Discussion Forum

# why do you think to much energy is needed to launch a rocket to orbit the earth?

Why do you think to much energy is needed to launch a rocket to orbit the earth?

0 Followers

Most reacted comment
1 Comment authors
Recent comment authors
Subscribe
Notify of
Guest
ZeroByte

I did some back-of-the-napkin type calculations for another question of this nature some time ago, and cannot find my response, but in a nutshell, the potential and kinetic energy represented in a fully loaded space shuttle on an orbit like the ISS is on the order of megawatts. That is how much energy must remain in the shuttle for it to orbit. A lot more than the final orbit energy is spent getting it there, though, because the fuel is also being lifted as it burns, the weight of the main tank is being lifted while it is still attached,… Read more »

Guest
quizzard123

Why do we ‘think’ so much energy is needed? That implies it’s a matter of opinion. It’s not, it’s a matter of physics.

To orbit in a low earth orbit, the space shuttle needs to accelerate from zero to about 18,000 mph. That takes a LOT of energy.

Guest
laurahal42

Physics?

The object must be raised to the correct altitude, and must have the correct velocity to achieve orbit. Additionally, it must carry fuel to accelerate, unless it is launched at orbital velocity.

The numbers were understood in Newton’s time. Tsiolkovsky figured out the rocket stuff. This is well understood by all but Yahoo Answers users.

Guest
mental_absence

because rockets weight hundreds of tons.
F=ma (newtons law)
big mass (m) means bigger force needed.
work = force x distance so big force means big energy (work)