June 27, 2000
QuestChat with Christine Johnson
NASA Ames Research Center, Moffett Field, CA
Tue Jul 18 11:16:02 2000
The expert's featured url: http://asm.arc.nasa.gov/asm
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Hello to our early arriving chat participants. Today's NASA Quest Aerospace/Space
Team Online chat with Christine Johnson from NASA Ames Research Center
will begin in approximately 15 minutes. Be sure you have read Christine's
profile at http://quest.nasa.gov/aero/team/cjohnson.html to
prepare your questions.
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Once the chat begins, we will post a few questions in the chat room at
a time. This will help Christine keep up with us. You only need to submit
your questions once. We will post new questions for Christine every few
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At the conclusion of the chat, please visit our NASA QuestChat Information
Center at http://quest.nasa.gov/qchats to send us
your feedback about today's chat. We look forward to hearing from you
- 8 - 09:50:05 ]
RE: [Stephanie/Edmonton] Hey Oran!
Coming to you from the Space Physics Lab!
Stephanie, always a pleasure to have you online with us. We'll get started
in about 10 minutes. So please stay tuned. Great to hear form you again!
- 9 - 10:00:16 ]
Hello and welcome to today's NASA Quest Aerospace/Space Team Online chat
with Christine Johnson from NASA Ames research Center.
- 10 - 10:00:34 ]
Spacecraft that enter other planet's atmospheres, like Mars, also need
thermal protection system (TPS) materials to protect them spacecraft from
burning up. Christine Johnson spends much of her time developing new TPS
materials for spacecraft used in planetary exploration and sample gathering.
- 11 - 10:00:55 ]
RE: [Oran/NASAChatHost] Hello and welcome to today's
NASA Quest Aerospace/Space Team Online chat with Christine Johnson from
NASA Ames Research Center.
- 12 - 10:01:05 ]
And now, here is Christine Johnson to answer your questions.
- 13 - 10:01:55 ]
RE: [Oran/NASAChatHost] And now, here is Christine Johnson
to answer your questions.
- 17 - 10:06:21 ]
RE: [Stephanie/Edmonton] Hi Christine!
What did you get to do in SHARP?
I worked at NASA Dryden Flight Research Facility in Southern California
and got to work on a flow experiment on the F-14 (Top Gun fighter plane).
We had a "glove" on one wing and were doing experiments to try to evaluate
how much laminar (smooth) flow was going over the wing. Laminar flow is
important because it is better for the efficiency of the aircraft.
- 18 - 10:07:08 ]
RE: [Stephanie/Edmonton] I am in a similar
science research opportunity for high school girls. Actually now, I am
working on Interplanetary Magnetic Field data in the Space Physics Lab
at the university.
How wonderful! Keep that up!!
- 22 - 10:10:20 ]
RE: [Linda-Ms.Wallin/SEDOL] How do we encourage
our girls to pursue an interest in science, math or technology when there
is pressure from our society to see the role of women as being pretty
but not too smart.
I think teachers play an important part to encourage the girls in the
class to explore math and science. There are several Women Engineering
Groups that are really trying to encourage young girls to explore the
technical fields. And hopefully, we can continue to increase positive
role models (women astronauts, etc), and even chats like these, to interest
girls to shoot for the stars!!
- 24 - 10:11:39 ]
RE: [Stephanie/Edmonton] Could you describe
the shuttle's thermal blankets?
There are a couple of types on the shuttle. For very low temperature areas,
we use felts and for higher temperature areas we use ceramic, quilted
blankets, that are actually stitched.
- 25 - 10:12:44 ]
RE: [MrSmith/RCTC-Mr.Smith/RCTC] Was that
the same series of experiments that involved a section of the aircrafts
wing having hundreds of small holes in it?
We did have an experiment of that type to try to actually "suck" the outside
air into those holes, to create a smoother flow over the wing surface.
- 28 - 10:16:13 ]
RE: [Grace-gfrantz/DeerPathMiddleSchool] Hello
from Deer Path Middle School in Lake Forest, Illinois. In a class chat
session, we have been discussing the gender gap in Math, Science and Technology
What a pleasure it is to be chatting with someone who stands at the top
of her field and is enjoying work in what used to be a male dominated
area. In the development of new materials that stand the test of such
extreme heat, do you work in teams or independently?
Hello Deer Path! I do really enjoy this work and am glad I pursued this
field. My dad and all my brothers are engineers (and my Mom is a third
grade teacher!) so I grew up with a technical family and was encouraged
to pursue it. We generally have technical "leads", which are one person
for a particular material (blankets, ablators, etc.). These people lead
the research which involves many other people. We also support a lot of
projects these days (Mars Pathfinder, etc) and we have a team of people
- 29 - 10:18:02 ]
RE: [Mr.Smith/RCTC] Were the experiments
on laminar flow disigned to improve the fuel effeciency of the aircraft
or its preformance?
Yes, the experiments were primarily looking at ways to improve the fuel
efficiency of aircraft. This has important applications to the airline
industry to hopefully continue to make our travel less expensive!
- 33 - 10:23:13 ]
RE: [Linda-Ms.Wallin/SEDOL] Is there any
sort of a routine with your work? How much of your time is spent in research,
theory and/or working with materials?
Right now there is a big interest in Mars and we have been building spacecraft
to go there every few years. Since all these spacecraft need TPS, we have
to support these projects. So right now, I spend most of my time supporting
actual projects. We design a TPS for a particular mission, and make test
models to make sure our design will work. Lately I have been spending
most of my time supporting these projects and arc jet testing materials,
and only a small amount of time doing research. I also do a lot of report
writing. It is mostly "hands-on" work, which is really fun!
- 35 - 10:25:29 ]
RE: [Stephanie/Edmonton] Are there different
factors to consider while designing a heatshield for spacecraft reentering
from outside Earth orbit (Apollo) as opposed to one just deorbiting (shuttle)?
Good question! Yes - a spacecraft that is coming back from the moon or
another planet, for instance, is going MUCH faster than a vehicle re-entering
from low earth orbit. Faster means hotter, so we have to protect them
- 37 - 10:26:46 ]
RE: [Mr.Smith/RCTC] Have you had
any involvement in the Deep Space 1 mission or in its experimental Ion
No, but we worked on the Deep Space II Microprobes that recently entered
Mars. We developed a new heatshield material for those two probes.
- 38 - 10:30:30 ]
RE: [Linda] I think it's interesting
that you need good writing skills. My sons would go into science to avoid
writing papers! How much of your education was spent on learning good
writing skills? Do you get any training from Nasa on how to write these
It is definitely important to have good writing skills for most careers,
I believe. You need to be able to communicate to others, both in speaking
and writing, to get your work across to others. I always enjoyed English
classes and writing reports, but I found it interesting that for my engineering
degree in college, they only required 1 English class!! Hopefully the
curriculum has added more of that, because it really is a critical skill!
NASA does offer training courses for MANY things, and I did take a report
writing class to work on those skills.
- 39 - 10:31:58 ]
We appreciate your patience as Christine answers your questions as quickly
as she can. As a reminder, at the conclusion of today's chat, please visit
our NASA QuestChat Information Center at http://quest.nasa.gov/qchats to send us your comments. We look
forward to hearing from you!
- 41 - 10:36:44 ]
RE: [Mr.Smith/RCTC] Do you just develope
the meterals that heatshields are made from or do you actually manufacture
the shields in house?
Ideally, we develop the materials and then transfer the technology to
industry for production. But recently, there has been such an interest
in our lightweight materials that we sometimes have to manufacture them
in-house to meet the project schedule! For instance, the back plate TPS
on Mars Pathfinder was manufactured here at Ames, and the same material
was manufactured here to support the X-34 vehicle. It takes time to transfer
the technology to industry, and some projects don't have the time to wait!
- 42 - 10:40:07 ]
RE: [Grace-gfrantz/DeerPathMiddleSchool] Within
each research group, other types of engineers, mathematicians and scientists
must be represented. What percentage of your working time is spent on
Sorry Deer Path! Just noticed your question at the top of my screen! I
spend a lot of time on my computer plotting data, writing reports, e-mailing
to people on projects, etc. I have a good mix of hands-on in the lab with
models and testing and computer work.
- 46 - 10:43:57 ]
RE: [Stephanie/Edmonton] How might
aerogel be incorporated into the shield?
Interesting question because we have been looking into that. There is
one group of people here that are developing ways to put the aerogel inside
other materials to lower the thermal conductivity of the material. Aerogel
is a fantastic insulator, but is so fragile. We have to come up with novel
ways to make use of those fantastic properties while still having a strong
- 47 - 10:44:16 ]
RE: [Grace] Thank you for an interesting
and educational chat! Good bye
Grace, we're glad you could join us today, and thank you for your questions.
Be sure to send us your feedback at http://quest.nasa.gov/qchats. Have a good day.
- 48 - 10:44:21 ]
RE: [Grace] Thank you for an interesting
and educational chat! Good bye
- 49 - 10:46:07 ]
RE: [Stephanie/Edmonton] Why does
a honeycomb structure provide good protection?
I've been exposed to honeycomb structures as the structure for the TPS
material. The spacecraft would be made out of this honeycomb structure
and the TPS would be bonded to that. Honeycomb structures have good strength
and are lighter than a full metal structure.
- 52 - 10:51:10 ]
RE: [Mr.Smith/RCTC] In Regard to the Space
Shuttle tiles, if you were asked to protect a shuttle now with current
TPS materials would you use a different method or are tiles the best solution
for the shuttles?
There is a lot of work going on now for 2nd and 3rd generation Reusable
Vehicles. There has been ongoing research in the tile area to make tiles
go to higher temperatures, to make them more durable, and to make them
simple to maintain. So these "next generation" tiles are still good candidates!
- 53 - 10:53:34 ]
RE: [Stephanie/Edmonton] How does mechanical
engineering relate to your work? Isn't this more materials eng.?
Very observant! One of the reasons I chose a Mechanical Engrg degree was
because it is very versatile. You can go into a lot of different areas
with an M.E. degree. Yes, this job is more materials related, so I have
had to learn a lot "on the job" . The testing aspect of the job is more
M.E. as I have to design the models and the model holders, and work with
the machinists who make them.
- 59 - 10:58:30 ]
RE: [Mr.Smith/RCTC] Has there been any interest
in making a "solid" shield maybe a type of ceramic, as apposed to one
made of tiles?
YES! For the Stardust Sample Return Capsule (it is out there now collecting
comet dust and will return them to earth in the capsule), we made a single
piece heatshield. The heatshield was molded to shape and a final machining
process made it to the exact shape that was needed.
- 60 - 10:58:45 ]
Linda, our thanks to you for joining us today. We look forward to hearing
from you via our online surveys, at http://quest.nasa.gov/qchats. Have a good day!
- 61 - 10:59:24 ]
This concludes today's Aerospace/Space Team Online chat with Christine
Johnson from NASA Ames Research Center. We would like to thank everyone
for their great questions, and offer our special thanks to Christine Johnson
for her thoughtful responses to our questions, and for sharing her career
expertise with us today. THANK YOU, Christine!!
[ Mr.Smith/RCTC - 62 - 10:59:48 ]
Thank you. Have a good afternoon.
- 63 - 11:00:02 ]
RE: [Linda-Ms.Wallin/SEDOL] Thank you so
much for a wonderful chat experience. I teach very young children, so
we are not able to do this as a class. It has been inspiring, though.
Thank you all for your time.
You are so welcome! Contact Oran Cox at firstname.lastname@example.org,
[who will inform] me if there is anything else I can do for you! You are
so important to helping these children become whatever they want to be!
- 64 - 11:00:37 ]
RE: [Stephanie/Edmonton] Thanks Christine
for chatting with us! Hope to "talk" with you again!
Thank you. Keep up the good work!
- 66 - 11:01:13 ]
RE: [Mr.Smith/RCTC] Thank you. Have a good
Thank you for participating! GREAT QUESTIONS!
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An archive of today's chat will be available soon. As a final reminder,
please send your comments about today's chat to us at http://quest.nasa.gov/qchats. Thanks again for joining us
today, and have a great day!