current technology and geopolitics. But, the main thing to note about the boost phase is that it is defined by the missile being in powered flight. This has an obvious benefit: a successful intercept in the boost phase guarantees that the missile will not impact its target (as it has not yet achieved its ballistic trajectory). That is a huge “win” that cannot be found in any other stage of the post-launch cycle. However, regardless of the stage, there are three criteria that must be met for a successful intercept: 1) The ability to detect the missile leaving the launcher, or shortly after. 2) The interceptor’s fly-out velocity is comparatively greater than the missile’s speed (when factoring for acceleration), and 3) the missile’s motion can be tracked by the interceptor. Put simply, this is “Detection, Kinematics, and Tracking.” A failure in any one of these three will result in a failed intercept. Let's work through a simulated launch timeline and where various intercepts might occur. But before we get to that, an (extended) note about rocket fuels. Boost Phase and Type of Fuel In the boost phase, the missile launches and proceeds in powered flight outside the atmosphere. The boost phase is relatively short, limited by the missile’s fuel supply, and what type of fuel it is using (liquid or solid). Liquid-fueled missiles (LFM's) make up the vast majority of North Korea's arsenal, especially their short range SCUD/Nodong missiles, as well as their older variants of medium and intercontinental missiles. Liquid fueling has some major advantages, the main being simplicity. LFMs create much lower internal pressure, meaning their casings can be made from a much wider variety of materials. Weight is absolutely critical to a ballistic missile, where the fuel for the boost phase can take up over half the missile's mass. Reducing weight directly equates to increasing range. Weight reduction is typically used by swapping out metal for things like carbon fiber or composite materials; LFM's essentially give significantly more leeway in this regard. However, they have SERIOUS downsides, making them somewhat difficult to use in combat. First, they have to be fueled. This can be dangerous -- especially when done horizontally in caves, as is North Korean current practice. Second, this fueling typically needs to happen at or near a launch site, and can sometimes take hours. North Korea's largest LFMs, such as the Taepodong series, would be required to sit very visibly on a launch pad for such a long time, they'd be inevitably destroyed before launch. This is much less of a problem for their smaller, road-launched missiles. Also, notably, LFMs have much lower initial thrust-to-weight ratios and longer boost phase flight times than their solid counterparts, making them vulnerable for a longer period of time. PGS-2 solid-fueled missile being launched from its canister. Solid Fueled Missiles (SFMs) are self-contained, with the solid fuel built into the missile casing itself. Due to the construction, the missile casing must be capable of withstanding significantly higher pressures. For a nation like North Korea, this typically means metal casings, with the requisite weight increase/range decrease. However, in August 2017, North Korea released footage of what is believed to be a wound filament composite missile casing. Most arms control analysts cite the ability to domestically produce this type of casing as the major obstacle to a modern SFM., , The timing on this lines up with recent test launches of North Korea's solid fueled PGS-1 and PGS-2 ballistic missiles. Now, why would you want solid fuel, if it's so much more finicky to produce into a usable missile? Well, for starters, you can launch them on the order of a few minutes, instead of potentially hours for a LFM. Because of this, SFMs are much more feasible for "road-mobile" launchers, which do not require a fixed launch site. Think about this for a second. North Korea can disperse these launchers throughout the country, hiding them until needed and then launching with only a few minutes of preparation from any field, forest clearing, highway, or lake shore. Then, they scatter and disperse. Consider also that "SCUD hunting" was abysmally unsuccessful in the Gulf War.... in a big open desert, in a far less hostile battlespace. Additionally, SFMs have a much quicker boost phase than their LFM counterparts, making them more difficult to detect and intercept for the purposes of this question. (The other drawback of SFMs is maintenance. SFMs are typically stored in a sealed canister until launch, which both protects them and potentially obscures problems. Additionally, North Korea's SFMs have a tendency to melt their launcher vehicles. Due to sanctions, NK does not have an irreplaceable supply of them.) OK, back to the launch timeline. Note: For the purposes of this timeline, I’m going to assume we’re dealing with a solid-fueled, multistage ICBM. Where there are important timeline deviations for a LFM I will note them. Launch Timeline: L+00:00:00 So, when the launch command is given, the missile's fuel is ignited (LFM or hot-launched SFM) or the missile is ejected from its casing (cold-launch SFM) and it begins to launch from its transporter (or launch pad. North Korea does not typically use silos the way we do.) Unless we are physically watching the launch site from either ground, aerial, or satellite surveillance, we will not have real-time notification of the launch. (We tend to time satellite overflights to the most historically likely launch windows). Depending on launch site, it is unlikely that aircraft flying outside NK airspace will be able to detect the launch. Specialized aircraft, such as certain members of the RC-135 family (e.g. the “Cobra Ball”) can, but are themselves vulnerable, and would need to be escorted....creating a provocation that is diplomatically unfeasible., , There is a possibility that some of the sensors on the F-35 could be used as an ersatz AEW platform, however that is likely some years off in the future. At this point, the missile is only a few hundred to a few thousand feet off the ground, climbing and accelerating. It is masked from naval and ground-based detection by the "radar horizon" until it reaches sufficient altitude. Unfortunately, every second of the boost phase, it is accelerating. L+00:00:30 The earliest reasonably possible detection of the launch will likely come around 30-45 seconds after launch. Keep in mind that at this point we have no clue where the missile is going — we can speculate based on launch site, general practice, rotation of the earth, etc, but we cannot derive much useful information from the missile’s trajectory yet while the engine is still burning. The main bit of data we can use at this point is “Which cardinal direction is it travelling?” A missile fired due north (Azimuth 360) is minimally impacted by the earth’s rotation - perhaps a 2–3% reduction in range from the theoretical ground maximum on a non-rotating Earth. However, the exact same missile fired 45 degrees west of north (Azimuth 315) will be significantly reduced in range — potentially as much as 20%. The reverse occurs with a missile fired easterly — the range is increased. This means we can rule out certain targets, based on the types of missiles known to be fired from a known location. For instance — and I’m going to deviate to Iran for a second, for ease of numbers — if Iran fired a notional 12,000 km range ballistic missile due west at Pensacola Naval Air Station, despite it being within a 12,000 km “great circle” range, the rotational effects of the Earth would actually require a 14,000 km capable missile. Yeah, I know. It’s a lot of math. But it’s important. Since the longest ground range needed determines the minimum energy trajectory for a given missile, a longer range with its lower flight path angle and altitude at boost termination as well as in midcourse flight, this range also determines the reach required for early intercept of an ICBM aimed at the United States. And herein lies the biggest problem with boost phase intercepts: range. Remember criteria #2? The interceptor’s fly-out speed must be great enough to catch a constantly accelerating missile? The farther away your interceptor launches from, the narrower your intercept window is. Sure, you can boost the interceptor’s speed or weight — to a point, and at great cost, and with tradeoffs in your kill probability. Hold this thought, we’ll come back to it later. Back to timeline. L+00:00:45 Around 15 seconds after detection is the earliest that our ballistic missile defense network would be capable of calculating, verifying, and confirming a firing solution. This is the earliest theoretical possible point that an interceptor could be fired, however, this does not account for delays and human reaction time. Most reasonable models assume a 30 second delay between firing solution and interceptor kill-vehicle fly-out. L+00:01:15 At 75 seconds, we are just now, in a realistic best-case scenario, launching the first interceptor kill-vehicle. So, let’s consider where the ICBM will be — and where it will be going — at 75 seconds from launch. For this purpose, we’re going to use a notional SM-III-based interceptor that has a 6 km/s flight speed and burns for 70 sec. Remember, we still don’t know where it’s going to hit. We don’t even know if it’s going to hit the U.S. (or Canada — as you will see, for the purposes of BMD there is often little difference). The exact time at which the ICBM enters thrust cut-off will dictate the approximate impact location. Even a difference of just a few seconds can mean the difference between a target of northern Alaska or San Diego. It may be easier to think of from a different angle: the red region is the ground range in which boost termination results in an impact on the U.S. or Canada (left is LFM, right is SFM). As you can see, the rocket’s engine is burning out roughly 550km, give or take a couple dozen, from the launch site. This is where you’re going to have to engage the missile, if you want a boost-phase intercept. L+00:02:30 This is the last chance to intercept (SFM) before it becomes kinematically impossible to do so during the boost phase. (For a LFM, this will be about 1.25 minutes later — LFMs are significantly easier to intercept in boost phase, which is one reason why the U.S. and Russia have moved away from them). L+ 00:03:00 Engine burn-out for a SFM. At this point, the boost phase is over, and for the purposes of this question, if a missile has not been intercepted yet, it’s a failure. (Again, add another approximately 1.25 minutes for a LFM) So — as you can see ,the window in which to intercept an incoming missile from North Korea is less than two minutes in the worst case scenario,, or roughly three for a liquid fueled missile. ,And if we wait to intercept until we’ve confirmed that the U.S./Canada are the target, we’re talking literally a matter of a few seconds engagement window. Let’s take a break from the timeline to look at what platforms can intercept in the boost phase, before we continue on with the rest of the launch timeline and get to non-boost phase intercept options. … OK, you good? That’s right. ,There are none., Let’s take a further look. Notice how ,every single entry, in Boost Phase is either “inactive, terminated, redirected” or “being considered”? Not one is either operational or in serious development. Further, none of them are ship-based ABM systems. SBI is space-based. ABL and ALHK are aerial platforms. KEI is a land-based system. It’s not until the Ascent Phase (which typically is considered as the early part of the Midcourse phase) that we can begin to engage with SM-3 IIB surface-to-air missiles, fired from naval platforms, assuming that the positioning, range, and kinematics even allow for a shot. This graph is important, but a bit tricky to read. The arc we’re concerned with is the top-most one, representing intercepts at the altitudes encountered by an ICBM. Notice how the SM3 Block IIA cannot engage until just over 400km altitude in the ascent. This is the minimum altitude at which it can kinematically defeat an in-flight ICBM on a typical “minimum-energy” trajectory (minimum energy in this context means “not lofted”, or “shortest flight time to target”). An ICBM with a longer maximum range, that could be fired from a lofted trajectory would have an even more narrow window of engagement, potentially such that even SM3 IIA’s would not be able to engage it until the terminal phase. Incidentally, this is why “more modern/advanced/higher number” is not necessarily better — the Block I SM-3’s can engage at lower altitudes (as low as ~100km altitude by some reports), making them valuable against short range missiles. Let’s compare with a three-stage solid-fueled ICBM comparable to the Russian Topol-M (North Korea has shown at #JucheFest2017 this year a missile that appears to be based on this design) — the ICBM will reach 25 miles altitude within the first 60 seconds of flight, 75 miles altitude within 120 seconds, 150 miles at 180 seconds, and will burn for just under 200 seconds total at which point it will have reached 175 nautical miles altitude. With a 70 second burn time on the SM-3, you can see why boost stage intercepts simply won’t work. Of course, that’s assuming we have SM3 Block II missiles in sufficient numbers in the first place. Before you immediately go to Wikipedia to complain to me that a Ticonderoga-class AEGIS cruiser has 122x vertical launch cells and can fire the SM3 Block II….. consider that we recently cut procurement on these missiles from 52 per year, to 35 per year (planned target of around 350 total missiles), and that each missile costs around $25 million. (Fun game: the next time you hear someone talk about “our depleted military” and you’re not sure they know exactly what that means, ask them how many missiles they think we have. Doesn’t matter what kind of missile…they’ll probably guess at least an order of magnitude too high.) Consider also that we only have around 33 BMD capable ships in the Navy, (two of which are now going to be out of service for some time due to collisions) and you begin to see the problem. Also, remember how our notional interceptor based on an SM-III Block IIA had a 6 km/s fly-out speed? That’s because it’s a notional future variant. The actual SM-II Block IIA is typically assumed to have a 4.5 km/s fly-out speed. OK, let’s take a brief look at the ,Midcourse Phase. GMD interceptor test-launching. During the Midcourse Phase, the missile is exo-atmospheric, and typically not in powered flight -- it is travelling on a ballistic trajectory. During this stage, the missile will orient itself to the location of its target, and at the appropriate point in the trajectory, will release the RV onto the target. The challenge in the midcourse phase is threefold. 1) The extremely high altitudes involved limit the types of missiles that can intercept, though thankfully the actual kinematics of midcourse interception are not particularly different than an Anti-Satellite (ASAT) launch and we’re pretty accurate with those (at speeds greater than that of an exo-atmospheric ICBM, no less). 2) Midcourse interceptors tend to look an awful lot like hostile ballistic missile launches to foreign early warning radar. Additionally, nearly any launch from the U.S. against a NK ballistic missile will cause the interceptor vehicles to fly on a trajectory that would cause them to overfly or land in Russia, if it fails to intercept. Russia, as I've written about on the Defense Quorum, does not have significant EW radar assets pointing at North Korea. (China is only just now beginning to start looking in that direction as well). It's entirely possible that Russia's first indication of a North Korean launch would be a U.S. missile launch appearing on their radar, with no context as to whether it is offensive or not. 3) During the midcourse phase, because it is exo-atmospheric and all objects travel on a similar ballistic trajectory regardless of mass, it is the phase where decoys and countermeasures are the most effective. This is called the “midcourse discrimination problem” — any midcourse interceptor must be able to discriminate between non-hostile junk (spent boost stages, debris, etc.) hostile countermeasures, and actual RVs. North Korea is believed to be nearing the point where it would be testing countermeasures -- in fact, today's (8/28/2017) launch overflying Japan is believed by experts to have been a possible attempt to bait the U.S. or Japan into an intercept attempt that would test NK's countermeasures, if deployed. With the extreme cost of interceptors (and the fact that the GMD is running something like 50% above what it should cost, due to dysfunction at the Missile Defense Agency and contractor/political shenanigans) this is not an insignificant problem. It’s easy for us to *hit* the target. It’s harder for us to know *which* target to hit with our hugely expensive and limited interceptors. A related issue is that our primary ground based interceptor (GBI), the GMD, is .....inadequate, to put it bluntly. It's track record is atrocious, and the military is on record as saying it is questionable whether it could even hit the simplest of ballistic missiles with any regularity. There is exactly zero urgency to fix this, while we spend enormous amounts of money chasing this failed system (and we'll never cancel the program, no matter how ineffective -- not in this nuclear risk climate). If you're not terrified at this point, I got nothing for you. The midcourse phase is by far the most important for intercept, in real-world terms, given the difficulties of boost-phase intercepts. It protects a large footprint, and intercepts during this time can adapt to changing conditions, malfunctions, or failures. However, if we’re unable to make an intercept successfully during midcourse, we have another chance. Though the ,terminal phase, is the final stage of a ballistic missile flight, it's actually the point where it is most vulnerable to interception. During the terminal phase, the re-entry vehicle(s) containing the nuclear warheads are streaking down to earth from extremely high (exoatmospheric) altitudes. A very basic ballistic missile will have a single warhead with no countermeasures and no maneuvering capability. It will simply hit whatever it's aimed at (or not) during the midcourse phase. North Korea's most accurate missile (also one of its smallest) is believed to be of this type. More advanced missiles will feature a Maneuverable Re-entry Vehicle (MaRV) -- North Korea is presumed to have this on at least one variant of their SCUD-based ballistic missiles, though its efficacy is questionable. A MaRV is typically used to evade interceptors, or make course corrections during re-entry. It's also capable of being used an an anti-ship missile role (though NK lacks the ISR assets to accurately use it in this fashion). Even more advanced missiles will have multiple warheads/re-entry vehicles per missile. This can come in the form of a MRV (Multiple Re-entry Vehicle -- basically a shotgun blast of multiple warheads at a single target) or a MIRV (Multiple Independently-Targeted Re-entry Vehicle -- each RV can independently target a different location, potentially dozens or hundreds of km away). North Korea is not believed to have either of these capabilities at this time. The number of warheads you're firing matters -- each warhead requires an interceptor vehicle (an interceptor in this case is a technical term for an "anti-missile") to kill it, and to guarantee a kill you will typically fire between 2-4 interceptors per launch. Interceptors are expensive, limited in number, can be slow to reload, and can easily be overwhelmed. It should also be noted that detection is very much not a problem during the terminal phase: the heat from re-entry will cause the RV to glow like a beacon on any sensors watching. There are countermeasures (typically “dummy” warheads) during this stage, but they tend to be less effective and easier to distinguish than during midcourse. During the terminal stage, we’ll be firing SM-2’s, SM-3’s, MEADS, THAAD, and PAC-3 missiles at various altitudes until the missile is successfully intercepted (or not.) Some brief notes on each follow. SM-3: Kinematically, these have roughly 50% of the burnout velocity of a GMD interceptor (lesser coverage footprint) and require more accurate target tracking for the kinetic kill vehicle to hit (due to more limited divert capability). SM-3’s are only useful in the earliest part of the terminal phase (or the latest part of the midcourse descent phase). Otherwise, we discuss its capabilities above. SM-2: These are used for endoatmospheric terminal defense against maneuvering missiles. Instead of a hit-to-kill, they have a blast-fragmentation warhead. However, it has the added advantage (along with the SM-3) of being a valuable part of the Navy’s air defense arsenal outside of the BMD mission — in other words, we’re going to be buying these anyway, regardless of what North Korea does. THAAD launch. The swirl is a maneuver used to burn off excess energy. THAAD: an acronym for Terminal High Altitude Area Defense system, it provides both endoatmospheric and exoatmospheric intercept capability, and mainly serves to fill the gap between SM-3 and PAC-3 intercept capability for point defense of small footprint targets. THAAD has notably had a much better success record than many of it’s counterparts — since 1999 (prior to production contract) it has not failed an operational test. Because of the weird place that THAAD occupies in a layered BMD network, it sometimes seems like neither fish nor fowl — not as long-legged as SM-3, but with a minimum engagement altitude significantly higher than PAC-3. However, due to the way engagement envelopes work, there are some places that basically ONLY can be reasonably defended by THAAD — portions of Turkey (against a notional Iranian short-range launch) most notably. THAAD is a hit-to-kill system. This is what THAAD sees. PAC-3: This is the Patriot Missile system, 3rd generation capability. Filling the final terminal air defense role, it defends a limited footprint area at low altitudes (for ballistic missile purposes, that is) against all air-breathing threats, ballistic missiles, and cruise missiles. MEADS: This is not really a thing as far as the U.S. and North Korea are concerned, but worth noting — it was intended to be a joint US, German and Italian replacement for the Patriot, Nike Hercules, and Hawk missile launchers. The Germans have actually chosen to adopt it to replace their Patriots (it’s unlikely the U.S. will do the same.) The main benefit is 360 degree coverage, and the ability to engage simultaneous incoming targets from opposite directions, allowing it an 8x larger footprint than PAC-3. Poland is potentially going to adopt it as well. Final Thoughts: If you take away nothing else from this massive pile of text, know these things: The U.S. relies on a multi-layered ballistic missile defense system; however none of it effectively relies on boost-phase intercepts, which are essentially infeasible for all practical purposes (with the exception of certain North Korean liquid fueled missiles, that would require extremely fortunate timing for our ships to be positioned to engage). Though the U.S. is by far the world leader in ballistic missile defense, we lack any significant capability to defeat a near-peer opponent’s missiles. We are barely capable of intercepting North Korea’s existing missiles, and even that is not a given, and would be grotesquely expensive. The solution *probably* lies in a more effective procurement of advanced SM-3 variants, extending AEGIS Ashore, improvements to the GMD system to make it not suck, an extended-range version of THAAD, backed by either an advanced replacement to PAC-3 or MEADS for point defense. Money spent on things like airborne lasers, space-based satellite kill vehicles, or ground-based boost-phase interceptors, is money completely wasted. You could teach entire classes on physics based on nothing more than the development, launching, and detonation of nuclear-tipped ICBMs. I wish my high school professor had gone down that route, rather than dry reading from decades old textbooks. We should bring back the Sprint missile, because it owns. (See below video) Thanks for sticking with me through this! If you liked this kind of analysis, ,please subscribe to my ,Patreon,, which helps defray the cost of access to the research used to write articles like this. I regularly write about national security, intelligence community, military, and diplomatic/foreign affairs topics both on my ,Patreon,, on twitter at ,They called him Leif, (@SWATJester), and here on Quora at my blog, ,Defense Quorum,, which is Quora’s premiere resource for national security news and analysis.
So, I assume we’re talking about Modern engineering Great War materials Great War technology Even using the same engines ,(~100 hp ,inline, or ,rotary engines,) ,and materials, (wood, canvas, ,electrical steel,, and ,duralumin,), ,modern engineering would presumably be able to make an aircraft much better performing than the aircraft of that time., The main reasons are experience and rapid testing methods. Back in the Great War days, in order to test the performance of an aircraft design, you had to either build the whole aircraft, or have modelers construct a scale model for wind testing—and ,wind tunnels, were few and far between. Now, we have several more tools to help us. The first is 3D printing. A detailed scale model of a new aircraft design can be printed in a few hours and referred to a wind tunnel for testing. The second is computer simulations. Problems that would then take hours (at least) of physical testing to find can be detected by importing a virtual model into a fluid simulation, typing a few numbers, and pressing play. ,I have a ,SWAG, (Scientific Wild-Ass Guess) that with modern engineering, ,drag, could be reduced to at least 50% of that in Great War aircraft, which, (as drag is proportional to the square of ,airspeed,) ,would lead to a maximum speed (1.414) times higher and a maximum range twice as high., Correct me if I’m off, though. For ammo… ,there’s, where things can get a little interesting., Now, the conventional armament of Great War aircraft was one low-caliber machine gun, typically fired through the propeller. Initially, they were not ,synchronized, with the propeller, meaning if you tried to shoot down another aircraft for too long, ,you shot yourself down., Some aircraft had metal plates on the propellers that deflected bullets, however ricocheting bullets ,aren’t exactly the safest thing to experience, either., This was fixed by the end of 1915. Later in the war, aircraft started being mounted with 2 machine guns. However, there was also an experiment to mount ,anti-air rockets, on aircraft to shoot down ,Zeppelins, and ,observation balloons,., They were called ,Le Prieur rockets, for their inventor ,Yves Le Prieur,. Filled with ,black powder,, made of cardboard, and stabilized by a wooden dowel, they were less advanced than ,even the ,Mysorean rockets, first used against the British 136 years before,, which at least used iron casings. They were most comparable to the primitive Chinese rockets developed in the 1200s CE. As such, ,they were a load of shit,. Without guidance, ,gyroscopic, ,spin stabilization,, or even ,fin stabilization, (which even many of those Chinese rockets had), their accuracy was truly abominable, with an effective range of only 115 meters. Their poor accuracy and low velocity made them kill exactly ,zero, Zeppelins during the War. Just look at those goofy, pathetic rockets! :rofl: Damn, I’ve been distracted too much with DeviantArt… But, there was someone working on a far better rocket, in the distant land of America—Doctor ,Robert H. Goddard,. “Wait!”,, you might say, ,“I thought he developed ,liquid rockets, in the 1920s, much after the Great War!”,. ,Yup. But his contributions to rocket science stretch back further, with his work on nozzles. To understand his developments, we need to know basic fluid dynamics first., ,The continuity equation states that assuming no ,turbulence,, no viscosity, no drag, and that ,cows are spherical,, the speed of a fluid is directly proportional to the cross-sectional area of the stream,. For example, if you have a stream of water moving at 10 m/s through a 1 cm^2 pipe and choke that pipe to 0.25 cm^2, to ensure constant volume flow the water will be moving at 40 m/s. However,, that only really applies for fluid flows below the fluid’s ,speed of sound,, when they typically follow ,incompressible flow,. ,After the speed of sound, nearly the opposite is true—the fluid speeds up as it ,expands,, as its own internal pressure pushes it outwards. Therefore, if you want a really high-speed fluid, you force it first through a converging pipe, then once the velocity reaches that of sound, you change course and have the pipe open up. ,This creates a ,De Laval (or converging-diverging) nozzle,, named for its inventor ,Gustaf de Laval, who designed it in the 1880s and intended for it to be used for ,steam turbines,. The principle of the De Laval Nozzle. For whatever reason, no one had applied this concept to rocketry, at least experimentally, until Goddard. Thus, previous rockets were extremely limited in the exhaust velocity they could achieve,, typically to below 600 meters per second. However, by September 1916, Goddard and his team achieved an exhaust velocity of 2,438 m/s, which corresponds to a ,specific impulse, of 248.6 seconds, a nearly modern value! Earlier in 1915, he proved that contrary to popular belief at the time, rockets not only functioned in a vacuum, but functioned ,even better, than in atmospheric pressure! Now, suppose that Goddard started seeking to publish his findings right after he got funding from the Smithsonian for his experiments in 1916, and Le Prieur came upon his articles., He responds by designing replacement fin-and-spin-stabilized rockets with steel casings, more efficient propellants, and most importantly the De Laval nozzle. Effectively, these would be analogous to the ,Loki, or Baby Sergeant rockets. Through experimental tests in Kerbal Space Program with the ,Realism Overhaul, suite of mods (,see what I said about computer simulations?,), I’ve determined that such rockets could reach velocities of up to 1 kilometer per second (,Mach, 3). These would be enough to penetrate a few more things than observation balloons, such as tanks. And by tanks I mean this: Yup. Those are M1 Abrams. These rockets would be an appropriate mass for modification into infantry anti-tank weapons. In fact, they were considered—the United States Army contacted Goddard for the development of such a weapon, and the first test took place on 1918–11–06… just 5 days prior to the ,Armistice,, when the work was cancelled. But if Le Prieur came up with the idea, or if the Great War lasted longer, there could have been a whole different story. Anti-air, ground-attack, and anti-tank rockets are fine, but ,due to their reliance on internally stored ,fuel, and ,oxidizer,, chemical rockets have inherently higher ,fuel consumption for the same thrust, compared to air-breathing engines., This means they are limited in endurance and thus range. ,“Now, sticking a propeller engine onto a rocket wouldn’t work! They’re way too slow! It’s not like there were any jet engines in the Great War, right?”,, you’re probably thinking. But again, that’s wrong. Between 1908 and 1913, a Frenchman named René Lorin developed the basis behind the workings of the ,ramjet, engine., A ramjet is unlike a typical ,turbojet,/,fan, engine in that it requires no moving parts—air flows in the inlet, is mixed with fuel in a combustion chamber, and the hot exhaust is expelled through a De Laval nozzle to produce thrust. There’s a problem, there… air ,flows, into the inlet. ,A ramjet cannot work at zero airspeed, and has abominable thrust and fuel consumption below about Mach 0.5, well above the speed of any Great War aircraft. So, he could not build one, not because one couldn’t be made, but because the conditions required for it to operate could not be created at the time., Except through one method—in 1915, ,Albert Fonó, of ,Austria-Hungary, proposed using a ,phosphorus,-fueled ramjet on an artillery shell to greatly extend its range. That was rejected. But with good rockets… now you have another method, and a far more convenient one at that. The principles behind the ramjet engine. ,(image source here.,) Rocket-ramjet missiles could be fired from any platform, and could travel for hundreds of kilometers at Mach 3 towards a landing site. Now, these probably couldn’t be what we would think of today as ,missiles,, as they would be unguided… ,or could they? Beginning in 1913, the United States Navy had a program to develop an “aerial torpedo”, (in modern parlance, a ,cruise missile,) with ,Elmer Sperry,, the developer of a ,gyroscopic stabilization system, for naval destroyers, and ,Peter Cooper Hewitt,, a pioneer in radio. ,This program developed the ,Hewitt-Sperry Automatic Airplane,, the very first device with an autopilot and ,inertial navigation system,., It had a stabilization gyroscope connected to servos on the ,flight control surfaces,, a ,barometric altimeter, to determine height, and a propeller gear counter to estimate distance. In the first test in September 1917, using the inertial system alone with Sperry himself on the aircraft to pilot the takeoff, the aircraft dropped a bag of sand 2 miles from the point it was supposed to drop it, after having traveled 30 miles. This accuracy is… abominable, but keep in mind that the takeoff and landing was manual, and the plane was laden with the extra weight and drag of a human for this test. The ,radio-control system, originally intended to be used on the aircraft was never used on it itself, but was tested in 1921 with successful results for ranges of 30, 60, and 90 miles (48.27, 96.54, and 144.81 kilometers). Hewitt-Sperry automatic airplane, ready for a test launch from a catapult. Vigorously tuning the inertial navigation system and combining it with the radio-control system for mid-course corrections (forming a radio-inertial guidance system), could probably (SWAG Alert) increase the accuracy of the drone to 1:225, meaning a ,circular error probable, of 704 feet (215 meters) from 30 miles (48.27 kilometers) range. ,Although not “good” by modern standards and poor for ,strategic bombing, or ,precision strikes,, they’d still be useful for terrorizing cities like the ,V2, did in real life. Also, in adapting the system for ramjet use, the propeller-gear distance sensor will have to be replaced with a ,pitot-static, speed sensor. This would be a fundamentally more accurate system, although a different ,odometer, system would have to be used. Although radios were bulky in the Great War era, they weren’t too heavy for installation on a cruise missile or drone,—in ,Halberstadt D.II aircrafts used for trials in radio communication, in late 1916 and early 1917, the radio system with battery and engine-powered generator massed 25–30 kg, with the radio itself massing 12.5–15 kg. So, yep, rockets and ramjet-powered cruise missiles could fall under “WW1 ammo”. “So, you can upscale this system to manned rocket-ramjet aircraft, rocket artillery, and ballistic missiles, right?”, ,Nope, not really., The reason is that the solid rocket motor technology of the time—in particular the propellant mixtures—made motors larger than ~100 kg impractical, and above ~600 kg effectively impossible. ,Read ,Grant Hartlage's answer to Why did Goddard think liquid fuel was better than solid for rockets? Did it allow higher speeds?, to find out about the drawbacks of solids at the time. Practical manned ,supersonic, ,flight, would have to wait for either: Better solid-propellant rocket technology (optimally combined with ramjets for higher specific impulse). Liquid-propellant rocket technology (optimally combined with ramjets for higher specific impulse). Turbojets. Note: Yes, I am developing an alternate history based on many of these elements.