STS-117 (13A) Mission- Part II

Page 16 - Seeking answers about space? Join the Space community: the premier source of space exploration, innovation, and astronomy news, chronicling (and celebrating) humanity's ongoing expansion across the final frontier.
Toggle sidebar Toggle sidebar
Status
Not open for further replies.
M

MeteorWayne

Guest
Yes, not even the power up of the arrays, but just the mere connection may have increased noise on the power bus.<br /><br />Apparently the computers are very ? sensitive <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
D

dougbaker

Guest
From briefing on Nasa TV 6:30 eastern<br />Computers are very sensitive to noise.<br /><br />Noise from the truss could be the problem with the computers. Even when the power was off. First problems detected when connections made. <br /><br /><br />Trouble shooting overnight.<br /><br />Nasa working on procedure to look for noise.<br />Verifying procedure, will have it sometime today.<br /><br />Sorry to be redundant, when I was fixing the spelling and when I posted, others beat me to it.<br /><br />
 
B

baktothemoon

Guest
What do you mean by "noise"? You mean electronic interference or something like that?
 
M

MeteorWayne

Guest
Mission Status briefing still coming up in 12 minutes plus...6:45 EDT <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
M

MeteorWayne

Guest
Noise on the power bus. It's looking for pure DC voltage. Noise is variations from that.<br />Spiles, peaks, sags, etc.<br /><br />If the power supply is not designed to filter that, the spikes or dips can exceed or go below the operating voltage of the processor or memory chips.<br /><br />They don't like that, and their behavior can be erratic, or worse.<br /><br />That's why, if you have apower failure with your home PC it is better that it just clicks off, rather than sputter, with the voltage going up or down for a few seconds where the voltage gets into that goofy range. Same when it comes back up<br /><br />During a power failure, I always shut off the power strip for the computer (as well as freezer and fridge) so if it comes up ugly no damage is done.<br /><br />After 5 or 10 minutes, if it looks OK, I'll switch stuff back on.<br /><br />Some power supplies don't like to run on poorly filtered inverters of Generators. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
T

Testing

Guest
Yes, possibly a ground loop causing havock with the power supplies to the computers. Ground loops are bad for electronics of any kind, like feed back on a PA. <div class="Discussion_UserSignature"> </div>
 
T

Testing

Guest
Wayne, what do you do for a living? <div class="Discussion_UserSignature"> </div>
 
D

dougbaker

Guest
I am not an eletrical engineer, just a computer guy.<br />But yes, eletrical noise, is eletrical interferance. <br /><br />
 
E

erioladastra

Guest
Quick scribbles:<br /><br /><br />We were able to get one of the american to us converters working when the Russian computers were up for 7 minutes this morning. So at least some power is there. Then the computers went down. Looking at procedures to go into the pin level seetings and jumps start another one if needed. We used to have a computer path from the USOS to the FGB but that was broken years ago when the SM came up.<br /><br />We CANNOT undock without the Russian computers. You need the SMCC for Progress control. You need the SMCC to bring up the TORU for crew control. We might be able to do manual (ala Soyuz on Mir) but you are limited in time - you have to get back to essentially the exact right place in momentum before the CMGs can take over. Very trick (shuttle failed in this Monday). We don’t (yet) think we can do a manual desat.<br /><br />Code is not in english. We are talking to coders, engineers on their side.<br /><br />Many key systems can run without the computers - but many key including external thermal loop is not one of them. Can’t use the treadmill at all. Fire detection system is completely off-line without the computers.<br /><br />Ground testing years ago showed the RS comupters senseitive to power line noise - hence why folks are looking at the new US power system.<br /><br />Triple hardware failure is unlikely (yet, it did happen on 6A on the USOS!). But not liekly since this is 6 separate boxes. They can get 1-2 of each set up but then they quickly go down.<br /><br />We are taking the scope meter and working out to use it as an oscilliscope to measure line noise. We are also going to isolate the new US poer feeds from the RS before they try some more restarts.<br /><br /><br />
 
T

Testing

Guest
How do you explain a ground loop to a non techie? <div class="Discussion_UserSignature"> </div>
 
T

thereiwas

Guest
Ah, so they do have a 'scope on board. That is the perfect instrument to diagnose this sort of problem. And a multimeter. (and I <i>am</i> an electrical engineer.) <br /><br />
 
M

MeteorWayne

Guest
Any wire acts as an antenna to a certain extent.<br />Hence it picks up electroagnetic fields and converts them into volatges. <br />Even a ground wire. <br />In audio systems, it is standard practice to only ground one end of a line, if both are grounded any minute voltage differences between power supplies on the ends can result in hum. Just an example, not necessarily relevant. More later after the briefing is finished.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
M

MeteorWayne

Guest
Scope is probably more useful in this case. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
T

thereiwas

Guest
What I don't understand is why the restart attempts have to wait for the ISS to be over Russia. Don't we let them use TDRS? Or patch it thru to them?<br /><br />Right, given a choice I'd take the scope. A modern digital scope includes those other functions anyway.
 
M

MeteorWayne

Guest
Corrently unemployed. 35 years in the electronics biz.<br />Electronic and mechanical engineering for a few years, A few years as a Roadie for a band, 20 years at Tektronix in Test and measurement repair and calibration and metrology, the last decade plus specializing in Television products, then 5 years for Leitch, a TV broadcast and production equipment manufacturer as as field engineer.<br /><br />MW <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
M

MeteorWayne

Guest
A digital scope may or may not be the best choice, but it's probably what they have.<br />Give me a 465 any time <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
T

thereiwas

Guest
<blockquote><font class="small">In reply to:</font><hr /><p>Give me a 465 any time<p><hr /></p></p></blockquote><br />And it weighs 23 pounds! <img src="/images/icons/smile.gif" />
 
T

Testing

Guest
Methinks they have one of those Tecktronics handhelds aboard, good move. I love the new LCD storage scopes. <div class="Discussion_UserSignature"> </div>
 
M

MeteorWayne

Guest
Which is exactly why they probably have a lightweight digital scope on board.<br /><br />However, because a digital scope uses sampling, rather than the continual direct input to waveform of an analog scope, it can miss some things unless set up very carefully.<br /><br />Like any tool, it needs to be used well for the task at hand. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
T

Testing

Guest
God and I know what a 465 is, but now no more scopecarts! <div class="Discussion_UserSignature"> </div>
 
M

MeteorWayne

Guest
You may love em, as do I, but it takes some care and knowledge of it's charachteristics to search for a problem like this. <br />It's not just hook up the probes and the problem will show itself. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
M

MeteorWayne

Guest
A little strip of Velcro, and you can attach them to your forehead <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
T

Testing

Guest
True Sir, but we are running out of floorspace and walking thru the lab is getting difficult. <div class="Discussion_UserSignature"> </div>
 
D

dougbaker

Guest
you guys are very funny. <br />This must be very hard to explain to the general public. <br />They have limited understanding anyway. It is all just magic.<br />any remote control computer scopes?<br />that way the ground expert can pick the right parameters to look at the signal? <br />
 
Status
Not open for further replies.

Similar threads

M
  • Locked
Discovery: ISS 1J Mission (STS-124) Post Launch Thread
Replies
206
Views
26K
International Space Station
shuttle_guy
S
M
  • Locked
STS-129 Mission thread (Discovery) [Oct 2009?]
Replies
1
Views
2K
International Space Station
shuttle_guy
S
3
  • Locked
STS 126 (ULF2) Endeavour post launch mission.
Replies
87
Views
13K
International Space Station
Testing
T
M
  • Locked
Odyssey Mission Extended to Sept 2010
Replies
2
Views
2K
International Space Station
MeteorWayne
M
M
  • Locked
(1E) STS 122 Post Launch Mission thread
Replies
494
Views
31K
International Space Station
SpaceKiwi
S

TRENDING THREADS

Latest posts

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom