Why don’t we use jets to boost rockets into orbit?
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- čas přidán 8. 02. 2024
- Can’t we build a better orbital launch system? Why aren’t we using more efficient air breathing engines in launch vehicles instead of thirsty rocket engines? Air launching a rocket is perhaps the most tantalizing concept.
#SpaceX #Rockets #RocketScience #NASA - Věda a technologie
Hear me out. 10 kilometer high trebuchet.
Wait… he has a point
Im listening
Don’t let Elon see this
@@t.p.7320after Mechazilla this should be easily accomplished 🤣
Check out project HARP for a 200t, 16 inch gun with a 119ft long barrel, that the Americans and Canadians used to shoot research payloads into space back in the 60's.
And while project HARP was canceled before it could fully devolp rocket assisted projectiles that could not just go to space, but reach orbit, spinlaunch is attempting something similar today.
In fact, Spinlaunches concept is even more similar to a trebuchet consisting of basically a 100m diameter slingshot that they spin up until the tip is moving at 2.1 km/s
A better explanation is; that 9/10 of a rocket's fuel is spent picking up enough horizontal speed to maintain an orbit, and only 1/10 is spent travelling up to space.
I think it is more like 50/50 at best. Air resistance is a female dog.
@@juliusfucik4011 It's only 70km (44 miles) to space. The ISS orbits at 8km/s (17900mph). It's easy to get to space, but hard to accelerate to a typical orbit velocity.
@@juliusfucik4011no, it's not 50/50. Do the math.
Travelling up to space is an exponential issue, though. Because the gravity's effect is constant, every instance of time not spent either on the ground or in orbit is the time that gravitational losses are adding up. As we move to heavier rockets, this becomes a big problem as we are now spending even more time flying.
So just comparing the distance to space and the (orbital) velocity needed is not good math.
If you really want to split it, then the ratio is approximately 1:5 for a common modern rocket. A fifth of the energy (dV) is spent fighting both gravity and air resistance. That is because doing the math right, you would compare a desired orbital velocity with the delta V (dV) needed to achieve it.
Yall out here not accounting for the rocket equation in your comments.
Tim, this has to be one of the best 1 min summaries of a full vid out there. Amazing video, we love all the work put into those. Deffo quality > quantity in this case. Take care!
Yeah the bro is right
The vast majority of the rocket fuel is spent to make it go FAST....not to lift it high.
The 900km/h you gain by dropping it from an airplane is nothing compared to the 28000km/h you need for low earth orbit.
There are air breathing jets that can travel up to Mach 3, though still not much compared to orbital speeds…
Then we need hypersonic!
@@kerbodynamicx472exactly. All these conversations are worthless. The math is very simple. spaceX is literally at the limit of physics when it comes to performance. You want better performance? You need a new engine, and a new fuel. Rotating detonation engines have good potential. They use a detonation instead of deflagration and theoretically can achieve 20% more efficiency. But until we have nuclear rockets or anti gravity, this is it.
For LEO the ratio of kinetic energy to potential energy is about 12 to 1. Just lifting a payload up into the sky doesn't come close to meeting orbital requirements. It's all about achieving an enormous *lateral* velocity, and jet engines offer no significant help in that respect. Also the thing they need to operate - oxygen - is only 20% of the atmosphere. The rest is just a drag.
Exactly.
900km/h means nothing when you need 28000km/h
The rest is just remass. High bypass turbofan, anyone?
And of course the correct way is to attach the jet engines as boosters and drop them when their effect becomes negative.
Fuel is like 3% of launch cost, I figured that out for Starship when I watched the full length version of this video. It's cheaper to make the fuel tanks a little bigger and add more fuel than to build and maintain a jet that can haul a rocket up to altitude. Elon's team figured out that logic extends to reuse, and added retro rocket landing, 1950's sci fi style.
Not just fuel, the entire booster can be much smaller. Minus the 70 tons of fuel it takes to get an F9 to 20 km, the booster tanks and airframe might be half of a ground launch. That’s real money.
My guess is the 2nd stage creates the problem. It must be 100% same diameter as ground launch for payload, same mass. Stacking that on top of a half size booster might be a mechanical problem, and a problem to hang off an aircraft.
Really? How is fuel such a small portion of launch cost when the entire rocket and engines are reusable for multiple missions. And even then, I'd figure that fuel is much more expensive, as you can't consider 'just' the cost of fuel, but also the cost of carrying that extra fuel. It terms of lost payload capacity. Otherwise, there wouldn't be such a massive drive to get single digit % fuel efficiency gains.
@@bayanzabihiyan7465 The push for fuel efficiency is to keep the weight to a minimum, so as to carry more payload, not to keep the cost of fuel down. Cost of fuel is typically much less than $1M for F9, vs $50-$200M for F9-size vehicle build cost, however many times booster reused.
In fact at some point with an imaginary really terrible fuel efficiency, vehicle could not get to orbit at all, no matter how much fuel onboard.
This is one major issue, but for small satellites this could be a practical system if only it were fully reusable with minimal refurbishment so that fuel efficiency is more considerable towards economic efficiency.
Jet engines and transonic airframes aren't that expensive to maintain at commercial scale, the issue is that a new launch aircraft needs to be developed and maintained that's large enough to throw a rocket with a worthwhile payload.
It's not begging to be built to fill any niche in the orbital launch market, but it could be competitive for small or medium size unitary payloads with difficult to reach orbits if it completely dominated that market to achieve a commercial economy of scale. The big advantage there is that the launch aircraft can go to any aerial launch window across the globe with some aerial refueling or a handful of orbital airstrips scattered around the world.
There's also the fact you have to reinforce a rocket to withstand being held sideways under a jet.
Like, how expensive would a skyscraper be if you also had to build it to be sideways too?
I really hate that part of shorts, where the ending leads into the beginning. I know Tim isn't doing it "on purpose", but it's the fact that CZcams is pushing it that I hate. "I just watched this, why are you making me watch it again?" It's really stupid IMO
I really hate that part of shorts, where the ending leads into the beginning. I know Tim isn't doing it "on purpose", but it's the fact that CZcams is pushing it that I really hate that part of shorts, where the ending leads into the beginning. I know Tim isn't doing it "on purpose", but it's the fact that CZcams is pushing it that I hate.
@@jeffmiller5428 Hey you make a good point
@@jeffmiller5428and that is why
Tim, this is amazing. Talk about putting as much info into a short as possible! Keep up the good work!
As he says, the problems outweigh the benefits.
Putting an airplane in the system adds a whole 'nother crew, vehicle, runway, hangar and fuel. Adapting the rocket to horizontal carriage is a weighty challenge. Switching the engines to remote start is a bit harder than ground launch. If the rocket explodes on the aircraft, the aircraft and crew will take damage. If the rocket fails to separate or if the launch is cancelled, the aircraft has to land with a wonky rocket hanging underneath.
Mostly, though, it just isn't a large-enough savings. Orbital altitude is roughly 200 kilometers up, while an airplane is doing real well to reach 10 kilom. The real snapper is orbital velocity, which is roughly 40 times as fast as an airplane.
An airplane may seem to be going high and fast, but it's just peanuts to space.
Why buy an airplane when you can just put more fuel in your rocket?
Virgin does this with the space plane.
It goes to space, but not to orbit.
I recommend basing a launch platform on heavy lift helicopter/blimps like the Piasecki PA-97 Helistat. Or, perhaps a blimp that is a delta wing that rotates a very large surface area. A few of these should be able to get a rocket up a few miles and reduce it's fuel use about 50%. All of that should allow for more payload or a lot less fuel.
Air launch's primary benefits are that 1) It's less prone to weather issues affecting launch windows 2) It could in theory be launched at any latitude to any inclination and 3) somewhat less ground supporting equipment.
It has its niche (on demand, emergency launches to odd orbits), just that the niche is too support to support a launch system as of now.
I still think there’s something to be said about launching fuel into space. Most of the fuel that’s needed in space is spent on the way into orbit, but over several launches we can build, stock, and man a space station, complete with complex equipment, computers, experiments, food, water, and backups of essential systems or supplies. My question, then, is in the interest of longer-distance space exploration; why are we not putting fuel tanks in orbit? Would there be any benefit, for example, to launching from earth, losing the boosters, then linking up with smaller boosters in orbit to facilitate acceleration towards far-flung destinations?
We hear quite often about how amazing it would be to visit other planets, other moons, or even other star systems. Accelerating to speeds that cut those trips to manageable times would be challenging enough, but that’s literally only half the battle. You’d still have to slow down again, meaning you’d have to turn your butt toward your destination and accelerate in the opposite direction. That seems awfully difficult to do if we have to expel a vast majority of fuel just getting past our own atmosphere.
the reason people won't do this is because any long-distance missions will use much more efficient fuels and engines (like ion thrusters, nuclear engines, solar sails, etc...) the reason we don't use them to get of earth is because they just don't produce enough thrust to lift a rocket off the ground. but once in orbit or deep space, thrust doesn't matter as much, and it is the efficiency that matters more. these type of engines use much less and lighter fuel, which wouldn't require huge tanks like other less efficient fuels would need.
@@hamzahkhan8952 That’s fair. Then again, most space travel so far for humans has been one of three options; into orbit and back, to the moon and back, or once around the moon. For unmanned crafts, it’s a majority of the travel has been relatively close-by in astronomical terms, and a great majority of those missions have been fly-by sightseeing. We had the chance to see Pluto because we accelerated a spacecraft fast enough to get there in ten years or so, but it flew by the planet (yes, I said it) very quickly, and kept on going under its own inertia. Had it been a manned mission, not only would they want to decrease the transit time significantly, but they’d also want to slow down enough to land safely on the surface, AND return home in the same fashion. Even a 10-year mission would require quite a lot of extra fuel compared to what a small probe requires; extra energy for speed, extra energy for slowing down, extra energy to avoid slingshot acceleration (radiation, gravity, and G forces around Jupiter, for example, pose their risks), and you’d need to account for all the extra mass compared to a conventional probe. Imagine sending the ISS on that mission, halving the travel time, AND expecting a round trip. Also, the probes we’ve sent have not only been guaranteed a one-way ticket, but they’ve been routinely given a great deal of leeway in terms of what counts as “success”. Our Mars landers might consider “success” to be a three-month trek, but have often lasted years, meaning scientists understand there’s a decent chance these machines will fail much sooner than they’re technically designed and equipped to. With occupants on board, those parameters need to be considerably narrowed, even if our astronauts understand there’s a strong possibility their venture won’t bring them home. That would mean extra food, extra water, extra oxygen, extra layers to the hull, extra equipment to make repairs, backups of everything (probably more than one), and extra fuel in cases of leaks or unforeseen problems that require extra time or detours. I understand that making it beyond our atmosphere is the hard part in conducting our space missions as they exist now, but if we’re ever going to travel longer distances (even sending probes to other systems), we may need to consider other options to give these ventures the best chances of success. For example, though it’s not very likely, it’s remotely possible we’ll one day be able to send a lander to a exoplanet. If, somehow, we were able to get out out there, it would have to be traveling very, very, very fast when it arrives in the general vicinity, but slow enough upon arrival to not end up a crater in an alien planet. That means turning around and burning a great deal of fuel to slow down, and we have never put enough fuel in orbit in a single launch to allow that to happen.
Just a few thoughts, which I’m sure are largely irrelevant at the moment anyway.
@@robertbeard230your thoughts are correct.
just one comment on the topic of travel to exo-planets: i think that, by the time humanity would be capable of travel to exoplanets, we should have extremely efficient fuels and engines capable of slowing down and accelerating spacecraft. travelling to exo-planets is atleast a century away, and by that time we would have unimaginable improvements in technology and sciene.
That's exactly what SpaceX Starship is planned to do on its lunar missions, IIRC.
First few launched Starships are just fuel tankers, which then refuel the lunar lander Starships in low Earth orbit.
@Adam-zt4cn pretty sure orbital refueling is not required for a moon mission, but that is how they're planning to get starship to Mars. and then refueling again on Mars to get back
It was good to see y’all out on Thursday
that loop was clean!
They also thought about an electromagnet rail gun but it’s huge because of the forces involved and power hungry too. Still needed chemical rockets anyway.
I propose we build a giant slingshot.
we can. they're called magnetic catapults but they need tracks/tunnels 600 miles long in order to have human survivable acceleration forces and exit points at 6-10km at least in order to not hit a wall of air.
i actually wondered this and now i know, thanks
The problem right now can be summed up in one word he used in his short:
BOEING
That's technically why the Falcon rockets have a reusable first stage that can return on their own.
also there seems to be a sweet spot (not sure if the calculations hold up) to having an engine that could do both aka ramjets
Here is an interesting thought….
You can also use a fighter jet engine as a booster.
E.g. a J58 engine produce around 100kN of thrust. A Merlin engine around 1000kN. But suppose that is ok you will install a large amount of J58 engines.
First you need less fuel, since the j58 use the atmosphere for oxidation.
But how long can you use these engines.
Imagine you have a a constant acceleration of 1g.
After 30s the rocket is flying at the speed of sound. Normally these engines can run at Mach 3 and more.
So the engines are useful for about 90s.
That mean you drop the booster stage.
It is a useful concept for smaller rockets. You can increase the payload drastically
okay, but, hear me out: a really big arm. you throw it. you throw the rocket like our ancestors taught us to throw rock. throw big rock real high, no come back down.
That’s the big push only at liftoff plan. Ballistics. Sure is easier if you can push the entire flight.
@@Nill757 partially! the truth of the matter, is that objects in motion will prefer to stay in motion, so you will expend far less fuel, and travel further, if you only need to keep going fast. Also The beginning of the flight is rife with aerodynamic and exhaust- related sonic dangers for any modern rocket, and by allowing it to leave the soupy lower atmosphere without having to contend with a high max Q (maximum dynamic pressure, AKA G-forces and aerodynamics), and less sound to shake it to bits, your designs can be simpler, lighter, and more reliable. As well, accelerating from a standstill is a MASSIVE waste of energy, but in the case of throwing things, at least that energy does not have to come from the object itself, further simplifying, miniaturizing, and therefore ruggedizing the rocket again, and leaving the complex, reusable bits that need maintenance on the ground where they belong. instead of an arm, though, I think I do prefer a maglev coaster. It can carry larger payloads, and you can brace it against a mountain to save material.
As the KSP doll in the thumbnail clearly suggests, you cannot launch jets vertically. They are simply too weak to get moving without an intake assist. That assist being _horizontal motion._
But but but isn't the weight/ size of rockets mostly for fuel for said rocket?
SABRE Engines, LET’S GO!
SWEET! Was always wondering that!
Who remembers “ moonraker “ .. launching a rocket from a plane can be bad .
Why not develop at space craft that has jet engines to take off and land but rocket engines to get into space.
When will you post the analysis of why don't they just use high performance jet engines for the first stage?
Think you meant to say “simply isn’t outweighed by the performance advantages.”
Being high is about the smallest part of being in orbit. It's far better to just go straight up to get OUT of the air that really doesn't help with anything- it only slows you down. Being FAST is the most important goal, as orbiting requires such high speed, a rocket gets you as fast as possible in the shortest time.
Excellent analysis.
Skylon would like a word with you....Allan Bond and Reaction Engines have actually solved this, it's an air breathing rocket using a very trick pre-cooler for the supersonic air intake, then finally switching to onboard LOX....
To bad we didn’t have a floating platform up that high
Large floating airship launch pad.
How about for the heat shield using another plasma, plasma against plasma? Only problem is generating that plasma in the front. Yeah, some kind of shielding agent micro bubbles or something that you could inject to shield it. It's a thought.
It's because we haven't been able to reverse engineer that part of the Transformers yet.
What about a system that starts horizontally on rails and uses a catapult system like aircraft carriers? I figure the rails would have an incline before release. We already have rocket sleds, maybe this would be effective for smaller missions.
Hypothetically, how big and what would the slingshot need to be made out of
So, the space for fuel saved by air launch would make the rocket considerably shorter than the Saturn rockets that were ground launched.
An example of the scale would be the space shuttle with its booster pods.
the rockets would be smaller for just a person size so it could be feasible still.
Alright.. why don’t we have a shipyard in LEO? How come we haven’t even tried using zero gravity to our advantage in ship construction?
We do. Some people like Richard Branson have working space jets, others use traditional rockets.
Actually, an airplane is meant to carry passengers, but this discussion would be better served if you reduced everything down to say that of a Tomahawk missile which utilizes a jet engine to lift it's payload up into the air.
You need a lot of power to escape the earths gravity. There’s no way a turbine engine can do that, especially with the payload amount.
How about a deep pit with a launch elevator powered by electric motors to do the initial boost? You can even charge the batteries/capacitors by first loading the rocket on the platform and then lowering it down while the motors work as generators.
Drilling a shaft down several times the length of the rocket sounds like an absolute nightmare. And then you have to rapidly accelerate 5000 tons
Is this the same reason why SSTOs aren’t a thing? Or is there some other reason for that?
not really. SSTOs are just big and heavy, so nearly all of it's mass is used to get the rocket into orbit.
if you are talking about SSTOs that use air-breathing engines and fly like a plane, then those would have the same issue that other air launched rockets would have: the vehicle would be heavier due to the structure needing to handle forces from multiple direction and needing to have multiple different types of engines.
Sexually Submissive Transvestite Organizations are definitely a thing....🤔😒
Tim is a smart guy. A little too wordy but he gets the job done. There is a better answer Tim but I don't just give that stuff away.
Love your content and aerospace questions mate...! A winged delivery vehicle needs to transit through WAY more atmosphere than a "traditional" vertical launch vehicle. That means more cost, fuel, time and software... Cheers mate. ! You are closer to launching on Starship...!
I always think, MASSIVE coiled up spring like push up off the ground. I’m talking MASSIVE!
Tim, maybe you have investigated the option of mixing a plasma engine with a portable nuclear reactor. Would that be more efficient?
Serious shade.
I'd assume the inertia of static launch would be huge. why not some form of stored energy system to give it a slight push or an extended fuel rail system that runs the engines for it to overcome the static inertia.
Lockheed-Martin uses this to launch all the military satellites and structures into orbit
Also most rockets only load fuel right before launch.
I think this will be the future and this will be next break through , only problem i see is this aircraft not design to lift rockets.
They did it in Superman Returns.
Goodbye Cosmic Girl. You were a good attempt.
Good luck lifting a starship with a plane
well .. maybe a new first stage with a ton of jet engines could work .. build like a octocopter or so ..
Thanks for making this video.
Lets ask the important question, why not put a rocket engine on a plane so fast go brrrr
What about a runway or rail based accelerator with an incline toward the end? I can’t be the only one who thinks achieving even a small amount of vertical thrust without stored fuel would be beneficial. Jets do it all the time. Too much weight?
Magnet rail at 45 angle, 1km tall.
Lunching speed 2000km/h
That has been a consept, I don't remember the name of the vehicle but hazegreyart made an animation of it.
Historically, you can look at project HARP, which shot research projectiles out of a 119ft long gun.
It was a joint US Canadian venture, and they actually managed to shoot a bunch of research payloads into space, but the project was canceled before they managed to stick a (working) rocket motor in the projectiles, that would actually take them to orbit.
Today, spinlaunch is trying to do something similar, but with a rotating tether inside a circular accelerator instead of a linearly accelerating gun system.
All those ideas have one thing in common: the gain from the new system is neglible to the total amount of accelleration you require.
Orbital speed is about 27000 km/h (16000 mph), orbital altitude is hundreds of km/miles.
It makes not sense to first accelerate to 1000 km/h or send the object to 10km height using some new system and then have the rocket do the remainder. The gain is just a few % and it adds complexity.
@@Rob2Exactly. You just said what I was about to say, but far better. The earth's escape velocity is a lot faster, than I think most people realize.
We need a scram jet
I keep thinking why not a electromagnetic sled that is a couple miles long like a roller coster or train that gets the rocket going 400 mph before it shoots into the sky off the ramp at the end?
A thought that may work out is the wings are to small of turbine engines in space you would be pushing against nothing but the projection of turbulance should still exist.
Just build an orbital ring.
Use some rocket fuel from the rocket while it’s still connected to get the plane to a more realistic speed for launch!
How about a balloon launch. You could probably double the useful payload by getting above 99% of the air first.
Forget it, air launching is rediculous have very limited launch weights. Just watch SpaceX and learn why thirsty rocket engines are the only option.
why is this even a question, this should be a no brainer to everyone
You are talking about Skylon
The chip on Branson's shoulder should stick to recoushining wheelchairs and leave the advanced fields to achievers
Most of the fuel is used to get the spacecraft up to orbital speed. Getting it off the ground isn’t the hard part
Im sure we will make a jet/rocket mix engine that has the thrust of a rocket but the efficiency of a jet engine
I'm fairly certain that's called a ram or scram engine. Problem is you have to be going super Sonic for those to work
I know one of the dudes who worked on White Knight. Interesting to see some of these ideas flushed out
A better solution would be torpedo method. We could shoot the rocket to a certain altitude, then start the rocket engine to pick up the pace...
Which means you're either strapping another rocket onto the rocket, or you want to rapidly accelerate 5000 tons using ground based systems
@@kapperbeastYT "Shoot it" like a gun or a catapult... Yeah, we can catapult 5000 tons, we know the science needed to do it...
I think all you gotta look at is the average thrust of a Jet engine (top out around ~130Klb of thrust for large turbofans and ~45Klbs for jet engines) meanwhile a single raptor just hit 269Klbs of thrust. And the super heavy booster has 33 of them... Air breathing engines just cannot compete here, it's compressed athmosphere vs highly dense liquid O2 being fed at 300+bars of pressure.
It's not about height, it's about speed. A rocket needs to be going fast, at an angle more or less a tangent to the Earth, to stay in orbit. If you just went straight up, it'd just fall straight back down again. There's still almost 100% gravity affecting objects in orbit. It's just that they're moving forward fast enough that, as they fall, they also move forward. Since the Earth is round, going forwards means the ground under you is further away, so you're effectively going "upward", away from the surface.
It's like chucking a ball at an upward-forward angle, it forms a parabola that falls back down to the ground. If you could throw it fast enough, by the time it fell back down, the ground wouldn't be under it any more and it would keep falling, round and round, in orbit.
The reason stuff seems to float about in space isn't, at all, zero G. It's because the spaceship, the astronauts, and all the items inside the spaceship are falling *at the same rate.* Like being in an elevator plummetting down the shaft. Everything would appear to float then, too. And the equivalent of moving out the way of the ground before you hit the bottom.
If most of the fuel is spent during the beginning of the launch why don't they use a linear induction rampto mitigate that expenditure
Put a runway on top of a blimp.
So they might do it in the future.
Very good reason. And something you didn't say anything about is approval licensing. You have the capacity of an airport to use existing structure as a launch area anywhere in the world that has that structure whereas launching a vertical rocket. You have to create the infrastructure or go from an existing space port. As with creation of different systems to Succeeded a task you have options More options the better specially when you have difficulty launching vertically
No public airports allowed for carrying fueled rockets.
I like when i see people try out my stupid ksp inventions in real life
Where is the orange astronaut suit. ?
The British proves in WWII that aircraft could tow 10 times to load it could lift. Have an aircraft take off from the ground towing another spacecraft. I guess off the ground the spacecraft drops is auxiliary wings. Then it tows the spacecraft up to 10,020,000 ft somewhere in there The aircraft refuels
Why not just making a ssto spaceplane ( idea for a next video )
A rocket wouldn’t need to be so massive if its air launched.
Why don't we launch them from higher up? Why do we need to start at 0 meters instead of from the top of a 3000meter mountain
I’ve got you covered! - Why Don't They Launch Rockets From Mountains Or The Equator?
czcams.com/video/4m75t4x1V2o/video.html
Maybe 10km and 1000km/h isn't that much of the orbital energy
You dont need the whole rocket the higher you get..
Why can't one use a bunch of jet engines just like side boosters? These boosters could run for 1.5 to 2 minutes and lift the entire Falcon9-like rocket to the height about 10 km and speed around 1000 km/h. After that mission the jet booster(s) could detach and autonomously land at it's land pad(s) near launch site. Such technique could convert Falcon9 from 2-stage rocket to 2.5-stage one and substantially increase it's payload capabilities especially on GTO/GEO and beyond.
Virgin orbit tried it,
Like you said , it wasnt economical
We've never seen a purpose built system for it. And it's really difficult to find the balance between technology, engineering and finances.
Ten kilometers with 800km/h is simply not good enough. And even if we could add on both, the second stage has to be reusable in order to make sense, as it has far more work to do.
@@jantjarks7946 There is some talk about a space plane. It would take off with jet engines and a navy style catapult from the ground. As it increases altitude oxygen augmentation will help it to accelerate.
At a certain point rocket engines take over bring it to destination Leo.
For something like this to work it would have to be huge. Benefits though are passenger sit in horizontal position and they can land not in water but a space port runway. Really long runway.
or just use a bigger catapult like we do for satalites
A space elevator and an orbital ring. We can build a space elevator by using seawater to be the structural material to fill up and pressurize fabric tubes inside a light metal frame going 70 miles up.
We won't be able to launch from there, you'll have the same problems launching from a plane. That's where we start building 3 other space elevators equally distant from one another on earth. Preferably around the equator.
From the top of each elevator we can start building an orbital ring. The ring will be fixed, it won't have to move or orbit the Earth. We will have to eventually build sections of the ring in a stationary orbit above the equator, probably 3000 miles up(not the actual distance). At this altitude the sections will rotate at the same speed as the rotation of Earth. We lower the sections into positon via very strong nanocarbon tube cables and rcs thrusters. Assemble the rest of the ring at the same time run a conductive cable to the ring.
The sections will have permanent magnets built to accept the conductive cable. Put the cable into a counter orbit of Earth's rotation through the magnetized sections of the ring. The cable will do 2 things. First, it keeps the ring sections ridged and creates a massive amount of power. Also, at the rings, we will still be within the Earth's gravity so we could build whatever we want on this ring. Including a magnetic launching system that we send any manner of rocket assisted vehicles into space. We can use Earth's atmosphere to pressurize the occupied sections of the ring. We can also build elevator to the stations that lowered the sections of the ring into place as collection areas for asteroids and the such to refine metals and other elements we can get from space.
All of this that I described can assist us in launching low fuel rockets to acquire an endless supply of building materials.
The are people on youtube that can describe this in more accurate detail than I, Issac Arthur is my favorite. He's an astrophysicist that has a slue of different shows talking about anything space related you could think of. Have fun.
Interesting, I’ve also seen something about using the limitless vacuum of space for power generation.
Your math is faulty. Geostationary orbit is ~22,000 miles in altitude, not 3,000.
Why not use jet engines for the first stage, vertical lift off, and then use rocket engines on the second stage, when in thinner atmosphere?
The gain from reducing the starting mass of the PH by ~30% is not worth the cost of creating a carrier aircraft and a missile.
More than 2 times!