Aero Team Online QuestChat

Date: October 15, 2001

Featuring: Imelda Terrazas-Salinas
Ames Research Center

Mon Oct 15 http://quest.arc.nasa.gov/aero/events/centennial/

[ Lori/NASAChatHost - 1 - 16:45:02 ]
Imelda Terrazas-Salinas will chat in Spanish and English. Imelda manages the arc jet, which is a facility for testing thermal protection materials.

[ Lori/NASAChatHost - 2 - 16:45:14 ]
You may go ahead and place questions in the chatroom now to be answered during the webchat. Please don't post test messages or repeats -- though you may not see your question, it is in the chatroom. Again, PLEASE do not repeat your questions. Enjoy the chat :-)

[ Susan/NASAChatHost - 4 - 09:27:15 ]
Buenos días! Imelda puede contestar sus preguntas en Español e Inglés.

[ Susan/NASAChatHost - 5 - 09:32:01 ]
Imelda trabaja en el "arc jet facility" la cuál es una instalación de NASA Ames, dónde se prueban materiales para protección contra las altas temperaturas.

[ Susan/NASAChatHost - 6 - 09:44:16 ]
Mándenos sus pregutas e Imelda se Las contestará durante su plática. No repita su pregunta aunque no la vea en su pantalla. Nuestra moderadora mostrará sus preguntas en El orden que Las recibe.

[ Lori/NASAChatHost - 7 - 10:48:36 ]
Hello to our early arriving participants! We will be starting in about 10 - 15 minutes!

[ Lori/NASAChatHost - 8 - 11:00:05 ]
We are ready to begin our webchat with Imelda! Welcome Imelda :-)

[ Imelda/ARC - 13 - 11:03:41 ]
RE: [Carmela] Es difícil trabajar en la NASA?
Carmela, Trabajar en Las NASA Es casi como cualquier otro trabajo en ingenieria. A veces Es dificil, a veces no. Si esta uno bien preparado con una buena educacion, no Es dificil.

[ Imelda/ARC - 15 - 11:04:54 ]
RE: [Efram] En su campo, necesita estudiar muchas matemáticas?
Efran, Si.

[ Imelda/ARC - 18 - 11:05:57 ]
RE: [Scott] How did you get interested in working at the arc-jet?
Scott, I was initially interested in working in the wind tunnels, but my first job involved arc jet testing and I found this was a very challenging area.

[ Imelda/ARC - 19 - 11:07:03 ]
RE: [John] Is it dangerous to work at the arc jet?
The arc jets can be very dangerous. We take a great deal of safety precautions in operating them, and this mitigates the risks significantly. If we are all careful, there's not much to worry about.

[ Imelda/ARC - 21 - 11:07:42 ]
RE: [Henry] Have you seen a shuttle launch?
I saw a shuttle launch once, but it was just as all the other tourists do, from far away.

[ Imelda/ARC - 22 - 11:09:03 ]
RE: [Susan] Where did you grow up?
I grew up in various places, mostly in Daly City, California (just south of San Francisco). I was born in Mexico and did some growing up there, before coming to the U.S.

[ Imelda/ARC - 24 - 11:10:09 ]
RE: [Mike] How many tests does the facility run in ayear?
We do many runs per year. I think our record is about 900 runs in one year (I'm not sure about the exact number, I'd need to go back through our records). I think our average is more like 600.

[ Imelda/ARC - 28 - 11:11:19 ]
RE: [Maria] Hay muchas mujeres en NASA?
Maria, Aqui donde yo trabajo, no hay muchas mujeres. Yo soy la unica ingeniero/a en nuestro grupo.

[ Imelda/ARC - 29 - 11:12:22 ]
RE: [Julia] I didn't really get what you said in your biographe about different runs for each test . Can you say more about that?
It's just a bookkeeping scheme that we use. Every customer is assigned their own test series. Within that test series, we count the number of runs performed for that customer.

[ Imelda/ARC - 31 - 11:14:27 ]
RE: [Efram] Qué cursos de matemáticas me recomiendas tomar ?
Efran, Necesitas tomar todos los cursos que puedas. En la escuela primaria y secundaria, Los cursos estan en order. Tomalos en la order recomendada por tu escuela. Luego en la universidad, debes seguir tomando cursos segun tu area de estudio. Tal vez en tu tercer ano de universidad, puedes dejar de tomar matematicas.

[ Imelda/ARC - 34 - 11:15:33 ]
RE: [Benny] Are all the tiles on the shuttle replaced after each flight?
No. The goal is not to have to replace any tiles, but some do get damaged and must be replaced. One of the areas of research is making more-durable tiles that won't have to be replaced as often.

[ Imelda/ARC - 35 - 11:16:07 ]
RE: [Dena] What hold the tiles to the shuttles?
They're basically glued on with a high temperature adhesive (RTV).

[ Imelda/ARC - 37 - 11:17:23 ]
RE: [Bob] Besides the shuttle, what else uses thermal protection tiles?
All vehicles that perform an atmospheric entry, whether into earth's atmosphere or some other planet's. The Mars entry missions use it, as do missiles. Every application requires different materials.

[ Imelda/ARC - 40 - 11:18:40 ]
RE: [Julia] Does the same test get run more than once or do they try different things in each test?
We do a little of both. For shuttle-tile-type materials, we usually run them several times. Higher-temperature materials usually get run only once.

[ Imelda/ARC - 41 - 11:20:28 ]
RE: [Nicole] does the arc jet use a lot of power?
Our power requirements depend on the type of test we're doing. Low-power tests run about 8 MW (that's million watts). Our high-power facility runs about 60 MW.

[ Imelda/ARC - 43 - 11:22:04 ]
RE: [Maria] Por que no hay muchas mujeres?
Maria, Creo que simplemente a Las mujeres no les ha interesado la ingenieria. Tal vez tambien Es por como nos hemos criado tradicionalmente. Muchas veces, a mi me preguntaban que si porque ingenieria, porque no algo mas tradicional?

[ Imelda/ARC - 45 - 11:24:09 ]
RE: [Justin] What happens when a test doesn't run properly? Can you give an example?
We try again. There are lots of things that can happen, from the somewhat simple that the facility won't run, to a failure of the test materials. When the facility won't run, we start trouble-shooting to find the cause of the problem. When we get the facility running again, we just resume the test. If the test materials fail, the customer (owner of the materials) must do some analysis and maybe modify their formulas and come back for more tests.

[ Imelda/ARC - 47 - 11:26:24 ]
RE: [Brooke] Have you used the arcjet facility to test materials other than those for thermal protection (i.e. meteoroid/orbital debris shielding?)? What is the benefit of the arcjet tester over other methods such as hypervelocity impact testing using light-gas guns?
In recent years, we are mostly doing materials testing. In their history, the arc jets have been used for other studies looking at meteoroid impact phenomena. The advantage of the arc jets is that they produce high temperature conditions for long durations. The gas guns are limited in their test time. We don't typically do impact studies -- these are also done in our branch, but using hypervelocity guns.

[ Imelda/ARC - 49 - 11:28:58 ]
RE: [MsWilson/8thgrade] What advice would you give students interested in aeronautics today?
That's a tough question. Obviously, they need to plan for a college education, take all the science and math classes available to them. If they are really serious about aeronautics, look for a college with an aeronautics department.

[ Imelda/ARC - 50 - 11:30:04 ]
RE: [Ben] Do you have to know about chenistry for your job?
Chemistry helps. It helps you understand what's going on in the test gas and the interactions of the materials you're testing.

[ Imelda/ARC - 54 - 11:31:54 ]
RE: [Tonie] What is the biggest challenge your group faces now?
Our biggest challenge right now is getting our job done with the current resources. Or did you mean technically?

[ Imelda/ARC - 57 - 11:35:05 ]
RE: [Molly] How can you tell when an individual heat shield tile fails, though it doesn't cause the others to fail?
They perform physical inspections. Failure can be subjective. You have to judge it relative to what it must accomplish. Sometimes a material may look really bad, but it does its job of protecting what's underneath it.

[ Imelda/ARC - 59 - 11:36:12 ]
RE: [Maria] En su trabajo, habla usted Éspanol?
Por lo regular, no. En MI grupo no hay mucha gente que habla espanol.

[ Imelda/ARC - 60 - 11:38:29 ]
RE: [MsWilson/8thgrade] What is your typical day like?
My days vary widely. There's the slow days, when I get a chance to catch up on my paperwork; then there are the test days. When we're doing a test, most of my day is spent in the test facility setting up some aspect of the test. The tests go very fast once they get started. There's the pre-run preparation, the run, and post-run data analysis. We typically do several runs per day.

[ Imelda/ARC - 63 - 11:40:58 ]
RE: [Nick] What other things have you tested as a test engineer?
Most of our tests deal with thermal protection materials. We did many tests for X-33 -- one of the tests was for an antenna window. We've tested leading-edge shapes. Many configurations, but all relating to TPS.

[ Imelda/ARC - 66 - 11:42:44 ]
RE: [Natalie] How do you use mathematics and science in your job daily?
It's such a big part of the job, that you don't really think about it much. I need to do many calculations; you need the math and science background to understand what's going on in the facility; especially when things don't go as you expected.

[ Imelda/ARC - 68 - 11:45:12 ]
RE: [Tonie] I know money is always a problem I meant technical challenge.
Tonie, sorry. We are always getting new challenges. The facilities were primarily developed for shuttle testing; so now with new programs coming along, they all want to test beyond our normal operating range. So our challenge is usually finding a way to run the facilities to give the customers the conditions they request. Lately, I've been getting a lot of these weird requests, where they want to test at both ends of the operating envelope at the same time.

[ Lori/NASAChatHost - 69 - 11:46:19 ]
Great questions! Please check the Calendar of Events for more events related to the Centennial of Flight Celebration, and our other events.

[ Imelda/ARC - 71 - 11:46:45 ]
RE: [Erik] How long have you been at NASA & how did you get to the job you have today?
I have been here since 1988. I was introduced to my first "boss" by a college professor.

[ Imelda/ARC - 72 - 11:48:10 ]
RE: [Jackson] Who is right -- Bernoulli's Principle or Newton's Law?
I was not aware that they were in contradiction. As far as I know, both still hold (admittedly, it's been a while, and I might need a refresher).

[ Lori/NASAChatHost - 73 - 11:48:48 ]
We have about 15 minutes left of our webchat with Imelda Terrazas-Salinas. Please take a moment & give us your feedback on the new NASA Quest re-design, and this webchat -- fill out our online survey.

[ Imelda/ARC - 77 - 11:50:28 ]
RE: [Molly] What are certain qualities you look for in acceptable materials for thermal protection?
Every material is tailored to its application. Usually, you judge it based on how it protects its structure. For testing, the materials are usually mounted to some sort of aluminum structure. You monitor the temperature of the aluminum. If it keeps the aluminum at an acceptable temperature, then it's probably a good material for that application.

[ Imelda/ARC - 78 - 11:51:12 ]
RE: [Jerry] Do you test things for regular aircraft?
No, not usually. I can't remember any such tests.

[ Imelda/ARC - 80 - 11:53:08 ]
RE: [Henry] En NASA hay muchas personas muy inteligente?
Como en cualquier lugar, aqui hay de todos. Si hay muchos cientificos muy inteligentes.

[ Lori/NASAChatHost - 81 - 11:54:16 ]
We have time for 2-3 more questions, before our time is up.

[ Imelda/ARC - 82 - 11:54:43 ]
RE: [Stella] Donde quiere éstar en vente años?
Me gusta mucho MI trabajo. Me gustaria estar aqui todavia, claro que con mas responsabilidad.

[ Imelda/ARC - 83 - 11:57:06 ]
RE: [Blaber] I am a Independent study student and I was wondering how we could incourperate Material science into a classroom project.
Have you checked out our teacher's resource center? They might have a little study sheet on TPS. A very popular demonstration is to show a torch heating shuttle tile while you hold the tile in your hand.

[ Imelda/ARC - 84 - 11:59:18 ]
RE: [Jackson] What kinds of materials are used for thermal protection now?
We are experimenting with UHTC's -- ultra high temperature ceramics. These use exotic materials such as halfnium diborides and a couple of other diborides. I haven't been keeping up on these lately.

[ Lori/NASAChatHost - 85 - 12:00:17 ]
I want to thank all of our participants for joining us today. Also a big thanks to Imelda for sharing her time and her NASA expertise with us today! Join us again . . . Have a great day :-)

[ Imelda/ARC - 86 - 12:00:25 ]
Thank you everyone for participating. I enjoyed chatting with you.

[ Maria - 87 - 12:01:30 ]
Adios!