E-Week and Legos

This coming week is National Engineers’ Week, a combined celebration of engineers’ technical accomplishments and outreach event designed to promote STEM field awareness. A couple of my co-workers and I visited a local high school to talk to some of the students about what we do as aerospace engineers. (I used my favorite, and not entirely inaccurate, job description phrase: I steer spaceships.)

As a guidance and control engineer, a lot of what I do requires a solid grasp of the motion of a spacecraft; the orientation of various sensors, thrusters, solar arrays, and transmitters; and the geometry of the spacecraft, the Earth, the Sun, and other things in the space environment. Some of the control algorithms I work with, for example, might be designed to point the solar panels at the Sun while a camera or transmitter stares at a spot on the Earth – all while the satellite zips along its orbit at several tens of thousands of miles an hour. Visualizing all this stuff going on can be tricky. We have some 3D graphical tools (a few written by me, as I was trying to puzzle all this stuff out). We do a lot of vector math and look at plots of vector components in various reference frames. But, often enough, we just can’t beat a good, solid, hand-held model of the spacecraft to swoosh around and help us try to picture what’s happening on the real thing.

As a result, just about everybody in my group has a little cube made out of paper, or cardboard, or foam board, that is labelled with relevant features of the satellite. I have this:

I used the free Design by Me software from Lego to design myself a model of our spacecraft, and then order all the parts I would need. (I was sure to get myself lots of extra doodads to be antennae, reflectors, sensors, thrusters, and other such stuff!) What you see in the picture above is a generic configuration of the spacecraft, representative of the class of satellites that I work on, rather than a specific spacecraft. Of course, at work I have lots of extra flat plates which I have labelled with various details!

While it’s certainly not to scale or completely accurate, it’s about the right shape and size and – important for visualization – I can move the solar panels around. It’s pretty easy to think to myself, “okay, the Earth is down there and the Sun is over there, so my satellite is doing this…” Legos give the model just the right amount of heft. And they are just plain fun!

This model is not just helpful at work, but it’s also a tremendous attention-getter. I find it valuable to make my work more concrete. So I certainly made sure to bring it with me on that school visit.

In the Arena

Well, since I just had some discussion about orbits and other fundamental physical concepts in science fiction, here’s a short scene I’ve been sitting on. It’s set in the Cathedral Galaxy, and I’m not quite sure what I want to do with it yet.


The Kite stretches his solar wings wide, spanning over five hundred meters. He fans out his array of electromagnetic membranes, thermal structures, transceiver antennae, and weapon emitters, flourishing. The Kite’s voice booms out over the electromagnetic spectrum, mingling with the others in the Coliseum, as they announce themselves to the assembled spectators:

“In salute, we die and live by the will of the Imperium!”

The Kite pulls one solar wing out from the light flux to tack. He wheels around, scanning and assessing his competitors. He catalogues their capabilities but pays special attention to their faces – distended from all the grafts and alterations, stone-gray and glassy-eyed from the environmental treatments, yet still faces. The younger competitors growl and sneer at him, while the more experienced repay his cool appraisal in kind. Today, The Tiger and The Worm worry him.

Silence falls across the EM bands, leaving The Kite with only the intermittent discharges from the Coliseum walls. His stomach (though no longer really a stomach) lurches in anticipation. A moment drags on in the flickering silvery shell of the Coliseum, buried in the sparse mist of an orange nebula. This could be the day, thinks The Kite, when I die. Again.

The call:“Begin!”

The Kite pulses an electromagnetic field, launching himself away from the spherical inner surface of the Coliseum. The others do the same. Continue reading In the Arena

Global Physics Department

Yesterday I was invited to give a presentation to the Global Physics Department, and online group of college and high school physics educators moderated by Prof. Andy Rundquist from Hamline University. The group gathers to hear virtual speakers on math, physics, science, and education on a weekly basis. Andy found my blog (hi!) and asked me to work up a presentation on science and its presence (or absence) in science fiction. You can see the recording here. (There are lots of other interesting presentations on the site, too.)

I spent a while thinking about the approach I wanted to take with this presentation. Of course, the easiest thing to do would have been to pick some choice examples from science fiction and pick them apart, criticizing the presence of sound in space or starships that move like boats and airplanes. I did a little of that, but I also wanted to bring up some other approaches that might encourage students to explore the intersections of science and science fiction, including looking at some of the things that science fiction gets mostly “right,” examining what it would take to give us science-fiction gadgetry using current knowledge, and trying to extrapolate realistic scenarios using scratch paper and our imaginations.

All in all, I think it was a fun evening – but I barely scratched the surface! My only “disappointment” was that it would have been fantastic to really open things up for discussion at the end. But with a topic so rich, it’s hard not to run into the time limit!

This makes me a *little* happier about the SLS

NASAspaceflight posted an article about the human spaceflight “exploration roadmap” using the Senate Space Launch System rocket. It makes me feel a bit better about the SLS situation.

I’m glad to see that the roadmap revolves around interplanetary vehicles assembled in space, and I’m glad to see that there’s some careful thought here about how to move the human presence throughout the Solar System in a more sustainable way than flags-and-footprints missions. Still, I’m not convinced that the SLS is an efficient or effective way to do that compared with, say, a cluster of Falcon launches. Remember: the SLS is not going to be up to its peak design payload capacity until 2020 2030, and it will likely fly once a year, which doesn’t bode well for the parts of this roadmap that call for a “fleet of SLS” launches.

The best apart about this article is that it demonstrates that NASA is still thinking about how it can achieve human spaceflight capabilities – regardless of what a petulant Congress insists on.