LSAM and an unmanned CEV in lunar orbit?

Quoting from http://www.spaceref.com/news/viewnews.html?id=1057 :

"Along with a CEV that carried the flight crew and their support
equipment and propulsion system package, a Lunar Surface Access Module
(LSAM) which was designed to undock from the CEV and take the entire
crew to land upon the moon's surface. Upon completion of the mission,
part of the LSAM would launch off the surface and rendezvous and dock
with the CEV, orbiting unmanned following departure of the flight crew
to the surface. The CEV and LSAM would use a similar approach to the
Apollo CSM/Lunar Module/S-IVB complex to get to and from the moon."

Questions:

What are the risks of having an unpiloted CEV in orbit, rather than
leaving a pilot onboard while the LSAM lands?

How have these risks changed since the days of manned lunar CSMs? Is it
just better automation available? Was having a CMP onboard just a
"consolation prize" in case the LM didn't make it back for a LOR?

How do four astronauts on the Moon make it a "better" mission than
three astronauts on the Moon? It sounds like a lot of ballast (both in
body mass and support materiel) to land and re-launch.

"TVDad Jim" wrote in message
oups.com...
Quoting from http://www.spaceref.com/news/viewnews.html?id=1057 :

"Along with a CEV that carried the flight crew and their support
equipment and propulsion system package, a Lunar Surface Access Module
(LSAM) which was designed to undock from the CEV and take the entire
crew to land upon the moon's surface. Upon completion of the mission,
part of the LSAM would launch off the surface and rendezvous and dock
with the CEV, orbiting unmanned following departure of the flight crew
to the surface. The CEV and LSAM would use a similar approach to the
Apollo CSM/Lunar Module/S-IVB complex to get to and from the moon."

Questions:

What are the risks of having an unpiloted CEV in orbit, rather than
leaving a pilot onboard while the LSAM lands?

Docking might be a problem if the LSAM has instrumental failure. I would
imagine that there would be a provision for a "rescue" mission if the CEV
failed during the lunar stay. (The LSAM will be capable of a much longer
stay than the LM.)
How have these risks changed since the days of manned lunar CSMs? Is it
just better automation available? Was having a CMP onboard just a
"consolation prize" in case the LM didn't make it back for a LOR?

Much, much, much better automation. The CMP was responsible for performing
orbital science (primarily photography), and the final phase of docking was
performed by the CSM.
How do four astronauts on the Moon make it a "better" mission than
three astronauts on the Moon? It sounds like a lot of ballast (both in
body mass and support materiel) to land and re-launch.

First, you should compare four with two. Second, the primary reason why it
is a better mission is that there will be a longer stay. Secondly, IIRC, the
new proposal calls for two rovers. I would imagine that a single one of the
new missions would cover as much ground as all the Apollo missions. (IIRC,
Apollo 15 alone covered more than all three of the successful non-LRV
missions).

Ami Silberman wrote:



How do four astronauts on the Moon make it a "better" mission than
three astronauts on the Moon? It sounds like a lot of ballast (both in
body mass and support materiel) to land and re-launch.



First, you should compare four with two. Second, the primary reason why it
is a better mission is that there will be a longer stay. Secondly, IIRC, the
new proposal calls for two rovers. I would imagine that a single one of the
new missions would cover as much ground as all the Apollo missions. (IIRC,
Apollo 15 alone covered more than all three of the successful non-LRV
missions).



Longer stay means more EVAs on the Lunar surface, and that means we need
beefed-up spacesuits to deal with the abrasive Lunar dust...have they
started working on those yet?

Pat

In article ,
Ami Silberman wrote:
...The CMP was responsible for performing
orbital science (primarily photography), and the final phase of docking was
performed by the CSM.

Note that the main reason for the CSM doing the docking was some awkward
design details of the spacecraft -- problems that could be avoided in a
new design, now we know about them.

For one thing, the LM's docking window was *overhead*, which was more than
slightly awkward. (This was fallout from the decision to specialize the
LM forward hatch for surface work, so it couldn't be used for docking --
the original plan used that hatch for post-ascent docking, so the LM guys
could look through the forward windows during docking.) But particularly
in a larger vehicle, it should be easy enough to put the docking controls
beside the docking hatch.

For another, the late change to a foil outer surface for the CM turned its
surface into a conical mirror, which made for a very confusing target for
eyeball tracking. Something as simple as pre-wrinkling the foil would
fix that.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

Henry Spencer wrote:

...The CMP was responsible for performing
orbital science (primarily photography), and the final phase of docking was
performed by the CSM.



Note that the main reason for the CSM doing the docking was some awkward
design details of the spacecraft -- problems that could be avoided in a
new design, now we know about them.

For one thing, the LM's docking window was *overhead*, which was more than
slightly awkward. (This was fallout from the decision to specialize the
LM forward hatch for surface work, so it couldn't be used for docking --
the original plan used that hatch for post-ascent docking, so the LM guys
could look through the forward windows during docking.) But particularly
in a larger vehicle, it should be easy enough to put the docking controls
beside the docking hatch.


I suspect that docking will be entirely automated, with a manual backup
system... by making the spacecraft capable of flying and docking
unmanned, you can derive a Progress type cargo craft from it with
minimal modifications. Simple cargo shipment to a space station could
up the payload by leaving the crew and associated equipment behind,
while saving yet more weight by not having an escape tower attached.

For another, the late change to a foil outer surface for the CM turned its
surface into a conical mirror, which made for a very confusing target for
eyeball tracking. Something as simple as pre-wrinkling the foil would
fix that.



I'll bet laser ranging will play a big part in the docking procedure.

Pat

(Henry Spencer) wrote:

For one thing, the LM's docking window was *overhead*, which was more than
slightly awkward. (This was fallout from the decision to specialize the
LM forward hatch for surface work, so it couldn't be used for docking --
the original plan used that hatch for post-ascent docking, so the LM guys
could look through the forward windows during docking.)

This decision wasn't made lightly - it was a consequence of the need
to reduce (drastically!) the weight of the LM. The square 'tinfoil'
hatch weighed far, far less than a docking assembly.

D.
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

In article ,
Derek Lyons wrote:
For one thing, the LM's docking window was *overhead*, which was more than
slightly awkward. (This was fallout from the decision to specialize the
LM forward hatch for surface work, so it couldn't be used for docking...

This decision wasn't made lightly...

Oh, it was definitely a reasonable thing to do, but it did complicate the
docking situation a bit.

it was a consequence of the need
to reduce (drastically!) the weight of the LM. The square 'tinfoil'
hatch weighed far, far less than a docking assembly.

Small correction: the LM side of the docking assembly actually didn't
weigh all that much. The mass came from the combination of the short
tunnel -- the docking assembly needed significant *depth* outside the
hatch -- and the structural effects of taking docking impact loads in two
places.
--
spsystems.net is temporarily off the air; | Henry Spencer
mail to henry at zoo.utoronto.ca instead. |

On Fri, 23 Sep 2005 23:51:29 -0500, Henry Spencer wrote
(in article ):

In article ,
Derek Lyons wrote:
For one thing, the LM's docking window was *overhead*, which was more than
slightly awkward. (This was fallout from the decision to specialize the
LM forward hatch for surface work, so it couldn't be used for docking...

This decision wasn't made lightly...

Oh, it was definitely a reasonable thing to do, but it did complicate the
docking situation a bit.

it was a consequence of the need
to reduce (drastically!) the weight of the LM. The square 'tinfoil'
hatch weighed far, far less than a docking assembly.

Small correction: the LM side of the docking assembly actually didn't
weigh all that much. The mass came from the combination of the short
tunnel -- the docking assembly needed significant *depth* outside the
hatch -- and the structural effects of taking docking impact loads in two
places.


Minor nit to the small correction: I think you should have written,
"--- and the structural effects of taking docking impact loads in two
places *and in perpendicular vectors*."

--
"Fame may be fleeting but obscurity is forever." ~Anonymous
"I believe as little as possible and know as much as I can."
~Todd Stuart Phillips
www.angryherb.net

On Thu, 22 Sep 2005, Henry Spencer wrote:

Note that the main reason for the CSM doing the docking was some awkward
design details of the spacecraft -- problems that could be avoided in a
new design, now we know about them.

For one thing, the LM's docking window was *overhead*, which was more than
slightly awkward.
[...]
For another, the late change to a foil outer surface for the CM turned its
surface into a conical mirror, which made for a very confusing target for
eyeball tracking. Something as simple as pre-wrinkling the foil would
fix that.

Man, there's a job I want. Foil pre-wrinkler for next-generation lunar
spacecraft. Of course, I would need to be trained to meet exacting NASA
pre-wrinkling quality standards.

In my spare time, I would visit grade schools, rolls of aluminum foil tucked
under my arm, and give talks and demonstrations, hoping to inspire young
people to enter careers in pre-wrinkling.

"Someday, humans will set foot on Mars. The foil on their spacecraft may be
pre-wrinkled by someone in this classroom!"

At Thanksgiving, I would appear on TV talk shows, giving tips on how to wrap
your turkey to make it look like a CEV.

Eventually, wrinkled myself, I would write a book about my glorious
pre-wrinkling days. It would be nitpicked on sci.space.history by young
punks and old curmudgeons.

--
Bill Higgins | "Has anybody put a wrench to a rocketship,
Fermilab | who hasn't read it?"
| --Jaime Frontero on science fiction

Bill Higgins wrote:


Man, there's a job I want. Foil pre-wrinkler for next-generation
lunar spacecraft. Of course, I would need to be trained to meet
exacting NASA pre-wrinkling quality standards.


I already have the experience for the job; I've wrinkled foil for around
eight LMs in different scales, one MOL, one Soyuz, the sunshade parasol
on the Skylab, and my big Saturn exploration ship.
Do not try to glue wrinkled foil down with liquid superglue; superglue
gel is the stuff to use.


In my spare time, I would visit grade schools, rolls of aluminum foil
tucked under my arm, and give talks and demonstrations, hoping to
inspire young people to enter careers in pre-wrinkling.

"Someday, humans will set foot on Mars. The foil on their spacecraft
may be pre-wrinkled by someone in this classroom!"

At Thanksgiving, I would appear on TV talk shows, giving tips on how
to wrap your turkey to make it look like a CEV.

Eventually, wrinkled myself, I would write a book about my glorious
pre-wrinkling days. It would be nitpicked on sci.space.history by
young punks and old curmudgeons.


I wrapped one of the main domed-end cylindrical fuel tanks for the big
Saturn ship in gold foil- it ended up looking like some sort of festive
holiday sausage.

Pat