Am 17.10.2011 07:01, schrieb Scout:


...

For Earth orbit you need much faster flight than you would need to
stay in orbit around the moon, but nevertheless it is quite fast. On
Earth it took a Saturn V rocket, to lift the craft into orbit. On the
Moon it would take less fuel, but way more, than the few gallons, they
had in the lander.

Ok, let's see your math.

I mean if you know they needed more, then clearly you have calculated
all this out and know exactly how much they would need and whether they
could have that much on the lander.

So let's see your work.

---- Insert mathematical proof here.

Here I will even aid you with the specifications for the mass, amount of
fuel, type of fuel, specific impulse, thrust provided, available
delta-V, and so on.

http://en.wikipedia.org/wiki/Apollo_...Specifications


Well, I'm a little too lazy, but a rough calculation is possible:

There is the Tsiolkovsky rocket equation
velocity_final=v_exhaust* ln(mass_start/mass_finish)

V_end= 2200 m/s * ln (4547 kg/(4547-2353) kg)

that is :
v_end approx. 1603 m/s

this is an estimated calculation without gravity.

the final velocity is reduced by
delta v = g_moon * (time of engine running)

Don't know that number (time_ engine)

Maybe 100 seconds (???)

makes:
delta v = 1.6 m/s²*100 s=160 m/s

What gives a rough estimate for the final velocity of the landers
ascending stage of
v_end = 1440 m/s.

Now the orbital velocity had to be compared. But I don't have the data
and actually I'm too lazy to find them out. But usual orbits should be a
little less than escape velocity, what is
v_orbit_escape = 2380 m/s.

V_end is a rough estimate ('thumb times pi'). For better calculations
someone with more experience in rocket science is needed.

I cannot even tell you, if the ascent stage is fast enough or not. But
my intuition tells me, it is not.


Greetings

Thomas