How big of a rocket would be necessary to launch out of earth orbit?

Draw a triangle, the tip, vertex is 15 lbs of payload, the rest is rocket fuel. See Element of Rocket Propulsion.

Draw a triangle, the tip, vertex is 15 lbs of payload, the rest is rocket fuel. See Element of Rocket Propulsion.

The space shuttles are being phased out. Cargo can be shot out using small rockets run on electromagnets, ion engines, or those powered by laser from the earth. Rockets with people have to be large, so it is better to move into the ISS in small groups using similar space shuttles, and then move out from there into space in another rocket built in outer space. Chanlijkk made an important point that fuel is 85% of LOAD. "Draw a triangle, the tip, vertex is 15 lbs of payload, the rest is rocket fuel. See Element of Rocket Propulsion. 7 hours ago" Richard has given many important points. Big Daddy, I think the distance is 640 km and NOT 6400 km, so the answer will be 4% saving and not 0.4% saving. Still the POINT is shown well that elevating a rocket using weather balloons to 20 odd km is not going to save much energy since the total distance is 640 km to get to the geostationary level. Hence summing up, we can reduce fuel required by 1. Electromagnetic guns for small cargo. 2. Ion engines. 3. Using laser guns to fire the rocket into space from earth, where the energy from the laser keeps the thrust for the rocket engines, so fuel is minimum. Any other way, after considering the above answers.

it's not rocket science; Oh wait it IS rocket science many factors the key is to reach escape velocity form earth. that is a number based on the mass of earth and the force of gravity. determined by calculus and available in reference books the rocket must provide AT LEAST the energy for the payload BUT also ENERGY for the rocket structure and fuel ( which need not reach E _ V multi stage Systems are more efficient since they do not need to lift the empty structure all the way the 85 K ft ( about 20 miles ? ) would help clearing the high friction atmosphere but would NOT make much difference to E-V required. and for a heavy rocket it would be a huge balloon early small rockets were boosted that way but could not come close to earth orbit much less escape the earliest ideas were carraiages pulled by flocks of birds in the 1600s cannon shell horizontal in 1800s and an early Science fiction movie about 1900 goddard and others experimented in the 1920s the Chinese used rocket arrows maybe 1000 years ago keep thinking there is an idea to use a very very long runway booster to gain initial horizonatal speed.

There's not a significant savings in energy from just going up. To escape from earth, you have to expend at least the total gravitational potential energy from the point you start at. From surface (R = 6400km, 10kg payload) U = -GMm/R U = -6.230 x 10^8 J From altitude (R = 6426km, 10kg payload) U = -6.206 x 10^8 J Savings = (6.230 - 6.206) / 6.230 Savings = 0.4% So at a probably large increase in complexity, you save less than one percent of the energy needed to escape. Now that's not the entire story, but it's a large part of it. Remember that while in the vicinity of the earth, you have to get to about 11km/s in velocity. Your balloon gets you a little bit of altitude, but none of the velocity you need. That's where most of the energy goes. There's no single answer to "how big of a rocket", it depends on lots and lots of parameters in the design of the rocket (the engine, the fuel, the mass fractions, etc.)

The most efficient way is to boost the payload up to 11.2 km/s. (added later) ... Typical rockets are 100 times heavier than the payload, so you're going to need a minimum 1500 pound rocket. Plus a very efficient fuel mix.

The space shuttles are being phased out. Cargo can be shot out using small rockets run on electromagnets, ion engines, or those powered by laser from the earth. Rockets with people have to be large, so it is better to move into the ISS in small groups using similar space shuttles, and then move out from there into space in another rocket built in outer space. Chanlijkk made an important point that fuel is 85% of LOAD. "Draw a triangle, the tip, vertex is 15 lbs of payload, the rest is rocket fuel. See Element of Rocket Propulsion. 7 hours ago" Richard has given many important points. Big Daddy, I think the distance is 640 km and NOT 6400 km, so the answer will be 4% saving and not 0.4% saving. Still the POINT is shown well that elevating a rocket using weather balloons to 20 odd km is not going to save much energy since the total distance is 640 km to get to the geostationary level. Hence summing up, we can reduce fuel required by 1. Electromagnetic guns for small cargo. 2. Ion engines. 3. Using laser guns to fire the rocket into space from earth, where the energy from the laser keeps the thrust for the rocket engines, so fuel is minimum. Any other way, after considering the above answers.

it's not rocket science; Oh wait it IS rocket science many factors the key is to reach escape velocity form earth. that is a number based on the mass of earth and the force of gravity. determined by calculus and available in reference books the rocket must provide AT LEAST the energy for the payload BUT also ENERGY for the rocket structure and fuel ( which need not reach E _ V multi stage Systems are more efficient since they do not need to lift the empty structure all the way the 85 K ft ( about 20 miles ? ) would help clearing the high friction atmosphere but would NOT make much difference to E-V required. and for a heavy rocket it would be a huge balloon early small rockets were boosted that way but could not come close to earth orbit much less escape the earliest ideas were carraiages pulled by flocks of birds in the 1600s cannon shell horizontal in 1800s and an early Science fiction movie about 1900 goddard and others experimented in the 1920s the Chinese used rocket arrows maybe 1000 years ago keep thinking there is an idea to use a very very long runway booster to gain initial horizonatal speed.

There's not a significant savings in energy from just going up. To escape from earth, you have to expend at least the total gravitational potential energy from the point you start at. From surface (R = 6400km, 10kg payload) U = -GMm/R U = -6.230 x 10^8 J From altitude (R = 6426km, 10kg payload) U = -6.206 x 10^8 J Savings = (6.230 - 6.206) / 6.230 Savings = 0.4% So at a probably large increase in complexity, you save less than one percent of the energy needed to escape. Now that's not the entire story, but it's a large part of it. Remember that while in the vicinity of the earth, you have to get to about 11km/s in velocity. Your balloon gets you a little bit of altitude, but none of the velocity you need. That's where most of the energy goes. There's no single answer to "how big of a rocket", it depends on lots and lots of parameters in the design of the rocket (the engine, the fuel, the mass fractions, etc.)