I just always assumed to achieve higher speeds in the universe you needed to be smaller and more aerodynamic. The Lockheed Blackbird is the fastest fighter jet we have and it goes only 2000mph. This fighter jet seems like it would be more aerodynamic than a rocket ship.
What is special about the rocket ships that allow them to achieve 25,000mph without being disintegrated when leaving the atmosphere and achieving escape velocity to go into space?
Any help would be greatly appreciated.
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Airplanes are horizontal and designed to fly carrying things point to point EG LAX-LHR. Rockets are vertical and 90% of the mass of the rocket is to elevate the comparatively small load of 400KG to space. As the rocket increases in elevation there is less air resistance and so the aerodynamic shape matters less
In terms of the universe none of these vehicles are close to getting to 90% of the speed of light (269M m/s) Once you leave Earth’s atmosphere aerodynamic considerations are irrelevant.
By the time a rocket reaches those speeds, it’s above the atmosphere. The higher you go, the thinner the air gets, until you’re not in the air anymore.
Supersonic airplanes still need to be in the atmosphere. They require airflow over their wing/body in order to fly.
The biggest difference is between a Jet engine and a Rocket engine. A jet engine burns regular old aviation fuel (which is very similar to diesel fuel) combined with air it has to scoop from the atmosphere.
Rocket fuel ignites an explosive and requires no air input, they just contain that explosion and eject it out the nozzle. That can produce a lot more thrust than a jet, and without needing air can continue to provide that thrust once they have left the atmosphere. So most of the speed of space craft is gained once the air resistance of the atmosphere is negligible. Jet engines need the air so can never get to that point.
also you seem to have a misconception of what escape velocity is. You do not need to achieve escape velocity to leave the atmosphere. In fact the ISS is sitting there orbiting earth at well below escape velocity. escape velocity is the speed at which the strength of a bodies gravitational pull (earth in this case) is not sufficient to ever pull you back down. In the case of our solar system once you achieve earth escape velocity you’ll no longer be in orbit around earth and will instead get pulled into orbit around the sun.
The ISS is orbiting at about 17,000mph escape velocity is 25,000mph
The Blackbird (technically not a fighter jet, it never carried weapons and the SR designation specifically stands for strategic reconnaissance) specifically stays in the atmosphere. Atmosphere is thick when it comes to high speeds. The Blackbird’s engines need air to work. It “only” went to about 85,000ft/16miles in altitude.
Rockets on the other hand, specifically are meant to leave the atmosphere. Rockets bring the oxygen they burn with them in the form of oxidizer. This allows them to launch higher than the atmosphere. At 40,000ft-ish the Artemis rocket is “only” going about 1,000mph. Which isn’t outlandish. The crazy orbital speeds only happen far out of the atmosphere.
What’s special is the type and amount of fuel. Notice a crew capsule of a rocket is a tiny room on top of a 10 story column of fuel. All that fuel (and it burns more powefully and quicker than normal fuel) is required to get the small payload to space. You may remember the Space Suttle needed extra fuel tanks because it was much more than a tiny room (but still small by airplane standards).
The rocket’s mass is mostly fuel and burns it all over a few minutes. The fighter jet carries far less fuel (though since it burns the fuel in atmosphere instead of carrying its own oxidizer, it’s far more fuel efficient) and burns that fuel over the course of hours.
Anyway, the answer is basically that
* the rocket motor generates far more thrust
* isn’t dependent on atmosphere to generate that thrust
* continues to accelerate when you get above the atmosphere, removing aerodynamic drag as a limitation to speed
Simply put, purpose is the reason.
Aircraft need to take off and land. They also have a precise destination they need to hit (runway).
Rockets are primarily aimed, and take off within a specific window so they have minimal navigating they need to do. Additionally, most of the navigation is done outside the atmosphere where you have more control over changes. Also, rockets don’t need to land in the same way aircraft need to land. Most rockets allow significant parts to be disposed of and simply fall into the ocean. SpaceX is the exception by attempting to maximize reuse. Even with SpaceX the navigation is limited. They use a landing vehicle in the water to catch up to the rocket and it does most of the maneuvering except in the last few moments of landing.
These purposes are very different allowing for different parameters to be used in their construction. We see the most significant difference in terms of speed.
Have an engine that doesn’t require air. Go high enough that there is no air resistance. That’s it. Rockets carry their own oxidizer.
Rocket ships are designed to reach those speeds outside of our atmosphere. High speed jets typically stay well within our atmosphere and actually rely on it just to power their thrusters.
Think of our atmosphere a bit like another gigantic ocean. They are both fluids, after all, but the air is less dense. When you travel faster, this matters a lot!
Think of riding on a boat traveling across some water. You can stick your hands out and “catch” some air (or the classic hand surfing from the car window). But if you were to stick your hand in the water there would be a MUCH larger drag on your hand because you have to move WAY more mass out of the way.
In space, there is no atmosphere. No “ocean” to move through. There is nothing to move out of the way so you can just keep going faster and faster with nothing to slow you down.
The only main problem is that it’s pretty tough to get things to space in the first place. If you and your rocket want to go to space it might take X amount of fuel to get that much weight there. But that fuel weighs a lot too! So you might need 2x the fuel, but that fuel is heavy so you need MORE fuel. Then you end up with 5X the fuel (arbitrary number) without even counting extra cargo or equipment.
But again, once you are out of the atmosphere and you’ve invested enough to carry even more extra fuel or another propulsion device, there isn’t much stopping you from going faster and faster.
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