Space Team Online QuestChat

Date: July 21, 1998

Featuring: Robert Dempsey
I.S.S. flight controller
NASA Johnson Space Center, Houston, TX

[ Oran/NASAChatHost - 6 - 12:45:07 ]
Hello to our early arriving Space Team Online participants! The Space Team Online chat with Robert Dempsey from NASA Johnson Space Center will at 1:00 p.m., Pacific Time. Please be sure you have read Robert's autobiography at http://quest.arc.nasa.gov/space/team/dempsey.html before joining this chat. Once the chat begins, Robert will attempt to answer as many of your questions as he can, but please be patient. We ask that you post one question at a time, and please wait a few minutes before posting new questions. This will greatly help us to keep up with and answer your questions. As a reminder, please 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 - 8 - 12:51:38 ]
RE: [James/WillowAvenueMiddleSchool] Hi Everyone
Welcome, James! We will begin our chat shortly. Please stay with us!

[ Oran/NASAChatHost - 9 - 12:59:53 ]
Hello and welcome to today's Space Team Online chat with Robert Dempsey from NASA Johnson Space Center! Robert is part of a large team that works with each computer system that will operate the International Space Station. Since the station is not up in orbit yet, they are currently trying to learn how the system will work and figure out what steps they will follow when they operate the systems.

[ Bob - 11 - 13:00:59 ]
RE: [Oran/NASAChatHost] And now, here is Robert Dempsey to answer your questions.
Thanks Oran, my pleasure to be here.

[ Bob - 14 - 13:03:17 ]
RE: [James-James/WillowAvenueMiddleSchool] Robert, will zero gravity affect the computers?
Actually no, micro gravity does not really affect the computer systems. However, the environment in space is pretty harsh for computers. Those that will be on the outside face extreme heat and cold, and all face energetic chagred particles that can seriously damage them.

[ Bob - 16 - 13:06:35 ]
RE: [James-James/WillowAvenueMiddleSchool] Could just a little damage shut down the system?
Not the whole system but parts of it could be shut down. The really core (critical) systems have 2, or in some cases, 3 sets of equipment. Thus, if one experiences a problem, another one is there to immediately take control. However, some computers that control less critical may not have a backup. That is because if they fail we can then have an astronaut go, make a quick repair and start it up again.

[ Bob - 18 - 13:08:58 ]
An example of a non critical computer might be one controlling a video telecon with the astronauts. A critical one controls the life control, power and attitude of the space craft.

[ Bob - 19 - 13:10:47 ]
RE: [James-James/WillowAvenueMiddleSchool] I am assuming that all the systems are Y2K compliant.Am I right?
Well we hope it is! You might be surprised but some of the computers and the system were designed or built up to 10 years ago! But we have been working the Y2K problem for years and all should be good. In fact, this fall we will begin testing the entire time system and software to make sure. We are in good shape since we think we are all set and we are starting testing now.

[ Bob - 22 - 13:13:12 ]
RE: [James-James/WillowAvenueMiddleSchool] Good to hear that!
In a way that almost seems like a trivial problem. Trying to get 44 computers from 4 different countries to all work together is a bigger trick. This is especially true since they will not be in the same place to test until they are all on orbit!

[ Bob - 23 - 13:14:18 ]
RE: [James-James/WillowAvenueMiddleSchool] Do you know if there will be a Coca-Cola machine on the space station?
Well I believe there have been discussions to have a Coke machine up there - I know the astronauts would love to have one - but as of yet it is not scheduled. Probably later in the assembly they might have one.

[ Bob - 27 - 13:17:38 ]
RE: [James-James/WillowAvenueMiddleSchool] Do you think that other countries will have problems with the computer systems?
Well, it is not so much that they we will have trouble but that we all might. If in the US module something happens and we ship critical info the Japanese module, if they have trouble it could cause problems. But we are working NOW (the Japanese module is not going up for over 4 years) to make sure all is worked out before then. Takes LOTS of planning!

[ James-James/WillowAvenueMiddleSchool - 28 - 13:17:43 ]
Hi Stephanie

[ Bob - 30 - 13:18:17 ]
RE: [Stephanie/Edmonton] Good afternoon!
Good afternoon!

[ Oran/NASAChatHost - 31 - 13:18:25 ]
Stephanie, we're always glad to have you online. Welcome back!

[ Stephanie/Edmonton - 32 - 13:18:44 ]
Hi James. What grade are you in?

[ Bob - 39 - 13:22:36 ]
RE: [James-James/WillowAvenueMiddleSchool] I'm going into 7th Grade,Stephanie
James, Stephanie - so do you have any idea what you wish to do or study later on?

[ Bob - 45 - 13:25:44 ]
RE: [James-James/WillowAvenueMiddleSchool] Yep.I want to be a rocket scientist!
Cool! I wanted to be a rocket scientist ever since I was in first grade!

[ James-James/WillowAvenueMiddleSchool - 46 - 13:26:13 ]
That sounds like a cool job.

[ Bob - 50 - 13:28:44 ]
RE: [Stephanie/Edmonton] I want to be something in between aerospace engineering and planetary geologist. By the way, I'm going into gr. 10.
That is a good combination. IN college I started studying planetary astronomy, then switched to stars, then went into aerospace, and now I am here. IN the next 10-20 years there may be a lot of planetary probes and hopefully a manned tripped to Mars. We will need people with that background.

[ Bob - 34 - 13:19:20 ]
RE: [Stephanie/Edmonton] Is it hard for you to be communicating with so many people around the world?
Well, that is the joy of modern technology - it is realtively easy. I am sitting here in my office doing this - never have to leave here! IN my job you have to get used to doing several things at once - it is very critical when we are doing a mission.

[ Bob - 36 - 13:21:00 ]
RE: [James-James/WillowAvenueMiddleSchool] What types of projects will be worked on? Anything Top-Secret?!
All kinds of projects but none top secret. Most will be experiments in biology (how life reacts to zero-G), chemsitry (how to make better drugs or materials), remote sensing of the earth (where you look and photograph the earth to do science).

[ Bob - 41 - 13:23:29 ]
RE: [James-James/WillowAvenueMiddleSchool] Will the space station run on all solar power?
Yes, totally on solar power. There will be big solar panels that collect the sun. The core computer systems will make sure that as the station orbits the earth the panels are always pointed to the sun (when visible).

[ Bob - 42 - 13:24:51 ]
RE: [Stephanie/Edmonton] Do you know of any of the results of the microgravity combustion experiments?
You mean the experiements done on the shuttle? I know a little about them but not too much. They basically showed that fire behaves very different in zero-G. Since you don't have gravity you don't get convection so fresh oxygen is not sucked into the fire. Thus shortly the fire will burn itself out.

[ Bob - 47 - 13:27:08 ]
RE: [James-James/WillowAvenueMiddleSchool] What happens if a solar panel breaks or crashes into something ( like on Mir )?
Then we have what we say as "a bad day". If one just fails or breaks then we are probably ok. Like the computer we tried to build in redundancy into the key systems. So if we lose one, we will power down some less critical stuff and have the astronauts go fix it. It is not likely that a solar panel could hit the station.

[ Bob - 51 - 13:29:44 ]
RE: [Stephanie/Edmonton] Will there be lots of space junk in the vicinity of where the ISS will be orbiting. I'm glad of its 51.6 inclination so I can view it!
There will be some space junk. The station is shielded from the small stuff but a big piece could be a problem. If it is big enough we will track and see it first and then move out of the way.

[ Bob - 52 - 13:30:28 ]
RE: [James-James/WillowAvenueMiddleSchool] Well Mr. Dempsy, it looks like your dream came true!
Yes. I am doing all the things I like to do.

[ Bob - 55 - 13:32:08 ]
RE: [James/WillowAvenueMiddleSchool] how much memory is in the computers?
Well you will laugh but the largest computer has 1 megabytes of memory and has a 386 processor! However, some will have hard drives like a PC with 1 gigabyte of memory. Plus the astronauts will take laptops with them that have a little more memory and are even Pentiums.

[ Bob - 57 - 13:33:33 ]
RE: [Stephanie/Edmonton] When will be the next Hubble servicing mission?
The next mission will be in December 1999 or January 2000. They will put on some new solar panels and "fix" the Near Infrared Imagimg Camera. By the way, I used to work with the Hubble for 5 years before coming here - both as an observer doing research and operating the vehicle.

[ Bob - 58 - 13:34:40 ]
RE: [James-James/WillowAvenueMiddleSchool] What subjects should I be taking in school?
Math, science and more math! You can't get enough math. While astronomy or physics can be good, really any science is good.

[ Bob - 61 - 13:36:29 ]
RE: [James-James/WillowAvenueMiddleSchool] Thanks. My mom will love to here that
You are welcome.

[ Bob - 64 - 13:38:17 ]
RE: [Stephanie/Edmonton] Why are the pictures from WFPC2 cut off (jagged) like that?
WFPC2 is a different instrument and they are looking wonderful. In fact so nice that NASA has announced they will add a WFPC3 in 2002 - not originally planned. No, the infrared camera has to be kept zeveral hundred degrees below zero to work. Due to a problem it will run out of liguid helium (which keeps it cold) this fall. So they will lieterally tack on a fridge on the outside which will mechanically cool it!

[ Bob - 66 - 13:39:07 ]
RE: [Stephanie/Edmonton] Should I take CADD if I want to be an engineer?
It would help. Now a days, things like CADD are used heavily in our work. The more computer stuff like that you know the better.

[ Bob - 67 - 13:40:27 ]
RE: [James-James/WillowAvenueMiddleSchool] I was in a wind tunnel at Nasa Langley Research Center on vacation.There was a really big echo and I was surprised at the size of the tunnel.It was considered small!
You should see the ones out at Ames research center in california - they are big enough to put a large, full size plane in them. Amazing. At the university of Michigan they used to have a medium one. Once a year they would let people go in and they would turn it on and blow people in to a pile of cushions!

[ Bob - 70 - 13:41:41 ]
RE: [Stephanie/Edmonton] Have you seen Armageddon? If so, what do you think of its scientific accuracy?
Have not seen the movie but want to since they filmed some of it here at NASA in Houston. However, from clips etc I see they have some major problems - for example the shuttle could not take off from the asteroid without the big external tank used during launch.

[ Bob - 71 - 13:42:33 ]
RE: [Stephanie/Edmonton] Is Node 1 or another Russian module being put up in orbit first?
The russian FGB (functional cargo block now called Zarya for sunrise) will go first late November. Then the Node 1 (or Unity) will go early December.

[ Bob - 72 - 13:42:48 ]
RE: [James-James/WillowAvenueMiddleSchool] That must have been fun!!!!!!!!!!!!!!!!!!!
Yes it was!

[ Bob - 74 - 13:44:37 ]
RE: [Stephanie/Edmonton] Is Node 1 or another Russian module being put up in orbit first?
Stephanie - where are you thinking of going for college, if you have thought that far yet :)

[ Bob - 76 - 13:46:00 ]
RE: [James-James/WillowAvenueMiddleSchool] Do you work with computer graphics a lot? Should I take that course in school?
Yes, I use computer graphics all the time. Between my astronomical research with Hubble and my work here I have used most computer graphical and software systems available. And that experince has been very useful

[ Bob - 77 - 13:46:54 ]
RE: [Stephanie/Edmonton] Do you think NASA will be more lenient on the sight requirements for astronauts in the future?
I REALLY, REALLY hope so! I made it it pretty far in the astronaut selection but then was rejected because of my eyes!

[ Bob - 79 - 13:48:08 ]
RE: [Stephanie/Edmonton] Do you think NASA will be more lenient on the sight requirements for astronauts in the future?
Keep in mind they have already relaxed them some in recent years. Are you interested in becoming one?

[ Bob - 81 - 13:48:53 ]
RE: [Stephanie/Edmonton] I have no idea of where to go to college. I'm in Canada, and there are very few space courses to take. I'm thinking of taking B.S. in mechanical engineering and going somewhere like Caltech for planetary science. Who knows?
Yes, who knows. Read my bio and you will see that you can never really predict your path even when you know what you want!

[ Bob - 82 - 13:50:12 ]
RE: [James-James/WillowAvenueMiddleSchool] Do you read Popular Science or Popular Mechanics?I read them and I think they are pretty interesting.What do you think of them?What do you read?
I used to read them in the past. But lately I tend to read Sky and Telescope, Scientific American, Smithsonian and Space News. I would like to read Aviation Week (started subscribing in high school actually) but don't always have time to read it and it is expensive.

[ Bob - 85 - 13:51:27 ]
RE: [James-James/WillowAvenueMiddleSchool] What college should I go to? I live in New York?
Well it really depends on what you want to do. SUNY at Stony Brook is pretty good. Boston (MIT) is not too far, and Penn State UNiv is also very good.

[ Bob - 87 - 13:52:30 ]
RE: [Stephanie/Edmonton] Yes, I REALLY want to be an astronaut, but I wear glasses and probably over the 20/200 (I think) limit for mission specialists.
Well you can get that checked. I suspect they will relax the 20/200 limit. But you also have to make sure the total corrective refractive error (a fancy way of saying how strong your glasses are) is under their limit.

[ Bob - 89 - 13:53:04 ]
RE: [Stephanie/Edmonton] Do you like hockey? :)
I grew up in Detroit - home of the Stanley Cup champs for 2 years in a row!

[ James-James/WillowAvenueMiddleSchool - 88 - 13:52:52 ]
I like hockey :)

[ Bob - 91 - 13:55:49 ]
RE: [James-James/WillowAvenueMiddleSchool] I hope you can be an astronaut. Sounds like you can be a really good one!:)
Thanks. And I will keep trying - thats what it takes!

[ James-James/WillowAvenueMiddleSchool - 92 - 13:56:09 ]
Mr. Dempsy, how big will ISS be (dimensions)?

[ Bob - 93 - 13:57:30 ]
When complete, big enough to see from the earth! 359 feet (108 meters) wide, 290 feet (87m) long, weigh 470 tons and hold 7 people.

[ Bob - 95 - 13:58:33 ]
RE: [Stephanie/Edmonton] Good luck in your quest to be an astronaut!
Thanks - you too!

[ Bob - 100 - 14:00:07 ]
RE: [Stephanie/Edmonton] How many modules will make up the space station?
Well there are about 35 pieces - some are modules some are solar panels on trusses.

[ Oran/NASAChatHost - 101 - 14:00:33 ]
RE: [Stephanie/Edmonton] This was a great chat. Thanks!
Stephanie, we're glad you could join us once again. Check the STO chat schedule at http://quest.arc.nasa.arc.gov/space/chats/index.html for upcoming chats. We hope you can join us!

[ Bob - 102 - 14:00:39 ]
RE: [James-James/WillowAvenueMiddleSchool] Have you ever worked on anything Top-Secret? I'll understand if you can't say.
Well, no I haven't and you can believe me that I am not denying it because I have. Astronomy is never top secret! :)

[ Bob - 104 - 14:00:51 ]
RE: [Stephanie/Edmonton] This was a great chat. Thanks!
Your welcome!

[ Bob - 105 - 14:01:11 ]
RE: [James-James/WillowAvenueMiddleSchool] Thanks Mr. Dempsy. Good luck Stephanie!
Good luck. Thanks for the good questions!

[ James-James/WillowAvenueMiddleSchool - 106 - 14:02:04 ]
Bye!