Category Archives: Graduate school

Graduate school, Space

First spacecraft from my graduate lab launched!

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Just a quick note to share some exciting news: the first spacecraft to come out of my graduate research lab – Cornell University’s Space Systems Design Studio – launched with the SpaceX Falcon 1.1 debut yesterday. SpaceX says that the CUSat technology demonstrator vehicles deployed nominally. You can read more about the launch here. I did only a tiny bit of work for CUSat, but I know other students who did a lot more! Congrats to the CUSat team. It’s been a long wait.

The next launch out of my old stomping ground lab will be KickSat, going up on the next Falcon to carry supplies to the International Space Station.

Concepts, Graduate school, Research, Science Fiction, Space

Spacecraft Research is at it again

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It’s been a little while since I checked in with the goings-on back at my Cornell research lab. Totally unsurprisingly, some very cool things are happening there!

One is that the Sprite and KickSat project has gone all the way from a back-of-the-envelope concept when I was at the lab to a flight manifest! Sprites are tiny spacecraft – think the size of a coin – that consist of little more than a solar cell, a little CPU, and a diminutive radio. They are pathfinders for an idea that, rather than relying on a single monolithic (and super-expensive) spacecraft, instead we could just run off a batch of a million tiny satellites and fling them all out into space to cooperatively complete a mission. Some of the applications we talked about included integrating basic lab-on-chip functionality to test for biomarkers, and then rain a bunch of the Sprites down onto Mars or Europa. They wouldn’t return the same wealth of data of a NASA flagship mission, but they would tell us where the interesting things are. Another reason why tiny spacecraft are cool is because they interact differently with Solar System objects than large vehicles do – so they might be able to take advantage of light, magnetism, or planetary atmospheres in different ways.

The KickSat project was the brainchild of grad student Zac Manchester. It’s a simple CubeSat design with a spring-loaded deployer, designed to release a couple hundred Sprites. On the ground, Zac can then track the intermittent radio signals from all these mini-spacecraft, and evaluate how well their unshielded components survive in space. Radiation will eventually kill them, but with many copies of the same spacecraft, we’d expect to see them die out statistically. They’re spacecraft with a half-life, and as long as the half-life is long enough to complete the mission, we don’t care that a huge number of Sprites burned out.

When I left the lab, Zac was applying for grants to build the KickSat hardware. But – despite the cool concept – there weren’t any takers. Eventually, he decided to turn to KickStarter to see if he could crowd-fund some spacecraft research. He ended up raising almost three and a half times as much money as he asked for, and become something of a pioneer for crowdfunded space activities! Zac is now working at Ames Research Center to perfect the Sprite and KickSat designs. They will be launching on the same SpaceX Falcon 9 rocket that will carry supplies to the International Space Station in September. This is actually the first CubeSat from my lab to make it all the way to launch, so I say: Go Zac!

Second, a project that is perhaps a little less flashy but a little closer to my heart has been making some great strides. Ben Reinhardt has been squirreled away in the same basement lab I remember, working on what he calls “eddy-current actuators.” The more fanciful – and very nearly accurate – name for the devices he is working on would be “tractor beams.” He wants to use these to grab onto defunct satellites, the outside of the Space Station, or maybe even some asteroids and comets, all without mechanical contact.

I was still active in the lab when this project got off the ground. In fact, I put together one of our first tabletop demonstrations of the principles involved: a changing magnetic field generates eddy currents in conductive materials; these currents have their own magnetic fields which we can push or pull with magnets. That’s where I left the project, though…a quick video where I waved a magnet around, some rough number-crunching to show that the induced forces were feasible for applications, and then I was out to let other members of the lab hash out the details. (That’s the fifth-year grad student for you!)

The cool news is that Ben has gone from my rough video to a much more carefully controlled demonstration. He’s generated attractive and repulsive forces in a bare piece of aluminum (not unlike the skin of a spacecraft), without touching it, and he’s working on characterizing the design space of his device. This is a critical step in figuring out how to go from proof of concept to a useful technology, and it’s a step I remember quite well. While Ben’s twitching pendulum might not look to you like the tractor beams from Star Trek, it is a clear and measurable experiment illustrating the device. I went from similar experiments in my first two-ish years of grad school to flight demonstrations in my third and fourth; I hope Ben follows a similar trajectory. And who knows – if some companies or space agencies take an interest, we may soon see spacecraft grappling asteroids and assembling components with eddy-current tugs!

Ben and some of the other Cornell Space System Design Studio grad students are keeping a blog about their technology research projects, which you can read here. I think it’s very cool to see what’s going on in the lab!

Graduate school, Original fiction, People, Science, Science Fiction, Space, The Cathedral Galaxy

Original Fiction: “Conference” (final draft)

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I had been trying to sell this story for a while now, but was not successful. There’s a bit of a catch-22 to selling a short story for the first time: without any feedback from editors and readers, there is no way for me to tell whether a rejection was because the story didn’t align with a publication’s interest at the time, or whether they didn’t think the story was very good. (And if it wasn’t very good…what it did wrong.)

This makes me sad, because I got lots of positive feedback from people who went to graduate school in a technical field. I think that maybe that’s the problem: the story appeals to too much of a niche crowd.

Anyway, here it is, the version of the story I most recently tried to sell. It’s about a young scientist presenting her findings at a research conference, and the unexpected reception she encounters there. It was inspired by some of my own experiences in grad school.

Conference

The numbers didn’t match up. Ceren Aydomi tapped her desk, frowning at the resonance spectra before her. The projections cast pale purple and green light over Ceren’s face, spilling down the front of her body and glinting from the polished glass surface of her desk. The peaks of each spectrum marched onward, rapidly deviating from her calculations. And the Three Hundred Seventy-Eighth Channel Interstice Studies Meeting was only two days away. Continue reading Original Fiction: “Conference” (final draft) →

Graduate school, Politics

Support

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I am a member of the “millennial” generation. You know, the stereotypical hipster kids who like some band you’ve probably never heard of and are living with their parents, unemployed. Except…that’s not me.

I graduated from college and immediately went to grad school. In the sciences, math, and engineering, students generally get paid stipends to go to grad school. Oh, sure, it wasn’t a huge stipend, but it was enough not only to pay the bills but also to let me squirrel away some savings. I was in graduate school during the big financial bust of 2008, but I kept working and kept getting that stipend, thanks in part to the fact that my university valued its grad students enough to guarantee our funding, and in part to support my lab received from various organizations, including NASA – an agency of the federal government.

Immediately after I finished my degree, I got a job. In fact, I even had to push my start date back a little bit, because I needed some time to finish up university obligations and organize my final dissertation. My total period of unemployment was about a week, in early 2011, and then I started working. As it happens, the job I took is with a major commercial spacecraft company; the biggest program we are working right now is a batch of satellites that the US Air Force bought to replace older models.

So, here’s one person’s story: I’ve directly benefited from a government and from institutions that value advanced education, basic research, high technology, and infrastructure investments. And the recession didn’t touch me.

Huh. How about that.

Concepts, Graduate school, Research, Space

Kick Yourself into Orbit!

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Ah, I’ve only been out a few months, but I already miss some things about being in grad school! For instance, I miss all the crazy brainstorming of new and wild space systems, missions, and technologies. No doubt you, dear reader, also miss my crazy brainstorming: after all, that is how I ended up writing blogs about space battles or missions to Europa or what the Earth would look like with rings or the science of Avatar. Now I have an industry job where people tend to care more about “affordability” and “reliability” and “performance,” than they do about harebrained schemes to drop space probes into the Europan ocean.

But, fear not, intrepid reader who has been sticking it out hoping for another crazy notion to appear here! You see, my research group at Cornell is still working at churning out wild ideas. And you can participate!

Check out this message from Zac, who was starting his Ph.D. as I was on my way out:

Zac has set up a page on KickStarter, which you can jump to by visiting KickSat.org. The idea behind KickSat is to make a bare-bones 10x10x10 cm CubeSat which contains hundreds or thousands of microchip-sized satellites called Sprites and will deploy them all in low Earth orbit. The KickStarter platform means that, if you want, you can sponsor your very own Sprite – Zac has even defined a sponsorship level at which you get to write your own flight code for the tiny spacecraft to run in orbit!

The spacecraft, which each could fit comfortably in the palm of your hand, are very simplistic as far as spacecraft go – they consist of solar cells to charge a little bank of capacitors, a teeny TI processor for a brain, and a little antenna. These are proof-of-concept spacecraft, and are actually derived from three test units which my lab group sent up to the Space Station on the last launch of the Space Shuttle Endeavour! In the future, they hope to integrate other sensors onto the chips to give Sprites more capabilities. One of the ideas batted around during lab meetings that I consider a personal favorite: put “lab-on-chip” detectors on a Sprite to look for characteristic organic compounds (like nucleic acids!) and program them to simply send a chirp back if they get a positive result. Send a million Sprites to Mars, and listen to the peeps – and then you know where on the Red Planet the next big flagship mission has just got to go!

Imagine if you got the shot at writing the flight code. If you could put a solar cell in space and make it beep, what could you measure? How creative can you get in getting the Sprite’s whisper of a radio signal to carry information? Could you receive enough data to tell how fast the chip is spinning and seeing the Sun, or how much average power it has to work with, or how long it lasts before an errant proton from the solar wind blasts your Sprite out of the sky? The chance to put your own code on a spacecraft, even such a simplistic one, offers a lot of learning opportunities.

(Incidentally: one question that Zac and his research advisor, Dr. Mason Peck, get a lot is some variation on: “Hey, paint flecs moving at orbital velocity are enough to crash through the Space Shuttle windows. Aren’t these Sprites going to become dangerous space junk?” The answer is that yes, the Sprites could be hazardous as long as they are in orbit; but the orbit that KickSat will reach is going to be within just enough of the Earth’s atmosphere that all the Sprites will get dragged down in a couple days. The special property Sprites have that influences this fast orbital decay – and other effects – is a high surface-area-to-mass ratio.)

KickSat has already reached its minimum fundraising goal to start building hardware. However, the project is still looking for more backers to secure a commercial launch opportunity, which will offer more certainty than applying for a free launch program through NASA. But if Zac gets to about $300,000 of funding, he thinks that will be enough to start looking at new technologies to shrink the Sprite chips down to even smaller sizes – and offer even more capability in the future!

Cool stuff. I’m glad to see the Cornell Space Systems Design Studio keeping the wild space ideas flowing!

Graduate school, Politics, Science, Social commentary

It’s How You Use It

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A couple years ago, I was at a house party in Ithaca where I met a first-year grad student who asked me what I was studying.

“Aerospace engineering,” I said.

“Cool,” he replied. “Just don’t ever work for Lockheed Martin.”

(Ha.) I asked him why not. His answer: “They build weapons.”

This student was also extremely frightened of the “Big Dog” robot, which had just exploded onto the Internet in a series of awesome demonstration videos on YouTube. Why? “Just imagine what the military will be doing with that. They’re funding it, you know.” Did he have any specific examples or concerns? No. And I pointed out how invaluable such a robot would be in, say, rugged-terrain search and rescue or disaster response efforts. But none of that mattered, this student insisted, because the project received military funding. Somehow, in his mind, if the Red Cross shelled out millions for the development of Big Dog, it would be okay – but not if that money came from the US Army.

This attitude struck me as extremely naive. (And not just because this first-year was wearing a chai.) Some of the best work in science, engineering, and medicine gets funding from the military, because the military is naturally interested in those things. But I don’t think that means that even the pacifists among us should abandon all those lines of inquiry. You see, I believe in the adage that technology is neither good nor evil – it’s how we choose to use it that defines our goodness or evilness.

I have long since come to terms with the fact that many of the engineering challenges and scientific problems that I want to solve have both military and civilian applications. I want to, for example, land robots on Europa or Titan. Doing such a thing will require precision guidance and pointing systems – exactly the same kinds of systems that could control ballistic missiles or smart bombs. Some of the same technologies that let us aim the Hubble telescope precisely enough to image galaxies billions of light-years away can aim the airborne cannons on an AC-130. The rockets that bring astronauts to the International Space Station, a peaceful, collaborative venture between many nations, operate on the same principles and use the same fuels and control systems that go into ballistic missiles. The key difference in all of these cases is in where we, the human operators of such devices, point them to go.

To take an extreme example: the most devastating weapon we are capable of producing is the nuclear warhead. It is a terrible weapon, and nobody in their right mind would tell you otherwise. Some activists out there are so vehemently set against this weapon that they oppose all use of nuclear power and all refinement of nuclear isotopes. But here’s the thing: high-grade plutonium isotopes are what power all interplanetary probes to the outer Solar System! (Beyond about Mars orbit, sunlight is too weak for solar panels to provide enough power for a spacecraft.) Our country has stopped refining high-grade plutonium, and this is actually a big problem in the planetary science community. Again, I want my Europa and Titan landers…and I can’t have them without a stash of plutonium-238!

(For those astute readers who point out that Pu-238 isn’t weapons-grade plutonium, I would argue that the refining techniques are the same. And, for good measure, here’s one of the most peaceful people ever to walk the face of the Earth explaining a constructive use of the nuclear weapons themselves. Though nowadays we view that concept as not very practical, the next iteration might be antimatter-powered rockets capable of taking humans across light-years – but these would be even more destructive if used as weapons.)

In my doctoral research, I worked on new technologies for spacecraft. Fortunately for my moral ideals, flux-pinning interfaces for modular spacecraft are something that we had a hard time coming up with direct military applications for. Nevertheless, they may exist: we thought of looking for a way to develop a device that uses flux pinning to grab onto a target spacecraft without touching it – tractor-beam style. That I am sure that DARPA would be interested in. We did even end up pursuing that idea down a related, non-flux-pinning line to a small-scale proof-of-concept demo. (Our target application was rescuing derelict or malfunctioning satellites.)

Recently, I heard an Air Force colonel refer to GPS, which is a military-developed technology, as a “weapons system.” Now that I’ve gone from university research into the commercial spacecraft industry, I contribute to systems like GPS satellites, so this observation hits close to home. How many people out there using Garmins or iPhones or Google Maps would have thought that they were using something that the military considers to be a weapons system? GPS guides aircraft, boats, and cars throughout the civilian community. It gives researchers a powerful tool to advance geoscience. (Did you know that nowadays we directly measure continental drift speeds with GPS?!) And keep in mind that GPS is what gives us the capability for automated farm equipment to efficiently produce more food, or aid workers to reach remote destinations, or emergency responders to locate missing people and map out disaster zones. I am more than happy to contribute to those endeavors!

So, do we use our knowledge of particle physics to make the most devastating weapons the world has ever known, or do we use it to power the probes that will help explain our origins and find our place in the universe? For me, the answer is clear; but it is also clear that science isn’t necessarily good or evil. (Neither are scientists, for that matter.) Making it one or the other is entirely up to human decisions.

Graduate school, Research, Science

The Television Episode Experience

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I finally got a chance to watch the episode of the National Geographic Channel’s “Known Universe” that filmed partly in my Cornell research lab. The episode is about how we currently build stuff in space, and how we might build more advanced or complicated structures in the future. Naturally, my flux pinning research fits into the “future” part of the show. And, at my research adviser’s suggestion, I was the guy on camera with the host. (Probably due to my propensity for putting research stuff on YouTube!)

This whole thing was a really interesting and fun experience for me. It all started with some idle speculation on space battles, which turned into one of Gizmodo’s hottest articles in December ’09, which ended up with a Nat Geo producer calling me on the phone. To my immense grad-student pleasure, he asked me what my research was about. And ta-da, our lab got featured on one of their shows!

Kids: let this be a lesson to you about what happens when you have thoughts and put them on the Internet in a blog!

We spent the better part of a month preparing equipment in our lab for the TV shoot, and an entire working day doing the actual filming, all for a five-minute segment in the episode. I have to say, I’m impressed with how well our topic got covered in such a short time, given how long I usually spend explaining it and how much material we spent filming! There’s a lot to be said for having professional editors who want to tell your story. If you caught the episode last Thursday (it will re-run soon; I believe tomorrow at 3 PM is one slot), you saw me show the host, Johns Hopkins physicist David Kaplan, three features of magnetic flux pinning that we feel could make it the basis for a future in-space construction technology:

"Known Universe" host David Kaplan pokes at one of our levitating magnets in the lab. (Photo Credit: ©NGC)
  1. Pinned magnets and superconductors can attract one another and stick together without physically touching. David best demonstrated this when he held a superconductor in one hand and a magnet in the other, and the magnet jumped across a distance of a foot or two to lock back onto the superconductor.
  2. This effect does not necessarily require any power or control inputs. I explained at one point during filming that, although we have to supply liquid nitrogen or power a cryocooler in order to get flux pinning to work on Earth, a spacecraft might only need to shield its superconducting elements from sunlight. (That detail didn’t make it into the final segment.)
  3. Flux pinning can not only lock structures into place, but it can also form the basis for reconfigurable multiple-module space structures that change their shape in response to changing mission goals. Our research group likes to think about morphing space telescopes, planetary orbiters, or solar power satellites, but there’s no reason why human-habitable space stations are out of the question! (If you provide flexible tubes for inhabitants to get from module to module, of course.)

Continue reading The Television Episode Experience →

Graduate school, Research

I’m…on…TV!

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Next Thursday, 9 June, an episode of “Known Universe” will air on the National Geographic Channel entitled “Construction Zone,” about the ways humans build things in space – or might build them in the future. For a couple-minute segment about future space construction technologies, the host and crew came to my Cornell research lab and filmed a bit with me about my flux-pinning technology research!

I’m excited and nervous – excited, because this is my first real TV appearance, it’s all about the cool possibilities that could come from my graduate research, and I want to see how it comes out – but nervous, because as a researcher, I know what kind of story I want to tell about my subject, and I don’t know if it will come out the same way after editing. I know what footage we shot, but I haven’t seen the finished product yet!

For now, I can say this: I had a blast filming. Explaining the concepts to the host and doing demonstrations with him was a lot of fun. I think there was plenty of footage that made my research come across well.

The only downside is that I don’t have cable in my new apartment!

Graduate school, Research

I Guess That’s It

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I have successfully defended my dissertation. I would appreciate it if you would address me by my correct title, now: Doctor of Rocket Science.

(I’m kidding.)

The funniest thing about this to me is that I know that the research I’ve been working on isn’t done. There are more investigations to pursue, more refinements to write into the code, more variations to try in simulation, and more experimental verification to perform. Research never stops. But at some point, we grad students have to decide, with our advisers, when we have made a sufficient contribution and should wrap up our work into a complete dissertation. Still, it doesn’t quite feel like I’m “done,” because I know that the research has much further to go! It’s kind of anticlimactic.

A rather nice capstone, though, was spending last week getting the lab ready for, and filming, a bit for the National Geographic show “Known Universe!”

Concepts, Gadgets, Graduate school, Research, Science

How to Build a Tractor Beam

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Hello, Intertubes! I have been slacking off on the blog in favor of preparing my dissertation and the presentation for my defense. I know, excuses, excuses…

To keep all eighteen of my intrepid readers happy, here is a video that recently went up on my lab group’s YouTube channel:

That’s me demonstrating the physical principles that could be used to make a real-life tractor beam that can push, pull, and manipulate spacecraft. The device would work by pumping changing magnetic fields at a target spacecraft, exciting eddy currents in the spacecraft’s aluminum skin. These currents interact with the magnetic field from the tractor beam device, allowing it to push, pull, or rotate the target.

In the video, I generate these changing magnetic fields by moving a big rare-earth magnet around. On a spacecraft, a more likely tractor beam device would be a set of electromagnet coils. I calculated that, with reasonable power requirements, such a device could exert ion-engine-scale forces on a target several meters away. More powerful electromagnets would increase that range.