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!

The MIT Space Propulsion Lab has been developing these as little patch thrusters that they can put on CubeSats. The thrusters are 1×1 cm patches and seem to generate forces in the range of ten or so micronewtons. (That would be, say, 1% of the weight of a postage stamp.) These are very small forces, but we are talking about very small satellites and we can leave the thrusters on for a very long time.

The idea that stuck in my head when I learned about these devices, though, is that they are mechanically very simple: all we have to do is texture a surface appropriately, touch the ionic liquid to it, and energize part of it. We could probably develop a fabrication method to print the thruster “texture” onto a flexible membrane or fabric of some kind.

And then we could deploy it like a sail.

10 micronewtons from a 1×1 cm thruster gives a thrust density of 0.1 N/m^2. So a 1×1 meter sail would produce a thrust force of about a tenth of a newton. On a standard 3U CubeSat, this corresponds to an acceleration of 3.4 milligees – which is actually getting up to the acceleration regime of the chemical thrusters on large spacecraft! With such acceleration, it would take five minutes for the CubeSat to add one meter per second to its velocity. Starting from low Earth orbit, this miniature sailing vessel would need only twenty minutes to hit Earth escape velocity!

3U CubeSat with 1 meter sail

What probably makes the most sense from a propulsion perspective is to deploy the membrane engine behind the spacecraft, maximizing the engine area and minimizing any adverse effects of the ion exhaust. (All those high-energy ions might eat away at the spacecraft’s solar cells or other surfaces!) However, there might be some challenges in running the ionic liquid down to the sail.

A good compromise would be a sail mounted to the back or middle of the CubeSat – think of  the NanoSail-D configuration – where a reservoir of ionic liquid could supply a steady stream of propellant to the membrane and most of the zooming ions will miss the back of the spacecraft. The forward-facing part of the membrane might also be usable area, for things like solar cells. Or CCDs.

Ion engines caused a shift in the way spacecraft engineers thought about propulsion: instead of brief, impulsive maneuvers, they could use a gentle but steady acceleration for a long period of time. The ability to spread an ion engine over a large area might be a way to create a high-efficiency thruster that also produces a large force, and with few moving or complex parts. That’s the kind of device we might use to send a small spacecraft to the outer Solar System. Of course, we’d need a lot of electrical power, but that’s why the DOE is starting plutonium refining again…

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.

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!

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!

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!

…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 pre-Columbian 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.

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 north 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. In areas predominantly located to the west and east of the substellar point, the crust can stretch and crack open into concentric ring-like shapes⁴ - like parentheses around the center of the disc. Blocks of rock surrounded by these faults drop downward slightly into arc-shaped rift called graben. These graben are the primary tectonic features on the planet.

Recent graben on Zarmina

You might notice, however, that there are a number of graben with orientations that don’t match the distribution described above. Instead of being centered to the east and west sides of the disc, and curving around the middle of the circle, they have a center point somewhere to the north:

1st epoch graben

An explanation for these features involves true polar wander. Due to gravitational tides, volcanos, or other forces, the mass distribution of the planet’s crust changed enough that the entire world shifted. Its spin axis flipped around, over a geologically short period of time. Zarmina is predisposed to have land in the center of its disc, and ocean towards the edge – so the land mass to the north of the disc must be the ancient substellar point. This point in time serves as a convenient marker for Zarminan geologic history: we divide events on the planet into the “first epoch” and “second epoch” according to whether they happened before or after the polar wander.

The arc-shaped graben are surrounded by faults – weak points in the planetary crust. Though Zarmina shows no evidence of plate tectonics, it does have a liquid core and mantle. (The liquid core is the source of Zarmina’s magnetic dynamo.) Magma from the mantle can ooze its way to the surface wherever a “hot spot” coincides with a weak point in the crust, eventually building up a shield volcano or spatter cone and extruding lava flows.⁵ In the absence of tectonic plate collisions, volcanism is the only major mountain-building process on Zarmina. A few active volcanoes are even gradually building Hawai’ian-style islands in the ocean.

2nd epoch shield volcano locations

Unlike on Earth, many well-preserved impact craters are visible on Zarmina. Earth’s plate tectonics warp and change surface features fast enough to eliminate craters quickly. But on Zarmina, without plate tectonics, craters last a long time.⁶ Surface erosion from water and wind eventually smooths out the craters, though, especially the older ones from the first epoch. In addition, the thick atmosphere prevents bolides (meteors) below a critical size from reaching the surface, so impact craters on Zarmina are all larger than a certain minimum diameter.

Craters

Some of the most dramatic examples of craters are near the substellar point. In the desert close to the center point of the disc is a first-epoch impact site, degraded by erosion. Nearby, a set of barchan dunes of sand demonstrates that wind-driven erosion is still happening. To the southwest, a more recent crater hasa well-defined circular edge and a central peak (though it is mostly filled with seawater at present, since several graben pierced the raised crater rim and opened a channel to the ocean).

Desert craters

The older, northern terrain – the ancient substellar point – is more heavily cratered than the remaining surface. Approximately 12 of the easily apparent craters date from the first epoch. The remaining six obvious craters in the map above occurred after the episode of polar wander.⁷ They also happen to be near the equator, since the planetary equator is closely aligned with the orbital plane of the entire star system – where asteroids are more likely to be.

Geological map of Zarmina (hatching indicates first epoch features)

The three major processes of graben formation, volcanism, and impact cratering have been continuously active throughout the history of Zarmina’s visible surface. Complex surface features appear throughout the disc, where these processes collide. A striking combination of geologic processes formed an island towards the southeast of the disc:

Cratergraben isle

This island is composed of a basaltic lava flow from the active shield volcano to its west. (There is some variation in composition where the impact to the southwest threw up an ejecta blanket.) The unusually regular shape of this island comes from two older features: a  graben, which stopped the flow from moving southeast and instead diverted it to the north and southwest; and an impact crater which filled with lava. The entire island is an example of inverted topography, composed of erosion-resistant basalt filling in the gaps left by the older landforms. When the lava originally flowed out from the volcano, it would have formed a peninsula connected to the main continent – a later graben (and a later crater) created the long, curving strait. Other areas of the planet also contain lava flows spilling into graben, or regions where the flows interact with canyons and other features.

In the northeast of the central continent, tectonic forces formed a graben directly through an extinct volcano. This volcano shows a great deal of other evidence of erosion, including rainwater channels cutting into the rock face and sculpted shapes from the high winds coming off the ocean. (In fact, this tropical region of the planet contains a large number of fanciful jungle hoodoos due to a soft rock composition and the sea winds.) This is not the only place on Zarmina where the interior of an old volcano is exposed, revealing orange-red sculpted rock in the welded volcanic neck.

Graben-sliced volcano

The wind patterns on Zarmina move generally from the ice line in toward the center of the planet, where the red dwarf heats the surface and the air rises. Intervening terrain bends the major air currents to follow the topography. Air picks up moisture as it passes over the oceans; this moisture rains out when the air moves to higher altitudes over land. So, the coastal areas of the planet receive most of Zarmina’s rainfall – and endure most of the wind- and water-caused erosion. (The sea winds explain the frequent erosion pattern of the volcanoes: the wind collapses the mountainsides and carves them into crescents opening toward the sea.) There is a stagnation point towards the middle of the disc where the air currents turn upwards; the taller mountains on the western coast form a partial barrier and so the easterly winds penetrate as far inland as the substellar point.⁸

Wind patterns on Zarmina

In general, the climate of Zarmina is warm at the substellar point and cold at the ice line. Moving from the center of the disc to the edge, you would encounter desert, tropical jungles, temperate regions, taiga, and finally tundra. At the ice line, rocky land and ocean both disappear under a cap of water ice and conditions rapidly become inhospitable. Vegetation appears on Zarmina’s landmasses wherever the local climate conditions allow: most of the wind-stripped coastline is sparsely covered, but lush areas are located further inland where the wind speed is not as high and there is more fresh water from rainfall. Plant life concentrates in regions near lava flows and crater ejecta, where the surface rock has been churned up into soil. Most mountains have a rain shadow on their inland (lee) side. The southern coastal regions are rich plains; the northeastern islands are low, windswept barrens; the northern continent disappears into snow and ice. The most verdant areas are those where the general circulation pattern brings rain over the land, but local topography tempers the wind speeds.

This is a world that, to those of us familiar with Earth, is truly alien. The very structure of the world predisposes us to think of it as a flat disc with a finite edge, and the processes shaping the surface of Zarmina create bizarre and unfamiliar landforms. Yet, regions of Zarmina echo the settings we find on Earth. The cultures that have evolved on this planet are surely just as alien…and just as eerily familiar. We will have to wait for the next round of interstellar probes to find out.

Postscript

I had a tremendous amount of fun developing this map. My usual process is more imaginative and artistic than scientific, though I do occasionally consider such phenomena as rain shadows and fault lines. This time, I came up with the basic structure of the world (land in the middle, sea at the edge) and a list of a couple geologic processes: graben formation, impact cratering, volcanism, erosion, and polar wander. Then I went through a couple iterations of applying them in sequence. That geologic map you saw above was actually my starting point – I threw craters and volcanoes on there, rotated the whole thing for polar wander, and repeated. The basic compositional units changed as I did this to reflect the history I was building up: siltstone where the land had been just offshore, limestone where it had been in deep water, and so on, and then I would imagine some of those rocks eroding more than others. The tough thing was deciding where to limit this process: it’s good that I only picked a couple basic mechanisms, instead of trying to account for, well, everything!

(I got to lean a lot on things remembered from some geology studies at Williams and Cornell. If Jim Bell is reading this, I hope he found it more entertaining than cringe-worthy.)

The really awesome thing, from an artistic point of view, is that this process took a lot of the control out of my hands. I was watching the world develop, and I had only very general things to say about how that happened. It became harder and harder to decide, “I want a mountain there and a canyon there!” Another effect I observed was that sometimes I ended up with really cool-looking landforms…and then as soon as I applied my next set of geologic processes, I’d see those locations obliterated. Of course, equally interesting features would pop up somewhere else on the planet. I will have to do some more maps this way, and see how they come out.

And do you know what I need? I need a better way to digitize these maps. This thing looks way better in person.

—

¹ This is the “eyeball Earth” scenario, first described by Dr. Raymond Pierrehumbert.

² Let’s get on this.

³ In fact, this is the decision about my map design about which I have the least confidence. But it’s a very basic decision. I just decided to go with it. The map is cool, dangit.

⁴ At least, according to my rough models, that’s where these features should concentrate and that’s how they should be shaped. In real life, this happens in rift valleys on Earth, but due to plate tectonics. Tides cause similar effects on worlds like Europa and Ganymede.

⁵ I decided that these hot spots have a sufficiently hard time getting through the crust that they’re more likely to sit at a weak point for a long time. So, we always always get the shield volcano to go with the flow.

⁶ If anything, I didn’t put enough craters on the map. I probably should have placed more on the more ancient first-epoch terrain to the north. Let’s just say the ice is covering up a lot of craters!

⁷ There are more under the ocean. That’s how we ended up with first-epoch craters in the more southerly terrain.

⁸ I’ll freely admit that I’m more geologist than climatologist. And I’m definitely more physicist than geologist, and more engineer than physicist, so climate modeling gets a pretty low level of expertise from me. I think this all sounds plausible, anyway!

If you found your way here by way of Dice, here’s a teaser for something I’ve got coming up…

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.

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.

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!