A Manifested SLS

NASA recently released details on their planned architecture for human spaceflight in the coming two decades. This was a welcome update, because before now the plan was little more than “we build SLS, we do something around the Moon, then we go to Mars”. You may think that I’m joking or exaggerating. I’m not.

Fortunately, we don’t have to speculate in the dark anymore. We have hard details about what the SLS will be launching and how it will help NASA eventually land humans on Mars. Well, sort of. We have details about what the SLS will be launching, in any case.

NASA’s Plan

The plan revolves around two new pieces of infrastructure: the Deep Space Gateway (DSG) and the Deep Space Transport (DST). The DSG is essentially a space station in orbit around the Moon. The DST is a spacecraft for transporting humans from the DSG to Mars. The DST is reusable, and only stays in orbit. That is, it is simply a shuttle between Martian orbit and lunar orbit. Both the DSG and DST will be equipped with solar electric propulsion (SEP) modules, allowing the DSG to change its orbit around the Moon and allowing the DST to fly between the Moon and Mars without ditching any mass or refueling (electric propulsion is very efficient). Finally, the Orion capsule is used to transport astronauts between Earth and the DSG.

The SLS, NASA’s big new rocket, can launch an Orion capsule to lunar orbit along with 10 metrics tons (mT) of cargo (this configuration is called a co-manifested payload, or CMP). The SLS can also launch 40 mT of cargo to the Moon if launched without a crew. The DSG will be composed of four modular chunks, each launched as a CMP with a group of astronauts (one launch per year from 2022 to 2025). The astronauts will help assemble the DSG in lunar orbit before returning to Earth.

After the DSG is complete, a cargo launch of the SLS will loft the DST in 2027 as a monolithic (non-modular) spacecraft. Astronauts will run the DST through a shakedown cruise around the Moon in 2029, before embarking on some sort of Mars mission after 2030.

You might notice that this plan doesn’t actually specify what the Mars missions will look like. There are some vague hand-waved mentions of a mission to Phobos or Deimos (the moons of Mars), and then maybe landing on Mars. What kind of science will the DST be able to do? Surface samples from Phobos? In-situ resource utilization (ISRU) experiments? How will NASA send landers to Mars? What will they look like? Will NASA be landing support equipment on the surface ahead of time? Instead of going to Mars quickly and cheaply, we are going to spend a decade or more jerking off in lunar orbit, and it’s not clear why. At the end of this (unintentionally long) post, I will propose a plan that accomplishes the same thing with less money, less time, and less infrastructure.

Why?

But before addressing these more concrete questions, there are some existential questions that need to be addressed. For example: why? Why are we spending billions of dollars to launch a handful of humans into lunar orbit, and why are they monkeying around up there?

In an effort to answer these questions, let’s step back and answer the larger question: why do we care about sending people into space? There are certainly motivations for having infrastructure in space: GPS, communications, Earth and space weather monitoring, climate research. These activities have real economic value, but they don’t justify sending humans.

There is the scientific motivation: learning more about the stars and about the formation of the solar system and the origin of life. This is the rationale that NASA often cites. However, there are countless arguments to be made in favor of widespread robotic exploration: it’s cheaper and faster, robots can go more places, robots don’t have to come back, robots can stick around for longer, we aren’t risking planetary contamination, etc. These concerns outweigh the few benefits that humans do provide.

A third motivation, one that I suspect a lot of people at NASA actually believe in but would never dare say: we landed people on the Moon, then we stopped. We need to land people on Mars because space travel is cool, but we can’t justify just going back to the Moon. I think this stems from a larger infatuation with the vision of the future instilled in us by decades of media consumption. Science fiction depicts humanity among the stars, so we must go. I suspect this motivation is rather rampant among human spaceflight fans. Needless to say, this motivation is fucking stupid.

The only meaningful motivator for human spaceflight is neither economic nor scientific. The only reason to kick off interplanetary human spaceflight (and therefore the only reason to be interested in human spaceflight at all) is the distant goal of establishing a permanent, self-sustaining human presence off of the Earth in order to make sure our species never dies out. As a species, we must invest in the intrinsic value of this motivator, or give up human spaceflight once and for all. Doing it for any other reason is simply masturbatory.

Ok, so we care about sending people into space because we eventually want to establish a self-sufficient colony. We care about going to Mars because the surface of Mars is, for a whole host of reasons, the best place to create that colony. But why do we care about spending billions of dollars on an unscalable architecture to send a handful of humans on short trips around the Moon and Mars?

The answer is: maybe we shouldn’t. There are good, well-formed arguments against the whole endeavor. However, NASA has always been an organization that pioneers research into really difficult problems, and then gives their results to the public so that private companies can improve and capitalize on those advancements. If the government is set on spending billions of dollars on human spaceflight, we might as well spend it in a way that will help the eventual colonization of Mars.

So what kinds of unanswered questions or nebulous roadblocks stand between humanity and our intrinsically-valued goal of surviving a potential devastation of the Earth? Cutting past the leagues of logistical questions about a surface colony:

  • Data on the effect of long-term partial gravity on human biology
  • More data on the effect of long-term (500+ days) exposure to solar radiation
  • More data on the psychological effect of long-term separation from Earth
  • Research on high-efficiency life support systems
  • Research on long-duration missions without access to resupply missions from Earth
  • A platform for small companies to test technologies from various staging points around the solar system (more on this later)

These can be divided into two categories: research on human factors, and research on vehicle systems which until now have been unnecessary.

Fortunately, thanks to Mir and the ISS, we have lots of data on the effects of long-term weightlessness on human biology, and lots of data on how space vehicles degrade over the course of years. However, we still lack experience with maintaining space vehicles without constant access to the Earth (e.g. manufacturing new parts in space or creating highly redundant systems). We also don’t have experience creating closed-loop life support systems with extremely efficient recycling (the ISS is rather wasteful).

We can also gather a lot of data about the human factors on Earth. Data on radiation exposure from nuclear workers and people exposed to radiation sources is abundant. We can run more experiments like Mars 500 to gather psychological data. Researching the effects of long-term partial gravity is unfortunately quite difficult, but it is also one of the least important factors for now. We can safely ignore it.

Finally, it must be considered a necessity to include commercial efforts at every step in the process. Ultimately, it will be corporate entities that enable and support colonization efforts. NASA can and should play a critical role in enabling the development and testing of technologies by private entities. We have seen how valuable this synergy can be in the ISS; from launching cubesats to mounting experimental modules, smaller companies can gain invaluable operational experience. Resupply contracts from NASA essentially kept SpaceX afloat, arguably one of NASA’s more important contributions in the last 20 years.

So, any effort by NASA should focus on two goals: tackle the problems of closed-loop life support and long-duration mission maintenance, and provide a configurable, expandable framework for commercial involvement. Naturally, this necessitates the launching of astronauts beyond Earth orbit, so I think we’ve solved our existential question. Let’s move on to critiquing NASA’s proposal.

Being Useful

NASA has done a fantastic job of shoehorning itself into a host of arbitrary design constraints by jumping from plan to plan over the course of 4 administrations. Let’s enumerate them, and then evaluate the new proposal by its satisfaction of the constraints and goals.

  • The Orion MPCV exists. It can only be launched by the SLS, it can carry 4 people, and it can only re-enter from lunar velocities or less (why didn’t they design it for re-entry from Martian velocities, you ask? Good question).
  • The SLS exists. Block 1B can carry 105 mT to LEO, and 39 mT to a Translunar Injection (TLI). If it launches a co-manifested payload (CMP) with Orion, it can send 10 mT to TLI. Block 2 (first flight planned 2029) can carry 130 mT to LEO and 45 mT to TLI. It will fly once a year.
  • We want to utilize the 40 kW SEP module that was designed for the cancelled Asteroid Redirect Mission (ARM).
  • We have to do things around the Moon. Because reasons.

That last bullet point is motivated by the annoyingly persistent faction within NASA and the general spaceflight community that advocates for the development of a lunar infrastructure. I could write a whole other blog post on why any effort to develop infrastructure on the lunar surface is a huge waste of time, but needless to say, we should avoid it.

Let’s look at the decision to recycle ARM technology to propel the DSG and DST. There are a couple of good arguments for using SEP to reach Mars. Since the thrusters are much more well-behaved than chemical propulsion, we don’t have to worry about losing engines (which would spell certain doom for the mission). You also don’t have to worry about the boil-off of cryogenic propellants during transit. Additionally, your specific impulse is much higher, meaning the propellant mass can be lower. Or, alternatively, with the added delta-V from the same fuel mass, we can perform more orbital maneuvers or even return from Mars without ditching any parts of the vehicle.

There are also some arguments against SEP. It is slow to accelerate, which means your astronauts are going to be spending more time in space (bad). It also means that you have to stage the mission from Lunar orbit or a Lagrange point, since the vehicle would take multiple years to reach escape velocity from low Earth orbit (LEO). Staging the mission from beyond LEO means mass budgets are tighter. You also can’t refuel the vehicle using ISRU, ever. Since the propellant is argon or xenon, rather than methalox or hydrolox, you can’t refine it from water and carbon dioxide.

Given these tradeoffs, it’s easy to see why NASA would pick SEP for its long-duration human spaceflight missions. NASA is risk averse: they don’t want to rely on ISRU (a huge technical and logistical unknown) for a critical mission component, so that downside of SEP doesn’t matter to them. NASA detests the idea of resting mission success on machinery as notoriously unreliable and complicated (read: unrepairable) as a chemical thruster. Finally, the fact that SEP “forces” NASA to develop a lunar infrastructure is just icing on the cake.

The fact that using SEP means you can get the whole vehicle back from Mars rather shakes up the design of a Mars mission architecture. It suddenly makes sense to assemble your mission in cis-lunar space rather than launching each monolithic component directly to Mars, like in the Mars Direct architecture. And if you are assembling a mission in cis-lunar space, then it makes sense to build a space station to assist you logistically. If your mission has to be assembled in lunar orbit (because of SEP’s low thrust) then you have to build the space station in lunar orbit, which means you need a large rocket capable of lofting space station components into lunar orbit. Suddenly everything NASA has been doing, from the ARM to the SLS, becomes rationalized.

Except, wait a second. This sounds suspiciously like the original proposal for the STS. You build a space shuttle to launch space station and spacecraft components, and then you send out missions to the Moon and Mars from LEO. In the case of the STS, the Moon and Mars missions got cancelled, leaving only the space shuttle and a pared-down space station. Suddenly you have a space station that doesn’t serve any purpose beyond providing justification for continuing the shuttle program.

The new proposal falls along the same lines so perfectly that I suspect it may have been intentional. The first launch of a DSG segment is in 2022, which (if Trump gets re-elected) will be near the end of this administration. With a piece of hardware in space, the next administration will have no choice but to continue its construction. The DST will get cancelled or transformed into something else, and NASA will have an excuse to keep launching the SLS, and the DSG will become the next ISS (as the ISS is decommissioned in 2024, around the first time a crew is launched to the DSG).

Regardless of politics, the proposal meets all the constraints. The Orion is regularly sent to lunar orbit carrying astronauts and a 10 mT CMP to be added to a space station around the Moon. The astronauts spend their time assembling the space station and testing out its thruster module, which is a modified version of the propulsion module from the ARM. You use the heavy-lift capacity of the SLS to launch a SEP spacecraft to rendezvous with the station in lunar orbit, then send astronauts to test it out before making excursions to Mars. It’s so neat and tidy that I could put a bow on it.

It’s so neat that it’s easy to forget that the architecture barely addresses any of the useful existential reasons for sending humans into space in the first place. With annual resupply missions to the DSG and no permanent human habitation, there is little motivation to develop a closed-loop life support system. This only happens when we get to the DST. The strange thing, then, is that the shakedown cruise of the DST happens while attached to the DSG. A mission which is supposed to demonstrate that the DST could operate for three years without resupply or repair instead gets access to 40 mT of equipment and logistical supplies in the DSG—something that won’t be available during the DST’s real cruise to Mars. There is some room for research on long-duration mission maintenance with the DST, although it seems remote from NASA’s goals or desires.

At least the proposal does a good job of providing a framework for commercial involvement. There are even explicit slots on the manifest for commercially-contracted launches to service the DSG, and one can imagine that the station could play a support role for any commercial missions on the surface of the Moon (e.g. teleoperation and observation of the surface from above). The DSG could play a similar role as the ISS, deploying small scientific and commercial payloads into various lunar orbits (given its ability to perform extensive orbital maneuvers), and playing host to commercially-constructed modules.

The proposal doesn’t do a great job of enabling the exploration of Mars, unfortunately. The key problem, I think, is that NASA doesn’t plan on making more than a single DST. This is confusing to me, because it means that heavy payloads like landers, rovers, and ISRU experiments will need to be launched and transported separately. If you had multiple DSTs acting as tugs for both habitation modules and support equipment, you could assemble a mission in cis-lunar space at the DSG. As it is, any missions that need serious support hardware will have to rendezvous in Martian orbit.

So this means that the only purpose of the DSG is to provide a rendezvous point for the DST and the Orion capsule. In other words, the DSG doesn’t serve any purpose at all. Remember that the DSG only made sense as a logistical support for the assembly of a Mars mission in lunar space. If there isn’t any assembly required, you don’t need a rendezvous point.

Let’s break it down: you launch in an Orion and rendezvous in lunar orbit. You transfer to the DST, take it to Mars, and then come back. You transfer to an Orion capsule, and return to Earth. At no point does the DSG play a role beyond “crew transfer tube”. If you think it’s a place to store your Orion until you get back, think again; the Orion capsule is designed to support crew actively for no more than 21 days, and to stay in space no more than 6 months. That means that the capsule you are returning to Earth in is different from the capsule you launched in. At some point, an Orion will have to make an automated rendezvous in lunar orbit, and an Orion will have to make an unmanned return from lunar orbit. This renders the DSG rather useless as a component of a Mars mission architecture.

There are more reasons why only building a single DST doesn’t make any sense. First of all, putting crew in an untested vehicle is anathema to NASA—wouldn’t it be smart to send an uncrewed DST on a shakedown cruise, perhaps even using it to boost a scientific payload to Mars (hint: Phobos sample return mission)? Then they can iterate on the design and start building crewed DSTs. In the current plan, the lone DST gets a crewed shakedown cruise. What happens when they discover a problem? Do they try to jury-rig a fix? Do they ship replacement parts from Earth? Do they abandon the mission? Since NASA won’t be building future DSTs, there aren’t any opportunities to employ the hard-learned lessons from operating a space vehicle for a long duration. This defeats the whole purpose of NASA doing a Mars mission in the first place.

I don’t think NASA has put any real stock in this plan. Why would NASA launch the DSG as four 10mT chunks riding along with an Orion each time, when the same station could be launched as a single 40mT monolithic block by a single cargo launch? Why even build the DSG? Why build only one DST?

The Real Plan

Here’s what I think. This whole mission architecture is a sly way of fulfilling NASA’s dream of returning to the Moon and reliving the glory days of Apollo. The political likelihood of the DST getting cancelled in 2024 is high, given a turnover of the administration and the fact that the plan doesn’t do a great job of getting us to Mars. With the DST cancelled but the production of the remaining components of the DSG in high-gear, the new administration will be forced to authorize the completion of the DSG to avoid looking bad. However, to distance themselves from the previous administration, they will mandate that instead of being used for future Mars missions, the DSG will play a critical support role for future Moon missions.

This makes a lot of sense, because the DSG is fantastic if your plan is to send people to the Moon, rather than to Mars. You can dock a single-stage lunar lander to the DSG and send refueling missions from Earth between each sortie to the surface. Moreover, NASA can fund companies interested in mining water on the Moon because the DSG will need a steady supply of water and oxygen for its astronauts. From 2024 to 2032, NASA will be positioned to enable a veritable renaissance for lunar exploration and exploitation.

I will leave it to a future blog post to explain why focusing on the Moon is a huge waste of humanity’s time and America’s money. For now, let it suffice to say that it doesn’t bring us any closer to our original goal of aiding the eventual settlement of a self-sustaining colony on Mars.

Assuming that what NASA has proposed is notionally feasible, I propose that with a little bit of reordering and restructuring, the plan can be turned into something that actually advances humanity towards our distant goal of colonization.

My Plan

First, NASA’s plan calls for an uncrewed test launch of the SLS and Orion in 2019, which is a good idea in my book. It tests out the SLS, and let’s NASA test the Orion capsule in a multi-week mission in lunar orbit. However, the mission is slated to use a temporary second stage, because the so-called Exploration Upper Stage (which all future SLS missions will use) will not be ready by 2019. NASA’s plan also calls for launching a probe to Jupiter in 2021, which I also think is a great idea. It allows NASA to test out the new second stage without crew on-board.

However, with the 2022 launch of the SLS, I propose that the entire DSG is launched as a monolithic 40 mT station. A crewed launch of the SLS in the following year would spend up to 6 months aboard the station, consuming the 10 mT of food, air, and water brought along as a CMP. This would give them a chance to test all the station’s system, perform any necessary setup or repair tasks, maneuver the station into various orbits, and release some cubesats. Much like Skylab, there will likely be some issues discovered after the station’s launch, giving NASA a year to develop some fixes and include them in the 10 mT of CMP cargo.

One might object by pointing out that this means NASA will have to construct the logistics, habitation, and airlock modules of the DSG up to three years sooner than in the initial plan, and accelerated timelines are a Bad Thing. I would counter by pointing out that by making the station monolithic, all the mass required for docking interfaces and independent power management is removed. The station would also be much less volume-constrained, as they would only be constrained by the large 8.4 meter cargo fairing, rather than the significantly smaller interstage fairing that a CMP must fit into. This means that NASA engineers wouldn’t need to spend as long shaving off mass and fitting components into a smaller volume. NASA would also have a year or two of schedule wiggle room before the next presidential election and change of administration.

After the first crewed SLS launch in 2023 to the monolithic DSG, I propose a year gap in the schedule. I find it unlikely that they can ramp up from a first launch in 2019 to a launch every year in 2021, 2022, and 2023. There will be schedule slip. So the next crew launch would be in 2025 (potentially earlier, if they can manage it), bringing a 10 mT life support module as CMP to test new closed-loop life support technology. The crew would stay this time for roughly a year, testing the new life support capabilities and receiving shipments of commercial equipment.

To that end, starting in 2024 or earlier, commercially-contracted missions would resupply the DSG with life support consumables and fuel. They would also haul up new modules and equipment, ranging from expandable habitat modules to scientific sensors and communications arrays for controlling surface rovers. These launches would ideally be timed to occur before or during a crewed mission. While the uncrewed freighters would likely be able to dock autonomously, the crew would be required for installing new equipment both inside and outside the station.

In 2026, a prototype DST would be launched with a probe for taking samples from Phobos or Deimos. It would leave for Mars in the 2026 transfer window, and leave Mars in 2028 to return in July 2029. A cargo launch in 2027 would launch a second DST equipped with an integrated habitation and life support module, which would dock with the DSG and await the next crew launch.

A crewed mission launched in early 2028 or late 2027 would remain aboard the DSG until the prototype DST returned from its mission (staying for more than a year, as a dress rehearsal for a flight to Mars). The astronauts would perform a checkout of the returned DST and return to Earth with Phobos/Deimos soil samples from the probe. During their stay, they could perform a shakedown flight of the second DST in lunar space. After their departure, the first DST could be repurposed for a second unmanned mission or (more likely) put through rigorous operations in lunar orbit for stress testing.

Finally, two launches in late 2028 and early 2029 would loft a third DST with a small Martian lander equipped with ISRU, and a crew to transfer into the DST that launched in 2027. Both DSTs would depart immediately for Mars during the transfer window. The lander would carry out ISRU experiments on the surface while the crew remotely operated it from orbit. This presents a nice opportunity to allow sample retrieval from a previous sample-collecting rover mission, launching the sample into orbit using an ascent craft carried down by the ISRU lander. The astronauts in Martian orbit would retrieve the ascent craft and return to Earth with Mars surface samples. They would depart during the 2030 window, returning in September 2031. This mission would last for more than a year and a half, setting the stage for more aggressive missions in the future.

Let’s compare my plan against NASA’s: the DSG is operational by 2022 in my plan, rather than 2026. As a downside, the first crewed flight occurs a year later in my plan, and only two crewed missions take place by 2026, as opposed to NASA’s four. However, in my plan the second mission would last for about a year, rather than NASA’s 16-42 day missions. Under my plan, the DST would launch a year earlier and immediately be subjected to a test flight to Mars. Also, my plan piggybacks a valuable scientific probe on this test mission, allowing for an unprecedented scientific return (nobody has ever returned samples from other moons or planets).

When NASA’s plan has a crew performing a 221-day checkout mission for the first time in 2027, my plan calls for a roughly 400-day endurance mission around the same time that both runs diagnostics on a crewed DST (the purpose of the 221-day flight in NASA’s plan) and returns with samples from Phobos or Deimos. When NASA’s plan has astronauts performing a 400-day shakedown mission on the DST around the Moon (2029), my plan has astronauts on their way to Mars, with multiple long-endurance missions under their belt to validate long-duration survival in deep space.

Best of all, NASA’s plan uses 12 SLS launches before getting around to a crewed Mars mission “sometime after 2030”, while my plan uses 10 SLS launches to achieve a crewed Mars mission and performs two sample return missions to boot.

I think the most reasonable explanation, as I iterated above, is that NASA is trying to put off its Mars missions as long as possible until a new presidential administration redirects them to focus on lunar activities alone. I will leave it to another blog post to debunk the rationalizations for this ambition.

The Interplanetary Transport System

Space has been on my brain a lot lately. One of the causes was the long-awaited presentation by Elon Musk at the International Astronautical Congress (IAC) last month. During the talk, he finally laid out the details of his “Interplanetary Transport System” (ITS). The architecture is designed to enable a massive number of flights to Mars for absurdly low costs, hopefully enabling the rapid and sustainable colonization of Mars. The motivation behind the plan is a good one: humanity needs to become a multi-planetary species. The sheer number of things that could take civilization down a few pegs or destroy it outright is frighteningly lengthy: engineered bio-weapons, nuclear bombs, asteroid strikes, and solar storms crippling our electrical infrastructure are some of the most obvious. Rampant AI, out-of-control self-replicating robots, and plain old nation-state collapse from war, disease, and famine are some other threats. In the face of all those horrifying things, what really keeps me up at night is the fact that if civilization collapses right now, we probably won’t get another shot. Ever. We’ve abused and exhausted the Earth’s resources so severely, we simply cannot reboot human civilization to its current state. This is the last and best chance we’ll ever get. If we don’t establish an independent, self-sufficient colony on Mars within 50 years, we’ll have solved the Fermi Paradox (so to speak).

But Musk’s Mars architecture, like most of his plans, is ambitious to the point of absurdity. It at once seems like both fanciful science fiction and impending reality. Because Musk works from first principles, his plans defy socio-political norms and cut straight to the heart of the matter and this lateral approach tends to rub the established thinkers of an industry the wrong way. But we’ve seen Musk prove people wrong again and again with SpaceX and Tesla. SpaceX has broken a lot of ground by being the first private company to achieve orbit (as well as return safely to Earth), to dock with the International Space Station, and to propulsively land a part of a rocket from an orbital launch. That last one is particularly important, since it was sheer engineering bravado that allowed them to stand in the face of ridicule from established aerospace figureheads. SpaceX is going to need that same sort of moxie in spades if they are going to succeed at building the ITS. Despite their track record, the ITS will be deceptively difficult to develop, and I wanted to explore the new and unsolved challenges that SpaceX will have to overcome if they want to follow through on Musk’s designs.

SpaceX ITS Diagram

The basics of the ITS architecture are simple enough: a large first stage launches a spaceship capable of carrying 100 people to orbit. More spaceships (outfitted as tankers) are launched to refill the craft with propellants before it departs for Mars during an open transfer window. After a 3 to 6 month flight to the Red Planet, the spaceship lands on Mars. It does so by at first bleeding off speed with a Space Shuttle-style belly-first descent, before flipping over and igniting its engines at supersonic speeds for a propulsive landing. After landing, the craft refill its tanks by processing water and carbon dioxide present in Mars’s environment and turning them into propellant for the trip back to Earth. Then the spaceship simply takes off from Mars, returns to Earth, and lands propulsively back at home.

Now, there are a lot of hidden challenges and unanswered questions present in this plan. The first stage is supposed to land back on the launch mount (instead of landing on a pad like the current Falcon 9 first stage), requiring centimeter-scale targeting precision. The spaceship needs to support 100 people during the flight over, and the psychology of a group that size in a confined space for 6 months is basically unstudied. Besides other concerns like storing highly cryogenic propellants for a months-long flight, radiation exposure during the flight, the difficulty of re-orienting 180 degrees during re-entry, and the feasibility of landing a multi-ton vehicle on soft Martian regolith using powerful rocket engines alone, there are the big questions of exactly how the colonists will live and what they will do when they get to Mars, where the colony infrastructure will come from, how easy it will be to mine water on Mars, and how the venture will become economically and technologically self-sufficient. Despite all of these roadblocks and question marks, the truly shocking thing about the proposal is the price tag. Musk wants the scalability of the ITS to eventually drive the per-person cost down to $200,000. While still high, this figure is a drop in the bucket compared to the per-capita cost of any other Mars architecture on the table. It’s well within the net-worth of the average American (although that figure is deceptive; the median American net-worth is only $45,000. As far as I can figure, somewhere between 30% and 40% of Americans would be able to afford the trip by liquidating most or all of their worldly assets). Can SpaceX actually achieve such a low operational cost?

Falcon 9 Production Floor

Remember that SpaceX was originally targeting a per-flight price of $27 million for the Falcon 9. Today, the price is more like $65 million. Granted, the cost to SpaceX might be more like $35 million per flight, and they haven’t even started re-using first stages. But it is not a guarantee that SpaceX can get the costs as low as they want. We have little data on the difficulty of re-using cores. Despite recovering several in various stages of post-flight damage, SpaceX has yet to re-fly one of them (hopefully that will change later this year or early next year).

That isn’t the whole story, though. The Falcon 9 was designed to have the lowest possible construction costs. The Merlin engines that power it use a well-studied engine design (gas generator), low chamber pressures, an easier propellant choice (RP-1 and LOX), and relatively simple fabrication techniques. The Falcon 9 uses aluminum tanks with a small diameter to enable easy transport. All of their design choices enabled SpaceX to undercut existing prices in the space launch industry.

But the ITS is going to be a whole other beast. They are using carbon fiber tanks to reduce weight, but have no experience in building large (12 meter diameter) carbon fiber tanks capable of holding extremely cryogenic liquids. The Raptor engine uses a hitherto unflown propellant combination (liquid methane and liquid oxygen). Its chamber pressure is going to be the highest of any engine ever built (30 MPa. The next highest is the RD-191 at 25 MPa). This means it will be very efficient, but also incredibly difficult to build and maintain. Since reliability and reusability are crucial for the ITS architecture, SpaceX is between a rock and a hard place with its proposed design. They need the efficiency to make the system feasible, but the high performance envelope means the system will suffer less abuse before needing repairs, reducing the reusability of the system and driving up costs. At the same time, reusability is crucial because the ITS will cost a lot to build, with its carbon fiber hull and exacting standards needed to survive re-entry at Mars and Earth many times over.

It’s almost like the ITS and Falcon 9 are on opposites. The Falcon 9 was designed to be cheap and easy to build, allowing it to be economical as an expendable launch vehicle, while still being able to function in a large performance envelope and take a beating before needing refurbishment. The ITS, on the other, needs all the performance gains it can get, uses exotic materials and construction techniques, and has to be used many times over to make it an economical vehicle.

All of these differences make me think that the timeline for the development of the ITS is, to put it mildly, optimistic. The Falcon 9 went from the drawing board to full-stack tests in 6 years, with a first flight a few years later. Although the SpaceX of 2004 is not the SpaceX of 2016, the ITS sure as hell isn’t the Falcon 9. A rocket using the some of the most traditional and well-worn engineering methods in the book took 6 years to design and build. A rocket of unprecedented scale, designed for an unprecedented mission profile, using cutting-edge construction techniques… is not going to take 6 years to design and build. Period. Given SpaceX’s endemic delays with the development of the Dragon 2 and the Falcon Heavy, which are a relatively normal sized spaceship and rocket, respectively, I suspect the development of a huge spaceship and rocket will take more like 10 years. Even when they do finally fly it, it will take years before the price of seat on a flight falls anywhere as low as $200,000.

Red Dragon over Mars

If SpaceX manages to launch their Red Dragon mission in time for the 2018 transfer window, then I will have a little more hope. The Red Dragon mission needs both a proven Falcon Heavy and a completely developed Dragon 2. It will also allow SpaceX to answer a variety of open questions about the mission profile of the ITS. How hard is it to land a multi-ton vehicle on Martian regolith using only a powered, propulsive descent? How difficult will it be to harvest water on Mars, and produce cryogenic propellants from in situ water and carbon dioxide? However, if SpaceX misses the launch window, I definitely won’t be holding my breath for humans on Mars by 2025.

Lone Wolf

I was struck by a muse and wrote an urban fantasy story. I’ve reproduced the first scene here; you can download the full PDF (40 pages) to read the rest.

1

I’ve never considered myself a “people person”. It isn’t that I don’t like people; I just never find the right thing to say, or end up doing something I later look back on with cringe-inducing horror. I mention this only to give you a notion of how deep in over my head I was from the moment I heard the faint knocking at my door.

It was a Friday, right around 8pm, and the last rays of dusk were filtering out of the sky. It started almost as a scratching, then escalated to a weak yet persistent tapping by the time I had navigated from the kitchenette, through the tight space of my apartment, to the front door.

I wasn’t expecting visitors, and the door’s peephole was non-functional (I had never worked up the courage to call a repair service), so I wrenched the door open knowing in the back of my mind that there was a roughly 30% chance that whatever stood on the other side wanted to kill me. But instead of a combatant, the body of a young woman, bloodied and weak, slumped through the doorway onto my carpet.

So four things quickly filtered through my mind in this moment. First I thought “oh shit.” That was quickly followed by the sinking realization that I was going to miss the TNG marathon later tonight. The last two came as I appraised the situation: it was no mere coincidence that this girl had chosen to rap on my door, and that literally the last thing I should do at this moment was phone the police.

I kicked into action. Although my interpersonal skills may be lacking, I do know a good amount of first-aid. I dragged her body into the cramped interior of my apartment and laid her on my couch. As I fetched my first-aid kit, I winced at the blood trail soaking into my carpet and upholstery.

Claw marks raked across her arms and back, and a gash on her scalp hinted at a treacherous fall. Fortunately for me (and her), it didn’t look like there was much internal damage besides maybe some fractured ribs. It would hurt to move and breathe for a few weeks, but she would recover. Judging by the head wound, she might also have suffered a light-to-moderate concussion. At least on this count, I thought as I started tending to the wounds, things could have gone a lot worse. I didn’t relish the idea of driving a half-dead girl with no relation to me to the hospital.

Of course, that was the least of my concerns at the moment. I mulled over several pieces of information that pointed to a whole lot of strife for me in the near future. First, she was a werewolf. I could smell it on her as clear as day. Second, she had been attacked by other werewolves – lingering scents pointed to a single pack. Third, after somehow escaping, she had – bleeding, in shock, and near-death — decided to head straight for my doorstep. If this didn’t already sound bad enough, it was made 10 times worse by the fact that I was a werewolf.

Read the rest here.

What Does It Take To Become A Programmer?

So these are my thoughts on this article (hint, it’s utter tripe): Programming Doesn’t Require Talent or Even Passion.

On the one hand, this article espouses a good sentiment (you don’t have to be gifted to learn programming). On the other, it completely disregards the important idea that being able to do something is not the same as being able to do it well.

I can draw, but anyone who has seen me draw would agree that I’m pretty shit at it. I can draw just well enough to get my concepts across to other people. However, if I intended on becoming an artist for a living, I should probably learn about proportions, shading, composition, perspective, color theory, and be able to work with a range of mediums. Of course, there isn’t some big secret to learning these things. You just practice every day and study good artistic work, analyzing how it was made. Maybe you take some courses, or read some books that formally teach certain techniques. After thousands of invested hours, you will find that your drawing has radically improved, as shown again and again by progress comparison pictures (that one is after 2 years of practice).

The same holds true for programming. Anyone can learn programming. It requires nothing except a little dedication and time. But the article starts out by promising to ‘debunk’ the following quote (I’m not sure if it’s actually a real quote – they don’t attribute it to anybody):

You not only need to have talent, you also need to be passionate to be able to become a good programmer.

The article immediately ignores the fact that the ‘quote’ is talking about good programmers. Just like becoming a good artist requires artistic talent and a passion for learning and improving every day, good programmers are driven by the need to learn and improve their skills. Perhaps an argument can be made for “talent” being something you acquire as a result of practice, and thus you don’t need talent to start becoming good; you become good as you acquire more and more talent. This is a debate for the ages, but I would say that almost invariably a passion for a skill will result in an early baseline proficiency, which is often called “talent”. Innate talent may or may not exist, and it may or may not influence learning ability.

It doesn’t really matter though, because the article then goes on to equate “talent” and “passion” with being a genius. It constructs a strawman who has always known how to program and has never been ignorant about a single thing. This strawman, allegedly, causes severe anxiety to every other programmer, forcing them to study programming at the exclusion of all else. It quotes the creator of Django (after affirming that, yes, programmers also suffer from imposter syndrome):

Programming is just a bunch of skills that can be learned, it doesn’t require that much talent, and it’s not shameful to be a mediocre programmer.

Honestly, though, the fact of the matter is that being a good programmer is incredibly valuable. If your job is to write code, you should be able to do it well. You should write code that doesn’t waste other people’s time, that doesn’t break, that is maintainable and performant. You need to be proud of your craft. Of course, not every writer or musician or carpenter takes pride in their craft. We call these people hacks and they churn out shitty fiction that only shallow people read, or uninteresting music, or houses that fall down in an earthquake and kill dozens of people.

So, unless you want to be responsible for incredibly costly and embarrassing software failures, you better be interested in becoming a good programmer if you plan on doing it for a career. But nobody starts out as a good programmer. People learn to be good programmers by having a passion for the craft, and by wanting to improve. If I look at older programmers and feel inferior by comparison, I know it’s not because they are a genius while I am only a humble human being. Their skill is a result of decades of self-improvement and experience creating software both good and bad.

I think it’s telling that the article only quotes programmers from web development. Web development is notorious for herds of code monkeys jumping from buzzword to buzzword, churning out code with barely-acceptable performance and immense technical debt. Each developer quote is followed by a paragraph that tears down the strawman that was erected earlier. At this point, the author has you cheering against the supposedly omnipresent and overpowering myth of the genius programmer — which, I might remind you, is much like the myth of the genius painter or genius writer; perhaps accepted by those with a fixed mindset, but dismissed by anybody with knowledge of how the craft functions. This sort of skill smokescreen is probably just a natural product of human behavior. In any case, it isn’t any stronger for programming than for art, writing, dance, or stunt-car driving.

The article really takes a turn for the worse in the second half, however. First, it effectively counters itself by quoting jokes from famous developers that prove the “genius programmer” myth doesn’t exist:

* One man’s crappy software is another man’s full time job. (Jessica Gaston)

* Any fool can write code that a computer can understand. Good programmers write code that humans can understand.

* Software and cathedrals are much the same — first we build them, then we pray. (Sam Redwine)

The author LITERALLY ASKS: “If programmers all really had so much talent and passion, then why are these jokes so popular amongst programmers?”, as if to prove that he was full of shit when he said back in the beginning “It’s as if people who write code had already decided that they were going to write code in the future by the time they were kids.”

But the absolute worst transgression the article makes is quoting Rasmus Lerdorf, creator of PHP. For those of you not “in the know”, PHP is a server-side language. It is also one of the worst affronts to good software design in recent history. The reason it was the de facto server-side language before the recent Javascript explosion is that it can be readily picked up by people who don’t know what they are doing. Like you would expect from a language designed by someone who “hates programming” and used by people who don’t what they are doing, PHP is responsible for thousands of insecure, slow, buggy websites.

PHP’s shortcoming are amusingly enumerated in this famous post: PHP – a fractal of bad design. In the post, the following analogy is used to illustrate how PHP is bad:

I can’t even say what’s wrong with PHP, because— okay. Imagine you have uh, a toolbox. A set of tools. Looks okay, standard stuff in there.

You pull out a screwdriver, and you see it’s one of those weird tri-headed things. Okay, well, that’s not very useful to you, but you guess it comes in handy sometimes.

You pull out the hammer, but to your dismay, it has the claw part on both sides. Still serviceable though, I mean, you can hit nails with the middle of the head holding it sideways.

You pull out the pliers, but they don’t have those serrated surfaces; it’s flat and smooth. That’s less useful, but it still turns bolts well enough, so whatever.

And on you go. Everything in the box is kind of weird and quirky, but maybe not enough to make it completely worthless. And there’s no clear problem with the set as a whole; it still has all the tools.

Now imagine you meet millions of carpenters using this toolbox who tell you “well hey what’s the problem with these tools? They’re all I’ve ever used and they work fine!” And the carpenters show you the houses they’ve built, where every room is a pentagon and the roof is upside-down. And you knock on the front door and it just collapses inwards and they all yell at you for breaking their door.

That’s what’s wrong with PHP.

And according to Rasmus Lerdorf, the creator of this language:

I’m not a real programmer. I throw together things until it works then I move on. The real programmers will say “Yeah it works but you’re leaking memory everywhere. Perhaps we should fix that.” I’ll just restart Apache every 10 requests.

It’s like the article is admitting that if you don’t take the time to learn good programming principles, you are going to be responsible for horrible systems that cause headaches five years down the line for the people maintaining them and that regularly allow hackers to access confidential personal information like patient information and social security numbers for millions of people.

So yes, if you aren’t planning on programming for a career, learning to program is fairly straightforward. It’s as easy as learning carpentry or glass-blowing. It might seem daunting, but invest a half dozen hours and you can have your foot solidly in the door.

But if you plan on building systems other people will rely on, you sure are hell better pick up some solid programming fundamentals. If you aren’t motivated to improve your skillset and become a better programmer, don’t bother learning at all. Don’t be the reason that the mobile web sucks, and don’t be the reason that 28 American soldiers died. Learn to be a good programmer.

Indiscriminately Valuing Non-Violent Games

Starting with the 1980s arcade games Galaxian and Missile Command, games and combat became nearly synonymous. This was only exacerbated in the 90s by the advent of wildly popular shooters like Doom. The choice to focus a game around antagonism, combat, and violence was not a conscious design decision, but a necessity of the industry and environment. There were abstract games that didn’t contain violence, but in general the highest-profile games were about, in essence, murder.

Doom screenshot

Doom: you shoot things. Dead simple.



Then a renaissance occurred in academia, and suddenly games were art. Nobody really knew what to do with this fact or what it meant, but it was revolutionary, and regardless of anything else, games were definitely art. To support this, a number of innovative (perhaps iconoclastic) non-violent games — games like Journey and Gone Home — were foisted up as evidence that games are art. “Games are art, they can convey aesthetics beyond violence.” Good, great. Innovative games that are fun without using violence in their designs are awesome.

Journey screenshot

Journey is one of the seminal games in the recent wave of “artistically-valuable” indie games.



However, this easily morphed into a reactionary movement. Since these games without violence or combat were touted as being somehow better or “more elevated” than your run-of-the-mill murder simulator, it became obvious that a game that was violent was inherently less.

Obviously, this sort of indiscriminate valuing of non-violent games is a terrible idea. A game that doesn’t use violence can be poorly designed and not-fun (Dear Esther, Mountain), just like a game that uses violence and combat can provoke deeper aesthetics (Hotline Miami, This War of Mine). Part of the problem is that nobody has developed the proper critical skills to analyze these non-violent, pacifistic games. Those that could view the design choices evenly and rationally are too busy climbing up their own assholes and praising the games for not using combat. On the other side, core gamers are immediately turned off by the lack of combat and write it off as boring.

This War Of Mine screenshot

Refugees have said This War of Mine accurately conveys the constant fear of living in a war-torn region.



One result of this dysfunction is the proliferation of so-called “walking simulators”. These are games whose main play involves walking around consuming either written, visual, or aural media, perhaps with light puzzle-solving mechanics (or similar accents). Many enterprising developers, whether they realize it consciously or not, have seized on the fact that making such a game guarantees some measure of success. They will be praised by academics and critics interested in furthering games as a legitimate medium, and have their game purchased by the small-but-steady audience of non-core, non-casual gamers (most of whom probably chafe at being called gamers).

Some walking simulators are great; I actually enjoyed Gone Home, in a way that I probably wouldn’t have if it had been a movie. They do a good job of immersing you in a focused, meaningful experience. Others are scattered or diluted by dissonant design decisions — like Corpse of Discovery. But nobody cares, because these games aren’t being evaluated on their merits as a game. They are either praised for being a game without combat mechanics, or they are ignored because they are a game without combat mechanics. Little else tends to go into the evaluation process.

Gone Home screenshot

Gone Home gives the player a meaningful experience despite being limited to looking at rooms and listening to audio.



A student game at USC, Chambara, got changed during development to be “non-violent”. The game originally saw samurai dueling in a starkly colored world. Now instead of blood, hitting an enemy produces a burst of feathers. Apparently this one tweak now qualifies it as “a transcendently beautiful and artistic entertainment game with a pacifistic outlook”. That is a direct quote from a faculty member at the school. You may see why this is troublesome to me. First of all, changing blood to feathers doesn’t change the fact that your game is about sneaking around and hitting other people with sticks before they hit you. That seems a far cry from a “pacifist outlook”. Second, this change actually hurts the game aesthetically. The blood splatters beautifully complemented the dichromatic nature of the game’s world. I consider the stark look of a blood splatter to be more artistic than a burst of feathers. Yet the game’s devs decided to make this tweak. Did they do it because it would benefit the game? No. According to the devs, “we were uncomfortable with the violence the game displayed and did not feel like it accurately reflected who we were and what we believed.” In other words, they value a game that contains bloodshed differently than a game that does not. Are they allowed to make this decision based on their personal beliefs? Absolutely. But isn’t it absurd to pretend that this tweak lends the game a “pacifist outlook”, and that it in turn allows the game to transcend to the angelic ranks of non-violent video games?

Blood Splatters

Blood splatters…


Feather Splatters

…and “feather splatters”.



I would urge critics and academics to judge pacifistic games on their merits as a game, not on their merits as a non-violent game. I would urge developers to treat the presence of combat and violence as just one among a countless sea of other design possibilities. If it aids your experience goal, you should include it and tailor it to the needs of your game as an experience. If it doesn’t don’t include it. But don’t decide to make your game non-violent or exclude combat mechanics just because it means your game will be valued as inherently better by a specific set of people.

Escaping UI Idioms

Personally I find that whenever my engineer brain switches on, my designer brain switches off. I have to step away from coding for a while in order to objectively make the best decisions about what to implement and how. When I let my engineer brain do the designing, I end up falling into age-old preconceptions about how things should be. This is especially true when it comes to UI design.

But is it the best idea to blindly follow UI conventions, either new or old? On the one hand, a familiar UI layout and universal UI idioms will make it easier for users to jump straight into your program. However, if those idioms aren’t well suited to your application, the user can quickly find themselves confused, frustrated, and lost. If the UI was unfamiliar but uniquely designed around your application, the users will be less confused because they have no expectations which can be unwittingly subverted.

Some bad features:

  • Confirmation emails which require you to click a link before you can do anything with your account. Confirmation emails that require a link to be clicked in 24 hours but which do not impede progress are much better.
  • The “re-enter your email” fields on signup forms. Every modern browser automatically enters your password.
  • Separating the “Find” and “Replace” functions, putting them in the “View” and “Edit” menus respectively.
  • Speaking of “View” and “Edit” menus, the standard “File”, “View”, “Edit” menu tabs often don’t suit applications. Choose menu item labels that suit your application.

An example of a good feature is the use of universal symbols for universal functions. Using a crazy new “save” icon is not a good subversion of conventional UI idioms. Another is exit confirmation; in a lot of cases, confirming whether you want to save before exiting is a great feature.

Here are two features which are not standard for applications with text-editing capability but which should be (I’ve only seen it in a handful of programs, of which Notepad++ is most prominent):

  • A “Rename” option under the File menu, which saves the file with a new name and removes the file with the old name. This saves the tiresome task of doing “Save As” and then deleting the file in the save window, or (God forbid) having to navigate to the file in your OS’s file browser and renaming the file there.
  • Special character (\t, \n) and Regex support in “Find and Replace” modes.

VR Isn’t Ready

Recently I’ve heard a lot of hubabaloo about VR, especially with regards to games. This wave of hype has been going on for while, but it has personally intensified for me because one of my professors this semester is running a VR startup. I’m also working on a VR-compatible game, so VR talk has become more relevant to me.

Array of current VR headsets

Array of current VR headsets



First off, I believe VR is still 10 years away from its prime-time. The tech is just not advanced to a viable level right now, and some fundamental issues of user experience have yet to be solved.

For example, my professor gave an example of why VR is such an immersive mode of interaction: the first time people put on the headset and jump into a virtual world, they reach out and try to touch objects. He trumpeted this as being evidence of a kinetic experience (i.e. it pushed them to “feel” things beyond what they immediately see). While is this kind of true, I see it far more as evidence of a fundamental shortcoming. The moment a user tries to interact with the world and fails, they are jerked out of the fantasy and immersion is broken. This is true in all games; if a user believes they can interact with the world in a certain way but the world doesn’t respond correctly, the user is made painfully and immediately aware that they are in a game, a simulation.

Control VR isn't enough.

Control VR isn’t enough.

This brings me to the first huge issue: the input problem. VR output is relatively advanced, what with Oculus and Gear VR and Morpheus. But we’ve seen little to no development effort targeted at ways for the user to interact with the world. Sure we have Control VR and such projects, but I think these haven’t caught on because they are so complicated to setup. Oculus made huge strides by turning the HMD into a relatively streamlined plug-and-play experience with a minimal mess of cables. We have yet to see how Oculus’s custom controllers affect the space, but I have a feeling they aren’t doing enough to bridge the haptic gap. We won’t see VR takeoff until users are no longer frustrated by the effort to give input to the game by these unintuitive means. As long as users are constantly reminded they are in a simulation, VR is no better than a big TV and a comfy couch.

Speaking of big TVs: the output tech isn’t good enough. The 1080p of the DK2 is nowhere near high enough to be immersive. Trust me: I’ve gotten to try out a DK2 extensively in the past few months at zero personal cost. My opinion is informed and unbiased. Trying to pick out details in the world is like peering through a blurry screen door. As long as I’m tempted to pop off the headset and peek at the monitor to figure out what I’m looking at, VR isn’t going to take off. Even the 2160×1200 of the consumer Oculus won’t be enough. When we get 3K or 4K resolutions in our HMDs, VR will be a viable alternative to monitor gaming. Of course, this tech is likely 5-10 years away for our average consumer.

These never caught on.

These never caught on.

This all isn’t to say that current VR efforts are for naught. These early adopter experiments are definitely useful for figuring out design paradigms and refining the tech, However, it would be foolish to operate under the assumption that VR is posed to take the gaming world by storm. VR is not the new mobile. VR is the new Kinect. And like the Wii and Kinect, VR is not a catch-all interaction mode; most gaming will always favor a static, laid-back experience. You can’t force people to give up lazy couch-potato gaming.

Of course, outside of gaming it may not be a niche interaction mode. In applications where immersion is not the goal and users expect to have to train in the operation of unnatural, intuitive controls, VR may very well thrive. Medicine, industrial operation, design, and engineering are obvious applications. It might even be useful for education purposes. But temper your expectations for gaming.

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