Space Team Online QuestChat
Date: November 5, 1998
Featuring: Sherri Carlson
Electrical Engineer
NASA Kennedy Space Center, Cape Canaveral, FL
[ Oran/NASAChatHost - 0 - 08:27:01 ]
Hello to our early arriving Space Team Online chat participants! Today's
Space Team Online chat with Sherri Carlson from NASA Kennedy Space Center
will begin at 9:00 a.m., Pacific Standard Time. Be sure you have read
Sherri's autobiography at http://quest.arc.nasa.gov/space/team/carlson.html
before joining this chat.
[ Oran/NASAChatHost - 1 - 08:29:16
]
Once the chat begins, Sherri will attempt to answer as many of your questions
as she can, but please be patient. Today's chat will be "moderated." This
means that only a few questions will be posted to the chat room at a time.
Don't worry if your questions do not appear on your screen immediately.
They will be posted as Sherri answers those ahead of you.
[ Oran/NASAChatHost - 2 - 08:29:40
]
As a reminder, remember to enter "Your Handle" in the box provided, before
posting questions to the chat room. Once you've done this, please let
us know that you have logged on for today's chat.
[ Oran/NASAChatHost - 5 - 08:31:32
]
At the conclusion of today's chat, we ask that you take a few minutes
to let us know what you thought about it. For your convenience, you may
use our online feedback forms at http://quest.arc.nasa.gov/qchats/qchat-surveys.
We look forward to hearing from you!
[ Oran/NASAChatHost - 7 - 08:32:02
]
RE: [Ashley] How many people are expected
here?
Ashley, we are expecting at least 50 participants for today's chat.
[ Oran/NASAChatHost - 8 - 08:51:56
]
Hello and welcome to today's Space Team Online chat with Sherri Carlson
from NASA Kennedy Space Center! Sherri works with 46 computers and almost
500 other electrical systems that will control all the subsystems on the
International Space Station. She is responsible for checking the designs
of the systems and making sure they will work together with the equipment
they control.
[ Oran/NASAChatHost - 9 - 08:52:14
]
And now, here is Sherri Carlson to answer your questions.
[ SherriCarlson/KSC - 12 - 08:54:08
]
Hello everyone! I'm ready for your Space Station questions so fire away!!
[ SherriCarlson/KSC - 13 - 08:55:29
]
RE: [David] Are we looking for lazer
communications in the future much like fiber optic cable is on earth?
Well, we are using some fiber technology on the station, but the communication
with the earth is Radio frequency. So I think we have a way to go before
we implement lazer technology for distance communication on spacecraft.
[ SherriCarlson/KSC - 14 - 08:56:24
]
RE: [Ashley/WashingtonJuniorHigh] *waves
hello* Hello
hello Ashley, you have some questions I can answer for you today? (I'm
waving back!)
[ SherriCarlson/KSC - 16 - 08:59:18
]
RE: [David] Do the extreme temperatures
of space effect the electronic components you use? Does this shorten the
life expectency? How about the negative atmospheric pressure? How do these
factors play with the life expectancy of components? Do they get replaced
each time the shuttle goes up?
We have made provisions to handle the extreme temps in space. Specifically
we have a external cooling system that uses ammonia to cool the components
on the outside of the station. Interior cooling systems use water as NH3
is a hazard to the crew.
[ SherriCarlson/KSC - 17 - 09:00:26
]
RE: [David] Do the extreme temperatures
of space effect the electronic components you use? Does this shorten the
life expectency? How about the negative atmospheric pressure? How do these
factors play with the life expectancy of components? Do they get replaced
each time the shuttle goes up?
All the station components, electrical and otherwise are required to 'live'
a minimum of 10 years. Typically we find components outlive the design
specifications by as much as three times, though. So they should be ok
for quite a while into the new century.
[ SherriCarlson/KSC - 20 - 09:02:27
]
RE: [SherriCarlson/KSC] All the station components, electrical
and otherwise are required to 'live' a minimum of 10 years. Typically
we find components outlive the design specifications by as much as three
times, though. So they should be ok for quite a while into the new century.
There is some provision to carry 'spares' but for the most part we have
a lot of redundancy built in to preclude it.
[ SherriCarlson/KSC - 21 - 09:02:52
]
RE: [Bob] Is there any problem with
the electronics anticipated with Y2K.
Please explain Y2K
[ SherriCarlson/KSC - 23 - 09:04:44
]
RE: [Yaitza] Hi! I wanted to know how
you plan for the unexpected when running all those sims? How to you account
for unknown variables
Wow. That is the biggest concern of my job! That's pretty much what I
do.
[ SherriCarlson/KSC - 25 - 09:06:45
]
RE: [Yaitza] Hi! I wanted to know how
you plan for the unexpected when running all those sims? How to you account
for unknown variables
Since I work software, my job 'touches' all of the other systems. So I
end up 'taking care of' the unexpected in test. Safety is our top priority,
first to personnel then to flight hardware. In fact, I was just (last
hour) identifying software issues that might 'crop up' and hurt something.
That type of analysis gets lot of attention as you can imagine! These
are things we are getting better at anticipatin rather than getting caught
by,
[ SherriCarlson/KSC - 26 - 09:08:03
]
RE: [Bob] I apologise, Chips that do
not recognise the year 2000.
We should be unaffected by that. All of our doftware code has been built
in the last two years, the firmware a little older than that but not significantly.
We are based in Ada and use 80186/286/386 machines for your reference.
[ SherriCarlson/KSC - 69 - 09:55:52
]
RE: [Wouter] Are there any more powerfull
computers in the International space station then the 80186, 80286 and
80386?
yes, one exception, the portable computers are pentium class
[ SherriCarlson/KSC - 27 - 09:09:43
]
RE: [David] Does electromagnetic radiation
play havock with your computers/communications much like lightening does
with radios on earth? What about solar flares and solar storms? Are voice
communications to space clear or like the fuzzy CB's here on earth? I
know you use frequencies in the gigahertz range, but are they clear?
SEUs, or single event upsets are a big concern for the electronics.especially
the top tier computers that handle the safing operations. We have a 'scrub'
algorithm that checks and corrects for single bit errors at 1Hz. Double
bit errors are flagged to operators on the ground and in some cases automatically
compensated for (with a redundant computer)
[ SherriCarlson/KSC - 30 - 09:11:19
]
Solar flares have been shown to increase the number of SEUs we experience
on Shuttle and Spacelab computers. Voice comm is pretty clear bt video
is not as good as you might expect. Too much bandwidth for great video
and we need it for other comm (example voice and safety data!)
[ SherriCarlson/KSC - 31 - 09:13:40
]
RE: [Yaitza] How do you start?
We start with a set of requirements to test. I wrote them for the Space
Station integrated testing. So then I look at the known software and hardware
problems and see how it will affect my 'tests.' If I need a function that
is not working in the software or if the hardware is missing or not working
properly, I can analyze if something will go wrong. This is a good method
for a good number of the problems but there are ALWAYS problems we cannot
anticipate. The trick id to build in enough safety that no one gets hurt
and we don't break any flight hardware.
[ SherriCarlson/KSC - 32 - 09:15:52
]
RE: [David] We have problems on the
F-14 with analog to digital converers. I know NASA doesn't use much analog
signals, but does the conversion present a problem? Do you use iterations
in the programming to correct for this?
We have some A/D problems as well, although non generic enough to affect
us across the board (that I know of). One I am aware of had to do with
the Command and Control MDM (the top-tier processors) internal temperature.
Since the conversion fails, we do not have an indication of the internal
temp. This is an example of the problems I work to anticipate (reference
Yaitza'a msg!).
[ SherriCarlson/KSC - 33 - 09:17:09
]
if the machine gets too hot and shuts down, we could have a safety concern
in test. So we levy a rqmt to fix it before we operate the flight hardware
in test (or at least identify a workaround to keep the configuration safe).
[ SherriCarlson/KSC - 36 - 09:26:17]
RE: [ Oran/NASAChatHost]
Sherri, can you give us a personal reflection about the recent launch
of STS-95?
STS-95 was amazing for several reasons. Firstly it is because it is a
shuttle launch! May sound trite but we never get tired of them here, they
are awesome. Especially since we see the effort that goes into each and
every one. Nothing goes unchecked and doublechecked.
[ SherriCarlson/KSC - 37 - 09:27:26
]
RE: [Oran/NASAChatHost] Sherri, can you give us a personal
reflection about the recent launch of STS-95?
Secondly because there were SO MANY people here! My goodness! In fact,
I did not even come in to my job site since the roads were literally flooded
with visitors. But I live so close I can see it from home.
[ SherriCarlson/KSC - 38 - 09:29:00
]
RE: [Oran/NASAChatHost] Sherri, can you give us a personal
reflection about the recent launch of STS-95?
And lastly because of Mr. Glenn. My dad-in-law worked on his first launch
here. It was like looking back in time to see it happen again (I wasn't
here for the first one!!). All of the astronauts are special, though.
I hope folks realize there are six other awesome individuals on the flight!!
[ Oran/NASAChatHost - 39 - 09:29:02
]
Sherri, sounds like things were really buzzing at the Cape leading up
to the launch.
[SherriCarlson/KSC - 41 - 09:33:15
]
RE: [David] What besides math and science
do my students need to learn to be proficient with computers and electronics?
i think 'people skills' are imperative! I say this because so many of
the anomalies we find here are related to communication problems. Specifically,
poorly written or misinterpretation of interface defintions (computer-to-copmputer)
and poorly documented problem reports contribute to a lot of lost time
and money, and in some cases put personnel and flight hardware at risk.
[ SherriCarlson/KSC - 44 - 09:35:45
]
RE: [David] What besides math and science
do my students need to learn to be proficient with computers and electronics?
Also it takes a skill to be able to talk technical issues with non technical
people. Very often key decisions are made by people other than the ones
who actually do the work and document the problems. One needs to be able
to convert very esoteric information to something a layperson can comprehend.
I find I use my communication skills as much or more often as my technical
skills.
[ SherriCarlson/KSC - 45 - 09:38:22
]
RE: [Yaitza] I am just starting college
and I want to become an electrical engineer. Are the any internships I
can try or mentor programs? Does KSC offer anything?
First, great! Electrical Engineering was my major! Secondly YES, there
are some really excellent programs out there. I took advantage of the
NASA co-op program. This allowed me to work and go to school on alternate
semesters. While it took a bit longer to get my degree, I had my pich
of assignments when I graduated because I had EXPERIENCE! Also since I
put myself through school, I earned income to do it. I cannot recommend
these programs highly enough! Each NASA center has this program and so
do a grat number of private companies.
[ Oran/NASAChatHost - 48 - 09:39:20
]
We would like to remind you to share your thoughts about today's chat
with us. At the conclusion of the chat, please send your comments to us
by using our online feedback forms at http://quest.arc.nasa.gov/qchats/qchat-surveys.
[ SherriCarlson/KSC - 49 - 09:40:05
]
RE: [Yaitza] I am just starting college
and I want to become an electrical engineer. Are the any internships I
can try or mentor programs? Does KSC offer anything?
One other word of encouragement. Don't get discouraged in school. Engineering
curriculum is challenging but do-able. When you see your friends changing
majors because it is 'too hard', stay the course. You'll be happy you
did. I changed my major the first time I went to college and was sorry
I did. I went back to engineering and am happy I did.
[ SherriCarlson/KSC - 50 - 09:41:12
]
RE: [David] When is the next Hubble
repair scheduled to happen?
Eeek, I must admit I don't know. NASA has several web pages that might
tell you. Sorry
[ Oran/NASAChatHost - 52 - 09:42:37
]
RE: [SherriCarlson/KSC] Eeek, I must admit I don't know.
NASA has several web pages that might tell you. Sorry
David, you may wish to check the NASA Johnson Space Center home page at
http://www.jsc.nasa.gov to learn
about upcoming mission and associated activities.
[ SherriCarlson/KSC - 54 - 09:46:39
]
RE: [Jennifer] Hi Sherry! I'm attending
college at the University of Oklahoma but am origionally from Houston.
I've worked at NASA for close to two years as a tour guide. My biggest
dream and goal is to become an astronaut and work on the Mars missions.
I would also LOVE to work on the space station. During the holidays I
will work temporarily at NASA again. I wanted to ask if you would give
me some interesting and/or exciting/informative facts about the space
station I can incorporate into my tour. In the past, I havn't known a
great deal about the space station to properly answer many of the guests
questions. Thanks!!!
Neat! I do some tours here as well. I especailly like it when we have
kids here. Some gee-wiz facts about Space Station? Well, it will be as
long and as wide as a football field when fully assembled. And it is easily
the greated integration challenge NASA has every faced.
[ SherriCarlson/KSC - 59 - 09:48:07
]
RE: [Jennifer] Hi Sherry! I'm attending
college at the University of Oklahoma but am origionally from Houston.
I've worked at NASA for close to two years as a tour guide. My biggest
dream and goal is to become an astronaut and work on the Mars missions.
I would also LOVE to work on the space station. During the holidays I
will work temporarily at NASA again. I wanted to ask if you would give
me some interesting and/or exciting/informative facts about the space
station I can incorporate into my tour. In the past, I havn't known a
great deal about the space station to properly answer many of the guests
questions. Thanks!!!
We have 12 International Partners although many people only know about
the Russians. The Japanese are providing a Lab Module (called the JEM
(Japanese Experiment Module) as are the Europeans (Columbus Orbiting Facility).
This is in addition to the US Lab flying next year.
[ SherriCarlson/KSC - 60 - 09:48:52
]
RE: [SherriCarlson/KSC] We have 12 International Partners
although many people only know about the Russians. The Japanese are providing
a Lab Module (called the JEM (Japanese Experiment Module) as are the Europeans
(Columbus Orbiting Facility). This is in addition to the US Lab flying
next year.
And we have over 500 individual computers on-board!
[ Oran/NASAChatHost - 61 - 09:49:05
]
As Sherri answers the final questions currently in the chat room, we would
once again like to ask for your feedback at http://quest.arc.nasa.gov/qchats/qchat-surveys/
at the conclusion of today's chat.
[ SherriCarlson/KSC - 62 - 09:50:10
]
RE: [Bob] David's question and your
answer prompted me to ask - With all the suppliers from contributing Countries,
is there a universal language (english)?
All the protocol agreements and specifications are in English. But I can
tell you from my Spacelab experience that things like software code comments
may be written in other languages. Even when translated, it can be very
difficult to follow!
[ SherriCarlson/KSC - 64 - 09:52:41
]
RE: [David] Do you forsee using xenon
ion propulsion system for any of the space station launches?
Not that I am aware of. All of the US elements are launched on the Shuttle
which uses cryo Hydrogen and Oxygen. I am not sure what the fuel / oxidizer
are for the Russian crafts. But I do not believe we are utilizing any
xenon ion propulsion. I wish I understood more and could answer you better,
one of our fluids engineers probably could.
[ Oran/NASAChatHost - 65 - 09:53:26
]
We invite you to join us on Thursday, November 12 at 10:00 a.m. Pacific
Standard Time for our next Space Team Online chat with Ric Adams from
NASA Kennedy Space Center. You can learn more about this chat at http://quest.arc.nasa.gov/space/chats.
[ SherriCarlson/KSC - 68 - 09:54:58
]
RE: [Oran/NASAChatHost] We will be ending our chat with
Sherri Carlson in just a few minutes. At this time, we would like to thank
you, our participants, for joining us for today's chat and for your GREAT
questions.
Watch us for our first US launch later this year! We are SO excited! All
the hard work will be worth it! Space Station is really important to NASA.
We will continue to make sure it works well and safely. Hope you will
join us in our excitement!
[ Oran/NASAChatHost - 70 - 09:55:54
]
A very special thanks to Sherri Carlson for sharing her time and expertise
with us online today!!!
[ SherriCarlson/KSC - 71 - 09:56:14
]
RE: [David] Many thanks from my class
of middle school students, May you have fair winds and following seas.
I enjoyed it as well. Good luck to all of you
[ Oran/NASAChatHost - 73 - 09:58:37
]
This concludes today's Space Team Online chat with Sherri Carlson from
NASA Kennedy Space Center!
[ Bob - 75 - 10:00:49 ]
Thank you for being with us. Having had the experience of watching the
first flight of John Glenn and seeing one more flight, Space is the new
frontier. It is good to know that we have a new generation of specialists
to carry us forward.
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