NASA Watch: "Bob Zubrin Steps In It Again"

Heh. This is worth a read:

http://www.nasawatch.com/archives/20...step.html#more

"Some advice Bob: sit down and shut up before you look even more
foolish than you already have."

Anybody want to make bets on whether this advice is followed?

Heh. This is worth a read:
http://www.nasawatch.com/archives/20...step.html#more

The key part is fairly short:

The zero-gravity health-effects budget has nothing to do with going to
Mars. It is just a matter of protecting the entitlements of as group
of people who have nothing better to do than to waste the taxpayer's
money on pointless and unethical experiments while blocking
engineering research that would eliminate the problem that serves as
their bowl of rice. Furthermore, by both preventing a solution to this
problem and wildly exaggerating its magnitude in order to justify
their funding, this crowd continues to actively mislead the political
class to believe that a human Mars mission is impossible. The sooner
these people can be shown the door, the better.

He's saying we are better off working on artificial gravity than
zero-gravity health-effects. That strikes me as a legitimate point of
view. Zubrin has called for a tether between two halves of a
Mars-bound craft (one half being a spent upper stage, and the other
half being the rest of the craft). What he means by "engineering
research" is presumably debugging this design (it sounds simple, but
there are various detail in getting it to work). See
http://ccar.colorado.edu/asen5050/pr...htlessness.htm

The tone of Zubrin's comments does seem a bit odd, but it wasn't clear
to me what audience he was writing for, so I guess I prefer to pay
more attention to the substance.

Jim Kingdon wrote:

The tone of Zubrin's comments does seem a bit odd, but it wasn't clear
to me what audience he was writing for, so I guess I prefer to pay
more attention to the substance.

In addition to the substance, let's look at the claimants :

Michael Griffin ... or Robert Zubrin; Mars?

Hmmm, you know, just offhand, I think I'll have to go with Bob Zubrin on
this one.

http://cosmic.lifeform.org

Jim Kingdon wrote:

Heh. This is worth a read:
http://www.nasawatch.com/archives/20...step.html#more



The key part is fairly short:

The zero-gravity health-effects budget has nothing to do with going to
Mars. It is just a matter of protecting the entitlements of as group
of people who have nothing better to do than to waste the taxpayer's
money on pointless and unethical experiments while blocking
engineering research that would eliminate the problem that serves as
their bowl of rice. Furthermore, by both preventing a solution to this
problem and wildly exaggerating its magnitude in order to justify
their funding, this crowd continues to actively mislead the political
class to believe that a human Mars mission is impossible. The sooner
these people can be shown the door, the better.

He's saying we are better off working on artificial gravity than
zero-gravity health-effects. That strikes me as a legitimate point of
view.

There are better ways to express that than a stream of insults.

The tone of Zubrin's comments does seem a bit odd,


Not if you've dealt with him.

but it wasn't clear
to me what audience he was writing for, so I guess I prefer to pay
more attention to the substance.


Well, the substance is that he in effect called those with the *other*
point of view to be liars, "unethical," "fakers," "bunk."

This from someone trying to build a politcal concensus towards manned
Mars exploration?



--
Collectivism killed 100 million people, and all I got was this lousy sig.

Thomas Lee Elifritz wrote:

I think I'll have to go with Bob Zubrin on this one.


From your keyboard to fates ears.


--
Collectivism killed 100 million people, and all I got was this lousy sig.

On 09 Jun 2006 17:04:22 -0400, Jim Kingdon wrote, in
part:

He's saying we are better off working on artificial gravity than
zero-gravity health-effects. That strikes me as a legitimate point of
view.

If he had claimed that we were better off working on some arrangement of
coils and capacitors that would produce a gravitational field, of
course, then he would be a nutcase.

Fortunately, he doesn't claim that - and you know that he doesn't - but
some uninformed people reading your post just might have gotten that
idea.

We don't really need to "work" on 'artificial gravity' of the kind
required. The centrifuge has already been invented. Making spaceships
that can hold together under the load, without being too massive -
*that's* what needs to be worked on.

John Savard
http://www.quadibloc.com/index.html
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On Sat, 10 Jun 2006 03:48:40 GMT, lid
(John Savard) wrote, in part:

We don't really need to "work" on 'artificial gravity' of the kind
required. The centrifuge has already been invented. Making spaceships
that can hold together under the load, without being too massive -
*that's* what needs to be worked on.

Upon reflection, the real problem - since tethers are well-known - is
resolving the conflict between a structure providing artificial gravity,
and a structure that can manoeuver in space. It seems that every time
one needs to apply a little thrust, one has to reel in those tethers
first.

Unless one happens to be so oriented that the thrust would be a gentle
pull on the tethers...

John Savard
http://www.quadibloc.com/index.html
_________________________________________
Usenet Zone Free Binaries Usenet Server
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John Savard wrote:

Upon reflection, the real problem - since tethers are well-known - is
resolving the conflict between a structure providing artificial gravity,
and a structure that can manoeuver in space. It seems that every time
one needs to apply a little thrust, one has to reel in those tethers
first.

In principle, you could equip each of the tethered masses with its own
propulsion so that the tether doesn't have to transmit additional
forces. Calculating just how to do that would be tricky, but doable.
And, if we're talking about maneuvers during interplanetary cruise,
thrusts can be very small and accelerations low. (I'd assume that the
tethers are reeled in and centrifugal "gravity" not used at the
beginning and end of such flights.)

BTW, I agree that, if we ever get serious about interplanetary flight,
more attention needs to be paid to centrifugal gravity possibilities --
and better propulsion to cut down flight times, of course.

John Savard wrote:

On 09 Jun 2006 17:04:22 -0400, Jim Kingdon wrote, in
part:


He's saying we are better off working on artificial gravity than
zero-gravity health-effects. That strikes me as a legitimate point of
view.


If he had claimed that we were better off working on some arrangement of
coils and capacitors that would produce a gravitational field, of
course, then he would be a nutcase.

Fortunately, he doesn't claim that - and you know that he doesn't - but
some uninformed people reading your post just might have gotten that
idea.

We don't really need to "work" on 'artificial gravity' of the kind
required. The centrifuge has already been invented. Making spaceships
that can hold together under the load, without being too massive -
*that's* what needs to be worked on.

Human tolerance to angular velocity seemed to be of great interest in
the sixties but less has been done in the recent past. Related to this
is human tolerance to acceleration gradient (a small radius results in a
steeper gradient). Also how many gees are required to maintain human
health? I believe they should be conducting research on this at the I.S.S.

Some researchers have suggested an 8%/meter gravity gradient is
acceptable. This would imply a minimum radius of 12.5 meters. Some
concluded that 3 rpm was acceptable. If lunar gravity is enough to
maintain health, you could get by with a radius of 17 meters spinning at
3 rpm.

Reducing size of tether and engineering for less stress would reduce the
payload mass. Research finding limits to maintain human health and
comfort would be a good investment.

Hop

Jim Kingdon wrote:
The tone of Zubrin's comments does seem a bit odd,

Not if you've dealt with him.

OK, that's fair. It is typical for Zubrin, I guess.

Nevertheless, the guy is has a point. I can't comment on 0-G research
as I don't know how much money was spent and how much clout those
people have, but the comparision with the earlier era NASA still
stands.

Personally, I think it is a bit of a moot point, as I don't see a Mars
mission happening near-term either the NASA way or the Zubrin way.

A lot of the "big problems" would become much less relevant if A:
cheap(er) launchers were available and B: nuclear engines were emplyed
for the Mars mission. However NASA pursued neither.

As a sideline, I remember a documentary in which a NASA Md. talked
about nanotechnology to repair celular damage resulted from radiation
during a flight to Mars. I guess we can all sit tight until such tech
is developed, to see the green light for Mars.