Jeff Findley wrote on Thu, 23 May 2019
07:19:43 -0400:
In article ,
says...
On 2019-05-21 22:42, Fred J. McCall wrote:
You're a bit confused. There are five LaGrange points, not just one.
https://space.stackexchange.com/ques...ear-halo-orbit
Thanks.
I take it this L2's advantage is that it gets closer to the moon from
time to time, giving opportunities to have less beefier transfer/landers?
From a requirements perspective, would the actuial lander (without
transfer) be required to be able to rejoin the Gateway at any altitude,
or only when it makes a low pass (since we're talking direst ascent)
There is no real advantage to L2, IMHO. This is necessary because Orion
is simply not capable of getting to a low lunar orbit and getting back
to earth. It's too heavy and lacks the necessary delta-V to do so.
I don't believe that's the case. I don't believe Gateway (nee Lunar
Orbital Gateway (nee Deep Space Gateway)) really reared its ugly head
until the asteroid recovery missions were planned. Apollo CSM only
needed about 50% of its delta-v capability to do the lunar missions.
Even Orion has more delta-v than that (around 65% or so of Apollo
CSM).
--
"The reasonable man adapts himself to the world; the unreasonable
man persists in trying to adapt the world to himself. Therefore,
all progress depends on the unreasonable man."
--George Bernard Shaw