One I am curious about would be resupply/docking of any floater (heh) in the atmosphere.
Residual propellant (+ stored gas) inflation of a (repackable) ballute or lifting body envelope, which doubles as both the entry system and as lift balloon when in the atmosphere. Ascent stages are very light on return, so it doesn't take a huge lift envelope to keep it buoyant in the atmosphere. Ballutes are already being well investigated as reentry systems alone for Venus, as it makes for a much lighter-weight entry system than an aeroshell. One of the considerations as a successor to the Saturn V was called ROOST; a "buoyant" version of it proposed just that, an inflatable aeroshell that transitioned to become a buoyant lift envelope in the atmosphere, to allow for a gentle landing. To dock on Venus, the reentry stage would maneuver into position below the habitat, connect via an arm or tethered drone, reduce lift to make the line go taut, and then be winched in.
An alternative possibility is NTR (nuclear thermal) - particularly variants like NTTR, which have a compressor and thus can hover. The predicted payload fractions on NTTR are huge (~50% on Earth), and using it on Venus, there would be a lot less NIMBY objection. Plus it'd help break a path for use of NTR on Earth if it can be demonstrated safe there. On Venus, NTTR would be disadvantaged by using the Bosch reaction rather than H2/O2 combustion, but the delta-V requirements and gravity losses are lower.
Well there are two problems. One would be sulfuric acid content of the stratosphere. Above the troposphere, the sulfuric acid content is believed to be high enough to present problems.
The sulfuric acid is more of a resource than a problem, and it'd be easier to colonize Venus if the sulfuric acid was denser. It's actually pretty sparse - a couple to a couple dozen milligrams per cubic meter. Standards for breathing sulfuric acid on Earth for an 8-hour shift are between one and a couple milligrams per cubic meter, if that puts it into perspective. It's like a bad smog (or more accurately, vog) than being like a bath in sulfuric acid. There are many polymers with excellent sulfuric acid compatibility.
The reason sulfuric acid is a resource is, first off, it's not 100% sulfuric acid, so there's the water content that can first be dehydrated. After further heating, you decompose H2SO4 to SO3 + H2O. Further heating, plus catalysts, can also decompose SO3 to SO2 + O2. Alternatively you can use the SO3 as a scrubber conditioning agent to help capture more moisture from the atmosphere. There's also the sulfur-iodine cycle for the generation of hydrogen.
The second would be the thick cloud cover even at the stratosphere would block out 75% of the light meaning powering any station difficult that uses solar cells.
Not so, the sunlight in the middle cloud layer is rather earthlike (depending on your latitude). The cloud decks have absorbed only about a third of the light by the time it reaches the middle cloud layer at the equator (more toward the poles), and Venus's solar constant is higher than Earth's, so it roughly equals out. Except that light comes from all sides.
Solar power has even been shown to be possible to use at the surface, albeit with extremely low power density. But enough to run, say, a seismic or weather station.
It only has an induced magnetosphere, like Mars (although about twice as powerful). But it's big defense against radiation is the thickness of its atmosphere; radiation has to pass through a lot of mass to get to habitable areas. The radiation levels within Venus's middle cloud layer are perfectly acceptable without extra shielding.
Granted the atmosphere, in terms of pressure alone, will kill you
Not in the middle cloud layer. Actually it's just the opposite, the pressure / temperature relation in the middle cloud layer means somewhat low (but still acceptable) pressures at normal Earth temperatures. But it's still by far the most Earthlike place in the solar system outside of Earth.
The unfortunate thing for Venus is that people think only in terms of surfaces; if Venus's atmosphere had stopped at its middle cloud layer, nobody would be talking about Mars today. But because Venus's atmosphere is carbon dioxide, almost any common gas can be used as a lifting gas. Including nitrogen and oxygen - ordinary Earth air is a lifting gas, offering about half as much lift as helium does on Earth. Meaning you can actually live inside your lift envelope. And airship envelopes are not particularly heavy, despite their large sizes. Your entire habitat is this completely mobile, constantly exploring new ground, accessing the surface as needed with bellows and/or phase-change balloons.
however, if we can devise a runaway method for trapping some of those gases into a more solid form...we could have a new planet to play with in a relatively short period of time. So ask yourself, what reusable catalyst would we need to create to transform that atmosphere into something a little more human friendly?
Now you're talking about terraforming, which we're nowhere near doing for any planet (not Mars either - Mars's biggest problem is that isotopic ratios indicate that almost all of the planet's nitrogen has been lost to space). Carl Sagan famously, before Venus's conditions were known, proposed seeding Venus's clouds with phototrophs in order to sequester carbon and create an oxygenated atmosphere. He later changed his mind, saying that you'd end up with a huge deep layer of carbon and a dense, hot oxygen atmosphere, and the whole planetary surface would explode. Further dampers were put on the concept when it was pointed out that, depending on what assumptions you make, it'd take tens of thousands to millions of years to sequester regardless.
Many, many different proposals for terraforming Venus have been made over the years, but honestly I think Sagan had the right idea, for the wrong reason. Namely, because we've seen this situation before. Earth used to be a world with a CO2-rich atmosphere, no oxygen, ferric oxide on its surface (well, more accurately, Fe+2 ions in the oceans), etc. Did Earth explode once microbes developed photosynthesis? Of course not. As fast as they could produce oxygen, the iron oxidized to ferric oxyhydroxide to magnetite and hematite, laying down bands of iron oxides (interspersed with sequestered carbon), which we now know as the banded iron formations. There was no "thick layer of graphite" or "dense explosive oxygen atmosphere being made" on Earth, and there's all the less reason to expect it on Venus, because in Venus's hot, dense surface conditions the abundant ferric oxide (and other species) will be even more reactive. Oxygen will be consumed as fast as it's created, until you've exhausted all available surface ferric oxide, which will take quite a long time. Indeed, if you took some of the "atmospheric ejection" or "atmosphere freezing" terraforming proposals, you'd be faced with a problem when you actually started producing oxygen in Venus - you'd be fighting against the rusting of the planet.
The low levels of hydrogen are IMHO more challenging; I don't like most of the proposals for getting more
Enough with Mars. We cannot live on Mars. Ever. The difference in gravity and radiation will guarantee that. You can't fix biology and evolution. And don't say "live in caves" or "underground". Give us all a break.
It's really simple. Regulators mandate safety standards so that - in real world conditions - you don't have cars constantly falling out of the sky due to failures or running into buildings. Engineers determine the designs to meet those standards. If they can't, they don't get to sell it.
Tell that to someone whose brakes go out. And furthermore, broken helicopters don't just drop (helicopters being the closest analogy to a VTOL flying car). The props autorotate. I'd much rather be in a helicopter that's lost its engine than an airplane.
The maximum efficiency of a prop, in newtons per watt, is 1 / (v_wake + v_freestream), where velocity is in meters per second. The faster you're moving (the freestream velocity), the less thrust you get per watt. Which is why large props are more efficient (more air moved at a lower wake speed), particularly at low speeds, and same for high bypass jet engines.
Now, in terms of "energy per 100km" or "miles per unit energy", obviously a hover yields "infinite joules per 100km" and "0 miles per joule", because you're not going anywhere. But that's an entirely different situation than propulsive efficiency. If you want to start factoring in motion, then your cross section / drag coefficient / L:D ratio / altitude (and thus density) and so forth come into play, and the optimum speed comes down to a balance between a wide range of factors - the faster you go, the less time you spend flying, but your drag increases quadratically, and your prop efficiency drops (the rate of drop relative to the difference between the freestream and wake velocities). Airplanes maximize this balancing point by having extremely low drag coefficients (Cd), far less than cars tend to have.
And more to the point, "broken helicopters" (to pick the closest analogy to many flying car concepts) don't just "drop"; the props autorotate, braking the vehicle on descent.Check it out for yourself.
The assumption is that if flying cars were common, there would be vastly more locations. As they basically function like helicopters (in most conceptions - VTOL), they need only something equivalent to a helipad, not an airport. Which is much cheaper and smaller footprint than an airport.
To get to the point of allowing takeoff and landing from, say, a driveway, you'd have to have a long track record of excellent proven safety, and levels of noise reduction that current technology doesn't yet support. It's certainly conceivable in the future, but is anything but a first step for companies working on flying cars today.
I personally view flying cars as pretty much inevitable (although not around the corner) regardless of whether or not they're pursued directly at present. Namely because of delivery drones. Businesses are not going to stop pushing for them because there's such an economic case for them (not having to drive a big truck around city streets, pairing trucks with drones to not have to go down each sidestreet or stop at each location, etc), and they'll advance the technology as needed to get approval - starting small. But economics will continually push them toward making larger and larger models, and the technology to get approval for those. And eventually you'll have models large enough to carry people around, wherein the question will inherently arise, "Why, exactly, aren't they carrying people?"
So your concept is that something statistically likely to crash and injure people would be approved by regulators, rather than manufacturers being forced to prove reliability in real-world usage conditions before being granted approval?
1) Flying cars would be allowed to just take off and land wherever they want. 2) People would be manually piloting them.
I don't know where you're getting your concept of flying cars, but none of the flying car advocates I've ever heard from advocate for either of those things.
I don't want to think of what they would be like as pilots
Yes, because when people talk about flying cars, they totally mean manual piloting.
I don't even want to consider those traffic jams.
Um...
Waterfall Sr.: Our peace ring has 'em trapped like a tiger in a washing machine! [The engine of the Planet Express ship flares up.] Leela: Get ready! Protestor #1: Look out! Protestor #2: Hold on! Waterfall Sr.: Here they come! [The ship rises up from the middle of the peace ring and tows the tanker over the top of the protestors. It flies away.] Leela: When you were planning this peace ring, didn't you realise spaceships can move in three dimensions? Waterfall Sr.: No, I did not.
Is that what he really thinks when he sees a flying bus (aka airplane)? An anxious panic, "That thing's going to come off and guilotine me as it comes flying past!"?
Yes, let's take one vehicle in its fifth generation (not counting subrevisions), and ignore its track record with all of its earlier versions that led up to this point and all of their failures, and all of Lockheed and Boeings' other launch vehicles over time, with all of their failures. Lets also ignore that they're going to have to switch engines soon, to an engine with zero track record.
Payloads typically launch on schedule or within a few weeks..... Some payloads have been waiting literally years due to delays.
Let's totally ignore that Atlas V launches once per two months, while SpaceX launches once per month, and that almost all of the wait time was due to investigation backlog. When it comes to hitting launch windows, SpaceX has a higher average success rate than average than Atlas V
And lets entirely fail to mention the point that ULA charges nearly double what SpaceX does per kilogram. Or that SpaceX is doing everything while rapidly evolving its rocket, to the point that they've basically even switched propellants partway through (denisification radically changes their properties). And while at the same time running an aggressive recovery and refurbishment programme and developing a heavy lift vehicle, with a small fraction as much capital.
As if liquid boosters can't fail catastrophically? Check out SpaceX's last failure. Liquids are hardly immune to catastrophic failure.
And actually more to the point, you've got it backwards. The SRB failure on Challenger was slow, more like a blowtorch. The explosion was when it compromised the external tank (which, obviously, stored liquids).
Solid propellants aren't like explosives. More to the point, you have to keep them under pressure to get the sort of burn rate that is desired for a rocket.
Could you remind me how many people SpaceX has killed? Boeing and Lockheed have certainly killed people in the past.
If you're referring to the AMOS 6 ground failure, ignoring that part of the whole point of flying a stack unmanned as much as you can before you fly it manned is to shake out any problems, is that a manned mission would have almost certainly survived that. Unless the launch escape system failed, despite the drama, that was an eminently survivable. How do we know this? Because AMOS-6's hypergolic propellant tanks didn't ignite until the satellite hit the ground. AMOS-6 had the fairing as some extra protection, but on the other hand, the satellite itself isn't nearly as durable as a crew dragon.
The launch escape system ignites within milliseconds of a failure being detected and almost immediately reaches full thrust, accelerating away at 10gs. Here's a graphic of Dragon's abort test superimposed over the AMOS-6 failure. Things like this are the very reason that launch escape systems exist. NASA's last manned space vehicle lacked such a system entirely. And while their design for the Shuttle ultimately wasn't chosen, you know what? Lockheed's proposal didn't have one either. And it had a strong impact on influencing the final Shuttle design outcome.
SLS Block 1 is less than 10% higher payload to LEO than Falcon Heavy. Not a particularly meaningful difference. Don't confuse Block 1 with Block 2 (which will probably never fly; the current schedule doesn't call for it until 2029 - and that's not accounting for the current delays).
SpaceX and Blue Origin would not use solids, not because there's something wrong with solids per se, but because they're not "fuel and go", which makes them expensive to reuse - and SpaceX and Blue Origin are all about reuse.
A lack of experience with hydrolox surely factors into the picture for SpaceX and Blue Origin; they'd get significantly higher payload fractions by using a hydrolox upper stage. But they're willing to accept lower payloads in order to simplify their manufacture and ground infrastructure, and in particular because the need their propellants to be storable, and storing LH for long periods is a PITA. Storing methalox is quite difficult, but nothing compared to hydrolox.
Solids really aren't that bad when reusability isn't a concern. They're very high thrust, which is exactly what you want out of a booster, and they're structurally very simple. Their low impulse and high structural mass are not particularly important aspects for boosters. Reuse of solids however gains you very little, because there's so much work in refurbishing them.
That's not the reason you don't use it for a first stage. The disadvantages of hydrolox (which are numerous) are offset by its incredible specific impulse. But for a first stage, specific impulse doesn't matter that much, while thrust matters a lot. Thrust is in large part proportional to fuel density, as a turbopump sweeps out a fixed volume per rotation, so the denser the fuel, the more mass (and generally all else being equal, energy) it pumps per rotation.
Another aspect is that first stages are big, meaning that cost is more important than specific impulse. By contrast, when dealing with an upper stage, a small increase in mass has a huge increase in first stage size, and since first stages are so large and expensive, that's a big cost. So you generally want a higher ISP upper stage. With the caveat that "storability" requirements for engines that need to restart can shift the balance; because hydrogen is so deeply cryogenic it's difficult to store for protracted lengths of time. Also, the longer you plan to have a stage in usage without maintenance, the more you tend to favour simple propellants over high performing ones, particularly when you're dealing with small, light engines. So for example if you have an interplanetary probe you'll tend to favour a self-pressurizing hypergolic system so that you only have to rely on a couple valves working, even though self-pressurizing propellant tanks are heavier and hypergolics tend to be lower specific impulse. Engines that are smaller still are often monoprops for an even greater degree of simplicity.
Slashdot Mirror
Already been done :)
(But it's long since time for a followup, that was just a very simple, short-term pair of probes)
Residual propellant (+ stored gas) inflation of a (repackable) ballute or lifting body envelope, which doubles as both the entry system and as lift balloon when in the atmosphere. Ascent stages are very light on return, so it doesn't take a huge lift envelope to keep it buoyant in the atmosphere. Ballutes are already being well investigated as reentry systems alone for Venus, as it makes for a much lighter-weight entry system than an aeroshell. One of the considerations as a successor to the Saturn V was called ROOST; a "buoyant" version of it proposed just that, an inflatable aeroshell that transitioned to become a buoyant lift envelope in the atmosphere, to allow for a gentle landing. To dock on Venus, the reentry stage would maneuver into position below the habitat, connect via an arm or tethered drone, reduce lift to make the line go taut, and then be winched in.
An alternative possibility is NTR (nuclear thermal) - particularly variants like NTTR, which have a compressor and thus can hover. The predicted payload fractions on NTTR are huge (~50% on Earth), and using it on Venus, there would be a lot less NIMBY objection. Plus it'd help break a path for use of NTR on Earth if it can be demonstrated safe there. On Venus, NTTR would be disadvantaged by using the Bosch reaction rather than H2/O2 combustion, but the delta-V requirements and gravity losses are lower.
The sulfuric acid is more of a resource than a problem, and it'd be easier to colonize Venus if the sulfuric acid was denser. It's actually pretty sparse - a couple to a couple dozen milligrams per cubic meter. Standards for breathing sulfuric acid on Earth for an 8-hour shift are between one and a couple milligrams per cubic meter, if that puts it into perspective. It's like a bad smog (or more accurately, vog) than being like a bath in sulfuric acid. There are many polymers with excellent sulfuric acid compatibility.
The reason sulfuric acid is a resource is, first off, it's not 100% sulfuric acid, so there's the water content that can first be dehydrated. After further heating, you decompose H2SO4 to SO3 + H2O. Further heating, plus catalysts, can also decompose SO3 to SO2 + O2. Alternatively you can use the SO3 as a scrubber conditioning agent to help capture more moisture from the atmosphere. There's also the sulfur-iodine cycle for the generation of hydrogen.
Not so, the sunlight in the middle cloud layer is rather earthlike (depending on your latitude). The cloud decks have absorbed only about a third of the light by the time it reaches the middle cloud layer at the equator (more toward the poles), and Venus's solar constant is higher than Earth's, so it roughly equals out. Except that light comes from all sides.
Solar power has even been shown to be possible to use at the surface, albeit with extremely low power density. But enough to run, say, a seismic or weather station.
It only has an induced magnetosphere, like Mars (although about twice as powerful). But it's big defense against radiation is the thickness of its atmosphere; radiation has to pass through a lot of mass to get to habitable areas. The radiation levels within Venus's middle cloud layer are perfectly acceptable without extra shielding.
Not in the middle cloud layer. Actually it's just the opposite, the pressure / temperature relation in the middle cloud layer means somewhat low (but still acceptable) pressures at normal Earth temperatures. But it's still by far the most Earthlike place in the solar system outside of Earth.
The unfortunate thing for Venus is that people think only in terms of surfaces; if Venus's atmosphere had stopped at its middle cloud layer, nobody would be talking about Mars today. But because Venus's atmosphere is carbon dioxide, almost any common gas can be used as a lifting gas. Including nitrogen and oxygen - ordinary Earth air is a lifting gas, offering about half as much lift as helium does on Earth. Meaning you can actually live inside your lift envelope. And airship envelopes are not particularly heavy, despite their large sizes. Your entire habitat is this completely mobile, constantly exploring new ground, accessing the surface as needed with bellows and/or phase-change balloons.
Now you're talking about terraforming, which we're nowhere near doing for any planet (not Mars either - Mars's biggest problem is that isotopic ratios indicate that almost all of the planet's nitrogen has been lost to space). Carl Sagan famously, before Venus's conditions were known, proposed seeding Venus's clouds with phototrophs in order to sequester carbon and create an oxygenated atmosphere. He later changed his mind, saying that you'd end up with a huge deep layer of carbon and a dense, hot oxygen atmosphere, and the whole planetary surface would explode. Further dampers were put on the concept when it was pointed out that, depending on what assumptions you make, it'd take tens of thousands to millions of years to sequester regardless.
Many, many different proposals for terraforming Venus have been made over the years, but honestly I think Sagan had the right idea, for the wrong reason. Namely, because we've seen this situation before. Earth used to be a world with a CO2-rich atmosphere, no oxygen, ferric oxide on its surface (well, more accurately, Fe+2 ions in the oceans), etc. Did Earth explode once microbes developed photosynthesis? Of course not. As fast as they could produce oxygen, the iron oxidized to ferric oxyhydroxide to magnetite and hematite, laying down bands of iron oxides (interspersed with sequestered carbon), which we now know as the banded iron formations. There was no "thick layer of graphite" or "dense explosive oxygen atmosphere being made" on Earth, and there's all the less reason to expect it on Venus, because in Venus's hot, dense surface conditions the abundant ferric oxide (and other species) will be even more reactive. Oxygen will be consumed as fast as it's created, until you've exhausted all available surface ferric oxide, which will take quite a long time. Indeed, if you took some of the "atmospheric ejection" or "atmosphere freezing" terraforming proposals, you'd be faced with a problem when you actually started producing oxygen in Venus - you'd be fighting against the rusting of the planet.
The low levels of hydrogen are IMHO more challenging; I don't like most of the proposals for getting more
So, Venus's middle cloud layer, then?
And you don't see the solution to that?
It's really simple. Regulators mandate safety standards so that - in real world conditions - you don't have cars constantly falling out of the sky due to failures or running into buildings. Engineers determine the designs to meet those standards. If they can't, they don't get to sell it.
Tell that to someone whose brakes go out. And furthermore, broken helicopters don't just drop (helicopters being the closest analogy to a VTOL flying car). The props autorotate. I'd much rather be in a helicopter that's lost its engine than an airplane.
Congratulations, you have it entirely backwards.
The maximum efficiency of a prop, in newtons per watt, is 1 / (v_wake + v_freestream), where velocity is in meters per second. The faster you're moving (the freestream velocity), the less thrust you get per watt. Which is why large props are more efficient (more air moved at a lower wake speed), particularly at low speeds, and same for high bypass jet engines.
Now, in terms of "energy per 100km" or "miles per unit energy", obviously a hover yields "infinite joules per 100km" and "0 miles per joule", because you're not going anywhere. But that's an entirely different situation than propulsive efficiency. If you want to start factoring in motion, then your cross section / drag coefficient / L:D ratio / altitude (and thus density) and so forth come into play, and the optimum speed comes down to a balance between a wide range of factors - the faster you go, the less time you spend flying, but your drag increases quadratically, and your prop efficiency drops (the rate of drop relative to the difference between the freestream and wake velocities). Airplanes maximize this balancing point by having extremely low drag coefficients (Cd), far less than cars tend to have.
And more to the point, "broken helicopters" (to pick the closest analogy to many flying car concepts) don't just "drop"; the props autorotate, braking the vehicle on descent.Check it out for yourself.
Tell that to someone whose brakes go out while they're driving.
The assumption is that if flying cars were common, there would be vastly more locations. As they basically function like helicopters (in most conceptions - VTOL), they need only something equivalent to a helipad, not an airport. Which is much cheaper and smaller footprint than an airport.
To get to the point of allowing takeoff and landing from, say, a driveway, you'd have to have a long track record of excellent proven safety, and levels of noise reduction that current technology doesn't yet support. It's certainly conceivable in the future, but is anything but a first step for companies working on flying cars today.
I personally view flying cars as pretty much inevitable (although not around the corner) regardless of whether or not they're pursued directly at present. Namely because of delivery drones. Businesses are not going to stop pushing for them because there's such an economic case for them (not having to drive a big truck around city streets, pairing trucks with drones to not have to go down each sidestreet or stop at each location, etc), and they'll advance the technology as needed to get approval - starting small. But economics will continually push them toward making larger and larger models, and the technology to get approval for those. And eventually you'll have models large enough to carry people around, wherein the question will inherently arise, "Why, exactly, aren't they carrying people?"
So your concept is that something statistically likely to crash and injure people would be approved by regulators, rather than manufacturers being forced to prove reliability in real-world usage conditions before being granted approval?
The assumptions involved in your post:
1) Flying cars would be allowed to just take off and land wherever they want.
2) People would be manually piloting them.
I don't know where you're getting your concept of flying cars, but none of the flying car advocates I've ever heard from advocate for either of those things.
Yes, because when people talk about flying cars, they totally mean manual piloting.
Um...
Yes, because that would totally be approved by federal regulators, and there's no way to reduce aircraft noise.
Is that what he really thinks when he sees a flying bus (aka airplane)? An anxious panic, "That thing's going to come off and guilotine me as it comes flying past!"?
If so, I recommend therapy.
Yes, let's take one vehicle in its fifth generation (not counting subrevisions), and ignore its track record with all of its earlier versions that led up to this point and all of their failures, and all of Lockheed and Boeings' other launch vehicles over time, with all of their failures. Lets also ignore that they're going to have to switch engines soon, to an engine with zero track record.
Let's totally ignore that Atlas V launches once per two months, while SpaceX launches once per month, and that almost all of the wait time was due to investigation backlog. When it comes to hitting launch windows, SpaceX has a higher average success rate than average than Atlas V
And lets entirely fail to mention the point that ULA charges nearly double what SpaceX does per kilogram. Or that SpaceX is doing everything while rapidly evolving its rocket, to the point that they've basically even switched propellants partway through (denisification radically changes their properties). And while at the same time running an aggressive recovery and refurbishment programme and developing a heavy lift vehicle, with a small fraction as much capital.
As if liquid boosters can't fail catastrophically? Check out SpaceX's last failure. Liquids are hardly immune to catastrophic failure.
And actually more to the point, you've got it backwards. The SRB failure on Challenger was slow, more like a blowtorch. The explosion was when it compromised the external tank (which, obviously, stored liquids).
Solid propellants aren't like explosives. More to the point, you have to keep them under pressure to get the sort of burn rate that is desired for a rocket.
Could you remind me how many people SpaceX has killed? Boeing and Lockheed have certainly killed people in the past.
If you're referring to the AMOS 6 ground failure, ignoring that part of the whole point of flying a stack unmanned as much as you can before you fly it manned is to shake out any problems, is that a manned mission would have almost certainly survived that. Unless the launch escape system failed, despite the drama, that was an eminently survivable. How do we know this? Because AMOS-6's hypergolic propellant tanks didn't ignite until the satellite hit the ground. AMOS-6 had the fairing as some extra protection, but on the other hand, the satellite itself isn't nearly as durable as a crew dragon.
The launch escape system ignites within milliseconds of a failure being detected and almost immediately reaches full thrust, accelerating away at 10gs. Here's a graphic of Dragon's abort test superimposed over the AMOS-6 failure. Things like this are the very reason that launch escape systems exist. NASA's last manned space vehicle lacked such a system entirely. And while their design for the Shuttle ultimately wasn't chosen, you know what? Lockheed's proposal didn't have one either. And it had a strong impact on influencing the final Shuttle design outcome.
SLS Block 1 is less than 10% higher payload to LEO than Falcon Heavy. Not a particularly meaningful difference. Don't confuse Block 1 with Block 2 (which will probably never fly; the current schedule doesn't call for it until 2029 - and that's not accounting for the current delays).
New Glenn doesn't count as a hedge?
SpaceX and Blue Origin would not use solids, not because there's something wrong with solids per se, but because they're not "fuel and go", which makes them expensive to reuse - and SpaceX and Blue Origin are all about reuse.
A lack of experience with hydrolox surely factors into the picture for SpaceX and Blue Origin; they'd get significantly higher payload fractions by using a hydrolox upper stage. But they're willing to accept lower payloads in order to simplify their manufacture and ground infrastructure, and in particular because the need their propellants to be storable, and storing LH for long periods is a PITA. Storing methalox is quite difficult, but nothing compared to hydrolox.
Solids really aren't that bad when reusability isn't a concern. They're very high thrust, which is exactly what you want out of a booster, and they're structurally very simple. Their low impulse and high structural mass are not particularly important aspects for boosters. Reuse of solids however gains you very little, because there's so much work in refurbishing them.
That's not the reason you don't use it for a first stage. The disadvantages of hydrolox (which are numerous) are offset by its incredible specific impulse. But for a first stage, specific impulse doesn't matter that much, while thrust matters a lot. Thrust is in large part proportional to fuel density, as a turbopump sweeps out a fixed volume per rotation, so the denser the fuel, the more mass (and generally all else being equal, energy) it pumps per rotation.
Another aspect is that first stages are big, meaning that cost is more important than specific impulse. By contrast, when dealing with an upper stage, a small increase in mass has a huge increase in first stage size, and since first stages are so large and expensive, that's a big cost. So you generally want a higher ISP upper stage. With the caveat that "storability" requirements for engines that need to restart can shift the balance; because hydrogen is so deeply cryogenic it's difficult to store for protracted lengths of time. Also, the longer you plan to have a stage in usage without maintenance, the more you tend to favour simple propellants over high performing ones, particularly when you're dealing with small, light engines. So for example if you have an interplanetary probe you'll tend to favour a self-pressurizing hypergolic system so that you only have to rely on a couple valves working, even though self-pressurizing propellant tanks are heavier and hypergolics tend to be lower specific impulse. Engines that are smaller still are often monoprops for an even greater degree of simplicity.
They also built a freaking massive hangar, which is now a tropical theme park.
It's not just huge by building standards, it's huge even by hangar standards. By far the largest in the world.