Quantum Rocketry

Hello again, Blogosphere!

I spent last week in Toronto at the annual AIAA Guidance, Navigation, and Control Conference. This is a huuuuuuuuuuge conference of engineers from academia, military, and industry all presenting papers about their research. So, I got to see a lot of Powerpoint presentations. (Okay, okay, supernerds, there were some PDFs and Keynotes. But “Powerpoint” is pretty much like “Kleenex” these days.) And an awful lot of the presentation slides I saw looked something like this:

Fine, right? I mean, this is a technical venue, full of super-brainy engineers. We want the facts, ma’am, just the facts, in all their glorious mathematical detail, and style means nothing. Right?

WRONG!

The first rule anyone will ever tell you about giving any kind of presentation is to know your audience. And if I’m in the audience at a conference like this, then I’m spending a full day listening to technical talks and you have only twenty minutes to make me think that your research is as cool, interesting, or relevant as the title made it sound when I picked it out of the lineup that morning. Because I’m still holding the conference program in my hand, and I have a notepad and pen ready to jot down research ideas the last cool presentation made me think of, and I might have my laptop in my bag, so I’m not at a loss for things to do if you’re not very exciting. In other words, not only do you need to convey your technical material, but you also need to keep me interested and/or entertained, at least enough to keep me listening to your technical stuff.

It’s a tall order.

I’ve been told that I do a good presentation, though, so I’m going to share a bit of my philosophy for what a technical presentation should be like. Here are the points that I start from:

1. Nobody wants to see lots of equations. Some are necessary, sure, and they can be a great way to add technical gravitas, but a 20-minute presentation is a much better time to show off results, pictures, movies, hypotheses, conclusions, possibilities, tricks, and excitement. And if the conference is like GNC, requiring a paper with each presentation, then all the equations go in there, anyways. The oral presentation is for highlights, not derivations.
2. These presentations come in the middle of a solid block of otherwise identical presentations that are going to blur together in the audience’s minds. So, they need to be distinctive. In other words, a bit of flash and polish goes a long way. Also, attention-grabby things like pictures and movies are good, but not if they’re just thrown together in a clip-art sort of way. (There’s good attention to grab, and bad attention to grab!)
3. Slides are visual aids. I mean both “visual” and “aids.” Think about both of those terms: slides are supposed to be for showing the audience things. And the slides in a live presentation are not supposed to be completely independent of the presenter: you should refer to them, but you are the one giving the presentation.

As an example of my own style, allow me to go through my recent GNC presentation slides and point out my thoughts on their layout, style, and content. If you want to follow along, most of the presentation itself is here on YouTube:

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When I’m not doing silly things like constructing languages, writing science fiction, or biking through the Great Smokey Mountains, I have a research job in a Cornell spacecraft engineering lab to maintain. Mostly, that stuff doesn’t go on my blog because it ends up on our research group web site or in published journal articles and conference papers. But I’ve hit a milestone, and I think it’s pretty cool.

I hand-coded, from scratch, a multibody dynamics simulation package for Matlab. Read the rest of this entry »

I recently spent over a week in full research-promotion mode, and I’m finding it tough to switch back into research-doing mode. Coincidentally, I don’t think I’ve actually written a blog about my graduate research yet, though I’ve put descriptions of it on both my personal web site and Cornell group web site. So, I’m going to try and get it all out of my system…

Suppose you ask: Hey, Joe! What’s your research about?

Well, it’s about building Transformers in space out of Legos connected by tractor beams. Seriously. Okay, fine, they’re not “tractor beams,” more like…”tractor fields.” But other than that, not a bad description. Here’s an old-ish video version:

First: Why?!

There are a lot of possible reasons why we ought to be thinking about building large-scale structures in space. Imagine assembling a huge space telescope out of hundreds of mirror segments, giving the telescope an effective light-gathering area of hundreds of meters and letting us peer into the dimmest corners of the Universe – from the most distant objects to extrasolar planets. Or, if we’re interested in space-based solar power (putting solar power collectors in space, where they could gather sunlight 24 hours a day without atmospheric filtering, and then beaming that power down to Earth) we would want to make the biggest collector area we can. Proponents of geoengineering approaches to climate change mitigation have been seriously considering constructing a giant sunshade to reduce solar incidence on the Earth, a short-term solution that could stave off environmental impacts while we work up longer-term fixes. And finally, if we want to maintain a long-term human presence in space – from Mars explorers to microgravity research and manufacturing technicians to paying space tourists – we will need vehicles and stations with enough room to accommodate many people, hold life support and other supplies, and provide equipment to stave off the detrimental effects of microgravity on human physiology.

All of these possible applications – any one of which would have tremendous implications for our lives on Earth – demand that we build a large structure in orbit out of smaller components. The reason for this is simple: launch vehicles can only carry so much mass and volume into orbit. Those limits are on the “stowed” size of spacecraft, so we do have the option to build craft that deploy, or unfold, out of their tightly-packed, mostly cylindrical launch configuration and into some more spindly and useful shape. For example, most Earth-orbiting satellites get their power from large solar panel “wings” that would not fit into a launch vehicle fairing unless rolled up in some clever way. There’s a lot of research these days on inflatable spacecraft, that could expand to many times their stowed size and get structural support from their internal pressure, but even those balloon-like craft cannot get indefinitely bigger than their launch envelope. Deployments and inflatables only make the volume or length of the spacecraft larger – so, for the same mass, you end up with spindlier structures, which might be fine for some applications but not others. So, in order to get the really big spacecraft, we must assemble smaller pieces to make the final system. Think of the International Space Station assembly process.  Read the rest of this entry »

I’m trying to write a conference paper manuscript for the AIAA GNC conference right now (why, oh, why isn’t it just an abstract, or even an extended abstract? a full manuscript at this point is going to be slathered with “TBD” and “preliminary” and “temporary” and promises for the future!), but I just discovered something that I had to write down for the benefit of other academic users of Microsoft Office since this has been bugging me since I got Office 2007:

I, personally, rebel against using TeX or its derivatives in my academic work. Yes, I can program in Matlab and Mathematica, and yes, I can create some pretty snazzy HTML/CSS web pages, so I’m not foreign to coding and markup languages, but really, I’m trying to concentrate on the science and engineering when I write a paper. I want to see what I will get. There is no reason at this point in the history of computers for me to have to use a command-line word processor that I have to compile. That sort of thing is for numerical scripts, not for documents.

Word 2007 took some great strides in the direction of making Office easier and better for technical purposes, with a WYSIWYG equation editor that you can control almost entirely from the keyboard using common operators and that automatically prettifies the equations as you write them. It’s way cool.

Word 2007 also has, from the beginning, included some automatic citation generating and outputting features. It’s almost like EndNote or BibTex and such, except that I don’t have to pay extra for them. However, it’s HUGE shortcoming was that it contained only 10 citation formats, and didn’t include some common technical formats. Right around the release of Office 2007, Microsoft blogs touting Word went on and on about how easy it would be for users to generate their own formats, since they used open XML files to create them. However, it turns out that those XML files are totally opaque to my understanding, and when I did try to change some things, I didn’t get what I expected. And it seemed like the rest of everybody agreed with me, because downloads for new citation formats did not immediately appear on the Internet.

I have finally, finally, finally found a web site with a small library of citation format files. It is here.

They unfortunately don’t have the AIAA format, which is what I use most often, but maybe they have something close. And, anyway, it adds to my options for the future.

My lab’s recent microgravity flights gave us some good data to demonstrate that we’re not totally crazy with this flux-pinned spacecraft idea. In fact, it actually works. We were able to get mockup CubeSat-sized spacecraft to pin together without touching, and use magnetic fields to form a non-contacting hinge.

An article just appeared in the Cornell Chronicle about our stuff.

We’ll be applying to fly a refined experiment on the Vomit Comet next summer, as well, through the NASA FAST program. (Check out the link to our video on the FAST front page!)

Those of you out there who follow me on Facebook or Picasa – or who know me personally – have already seen the pictures from my zero-g (well, microgravity) experience. Here’s the illustrated saga, for your reading pleasure:

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I have two things to write down some thoughts about.

First, while I do some of the more mechanical computer modeling work during the day, I’ve been listening to a lot of NPR streamed over the Tubes. Today, I learned some factoids that basically break down as follows:

1. If you figure out how many people in America get health care and the quality of care they recieve, you find that we actually have the most “rationed” healthcare system of industrialized nations. That is, in a country with omg-we-can’t-have-that single-payer healthcare, or even anything not as vile and disgusting as that, more people get the care they need when they need it than in the USA.
2. If you figure out how much health care costs in this country, and compare it to the cost of health care in other countries – not just premiums, mind you, but tax money that goes into health care as well – you find that Americans have the most expensive health care system in the world.

If you’re thinking what I’m thinking, it’s that the GOP is neither morally nor fiscally responsible; and that they are not really “conservative” in any actual definition of the word. If you’re not thinking that, you’re probably a Republican and have just pegged me as a pinko commie godless bleeding-heart Massachusetts liberal. (I will give you three of the words in that phrase, contend that there’s nothing wrong with at least those three, and the rest I contest.) In fact, I am merely a scientist and engineer, and I know how to read numbers and am willing to make policy decisions based on data. I’m also insulin-dependent diabetic, and would seriously appreciate a much lower cost and more assurance of the efficacy of the treatments just keeping myself alive.

Second, I have been hoping to come up with some good theoretical results to present in a conference paper on my research later this summer, and it just hasn’t happened. I’ve been too busy with other work-related things, and now I’m in a summer internship at NASA and don’t have the time to spare, so results are not going to be forthcoming before the paper deadline. This leads me to conclude that I much prefer being an experimentalist to being a theoretician. The reason is that labs sometimes go the experimenter’s way, and sometimes they don’t – but part of that is uncontrollable. The experimenter can, though, usually sift through data to find some useful results. Even negative results are useful. Any results at all will at least shed light on the techniques employed. If theoretical work doesn’t go the theoretician’s way, however…you are just left with a theoretician staring blankly at a piece of paper with a lot of scratchwork. And a lack of results just means that the theoretician hasn’t done the right thing or worked hard enough yet.

In other words, I have no results and it’s my own damn fault. I can’t even blame fault apparatus, numerical noise, or experimental error. I just didn’t do enough, or the right kind of, work. And that just makes me less motivated to continue this line of inquiry.