Apollo - Centaur

[Archibald]

A random idea about Apollo.

Let's suppose that, around 1973, a Saturn IB send a CSM into a parking orbit.

Then, a Titan IIIE put its Centaur upper stage onto the same orbit. Rendez-vous, docking in LM fashion.

Do you think the Centaur had enough energy and propellants to send the CSM into a lunar orbit ? (ala Apollo 8, without Saturn V!)

 

[Michel Van]

the CSM has mass of 15 tons
(the 15 tons is for Low orbit mission lunar mission the CSM weight is 30 tons)

so 15 tons CSM plus 17 tons Centaur-D makes = 32 tons
32/18,37 Tons = mass radio 1.7419
in(1,7419)x 4355,64 m/s = 2417.27 meter/sec
but Delta-V for Moon is 2997 meter/sec

means CSM is after Centaur shotdown on high elliptical orbit
on low point of this orbit the CSM must fire its engine (after the Centaur is dropt)
and get 579,73 meter/sec

the 15 tons CSM got delta V around 1400 meter/sec
left 820.27 meter/sec, not enough to get in or out the Lunar Orbit.
so the CSM can do only a Lunar fly-by and fall back to Earth

a Gemini capsule with a Agena stage in his back
launch on Saturn IB / Centaur
is better for such Lunar Orbit mission !

 

[Archibald]

Wow, thanks for the calculations. That's help a lot !

Do you think that might work better with two Centaurs instead of one ?