All posts by josephshoer

NASA, Space

Antares and tiny satellites

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This weekend was full of excitement for commercial space fans. Orbital Sciences Corporation launched the Antares rocket, making them only the second private company to put a vehicle into orbit. Like the SpaceX Falcon 9, Antares is intended to carry cargo to the International Space Station. Antares is cool for a couple of reasons – partly because it represents a further gain in the United States’ launch capability, but more notably because the target market for Antares commercial launches are smaller spacecraft than the usual several-thousand-ton geosynchronous birds.

Smaller spacecraft are particularly cool because – since their design, fabrication, and launch costs are lower than big satellites – satellite manufacturers are more willing to take risks with their design. I don’t mean “risks” to imply that these spacecraft are unsafe. I mean that they are not quite as tried-and-proven. In other words, they can be more cutting-edge. More innovative. More likely to push the envelope.

In that vein, what I find most exciting about the Antares launch is that the vehicle carried three NASA CubeSats specifically designed to puncture the conventional wisdom about how conservative spacecraft designs need to be. They are called “PhoneSats,” and what makes them special is that their flight computers are off-the-shelf Android cell phones. Their on-board avionics software is an app.

http://www.nasa.gov/directorates/spacetech/small_spacecraft/phonesat.html
PhoneSat 1.0 (from nasa.gov)

The idea behind these CubeSats is to test how robust spacecraft really need to be. Commercial spacecraft engineers design huge margins into their vehicles. We tend to be very careful and conservative. But since many spacecraft last well longer than their quoted design lifetimes…maybe we’re too conservative. The PhoneSats will help answer the question: If we just get commercial computer hardware and design a system that works – without so much conservatism – how long will it last in space? Maybe it will operate long enough to complete its mission.

If the PhoneSats stayed in orbit forever, they’d be likely to burn out. Their Android processors and flash memory would fail under the onslaught of cosmic rays. But, at under $7000 each, maybe even the short mission of these satellites would make them competitive with the longer-lasting multi-million-dollar vehicles.

I’ll be very interested in the results of the PhoneSat project!

Space

Where does the public see innovation?

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The Lockheed Martin corporation recently conducted a poll in which they asked members of the public to choose the company’s “ultimate innovation.” There were a lot of fancy gizmos in the poll, including some very recent ones that definitely qualify as “innovations.” The Joint Strike Fighter, for example – a jet that can take off vertically and then fly at supersonic speed – is pretty damn cool. The SR-71 is almost mythic in the aerospace world. There were underwater robots and fighters that helped us win World War II.

But what won the poll, in the eyes of the public? What was the “ultimate innovation?”

A twenty-three-year-old clunker of a machine. A device that was once universally panned as myopic and wasteful.

The Hubble Space Telescope.

These high-profile space exploration missions simply soar in the public imagination. More than any other aerospace or engineering innovation, they capture people’s attention and fire their spirit.

Clearly, we need more of them.

Not only is it good policy…it’s just good public relations!

Games, Science Fiction, Space

A spacecraft engineer’s review of Flotilla

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I just picked up the latest Humble Bundle sale entirely because of the gameplay video of Flotilla. Flotilla is a terrific little gem of a game that puts players in tactical command of a small squadron of combat spacecraft, with a little irreverent stomp-around-the-galaxy exploration to frame the battles.

Screenshot from the Flotilla web site.

What it gets right

Spacecraft physics-wise

The simultaneous turn-based mechanic. I’ve written before that a realistic movie depiction of space combat would play out like a submarine movie: long periods of tension between scenes of rapid action. Flotilla only allows players to issue orders every 30 seconds, and then watch how their tactics play out – which plays right into that tension/action dynamic. It also is probably pretty close to how communications lag and astronomical distances would force a true space fleet commander to operate.

The focus on both spacecraft position and orientation. Ships have well-defined firing arcs, strong points, and weak points. These features make it essential for players to consider the 3D orientation of their spacecraft and their targets: I learned very quickly that the basic orientation control mode (in which you specify an enemy for your ship to face) was not sufficient if I wanted to get through combat unscathed. The advanced mode (which lets you specify yaw, pitch, and roll Euler rotations for each ship) let me perform much more advanced maneuvers; faking out my opponents so that they exposed their vulnerable points to me while I absorbed incoming fire with armored surfaces.

Gameplay-wise

The simplified interface. The game is very clean, stylish, and accessible. It’s easy to set up complex tactics in the fully 3D environment. I also appreciate that you don’t have to keep track of a bazillion unit types and special abilities – but, at the same time, each ship class has particular strengths and weaknesses.

The combat balance. It’s possible to approach a battle with a large fleet and blast your enemies into space dust…and it’s also possible to slip in with a single destroyer and land surgical hits to wipe out a superior force. (It took a while, but about half a hour ago I took down two destroyers and four dreadnoughts with a single destroyer. I even tricked two of the dreadnoughts into colliding – that was very satisfying!)

What it gets wrong

Spacecraft physics-wise

The specifically top/front armor design. All ships have strong armor on their “tops” and “fronts,” with weak armor on their “bottoms” and “rears.” I think it’s great to have weak and strong faces, but if the engineers who designed these ships knew that they were going into space – where only the enemy’s gate is “down” – why would they make all ships the same in this regard? It would make more sense for the different ship classes to have different strong and weak faces.

Forces do not exist. There is no gravity, and no orbital motion. All battles take place in deep space. Orbital dynamics would certainly complicate the gameplay – but the cool thing about including orbits would be to add complexity to players’ tactical options. (In orbits, it’s actually easier to move in some directions than others. That’s a phenomenon that players could manipulate.) More importantly, the direction a ship’s engines are pointing has no effect on its motion. It would have been neat to see some coupling between the 3D positioning and spacecraft orientation, instead of letting vehicles slide “sideways” at the same speed that they move “forward.”

Gameplay-wise

No collision warnings. The movement hint lines really need to turn red or something when you accidentally drive them through an asteroid. Or when two ships’ movements will lead them into a collision halfway through your turn. Even after I knew to look out for these situations, I still sometimes drove my own spacecraft into each other. Those are real facepalm moments!

Orientation can be tricky. While I love the abstracted spacecraft graphics because they make me feel like a fleet admiral looking at a tactical display, it’s sometimes hard to tell at a glance which spaceship faces are “up.” A little extra coloration or something would help indicate the weak and strong spots. In addition, Euler angles are not my favorite way to represent and manipulate orientations of spacecraft. I would prefer to use the same planar/vertical interface that sets 3D motion to specify the front-facing direction of my ship, and then roll the spacecraft about that axis.

What it gets hilarious

Everything about the Adventure Mode. That owl warlord will rue the day he challenged my karaoke championship!

 

Art, Concepts, Geology, Maps, Original fiction, Science Fiction, Space

On the World Zarmina

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2014 update! You can now buy prints of this map!

…Preliminary report on image data from the LongShot-2 mission…

The planet Gliese 581g – also known as Zarmina – is a circular world.

It is not circular in the literal sense shown on ancient maps of the Earth, before we understood Earth to be a sphere. Rather, Gliese 581g spins at the same rate as it orbits its star, so its sun is always in the same place in its sky. Heat from the red dwarf, distributed by the circulation of the atmosphere, keeps a circular region under the star warm enough to melt ice into liquid water.  Thus, the habitable regions fall entirely within a disc under the constant light of the red star. Outside this region, water freezes – and the further one goes out onto the ice, the more inhospitable it gets. Travel to the far side of the planet is about as difficult as traveling from the Earth to the Moon – and so, to the inhabitants of Zarmina, their world might as well be a circle ringed in ice.1

This artist’s concept, based on image mapping from our recent interstellar probes, depicts the habitable region of Zarmina:

Zarmina, from above the substellar point
Zarmina, from above the substellar point.

For discussion of Zarmina, some reference points and directions are necessary. The circular boundary of the map is the ice line: beyond this point, water is certain to freeze. The center of the circle thus defined is the substellar point. When standing here, the red dwarf Gliese 581 is directly overhead. This image shows Zarmina oriented with is orbital plane horizontal. The planet has a south magnetic pole pointing roughly towards the top of the page, and so the “top” and “bottom” of this map become the cardinal directions north and south. East and west take on their usual definitions.

Gliese 581g is approximately three and a half times the mass of Earth. It is tidally locked to its star, meaning that one side always faces its Sun just as one side of the Moon always faces the Earth. Gravitational tides from the star also have the effect of pulling the rocky surface of the planet into an oblong shape, like a rugby ball. Since our probes reached the Gliese 581 system,2 we determined that the planet has a tiny orbital eccentricity (from perturbations by the other planets in the system) which causes a periodic shift in the gravity force on the planet: slightly east to slightly west, and back again, every Zarminan day (about 37 Earth days). The combination of the periodic variation in stellar tide and the fact that the ocean is more mobile than rock makes dry land much more common in the center of the disc than near the edge, as we see in the map.3

This variation in tidal force results in one of Zarmina’s most striking surface feature types. Continue reading On the World Zarmina →

NASA, Science, Space

Marswhelmed

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So, the Mars Science Laboratory “Curiosity” has discovered evidence that, about three billion years ago, the environment on the planet Mars could have supported Earth-like microbial life. Some news outlets (including the MSL Twitter feed) are billing this discovery as the accomplishment of Curiosity’s mission.

I have a confession to make.

I don’t really find this discovery all that exciting.

The MSL team’s discovery is a confirmation of a long-expected hypothesis. (Indeed, with the number of planetary environments out there, it would be statistically silly to think that Earth is the only life-supporting place!) It’s valuable to know, and it’s important to the scientific method to rack up such confirmations even when we’re as sure as we can be, but it doesn’t exactly have the same allure as striking out into the unknown. I think the spirit of exploration is important to maintain in our space programs, because brand-new missions and discoveries are what keeps space exploration in the public eye. After all, a recent study shows that not only do most Americans want to see exploring Mars as a national priority, but most Americans want to see a human mission to Mars and three-quarters of Americans want to see the NASA budget doubled. I am confident that the dramatic landing of the Curiosity rover, with its brand-new mission architecture, has something to do with that enthusiasm.

There’s also something I find slightly foreboding about Curiosity’s confirmation. In 2011, the National Research Council’s Planetary Sciences Decal Survey of Solar System exploration listed and prioritized the objectives of our planetary science program for 2013 through 2022. This is a study done every ten years to identify which of the flagship-sized missions NASA should fund, design, and launch in the coming decade. First on the list for 2013-2022: a mission to return samples of Martian rock and soil to Earth. The announced “Mars 2020” rover is in line with that objective.

I’m going to go out on a limb and predict the conclusion sentence of scientific findings from a Mars sample return mission:

Chemicals and minerals present on the surface of Mars indicate that ancient Mars may have included wet environments able to support Earth-like microbial life.

In other words, I don’t think a Mars sample return mission will give us any dramatically new information that we didn’t already have from MSL, MER, MRO, or any of the Martian samples we already have. See what’s got me worried? I don’t think we’re going to actually discover life – in fact, I would be very surprised if the 2020 rover included any instruments actually capable of recognizing a Martian if it walked right up, poked the rover with a Martian stick, and walked away. (Curiosity doesn’t!) I am afraid that we will put this rover on the Red Planet in 2020, cache a sample, retrieve the sample in 2030, and the public response will be, “wait a minute, we spent two decades confirming what we already knew in 2013? Come on, space program…where’s my jetpack?”

A Mars sample return mission would be a triumph…for the niche sub-field of Martian geochemistry. I don’t think it would have the sort of broad scientific and public impact that we should expect from a flagship-scale mission. Basic research science plods along, making incremental improvements in understanding and slow-but-steady progress. NASA should be sticking its neck out, thinking big, and going for the most challenging – and rewarding – missions. Instead of looking for environments that might have been habitable three billion years ago, we should be looking for actual life.

You see, even before MSL’s discovery, we already knew of the existence of a watery, potentially life-supporting environment. Jupiter’s moon Europa has an icy crust with a subsurface water ocean beneath. The ocean is warm enough to be liquid, because of the energy input from Jupiter’s tides. And scientists have found that that ocean contains lots of salts and minerals – and even organic (carbon-containing) compounds. Liquid water, energy sources, and chemical building blocks: everything an Earth-like life form needs! The main difference between Europa and Mars is that, while we’ve been able to observe the desolation of the Martian surface for decades and know that we could only expect to find evidence of ancient microbes, we have no idea what’s under the Europan ice sheet. It could be nothing…but it could also be life as rich and complex as what we find, on Earth, under Antarctic ice, in sealed cave systems, or around hydrothermal vents. Unlike Mars, where we have been forming preliminary conclusions for years, we won’t know until we get something under that ice layer. That’s the kind of exciting exploration work that I want to see from my NASA flagship missions.

The Decadal Survey did recognize the potential for alien life on Europa. Its executive summary says that “the second highest priority Flagship mission for the decade 2013-2022 is the Jupiter Europa Orbiter” but notes that “that both a decrease in mission scope and an increase in NASA’s planetary budget are necessary” to fly a mission to Europa. Personally, I’d prefer to discover alien creatures within my lifetime…but I don’t make policy or control the purse-strings. So, instead, off to Mars we’ll go again.

Space

Heritage

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Today, I saw a piece in The Space Review about what makes spacecraft launches complex and difficult. It occurred to me that this was a rather odd essay, coming as it does on the heels of the successful, high-profile flight test of a rocket that promises to seriously shake up the launch game. The essay is a full-throated defense of the Old Launch paradigm; the idea that the people who have been approaching space the same way for decades are the best at it by virtue of their heritage. If this essay had come out a few years ago, when SpaceX was experiencing strings of launch failures, it might be relevant; but now it is a perfect illustration of what’s wrong with space industry thinking.

Building and launching spacecraft is hard, no doubt about it. Satellites and rockets are complex systems. A lot of things have to happen very quickly, and some things have to happen in regimes where we don’t fully understand all the physics. The success rate for space missions is not 100%. (These days, though, it’s pretty darned close.) However, the inherent difficulty and complexity of space exploration and exploitation is a poor reason to shy away from innovation.

The Space Review essay opens with the following paragraph:

One of the most challenging aspects of launching payloads into space is that you not only get only one attempt for a particular set of hardware, but usually that one attempt is the first time that particular set of hardware experiences the actual flight environment. It may even be the only time that overall hardware configuration ever flies. Every flight is a test flight, like it or not. For that reason it is very, very important that the hardware gets built every single time in exactly in the same manner of other examples that were found to work properly. This is not easy; in fact, it may be hardest single requirement in the space launch business.

I’ve added some emphasis to a statement with which I cannot disagree more. The author says that the most important requirement for space hardware to meet is that it should be exactly the same as other space hardware that has already flown.  I think that what he should say instead is that it’s important to be sure that your hardware will work. Whether you prove that by simulation, analysis, experiment, back-of-the-envelope calculation, derivation, or by comparison to flight heritage is immaterial to me!

I think that this notion of valuing flight heritage above all other considerations is detrimental to the space industry, for a couple of reasons. First, it stifles innovation. If, over the past sixty years, we really hadn’t sent anything into space that hadn’t already been in space, we wouldn’t have any satellites at all. Or, if I’m going to give humanity the benefit of the doubt, we might have a couple satellites but they would all look like this. Space is a challenging but rewarding environment. Purely in economic terms, it’s worth it to stick our necks out a little and accept a couple failed launches in return for all the infrastructure that we have been able to deploy in space, from weather satellites to Earth imagery to military support. The more capabilities we want from our spacecraft, though, the more we need to innovate. Sometimes – heck, often – that means we have to build a vehicle that looks different from the things that have gone before.

Second, I don’t like the idea of flight heritage because it involves an implicit logical fallacy. Spacecraft engineers sometimes confuse a solution that worked in the past with the best solution to a problem. Sometimes, spacecraft launch with really state-of-the-art devices and programming. But, other times, they launch with only good hardware and software. Every now and then, they even launch with something on board that’s actually sub-par – and sometimes, that causes a problem. An engineer might think that if a design has heritage, it’s certain to work. But no such guarantees for success actually exist. Spacecraft are not like mass-market consumer goods: we can’t test thousands of samples and get a good statistical sense of whether we have the best design or not. We have to deal with small-number statistics for successful missions.

It’s important to look at spaceflight heritage with a critical eye: What worked? What didn’t? And why? Do we have the best solutions? Can we make them better? If so, what would it take? These are questions that drive innovation. They are more likely to come up at a New Space company – which has to innovate in order to survive – than an established Old Space company. I have great respect for the engineers that have been able to launch whole series of operational spacecraft. But I am wary of an approach that views prior success as a standard of perfection.

NASA, Politics

Money matters

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The whole public debate about sequestration, cutting the deficit, and stimulating the economy is looking in the wrong directions. The broad solutions are simple: (1) the federal government should not spend as much as it does in relation to its income; (2) the government should target its fiscal policies in a way that makes the US economy expand. The details, of course, are where everybody bogs down.

I’m an engineer. I like to solve problems by looking at data and figuring out where to apply pressure to a system to get it to do what I want. Clearly, where I apply that pressure matters: it’s better to target the big-ticket items than the small fry. This approach means, simply, that cutting federal discretionary spending is almost completely irrelevant. Instead, proposals for managing federal spending should be looking at cutting things like the military. (This is one good thing about the sequestration plan: it forces the issue of cutting our ludicrous amount of military spending.) The politicians resistant to touching the military budget sometimes argue about the number of jobs involved – not just soldiers, but civilian contractors to the military. We wouldn’t want to hurt the economy by cutting military spending, right? Well, as it turns out, the military budget is not well-correlated with GDP growth. One reason for this result might be that, while the military is certainly interested in investments, infrastructure, advanced technologies, and new medicines – all things that can make for jobs and growth in the wider economy – the military also isn’t exactly interested in sharing those things with the civilian community through a commercialization process. It wants to invest in itself alone. This does not help make the economy grow. So, there is plenty of room for cuts in the military budget (and plenty of room to remain comfortably secure, too).

A well-crafted budget plan should also look at diverting spending towards programs that have the greatest positive impact on our economy and society. Yes, I’m talking about increasing some areas of federal spending as part of a deficit reduction solution. That’s because of multiplier effects – sometimes, the government can take actions that reverberate throughout the economy and generate positive benefits for everybody: jobs and wealth for citizens, increased tax revenue for governments. Win-win!

Increasing spending happens to be about the same in deficit and revenue terms as cutting taxes, but the multiplier effect from tax cuts isn’t going to be much to help. They provide some amount of economic growth, but there are a lot of studies that show that the effect is less pronounced than changes in government spending. Here is a good article outlining both sides of issue. In my opinion, the preponderance of evidence is that most economic growth for every dollar cut from federal taxes is lower than the economic growth from boosting spending. However, even the studies that don’t agree with me tend to show that most of these actions have multipliers up to about 1.6 – for every $1 of taxes cut or spending increases, GDP grows by $1.6. As long as this number is greater than 1, there’s a positive effect on the economy, but a 60% return on investment may take a while to have positive effects in society at large.

Fortunately, there are some slam-dunk areas where a little government investment goes a long way. One example is highway infrastructure investment: it may not be sexy, but it apparently carries a multiplier greater than two! This means the if the federal government cut $2 from the Pentagon budget, but invested $1 in the Eisenhower Interstate Highway System, then not only would the deficit shrink by $1 but the economy would grow by $2! (Plus, we would have bridges that don’t fall down.)

Even highway spending, though, isn’t as good as the government could do.

There’s this one government program that happens to provide a staggering return on investment, and is hugely popular with all demographics, but doesn’t really get a lot of federal budget love. It’s called the National Aeronautics and Space Administration. (I bet you were wondering when I would say something about space!)

For every $1 that the government spends on NASA, it spends about $200 on other things. But for every $1 the government spends on NASA, the economy grows by….well, a Freakonomics panel says that the economy grows by $8 – an 800% return on investment. A Rutgers University report posted on the Johnson Space Center web site puts the return at $7 (not just for NASA, but for research and development in general, as well). And here’s a link to a 2002 article that suggests that for $64 million of investment from the government through NASA, private companies received a “value-added benefit” of $1.5 billion, making a ratio of over 1 to 23. If a broker came to you offering an investment account with a historical 2300% rate of return, wouldn’t you take it? Purely as an engine of economic investment, without getting into any of the scientific, technological, or sociological benefits, NASA is a tremendous success!

Certainly, our national representatives should be engaged in a thoughtful and difficult discussion over what programs to reduce and which to expand. If they are smart about it, though, they should look at preserving – or even enhancing – those programs that benefit us the most. They should look at the data and target their actions.

Therefore, cut defense – I have enormous confidence that the Pentagon will successfully figure out how to prioritize. Cut some entitlements – there are certainly bloated programs out there. But fund infrastructure. Fund research and development. Fund the NSF, NOAA, NIST, DOE, and USGS. And fund NASA!

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) →

NASA

That’s no moon…

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While somewhat facetious, this petition on whitehouse.gov makes an excellent point. With investment in space-related technology, science, and development,

the government can spur job creation in the fields of construction, engineering, space exploration, and more.

Ever dollar the federal government spends on NASA boosts the United States GDP by a much larger amount, with estimates ranging from 2 or 3 dollars to 14. (That’s anywhere between a 100% and 1300% return on investment. Any number there is a fantastically good deal.) Of course, the pure economic return doesn’t come close to capturing the effects of new technologies and inspirational missions.

If you got a laugh out of the Death Star petition, like I did, I’d suggest that when you’re done chuckling you take a look at this one, instead, or learn about advocacy groups like Penny4NASA and The Planetary Society.