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NASA Studying Russian 12-month Plan



 
 
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  #91  
Old May 1st 04, 04:28 AM
Greg D. Moore \(Strider\)
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Default NASA Studying Russian 12-month Plan


"jeff findley" wrote in message
...
"Greg D. Moore \(Strider\)" writes:

"jeff findley" wrote in message
...
(dave schneider) writes:

I didn't yet get the right google terms to find the answer to

-- How many Mir astronauts were on 6 month missions?
-- How many Mir astronauts were on 9 month missions?
-- How many Mir astronauts were on 12-14 month missions?

20 longest human flights (descended order)
http://space.kursknet.ru/cosmos/english/other/long.sht


Note however, the American's aren't far behind. Shannon Lucid is in

there
at 188+ days.


While true this was on a Mir mission, correct? The Russians were in
control of Mir while the US was participating. Now ISS is
(apparantly) being run by the US with the Russians participating.


Yes, but I'm not sure what your point is. I was just offering a data point.



Jeff
--
Remove "no" and "spam" from email address to reply.
If it says "This is not spam!", it's surely a lie.



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  #92  
Old May 1st 04, 04:34 AM
Greg D. Moore \(Strider\)
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Default NASA Studying Russian 12-month Plan


"Derek Lyons" wrote in message
...
"Greg D. Moore \(Strider\)" wrote:
"bob haller" wrote in message
Theres no reason a crew couldnt communicate often with their family.


Other than risking the security of the sub.


Keep in mind that hal regards PR and appearance far higher than actual
performance.


Well of course?


As the idea was to basically "leave port and not be seen again until we

get
home" the more time you spend at com depth, the greater risk you have of
exposing your position and what you're doing.


Keep in mind that since SSBN's were configured to receive The Word
24/7, and that The Word was never sent, there was a great deal of
unused bandwidth.


My understanding is that at station depth the only real signal the SSBNs
could get was the ELF (?) signal which was on the order of bits per second?

i.e. it made a 300 baud modem look fast. So, assuming 30 bits/second, or
roughly 4 ASCII characters/second. 240 characters per minute.

Hm, yeah, I guess that's higher than I initially thought.

Given the great deal of bandwidth unused, it was easy to send such
messages to the boat.

This was actually a measure to *increase* security. Even if you can't
read someone's messages, knowing who is talking to who, and how much,
and when, can give valuable indicators that Something is Up. (This is
called traffic analysis, http://en.wikipedia.org/wiki/Traffic_analysis
.) To prevent the black hats from deriving this information from the
tempo and volume on the SSBN broadcast, the 'cast was kept going 24/7.


Hmm, makes perfect sense. You can separate the wheat from the chaff, but
presumably the enemy can't, so they never know if the actual content of the
signal is changing.


This doesn't of course apply to SSN's which weren't/aren't on 24/7
alert, and pick up their messages by coming to periscope depth at
intervals and snagging their messages from SSIXS.


Even then I'd think the ones on patrol would tend to stay hidden enough to
track and surprise the enemy.


Transmissions from a submarine are of course a great security risk,
and are thus restricted.


Obviously. Though I wouldn't be surprised if Bob thought this was somehow
unfair to the families who couldn't hear from their loved ones on a daily
basis. :-/



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



  #93  
Old May 1st 04, 08:08 AM
Derek Lyons
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Default NASA Studying Russian 12-month Plan

"Greg D. Moore \(Strider\)" wrote:
My understanding is that at station depth the only real signal the SSBNs
could get was the ELF (?) signal which was on the order of bits per second?


You assume our antennae and our hull are at the same depth, they
aren't. Underway we stream a buoy above/behind the boat that carries
our antennae.

i.e. it made a 300 baud modem look fast. So, assuming 30 bits/second, or
roughly 4 ASCII characters/second. 240 characters per minute.

Hm, yeah, I guess that's higher than I initially thought.


It wasn't ASCII, it was alphanumeric teletype code.

30 bits/sec = 6 chars/sec = 360 characters a minute.
360 chars/min *60mins/hour *24hours/day = 518,400 chars/day.

Not much by 'modern' standards, but a half a meg of text is a
substantial chunk. Even more when you consider a goodly number of the
'words' are actually abbreviations.

D.
--
Touch-twice life. Eat. Drink. Laugh.
  #94  
Old May 1st 04, 05:09 PM
Kevin Willoughby
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Default NASA Studying Russian 12-month Plan

In article , derekl1963
@nospamyahoo.com says...
Given the great deal of bandwidth unused, it was easy to send such
messages to the boat.


How much bandwidth was really required?

A message of "uh-oh, attack the *******s according to plan CRM114"
requires few bits, and if that message is delayed for 60 or 120 seconds,
it doesn't make much difference. *Reliability* constraints are quite
extreme, but I don't see high bandwidth as necessary.
--
Kevin Willoughby lid

Imagine that, a FROG ON-OFF switch, hardly the work
for test pilots. -- Mike Collins
  #95  
Old May 1st 04, 09:49 PM
bob haller
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Default NASA Studying Russian 12-month Plan


Obviously. Though I wouldn't be surprised if Bob thought this was somehow
unfair to the families who couldn't hear from their loved ones on a daily
basis. :-/


Actually I heard some exotic technology allowed increased communication.

Today its mostly nmeaningless, who are we hiding from.???
HAVE A GREAT DAY!
  #96  
Old May 1st 04, 09:51 PM
bob haller
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Default NASA Studying Russian 12-month Plan

fference. *Reliability* constraints are quite
extreme, but I don't see high bandwidth as necessary.
--


What you do is send out a stready stream 24/7 some legit other filler to
confuse the enemy
HAVE A GREAT DAY!
  #97  
Old May 1st 04, 11:23 PM
Derek Lyons
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Default NASA Studying Russian 12-month Plan

Kevin Willoughby wrote:

In article , derekl1963
says...

Given the great deal of bandwidth unused, it was easy to send such
messages to the boat.


How much bandwidth was really required?

A message of "uh-oh, attack the *******s according to plan CRM114"
requires few bits, and if that message is delayed for 60 or 120 seconds,
it doesn't make much difference.


In reality? Not very much. The problem however was twofold: We
still needed a higher bandwidth channel to receive routine operational
traffic, the frequencies available were limited by physics and
international treaty, and we needed to hide exactly what was being
communicated and when. (As I said in an earlier message, knowing who
is talking to who, and when, and how much, is almost as valuable as
knowing exactly what is being said.)

The answer was to combine all possible uses onto one higher bandwith
circuit.

*Reliability* constraints are quite extreme, but I don't see high bandwidth
as necessary.


Indeed, high reliability and high connectivity are the twin
principles that drive the design of the entire communications system.
Not only are there multiple transmission sites for the main broadcast,
there are backup methods of conveying the important stuff as well.

However, as I point out above, the need for and availability of higher
bandwith was driven both other issues than immediate tactical need.

D.
--
Touch-twice life. Eat. Drink. Laugh.
  #99  
Old May 3rd 04, 11:33 PM
Kevin Willoughby
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Default NASA Studying Russian 12-month Plan

In article , derekl1963
@nospamyahoo.com says...
Kevin Willoughby wrote:
*Reliability* constraints are quite extreme, but I don't see high bandwidth
as necessary.


Indeed, high reliability and high connectivity are the twin
principles that drive the design of the entire communications system.
Not only are there multiple transmission sites for the main broadcast,
there are backup methods of conveying the important stuff as well.


Is any of this publicly available? It would be quite a case-study in
reliability engineering.
--
Kevin Willoughby lid

Imagine that, a FROG ON-OFF switch, hardly the work
for test pilots. -- Mike Collins
  #100  
Old May 4th 04, 08:31 AM
Derek Lyons
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Default NASA Studying Russian 12-month Plan

Kevin Willoughby wrote:
In article , derekl1963
says...
Kevin Willoughby wrote:
*Reliability* constraints are quite extreme, but I don't see high bandwidth
as necessary.


Indeed, high reliability and high connectivity are the twin
principles that drive the design of the entire communications system.
Not only are there multiple transmission sites for the main broadcast,
there are backup methods of conveying the important stuff as well.


Is any of this publicly available? It would be quite a case-study in
reliability engineering.


The only public sources (which go beyond what I have written) of which
I am aware are largely dated, and concentrate more on the politics
than on the engineering. (I.E. mostly critical of the 'warfighting' of
the Reagan era vice the dying remnants of 'wargasm' that proceeded
them.) Those that don't fit that niche are of the 'gee-whiz Buck
Rogers' variety. Also most of them concentrate mostly on the very
different problems that the USAF faced.

Spinardi ("From Polaris to Trident : The Development of US Fleet
Ballistic Missile Technology") covers some of this if you can get a
copy, and the best (only) technical work on the SSBN/FBM system.

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




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