But what if she goes from suck to blow?

It doesn't solve anything, just delays the problem. And it is going to be bigger when touching the solid surface. No parachute, no gradual stopping, just very rapid disassembly.

Wouldn’t we need the schwartz for that?

High speed terra firma@@TheBiggreenpig

You think you clever? Where do we get such big hoover to do the job?

What if the spacecraft is nuclear powered? Then you could break using less mass/fuel.

​@@HansMillingexplain. Nuclear power is just creating something very hot and radioactive. How would that be used to slow down a spacecraft.

@@CheradenZakalwe Nuclear rocket engines are a thing, And they are very efficient, at least when it comes to specific impulse, the few one tested (all on the ground), like NERVA archieved a specific impulse of more then 800s, thats double that of normal hydrogen rocket engine. Ofcourse they still use reaction mass (hydrogen), but the heat for expansion is provided by the nuclear reactor.

@@slome815did you know that the Chinese did experiment with using dense wood like oak as a heat shield and it did work. So, just to summarise some of the options for reentry: a nuclear engine, a lump of wood. I think the KISS principle favours the lump of wood.

I like how it airbrakes once then skips off the atmosphere like a stone and then plunges back down

And showed us that the starship is a. tough one

😂

What if your return somehow promoted vaccine hesitancy, would you consider staying out there to protect Granny?

Is it your granny or my granny?​@@dimitar297

I shared the idea of running refrigeration tubes through the epoxy that holds the tiles last week. Look what their doing now. Removing 18,000 tiles and epoxy. I expect they will probably follow a modified version of my suggestion. This would also resolve the oxygen freezing and shutting down engines by using oxygen for coolant.

@@JimmyRussell-zd5qo not sure if the added complexity and weight of the pipes makes it worth it. Maybe if we have refuelling on the moon, we can do a less complex more fail safe active cooling system, which can waste more fuel

And then speed up the video playback to 2x to get a 4x overall efficiency improvement.

@@privacyvalued4134 I can't compile all the information even on 0.5x speed

Ah, the TikTok ADHD technique.

@@nukesrus2663 is that a thing ??!!

​@@mindfornication4funnyes it's called the Subway Surfers technique

or in clear text, the weight of the fuel needed for slow descent is way higher then the weight we are able to decelerate by this method. Or to put it in some illustrative numbers, to use a slowed down re-entry of 50t module you need 75t of fuel, which means the module cant weight 50t since it has the fuel on board that is adding weight that at the end needs more fuel to slow down the module. (the numbers are strictly illustration, not any mathematical/physical equation)

This is a better answer than the “you can’t” Scott has in the video. Tell us what it costs. Obviously heat shields will be around for as long as we have chemical rockets. Maybe in some fictional future we’ll have fuel that doesn’t weigh as much. Note I said Fictional.

What if we give them a giant Ballon full of hydrogen just before reentry?

Just use an orbital Tug System. Its a space structure u dock at or connect to, that tug then de-orbits u by using its own propulsion to slow u down very quickly (so that you dont descend very far into atmosphere before coming to - say - mach 2), you then detach and descend on your own. (That solution I am not going into yet). The tug then accelerates itself back to orbit. You can argue the practicalities of that if you want, but you can't say its not possible. Its just an engineering problem not a physics problem.. Heck just look at a space elevator, no heat shields required there either.

Incidentally the reverse is also true. build smaller launch systems to get you to a very low earth orbit where the tug picks u up and then lifts you to a much higher orbit. Heck it could take u all the way to the moon, refuel your spacecraft and then de-orbit at the moon and release u a kilometer up so your tiny spacecraft could get the rest of the way. it then speeds back up and returns to earth carrying ships on a return trip.

Ah, that is what that is? I already wondered about that.

I just came from the bath room with the same effect.

The thrusters are scary sounding. Keeping the capsule right on the knife edge of catastrophe.

Amazing. Too bad it's fake. Space is fake and the Earth is flat. NASA lied to you. Sorry to tell you.

I knew his reasoning for why a winged design wouldn't work was flawed. Heating being a factor of speed and drag would means you don't need to dissipate as much heat should the speed be controlled.

That was an extremely raw simulator I guess considering the computing power at that time. I bet it didnt consider all the variables

Neil Armstrong flew the X15. Everyone who did was an engineer. I’d like a source for this story.

This is a very pragmatic way of doing things. It's good to try outsiders since they are not bound by any concepts. Sometimes experts get enslaved in their thinking. Ask the special forces.

@@chrisView So…the county should have me try to design the new bridge they’re going to build? I’m not an engineer, so I’m not “bound by any concepts.”

There is a full length video w/ ambient capsule sounds. It is mesmerizing. I'm surprised Scott didn't link to it. I can't.

um

I know the sounds in the background are the thrusters firing, but I like to think it's just Scott controlling it via keyboard while casually talking about reentry.

​@@logarhythmic6859it is lovely to think of it like a KSP video

i feel like he is the type of guy who would totally do that 🤣

Isn't it interesting that they don't seem to touch each other and instead partially deflate when they get too close to one another. I imagine those vents around the outer edge are forcing some air out to the sides to keep the parachutes apart but that's pure speculation on my part.

⁠@@tissuepaper9962I believe you’re right. The parachute system for soft touchdown after the terminal stages of atmospheric reentry is something I probably know the least about in terms of space hardware but, I believe those vents both around the edge and sometimes on the top do multiple things and one of them is to help provide stability as allowing some of the air through that parachute I believe helps to stabilize it by allowing for a less turbulent stream of air to flow through and this helps to keep the parachute inflated and the flowing air helps to keep it from oscillating violently, preventing the introduction of unnecessary structural stress into the lines and on the stitches of the parachute while being pulled down by the weight of the craft attached. I’m not 100% sure but, I believe that this at least part of their functions.

The inflatable heat shield idea led you to mention the idea of inflatable zeppelins. I kept waiting for you to go to inflatable wings on a space plane. Or, extremely large Kevlar parachutes. At the high altitudes, they could be ver thin and compact before deployment.

DONKEYSMELL

@@thinkingoutloud6741 The high altitude parachute doesn’t really work. There’s not enough air density to keep the parachute reliably inflated. Instead you have a “ballute”, with an enclosed volume and a ram-air scoop to pressurize it.

Easy to determine lift to drag ratio. Put the plane into level flight. You know what the fuel load is so you know the total mass of the aircraft. You also know what the trrust of the engines is because there will be known relationships between fuel consumption, rate ambient pressure, temperature and airspeed etc and thrust. Given that the lift must equal the current mass of the aircraft, lift to drag ratio is easily determined.

@@rogerphelps9939 theoretically you’re absolutely right, and aircraft manufacturers know all of this, but good luck finding those known relationships! I reckon the fuel burn curves of engines and the related thrust ones are among the best kept secrets in the industry, so we’ll have to rely on what the aircraft manufacturers say

Indeed. I am sure engine makers will tell airframe makers only as much as is strictly necessary.@@soffici1

It's called a sailplane

Glider, sailplane… different names for the same object In the USA there is the “soaring society of America”, in the UK the equivalenti is called “British gliding association”

yet someone can go into space and fall back to earth with a parachute.

@@Sticklebackthat someone was not in orbit. Being in space and being in orbit are indeed not the same.

given how much energy is avaliable, seems like an opportunity to use it. Thermo'electric or some high pressure turbine generator?

What about landing on a planet or moon with effectively no atmosphere like the earth's moon? Then you have no choice but to bring extra fuel for deceleration, right?

they aren't orbiting or were ever at a high speed@@Stickleback

I've had a few KSP re-entries like that. Come in too hot and need to spend a few orbits bouncing off the atmosphere while trying not to violently explode. Eventually the "water" has absorbed enough of the energy that the rock can land and sink to the bottom.

@@Knofbath I was thinking the same thing, so many close calls in that game!

More like shooting a bullet at a flat calm surface of water. At certain angles it’ll bounce off or it’ll penetrate.

@@longsleevethong1457 Both are awful analogies. Every contact with the atmo is slowing the craft and bringing it lower, it never really skips off anything.

@@Knofbath yeah the issue is that it works best in The Kerbal Space Program, as the Kerbals can go on living forever, without you having to consider caring for their basic needs. E.i. they won't die of starvation, oxygen or water running out or the spacecraft getting full of "Kerbal waste products". In real life going halfway back to the Moon, because you did not slow down enough the first time you entered the atmosphere, isn't really a doable thing.

Why don't they just install a really large parachute very high in the atmosphere during the skipping phase? With arbitrarily large area the parachute can fully stop the rocket to terminal velocity and radiate the heat away faster. It's essentially the same principle as this inflatable heat shield but parachutes are cheaper and simpler.

@@DominikPlaylists Cue the meme "HAHAHAHAHAHAHAH ........... Oh wait, ..you're serious? ........... HAHAHAHAHAHAHA."

Yes, this would be a great series/service!

people with these rejected ideas should try to figure it out for themselves.

@@briankale5977Damn dude, he’s just asking. Do you actually know the mathematical analysis required to shoot down that idea or just have an ego?

It was terrible. I understand reentry and why you can’t stop and then re enter, but I didn’t understand a word Scott said.

I think this footage (original with sound) was a first released to public (if I ain't mistaken).

I was blown away watching that!

Is there a version with telemetry displayed?

I came to comment the same, I've seen the video before and never even realised it was doing that; though now it seems obvious. Amazing indeed. Also the little flip manoeuvre it did too.

Totally agree. I thought the same thing. I’m also amazed that the capsule can be “steered”. Apparently the capsule is designed where the center of gravity is slightly offset. This causes the capsule to fall at a slight angle. By rotating it in the direction you want to move it you can steer. Amazing.

​@@TraderDan58 that is a pretty common thing with capsule desgins, still pretty cool

Numerical analysis

The Russians worked that out long ago: that's how they'd have brought back a lunar Soyuz. Several Zond probes demonstrated it.

What’s wrong with equations? The laws of Nature are written in the terms of math(s). Perhaps you do not like that because math is hard. Which is is. But noone promised you Nature chose to make things simple.

I like the equations because they help me understand what's going on especially contemplating the gliding scenario between space and aerodynamics. It makes sense that if you have enormous rockets burning tons of fuel to put a little payload into space and escape Earth, then that little payload must dissipate all that energy somehow to return to Earth.

@@brianjuelpedersen6389 , maybe OP wasn't suggesting "equations are bad" but rather they meant that Scott explained things so well, it was simple enough to understand wherein "utilizing equations" would've made it less understandable for the masses whose strong points are NOT "solving equations" because as you said "Math is hard." It's like the difference in hosting "a discussion with the general public" versus "a technical presentation for a body of professional peers."

Well I definitely missed those equations, I kinda got lost midway through the explanation without any visuals. I'm not saying it should be equations, but at least having some graphs or sketches would have helped a lot.

​@blackghost87 This is a video aimed at the laymen masses (such as myself) and thus of more value without equations. I understood what was being talked about throughout, and I'm not scientifically, or mathematically, minded *at all.* I'd posit that if you could understand the equations / graphs etc. underpinning what is described in the video, you can easily understand this video *without* them, as you are probably a lot more advanced mathematically / scientifically than the 'average joe'. I think this is, in essence, what the OP was getting at. The video described the reasoning for re-entry methods in an accessible manner that did *not* require complex maths to be shown (or rather maths that would be complex to an average person).

Scott has also presented this phenomenon very deeply. I was surprised of his explation: the shape is optimised for a pattern, where the hotest region is some centimeters (cm) from the spacecraft surface ! Not on the surface.

so if I take 1/2 mv2 = 3/2 kT, for mach 24 and O2, I get T = 86,000K ...so I think it's not the air temp, but the air speed. It has much more kinetic energy than thermal energy.

​@@DrDeuteronwhen two objects are travelling at different speeds, the interaction becomes heat. The energy has to go somewhere, and typically it becomes heat.

@@patreekotime4578 One of the things I notice as a lay-person (ie.. non-scientific but still technical person), is that when you have any kind of excess energy and you try to convert it to any other kind of energy you get a whole bunch of *Heat* in addition to your net result of energy in the final form you're working toward. I'm sure there are relevant laws and complex formulas (thermodynamics and physics) that can show this and predict and model this accurately. Just an observation from watching this and other videos on topics like this.

@@patreekotime4578 and what is the conversion between velocity and temperature? I mean how do you get from meters per second to kelvin?

Old anime were written by massive nerds, of course they were filled with good scifi! Recent stuff has gotten pretty terrible by comparison :/ You dont get these crazy high quality OVAs for example anymore.

Not only old Gundams, even modern Gundams are surprisingly good at the science and laws of physics once you get over big robots - and even big robots have proper inlore explanation. You also have to remember Gundams are the franchise that has multiple entries meant for different ages from little kids to adults.

⁠@@randomnickifyIt would be really interesting to learn that in-lore explanation for giant robot shaped war machines.

In the film 2010, the US-Soviet space ship uses a ballute as a speed brake as it slingshots through the upper atmosphere of Jupiter no

reentry heating was a serious plot point of one episode of the original show

Ps, I was all about it till they hit the water. Imagine a failure and survive space only to sink into the darkness and being killed by pressure or cold.

​@@erdngtn9942they float you know? Capsules? All the Apollo missions landed in the ocean...

I always wondered why nobody made a launch pad in the Andes. You save about 4 km of atmosphere and are at the equator so a launch eastwards will be most beneficial. Add to that the bulging and you can launch from the point furthest away from earth's center, the inactive volcano Chimborazo with about 2 km further out than Everest. You get less distance to space and less gravity to overcome.

*than Then is for sequence. Than is what you need for comparisons. ‘If it’s cheaper to A than B then be ready for C.’

Its not about gaining altitude. Its about getting enough speed to maintain orbit. Orbit is achieved when you fall back to earth at the same speed as the earth moves away from you. The ground moves away because you are flying sideways as you are falling. (to visualize this, draw a canon ball being shot from New York to Tokyo) You need to get to about 20,000 mph to reach low earth orbital speed. This is why there's little to be gained by Blimping a craft high up into the air first. Launching from the tip of Mt Everest will give you an extra 5 miles of radius relative to earths 4000 mile radius. The extra speed gained is a rounding error. Its far more effective to launch from closer to the equator

I think we will not have to add one as the rocket has at least three of them for inertial navigation.

I thought it displayed acceleration? That's basically the same thing right?

@@gottfriedheumesser1994 the rocket almost certainly has G sensores since they say they limit acceleration to 3G when carrying astronauts by throttling the engines.

@@HashtagBirdyy No they don't display acceleration. They only show altitude speed and time elapsed. I suppose if you wanted to do the math, you could figure it out, but for quick reference G rate display is what I meant.

@@ILikeDoritos456 No modern rocket or spacecraft can work without acceleration and rotation sensors regardless of whether manned or unmanned.

or it's just proprietary. but idk.

Coming back from the Moon unless you've got fuel to burn you're going to reenter at 11km/s-ish. From Mars it turns out it's not that much higher, iirc it's less than 13km/s. It's not the craft that matters, it's the trajectory.

​@tjthill Trajectory and especially Velocity that matters because the higher the Velocity the narrower the window of reentery and the more likely that the vessel will not survive reentry.

One thing missing is how stands the Dream Chaser space place for reentry. From what Scott said it should be less fiery than the capsule?

@@arthurzettel6618humans suck. Sure, we can send things out of our solar system, but so far, we’ve only ever returned craft as far as….the moon.

KSP does not correspond very well to reality. My son used to play with it a lot and the scaling factors were all wrong.

@@rogerphelps9939 That's why you need to install the Realism Overhaul and Real Solar System mods. There is a community of people trying to get close to reality.

​@@rogerphelps9939well kerbin is 1/8 the size of earth and atmosphere out to 70km. It's not meant to be like earth.

periApsis

@@daves6213 perryplatypus

Amazing

That's incredible! I did about 250 hours in a wooden/fabric ES-60 Boomerang back in the late 70's and it had a glide ratio of about 32:1. I gave up flying in 1979 but a 70:1 ration would be a dream!

-Modern High performance gliders are a dream, but you can get just as much fun out of an old Ka-8 with a L:D of 25:1. You are still alone in the air like a bird. @@BillysFingers

Diamant 18 has that L/D ratio, 60 has been achieved, with boundary layer suction near 80, I have the report by the University of Delft. Will send a copy to any one interested.

​@@arturoeugster7228 I am interested. How can I find that report?

JPAerospace is a leader in alternate ways to achieve orbit. Their design seems to be safer up and down as Scott seemed to suggest. G forces much reduced, and the orbital airship never has to land. That task is given to a more suitable and smaller craft when the Dark Sky Station is built.

Maybe it didn't go anywhere because you can't "drop" things from the ISS. They'll just end up orbiting with all the other space junk.

@@BrandyBalloon actually you can, the ISS is low enough there is a somewhat significant amount of atmospheric drag, so much it has to boost its orbit up on a regular basis

while at the same time securing the guinness world record for longest paper airplane flight (time and distance) for probably the rest of recorded history. very sneak, japan. very sneaky.

@@BrandyBalloon Nothing just stays in orbit forever, all those satellites still experience gravity and they will eventually fall back to earth. There are also varying distances of orbit and things closer to the Earth will of course come down sooner.

@watvannou It's not the gravity that will pull them down. Well, it will, because that's what gravity does, but it won't technically be gravity doing it. If they were high enough to be put of our atmosphere ENTIRELY, they'd essentially orbit forever, because they're going fast enough to counter Earth's gravity. That's how they orbit in the first place. No, it's the air resistance that will pull them down. Once they run out of any fuel on board used to boost their orbit and counter the drag from the extremely thin atmosphere in their orbit, the air resistance will eventually cause them to slow down enough to de-orbit. So no, it isn't gravity that will pull them down, it's the air resistance that will slow them enough that they can no longer counter gravity like they normally would.

Plus it was sped up...

Isn't there a design concept for a personal inflatable heat shield for one man escape pod. I saw it on vintage space. Its much easier to shed energy from 75kg of human going at 17500mph than 105 tons of space shuttle bricks. I just feel the deceleration may be too intense if you're very light.

@@dr_jaymz I think I've heard of that too. Talk about an extreme sport...

Holy moly! That’ll be one hell of a ride 😱. “You go first. I’ll watch”. 😂

@@dr_jaymz Not sure if we saw the same one or even if there was more than one but the one I saw was a giant mylar bag with individual cells on one side and several large cans of expanding foam, the idea being they filled the cells to form the parabola and then become the ablative layer for the Astronaut on the other side, which was clear and would look like a hopefully uncooked foam and cellophane packed cut of meat from the supermarket.

Orion is the first vehicle since Apollo that is capable of carrying humans to the moon and back. I agree that is a big deal. And it was done more efficiently and safer then was done with Apollo.

I might have the scale slightly wrong, but if the Earth was the size of a basketball, the safe re-entry corridor is the thickness of a piece of notebook paper.

@@teebob21Someone just watched Apollo 13, huh? They use that same analogy in the movie!

@@brookswoolson909 Well, it's been a hot minute since I watched that movie, but I also worked at NASA between 1989 and 2007. (Mars Global Surveyor, mainly)

@@teebob21 Very cool! I actually just rewatched Apollo 13 the other day, so that’s why it was top of mind. I bet this video is especially poignant for you because of MGS’s aerobraking technique?

I wonder if they've fixed the parachutes in KSP2 so they don't act like bosons and pile on top of each other.

😂😂😂

Now it’s just light pollution.

It's worse as it's not 1 ton but more like 50+ tons of fuel for 1 ton of payload. The Saturn V rocket burned 20 tons a SECOND for its first stage.

I guess you could refuel for reentry; especially if we start living in a world where many space craft are not designed to ever surface after they are launched like ISS.

and you'd still have to carry the goddamned heat shield in case your return rocket didn't light off right...

I have to correct him a little though: It IS possible to slow down on re-entry, we just don't have the technology for it yet. The 40's era rocket technology just doesn't cut it. Possibly in the future we will have more efficient sources of propulsion.

@@DrewReynolds We could just drag a fuel line to space. You know how a hose will extend out when you spin around with the hose in your hand? Just mega size that using earths rotation :P

Yyyeesssssss!

That's debatable.

Landing…fine, but no source of delta V for deceleration. :)

Or not thought of...yet.

It's certainly possible to use rockets to decelerate. I've done so multiple times (by accident) when I tremendously overbuilt my rockets on KSP 😂 Economical? Oh gods no. Possible? Definitely.

I would say it like this: Our (chemical rocket) tech is currently barely energetic enough able to have enough energy to get things into space, not to keep it there without using the magic of orbit paths and then get back on earth by using very little energy by using aero braking. When we have more energetic means (fusion, antimatter, Star Wars tech, etc.) then sure, one can spend the energy to slow down in space and come down as slowly as you want. Like in Star Wars, the ships are depicted as having very energetic propulsion systems and the ships are depicted as not orbiting planets, because they don’t need to.

@@GantryG I was curious about a video I watched earlier that talked about SpaceX and Nasa as well as Boeing. Supposedly they have built aircraft that may fly to satellite altitudes up to 350 miles. Is that still within an area that requires aero braking? Maybe they haven't tested them yet.

Here among other ksp players as Scott is one of us anyway there is also this way of adding not fuel but life support stuff because in ksp base game we can ignore it and we have the time speed up function so I avoid violent reentry by having some small wings on my return craft. (and it may take too much regular astronauts time) but in the game I would set my Periapsis inside the Kerbin atmosphere and I strife the atmosphere without heat shield to lower my Apoapsis by just a bit each pass and align the craft so that the small wings have maximum drag and at first I strife only the thinner atmosphere and carefully I go into the deeper parts of the atmosphere with more heating. And while at the Apoapsis I would raise my periapsis for minimum fuel mostly just monopropelant if I feel the heating is getting too much at that depth of the atmosphere where the periapsis is. And then when the orbit is getting circular I still try to keep it a bit eliptic to get some time to cool the craft. But I feel that mostly I almost don't burn at all so no heat shield. did not try with the life support mod. But hey It was just my aversion to my craft burning and it is just a game and my poor astronauts spent some time between the Mun and Kerbin. So do I say if the NASA astronauts took this idea seriously it would solve all problems? Well no but it may be another possible Variable to consider maybe one day it will come in handy for some mission. So technically you can avoid a lot if not all the burning during reentry at the cost of more time for the astronauts which may be absolutely too big a price to pay and totally useless in real life but it exists. If ksp did not make a huge miscalculation like leaving something out of the equation. And this idea came to me during early stages when one of my first attempt at a stable orbit did fail and I started to burn up but then suddenly the craft came out of the atmosphere because even thou I could not get my Apoapsis high enough in time I did get the peariapsis out of the atmospere on the other side so I found out against my intuition that once back in the atmospere does not mean forever back in the atmosphere. That is where the idea was born to gently reenter. Maybe someone can refute me let's have fun and try this for more refuting potential @Scott Manley

Just lie and tell them space elevators make it easier to blow up other places.

Assumingg we ever can figure out how to build a space elevator :/ We could totally do a station in geo synch. orbit though. Will we? Prob. not in the next 40 years unless its a private company cause NASA has a shoestring budget and everything they wanna do has to get the okay of our wonderful congress which never agrees on anything :/

You would still need fuel/propellant to dock with the port and elevator. The atmosphere basically is free propellant, so a bit wasteful not to use it. Maybe your argument is to dock a large spacecraft to a port in an orbit favourable to your incoming trajectory, then switch to a tiny vehicle which is much cheaper to take to the elevator, but you would still need tonnes of fuel to do either. So atmospheric breaking it is until we have warp drives...

space elevator for big planets like earth is just a pipe dream any civilization who can build a space elevator , is advanced enough to not need it.

The US just bombed the Nordstream 2 pipeline... So probably No space elevator anytime soon

To a point.

I recently started playing that. A miscalculation returning from the smaller moon meant I had to use up all the thrusters and push with the jetpacks just to get my orbit down to 65km, it still took dozens of passes to get back. The first few passes completely consumed the ablative part of the heat shield, whatever was left seems to have held up. Is the ablator just a placebo?

@@shanent5793 KSP1 parts are very tolerant to heat. To have a more realistic situation (and probably still not enough to be similar from a real Earth reentry), try to land on Eve.

I remember playing on Real Solar System and good lord, a few Km too low and you exploded, a few too high and you just shot through the atmosphere. Real difficult. I tried a winged reentry vehicle and it was really difficult to land too.

​@@shanent5793 for landing a single capsule on Kerbin, from orbit, essentially yes. If you want to bring home more than just the capsule or come straight in from an interplanetary trip, whether on Kerbin or somewhere else, that's when you're more likely to need the ablation.

Thats why when i do anything flying in rss i use A LOT of parachutes​ @@OsirusHandle

Heck, wooden heat shields have been used. These are however only useful as a single use item obviously.

Huh, I heard they used aerogel or something. TLI.

@@OsirusHandle The shuttle used ceramic tiles which were fairly exotic.

@@placeholdername0000 Not significantly ablative AFAIR (or did they have ablative coatings?)

@@DavidEsp1 True, they weren't meant to ablate.

Just one slight issue: we don't have enough handwavium to make reactionless thrusters capable of lifting a significant payload into orbit.

@@Runiat "Handwavium". I gotta remember that!!

you mean like a space elevator ?

@@tma2001 Yeah, that's a good example of "handwavium". The only place a space elevator works is at geo-stationary orbit.

@@tma2001 Space elevator is another one of those stupid invention ideas that by the time material science has developed to the state that it can be done, the whole issue with overcoming gravity will already be solved using solid state mechanics..

Problem with gliders is you would have to descend way earlier in order to get where you wanted, and you'd have a big chance of overshooting or undershooting the landing by a lot. You obviously need spacecraft to come down somewhere remote and safe, while also being specific. There's also the cost of recovering the craft...the more you're off course, the higher the cost, and not a trivial cost either. So heatshields just makes everything simpler and more predictable. These craft are also a lot heavier, because they need to be structurally strong for space, while maintaining an airtight atmosphere, and withstand things like flexing.

It's faster than that. What rifles do you know that fire at 2.75 km/s?

​@@sciencecompliance235it's probably a unit's confusion. 2.7 kilo-feet per second (worst unit ever) is pretty reasonable for rifle rounds.

I'm probably alone on this island, but I found *_"2 0 1 0"_* to be a *much* better and more interesting movie, than *_"2 0 0 1"_* was... Was a real shame they didn't make the third.

@@DUKE_of_RAMBLE They called it a "Ballute". There's a wikipedia article about the concept and it's actual applications.

@@rand0mn0 I'll assume quoting me was on accident... 😅

In theory certainly yes, in practice that would require a Lot of energy to push against it at such high energies and since you already have a plasma formed around the ship trying to use an electromagnetic tether could be a tad.. problematic shall we say. But yea if someone solved the engineering issues yes

The pushing is quite hard... We do it in fusion reactors (with huge magnets and induced currents and still barely manage to give it the desired ring shape) and Earth does deflect incoming charged particles with its magnetic field, but AFAIK there's no technology to take chaotically forming wildly varying masses of plasma that form near the front of our vehicle and ask them to take a step back.

Not a physicist. Plasma is positively charged. If you have some grid 1m ahead of the ship made from a heat resistant material, and charge it positively, would that not push against the plasma? And i dont think you need to control the plasma. Just push against the whole of the front wave. I presume the net effect would be decelerating...

Wouldn't that be like moving a conductor near a magnet? The magnet induces a current in the conductor and the electrical resistance causes drag. I think that would slow the plasma down which is less desirable than letting it quickly go around the spacecraft

*instead of messing with thousands of tiles which adds weight and complexity why not simply carry dry ice and heat it with the high reentry temperature so that it flows out thru nozzles at the FRONT at high pressure and encases the vehicle in cold CO2 gas for those few minutes of reentry? the cold co2 gas will act as a shield.*

Scary when you think about the kinetic energy in a crash involving a pickup truck at motorway speeds (0.02 kilometres per second)....then think about these capsules travelling at 11 kilometres per second.

@@YagiChanDan you’re right, this is why for me at least it’s so hard to wrap my head around it. The sole image of an object moving that fast is incredible considering that the fastest accelerating object I’ve seen is a top fuel dragster.