Pathfinder Alternative School
Seattle Washington

Dear Jim,

Today my students brainstormed questions for you. You can pick and choose
whichever seem most appropriate or fit together the best. Some obviously
don't apply to your expertise - some of my kids are pretty young. One thing
I'm trying to get them to see is the diversity of specialists and jobs on
something like a Mars mission, how independent and yet interdependent you all

Their questions in general categories:

How did you become a professional astronomer?

	I am an atmospheric scientist, not an astronomer, whose
	specialty is the lower atmosphere, commonly called the
	Planetary Boundary Layer. It's from a few meters deep at night
	and up to a few kilometers during the day, depending on wind
	speed, and the planet! I was involved in audio-visual
	technology during high school, electronics in the Navy, and
	entered MIT to study Electrical Engineering.

Why did you become a professional astronomer?

	I took an introductory course in meteorology as an
	undergraduate, went to work for the Weather Radar Project at
	MIT, and switched to meteorology due to its' challenges. It
	required electronics, physics and statistics, satisfying my
	curiosity and desire to advance and pioneer the development of
	new technology, things and techniques.

How long have you studied space?

	Roughly 32 years since I worked on the first "Mars weather
	station for the Voyager program which, in 1965 was to go to

How many years have you worked for NASA?

	I work at the University of Washington but get all of my funds
	from NASA or the National Science Foundation.

What qualities does it take to get into NASA?

	It depends on what you want to do. If it's engineering or
	science, it requires a strong background in mathematics,
	science and the ability to express your ideas clearly and

Were there grades on your work (for NASA)?

	Our closest equivalent to "grades" is whether your program,
	proposal, and research is funded and succeeds. There are many
	competing proposals for a small set of funds such as, Mars
	versus Venus, Pluto, asteroids, etc. Scientific advisory
	groups try to recommend balanced programs to NASA. However,
	the funding, and even program decisions, are strongly
	influenced by political considerations, administrative goals
	and competence.

Were there levels of work for beginners, intermediate, etc (for NASA)?

	Not in my personal work, where I am often trying to advance
	the state of the technology to meet increasing demands for
	smaller, lower power, lighter and even cheaper. However, there
	is room, given funds which are scarce, for capable individuals
	with less experience. One of my best workers was a student who
	worked for me one summer and had just graduated from Lakeside
	high school. Bill Gates and Paul Allen also graduated from

Do you work well with your partners?

	Depends on the attitude and capability of my partners. If its
	to work hard, try to understand your work, ask questions and
	get information from others who have already accomplished
	similar tasks, and communicate well, I think the answer is

	If they are stubborn, secretive, don't admit what they may not
	know, don't seek out information and "DON'T LISTEN", then I
	have problems. I like to discuss ideas in a free and healthy
	way, trying to consider the most important factors.

What's your favorite planet?

	Earth, and my second is Mars.
	Mars is the only other planet in our solar system where we can
	land a spacecraft and study the interaction of the wind,
	temperature, humidity, and sun with the surface for long

	My group and I played a key role in keeping Viking Lander 1
	alive for an extra 1,200 days on the surface of Mars.

Do you want to go into space?

	Yes, but as a payload I'm too old and heavy.

	I want you to go and do a better job than I could!

Is there life on planets?

	On Earth, I think so.

	In some solar system, somewhere I think the answer is YES.

	Is there life on other planets and moons in our solar system,
	I don't know but we should try to find out by studying Mars
	meteorites, Mars, and other likely places.

Can humans live  on planets?

	Yes, on Mars. They need pressurized suits and buildings and
	protection from the low temperatures and ultra-violet

Is there water on Mars?

	Yes. There is lots of water in the form of vapor in the
	atmosphere, water-ice clouds and snow, ice and perma-frost in
	the polar regions and under the ground.

What is the Viking made of?

	Aluminum, and lots of wires!

How did you help design the Viking?

	I didn't design Viking. Martin-Marietta designed the lander
	and TRW designed the Biology and Meteorology experiments. I
	was a science Team member on the Viking Meteorology Science
	Team and helped decide which proposal to accept, and some
	modifications to make in the instrument TRW developed.

 What did you add to the Viking?

	I initiated needed testing of the instrument in the NASA
	Langley Transonic Dynamics Tunnel, a 16 foot tunnel which is
	closed and can go down to Mars pressures. It cost $ 4,000 per
	hour to operate in 1975 and we received 2 weeks exclusive use
	of the tunnel. My group and I designed a computer system to
	control the meteorology instrument and some of the software to
	run it and analyze the test results.

	I made several meteorological discoveries such as

		The winds at Lander 1 in the summer were controlled
		by cooling of sloping terrain

		Fronts were more similar to Earth fronts than expected

		Global atmospheric resonances, sort of like the ringing
		of a glass or a guitar string at a "natural" frequency

		That planet wide, dust storms did not occur each year

		A possible mechanism for triggering great dust storms

How long did it take to design your part on the Viking?

	I didn't design anything except the computer system and
	interface for testing and data reduction. This took about a
	year with great cooperation from industry. Other analyses and
	publications have taken from 1976 to now. Currently, much more
	could be obtained by studying Viking Meteorology data but
	there are no funds.

What did your draft look like? (My students always do a rough draft for their
writing, so they imagined you do too.)

	Yes, I do rough drafts and they often are not very

How does the Viking see?

	It has two "camera's" with color filters, and photo
	sensors. It makes a picture by moving a single light sensor, in
	small steps, up, then over and up again, with a mirror for the
	up and down and by rotating the camera.

Does the Viking have computers?
	Yes, two, which never had an error, except possibly at the end
	for Lander 1

What was the most helpful thing on the Viking? What gave the most

	A difficult question, since biology was the dominant
	investigation and its' generally lack of finding "life" with
	one claimed exception. I like to think that the cameras
	followed by meteorology, were the most important.

Was it hard to design the Viking? Why or why not?

	Yes, since many new technologies had to be drastically reduced
	in size and use of resources. The three biology laboratories
	had to fit in a box lass than 2 feet on a side and the whole
	spacecraft used the power of a 50 watt light bulb.

Was it hard to work on the Viking with suits on? (They have seen pictures of
technicians working on the Pathfinder probe with white sanitary suits on.)

	I didn't do it but I don't think it was too difficult.

Did you help with the Pathfinder Rover?

	No, just the Pathfinder Meteorology

How long did it take to build the Pathfinder Mission?

	About 3 years

Are you working on another mission?

	Not now, although I have given advice on the next mission
	which is landing in the south polar region.

Do you believe in Martians?

	Not until you get there!

You are the future of Mars exploration.


J. Tillman