Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V10_3/V10_302.TXT

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Subject: SPACE Digest V10 #302

SPACE Digest                                     Volume 10 : Issue 302

Today's Topics:
        Re: Manned vs Unmanned Mission to Mars
        Re: Manned vs Unmanned Mission to Mars
        Re: Manned vs Unmanned Mission to Mars
           Re: Why NASA wants to go to Mars
              Re: SPACE Digest V10 #301
        Re: Manned vs Unmanned Mission to Mars
        Re: Manned vs Unmanned Mission to Mars
        Re: Manned vs Unmanned Mission to Mars
        Re: Manned vs Unmanned Mission to Mars
        Re: Incredible Shrinking Space Station
----------------------------------------------------------------------

Date: 3 Dec 89 20:51:19 GMT
From: mentor.cc.purdue.edu!l.cc.purdue.edu![e-mail]  (Herman Rubin)
Subject: Re: Manned vs Unmanned Mission to Mars

In article <[e-mail]>, [e-mail] (Henry Spencer) writes:
> In article <[e-mail]> [e-mail] (Nichael Cramer) writes:
> >>Aren't unmanned probes far less expensive and more efficient?
> >
> >Yes.

            ........................

> If you define the range of interesting activities for space missions as
> those that unmanned probes do best -- remote sensing -- then of course
> unmanned probes are better.

It will cost far more than Voyager cost to answer the interesting questions
that Voyager raised.  Even remote sensing for any protracted period is
difficult for unmanned probes.  What is the composition of Saturn's rings?
They have been suggested as a source of essential supplies for man to live
in space.  Can we get this information by unmanned probes?

Remember thay Voyager was a _flyby_, not even a probe, and conditions had
to be right for a flyby operating in that short number of years.  People
can improvise; unmanned probes cannot.  The questions Viking was supposed
to answer are in the same position of ignorance when the marvelous
microlab on Viking did its experiment, and could do nothing else.
--
Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907
Phone: [phone]
[e-mail] (Internet, bitnet, UUCP)

------------------------------

Date: 3 Dec 89 07:36:30 GMT
From: att!watmath!watserv1!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Manned vs Unmanned Mission to Mars

In article <[e-mail]> [e-mail] (Nichael Cramer) writes:
>>Unmanned Mars mission -
>>  Earth: "Viking, please point your receiving antenna at the ground."
>>  Viking: "OK"
>>    end of mission
>>
>Unmanned Mars Mission With Non-Unix Based Control Code:
>
>Viking: "Well, I've lost the carrier beam for over N seconds, guess I'd
>         better start looking for it.  Ah, there it is."

Hate to point this out, but Jonathan wasn't making that part up.  "OK"
followed by silence is exactly what happened to the Viking 1 lander.
Its control code was not Unix-based.
--
Mars can wait:  we've barely   |     Henry Spencer at U of Toronto Zoology
started exploring the Moon.    | uunet!attcan!utzoo!henry [e-mail]

------------------------------

Date: 3 Dec 89 05:49:13 GMT
From: bbn.com![e-mail]  (Nichael Cramer)
Subject: Re: Manned vs Unmanned Mission to Mars

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Nichael Cramer) writes:
>>>Aren't unmanned probes far less expensive and more efficient?
>>Yes.
>>As evidence, first consider the amount of scientific knowledge gained on
>>the Voyager trips vs the entire Apollo program.  Second compare their
>>respective price tags.
>Let's see.  We add the cost of developing Titan-Centaur to the Voyager
>bill, or else deduct the cost of the Saturns from Apollo's.

Fair enough, but let's not neglect the fact that manned flights require
larger boosters by their very nature because humans (as opposed to say
remote sensing experiments) make a very bulky, ineficient cargo.

But even ignoring this, the point is that on a per-flight basis, any given
manned flight to, say, Mars is going to be vastly more expensive than any
given remote-sensing flight.  With minimal gain in output.

>...Then add
>multiple outer-planet sample return missions ($$$$$!!!) to the Voyager
>budget, and the Ranger/Surveyor/LunarOrbiter missions ($) to the Apollo
>budget, so we're comparing apples to apples instead of apples to oranges.

I'm afraid I don't understand this point.  Presumably proposed manned
flight to Mars would have return missions?  ;) In any case it wasn't simply
the necessity for return flights that made Apollo so much more expensive
than comparable unmanned flights.

>Don't forget to ask the lunar-science people how much they learned from
>Apollo...

... and let's also ask them how much they could have learned *for the same
money* via remote sensing.

>... -- it is trendy to ignore Apollo's enormous science return, since
>the Moon is no longer fashionable...

Moreover, it also is (was?) fashionable to --erroneously-- maintain that
most of the stuff learned on the Apollo progam was learned *only* because
they were manned flights.

>... Then crank in some compensation for
>the fact that Apollo had to meet a tight deadline for political reasons,
>and would have been rather cheaper if done more gradually.

No argument here.

"Political" hits the nail right on the head.

>If you define the range of interesting activities for space missions as
>those that unmanned probes do best -- remote sensing -- then of course
>unmanned probes are better.

Well, let's say I certainly believe that remote sensing can accomplish the
vast majority of interesting, real science that a manned flight can
accomplish.  Furthermore, I'd argue that if what we're interested in is the
science per cost ratio --and keeping this on a per-mission basis-- the
advantages of remote sensing flights are overwhelming.

NICHAEL

|  Nichael Lynn Cramer     |   The inside real             |
|   --  [e-mail]    |     and the out sidereal.     |
|   --  [e-mail]    |      -- Ed Dorn "Gunslinger"  |

------------------------------

Date: Sun, 3 Dec 89 08:33:35 PST
From: mordor!lll-tis!ames!scubed!pnet01.cts.com![e-mail] (Jim Bowery)
To: ames!lll-tis!mordor!angband![e-mail]
Subject: Re: Why NASA wants to go to Mars

Henry Spencer writes:
>
>In article <[e-mail]> [e-mail] (John McKernan) writes:
>>Ideas like this and similar ideas about technological "spinoffs" are
>>mistaken. If you want to develop a propulsion system you do propulsion R&D.
>
>Except that if you don't have a specific mission to use that R&D on, the
>funds for it tend to get cut off.

Uh.... Henry...  if you don't have a use for the propulsion R&D other than
the mission it is supposed to "spin off" from...  where is it supposed to
"spin off" to?
---
Typical RESEARCH grant ($ = 1million):
$
Typical DEVELOPMENT contract:
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$

------------------------------

Date: Sun, 3 Dec 89 12:15 EDT
From: [e-mail]
Subject: Re: SPACE Digest V10 #301
Sender: [e-mail]
Reply-To: [e-mail]
X-Envelope-To: [e-mail]

Please remove me from the subsrciber list
Thanks
David Albert
DAALBERT@VASSAR

------------------------------

Date: 3 Dec 89 21:15:18 GMT
From: bfmny0![e-mail]  (Tom Neff)
Subject: Re: Manned vs Unmanned Mission to Mars

In article <[e-mail]> [e-mail] (Brian Yamauchi) writes:
>A better alternative which would satisfy both camps might be a manned
>landing with multiple fully autonomous rovers (or even fliers).  The
>rovers could explore and sample a larger area than humans alone, and
>the humans could monitor and follow up the most interesting
>discoveries.  Since they would be fully autonomous, the number of robots
>would not be limited by the number of teleoperators.

Another approach, if we absolutely must send something manned, would be
to orbit the meat and let it teleoperate rovers on the surface.  Send the
rovers first, including landing them (so you don't have an unpleasant
surprise after a long manned voyage).  Then send a "Mir-mobile" for a
six month stay in orbit, spent doing science both in orbit and on the
ground via telerobotics.  Eliminating the need to land men AT ALL will
simplify things greatly.  Mir technology allows automated replenishment.
In fact here's an approach:

    boost science modules and rovers to LEO
    assemble them for Mars transit from Mir
    send them on to Mars orbit
    Rovers land and deploy on arrival
    Meanwhile assemble manned Command module/living space in orbit
    Send it with crew to Mars orbit
    Dock there with science section
    Immediate Progress replenishment if appropriate
    Perform science mission incl. telerobotics
    Final Progress replenishment
    Detach command/living modules
    Return to Earth
    Rendezvous with Mir or shuttle for crew return to Earth

This does not include sample return, however you could design a
compatible but separate unmanned sample return mission where the
"return" is just to Martian orbit - rendezvous with the manned orbiter.

The only difficulty in the above scenario that I can see is finding any
place for the US. :-)  No actually, we have the edge in telerobotics
from what I understand, plus our unmanned stuff is more reliable once we
actually get it there.

It would be nice if US officials could afford to stop playing to the
peanut gallery and the Birchers-In-Space lobby and get to work on a
grand joint mission.  Before the Japanese do it for us...
--
To have a horror of the bourgeois   (\(    Tom Neff
is bourgeois. -- Jules Renard        )\)   [e-mail]

------------------------------

Date: 4 Dec 89 00:22:09 GMT
From: bbn.com![e-mail]  (Nichael Cramer)
Subject: Re: Manned vs Unmanned Mission to Mars

In article <[e-mail]> [e-mail] (Herman Rubin) writes:
>In article <[e-mail]>, [e-mail] (Henry Spencer) writes:
>> In article <[e-mail]> [e-mail] (Nichael Cramer) writes:
>> >>Aren't unmanned probes far less expensive and more efficient?
>> >Yes.
>> If you define the range of interesting activities for space missions as
>> those that unmanned probes do best -- remote sensing -- then of course
>> unmanned probes are better.
>It will cost far more than Voyager cost to answer the interesting questions
>that Voyager raised.  Even remote sensing for any protracted period is
>difficult for unmanned probes.  What is the composition of Saturn's rings?
>They have been suggested as a source of essential supplies for man to live
>in space.  Can we get this information by unmanned probes?

Yes, of course, if designed properly.

In point of fact, if the environment in near orbit around Saturn is
anything like it is around Jupiter (e.g. radiation), than we had *better*
do this with unmanned probes.

>Remember thay Voyager was a _flyby_, not even a probe, and conditions had
>to be right for a flyby operating in that short number of years.

Red Herring.  Conditions would need to be right for a manned probe, too.

>...People can improvise; unmanned probes cannot.

[flippant] Answer #1:
Would you care to explain to the people who worked on the Voyager team why
one can't improvise or recover from error or malfunction at long
distances?  ;)

[serious] Answer #2:
Yes people can improvise.  But maintaining them on a long mission is a
highly expensive, bulky, dangerous proposition.  Voyager suffered several
major system malfunctions and is *still* working.  Anything comparable on a
manned trip to Mars and the mission would have ended in tragedy.

It's not at all clear that the *net* robustness of the system is improved
by having humans on board.

>...The questions Viking was supposed
>to answer are in the same position of ignorance when the marvelous
>microlab on Viking did its experiment, and could do nothing else.

... and what else could it have done were the Viking project given an
appreciable fraction of the funding a manned flight would get.

Fund Viking to the tune of $400 billion and see how much data you get back.
That's where the real difference lies, not simply in the fact that Viking
was unmanned.


But, look, let's stop thrashing and ask some concrete questions:

  1] What would we realistically expect a manned mission to Mars to
     accomplish that we could not --in principle-- do with a remote
     probe?  Even if we spent the same amount of money?

  2] How much would we save if we decided to do without these (presumably)
     few experiments and sent and unmanned probe?

  3] Does the savings make it worth it?

  4] To give a base for discussion, can someone name me *anything*
     that Apollo accomplished that could not have been done by remote
     probes?  Was it worth the enourmous extra cost?

NICHAEL

------------------------------

Date: 4 Dec 89 00:31:37 GMT
From: rochester![e-mail]  (Paul Dietz)
Subject: Re: Manned vs Unmanned Mission to Mars

While the manned vs. unmanned debate is neverending (probably because
of unstated assumptions on both sides), there is, I think, one thing
that even the manned Mars mission folks will admit:  basing a $400 B
Mars program on Shuttle-C is *insane*.  For a fraction of $400 B we
could have much better launchers.

    Paul F. Dietz
    [e-mail]

------------------------------

Date: 3 Dec 89 19:47:31 GMT
From: rochester![e-mail]  (Brian Yamauchi)
Subject: Re: Manned vs Unmanned Mission to Mars

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>The best way to do an in-depth preliminary investigation of Mars would
>probably be a mixed approach:  teleoperation from a manned vessel in
>Mars orbit.

>Unfortunately, this doesn't seem to satisfy either
>ideology.  The robotniks say "keep those icky humans out of the plans",
>while the Mars-or-busters want a manned landing ASAP and no compromises.

A better alternative which would satisfy both camps might be a manned
landing with multiple fully autonomous rovers (or even fliers).  The
rovers could explore and sample a larger area than humans alone, and
the humans could monitor and follow up the most interesting
discoveries.  Since they would be fully autonomous, the number of robots
would not be limited by the number of teleoperators.

The presence of the humans would also allow the rovers to be designed
less conservatively, since the humans should be able to help the
rovers recover from some non-catastrophic failures modes (i.e. getting
stuck, becoming overturned, etc).

_______________________________________________________________________________

Brian Yamauchi                University of Rochester
[e-mail]        Computer Science Department
_______________________________________________________________________________

------------------------------

Date: 3 Dec 89 16:15:33 GMT
From: mcsun!ukc!icdoc!syma![e-mail]  (Nick Watkins)
Subject: Re: Incredible Shrinking Space Station

In article <[e-mail]> [e-mail] (Stephen R Fleming) writes:


>I also wonder if NASA really wants to build a space station or
>just wants to keep all their contractors busy?  Their record is
>pretty damning.  (No smiley; it's not a joke.)
See the comments of Bruce Murray in his book Journey into Space. He
seems to agree with you, much to his surprise. Looks like a good book
btw, I've only scanned it so far.

Nick
--
Nick Watkins, Space & Plasma Physics Group, School of Mathematical
& Physical Sciences, Univ. of Sussex, Brighton, E.Sussex, BN1 9QH, ENGLAND
JANET: [e-mail]   BITNET: [e-mail]

------------------------------

End of SPACE Digest V10 #302
*******************