How Space Exploration Works

How in the world did we accomplish this?

The Author

I love space exploration. It’s the most interesting, engaging and deeply thought-provoking subject I can imagine, and I am privileged to have been a part of it since 2010. It challenges us as humans on every level possible; emotionally, technically, and at the level of society itself. The discoveries it brings change our world, our view of our place in the universe, and our daily lives.

Purpose of this Article

Space exploration has changed the world in permanent, significant ways since the first human-made object entered Earth’s orbit in 1957. Many pages have been written about the history, technical details, politics, and related minutiae of this chapter in human history. Less has been written about the current process of exploration and how people work with each other to get things done. There are many books on how to calculate the orbit for a certain space mission, but little has been written about how that mission was imagined, communicated, proposed, debated, reviewed, and selected. Less still has been written about the day-to-day process by which mere human beings; flawed and sometimes emotional, tired, egotistic, depressed, excited, conflicted people actually make these remarkable missions happen. The purpose of this book is to tell these stories and reveal the hidden humanity too often obscured by headlines of space exploration. The article will not tell the history of NASA. Instead, it will tell the present of NASA, and explore how we labor to find our place among the stars upon the shifting sands of the modern world.

For every mission seen by the public, such as the Mars Rovers and the Hubble telescope, there are dozens more that have been designed, imagined, and developed to varying levels of maturity.

Structure of NASA, and why it matters

We must discuss NASA’s organization in order to fully understand how it works. The organization has changed over the decades since its formation in 1957. NASA was initially created in response to Sputnik. It is hard for many in the field to fully understand the terror that Sputnik wrought. This was a time before jet aircraft crossed the sky routinely and a time when only a small minority of people had even experienced powered flight. Political support for NASA was strong, and NASA was off and running. The Apollo moon landings are a subject for another book, but it is critical to understand that it was Nixon’s decision to cancel the last three Apollo flights that began the process of turning NASA into a mouth to feed, competing with the other agencies.

NASA is currently split into four departments called “directorates.” Each has responsibility over certain types of activities largely structured to achieve high-level goals. The directorates are HEOMD (Human Exploration and Operations Mission Directorate), SMD (Science Mission Directorate), ARMD (Aeronautics Research Mission Directorate), and STMD (Space Technology Mission Directorate). This small table roughly shows the breakdown of funds received by directorate.

There is, by design, little overlap between the programmatic responsibilities of the directorate, but there is overlap in the day-to-day functions. The dependencies and relationships between people across NASA and across time can significantly affect what gets to the launch pad and what lies fallow in the fertile minds of researchers.

Directorates, Programs, and Projects

HEOMD is responsible for all activities involving or related to spaceflight of human beings. It dominates the budget and public and political attention. HEOMD operates a wide range of activities ranging from a spacesuit-seamstress group that makes spacesuits by hand, to the largest swimming pool in the world that houses a full scale mockup of the International Space Station. Directorates are made up programs, which are made up of projects.

SMD will largely be the focus of this article. SMD is responsible for the overall category of science missions. This can be confusing because the other directorates conduct science; astronauts perform experiments on the space station, aeronautics researchers develop and advance materials, and so on. We will define science missions later.

ARMD ostensibly conducts research in the area of powered flight and aircraft. It is the smallest component of NASA by far and will not be covered in this article.

STMD in its current form is relatively new, and is an attempt to address the challenge of technology development for space missions. We will address this later in depth, but the core of the problem is that new technology development is risky, and no mission project manager wants to be responsible for the risk inherent in her mission AND risk inherent in some new piece of technology that has not yet been proven. In theory, STMD takes on that technology development risk (as opposed to the risk of flying a mission itself) and works to “infuse” new technologies across the missions conducted by the other directorates.

NASA Centers

NASA is physically distributed around the nation in nine primary NASA centers, research centers called FFRDCS (Federally Funded Research and Development Centers) and a smattering of infrastructure. NASA employs many people as federal employees, and many more as contractors. The term contractor can be misleading. A contractor might be a small company that provides administrative support to a single program at a NASA center. The largest contractor is the Jet Propulsion Laboratory, larger than several “real” NASA centers. JPL is “managed” by the California Institute of Technology for JPL.

This map shows the primary centers and several related facilities operated by the centers. Credit: NASA

Critical Infrastructure

Deep Space Network (DSN)

NASA-controlled infrastructure is also distributed around the nation, and indeed the world. The best example of this is the Deep Space Network, which is a set of three satellite dish facilities distributed evenly around the world in California, Australia and Spain. The effect of these three facilities is the ability to transmit to and receive information from anywhere in the solar system and some distance beyond. The Australia and Spain facilities are managed by NASA and the local government via agreements with the US government. The Australian facility was the subject of a wonderful film called “The Dish”, exploring the role of that facility in communicating with the Apollo spacecraft during the years leading up to the moon landing in 1969.

Near Earth Network (NEN)

The Near Earth Network is composed of a larger number of sites than the DSN, but each site has smaller satellite installations. As the name implies this network is used for communications with near-Earth spacecraft.

This map shows the mixture of DSN and NEN facilities around the world.

Industry

NASA relies on industry for many contributions, and for multiple reasons. Some missions have technology developed by small businesses or have entire spacecraft constructed by large aerospace and defense contractors. The diversity of capability across industry is a critical component of mission development strategy that we will delve further into later.

NASA has been a dynamic agency throughout its existence due to the changing priorities and missions assigned by Congress. This has resulted, unfortunately, in an agency adrift, alternating between missions and priorities every four years, with little long term progress in human spaceflight.

What is a Space Mission?

Our final point of introduction is to define in greater detail what we mean by “space mission.” In general we are referring to the design, construction, launch, and operation of a space vehicle, or space instrument in some cases, for the purpose of obtaining information about a process, place, or phenomena of scientific interest. What, then, do we mean by scientific interest? This can be as specific as measuring the heat emitted by the Earth over a two2 year period (a roughly $30M mission concept), to the much larger question of the potential habitability of the planet Mars. (the roughly $2.5B Mars Curiosity Rover.)

Stepping even further back we can ask the question “Why do we do space missions at all?” Generally we send a spacecraft somewhere (as near as Earth orbit to as far away as the edge of the Solar System) fundamentally because we cannot gather the desired information any other way. In fact one very easy way to get a mission concept rejected by NASA is to not explain why the science data can only be gathered with a space mission. Earth observing missions, for example, must be careful to demonstrate that a set of data cannot be gathered with a helicopter or aircraft, for example. It is more slightly more obvious that Mars rocks, for example, cannot be gathered without a spacecraft of some kind going to Mars, but the idea remains. A space mission is an extremely challenging undertaking even in the simplest case, and we do not perform them unless there is no other way to answer the question.

Space Missions and The Modern Scientific Process

It will be instructive to further explore the modern scientific process before we go much further into the details of space mission development. Professional scientists do experiments and publish results in scientific journals. A huge diversity of journals co-exists, from broad topics such as “Nature” to specialty-focused publications such as “Proceedings in Thermoelectrics” (that one may be made up, but serves the purpose of demonstrating the point.) At an oversimplified high level, the modern process of professional science exists as a kind of funding/publishing feedback loop. A scientist that has successfully published new work in a leading journal will be more successful in pursuing funding for their next project.

A student interested in becoming a professional scientist working on space missions has many decisions to make, but will likely follow a path roughly as follows: Undergraduate degree in a hard science such as Chemistry (for example) with some kind of university research project or activity, then applying to graduate school based on that research. The enterprising student will apply to graduate programs with prolific faculty experienced in her field of undergraduate research in order to chart a course to the Ph.D. level. In addition to a heavy load of courses, the Ph.D. student will be required to perform independent research and demonstrate the ability to contribute to human knowledge in a meaningful way. The completion of that project will show the faculty that she is ready to be a productive, independent scientist; that is the qualification conferred by a Ph.D. If she discovers early enough in her Ph.D. program that she wishes to be involved in space missions, she might be able to find an opportunity to complete her independent research on data from a space mission, or under the advice and guidance of a researcher involved in a space mission. That will position her upon graduation to seek employment at a facility or institution that is either actively participating in a space mission or working on one.

Many space missions take decades from inception to conclusion and “generation planning” is often a critical part of the development process. Senior scientists may well expect to be retired or dead by the time a mission reaches its destination (particularly in the case of the outer planets.) This means that a scientific team with wide age diversity is not only appealing on a personal level but is also critical to the success of the mission. Smaller institutions that have significant space mission experience often find themselves overloading their senior, experienced researchers (because those are the ones that can attract missions) to the exclusion of younger scientists. This is a continuous challenge in the modern research workplace where 25 year old scientists may share a table with 75 year olds. 

One of the effects of this process is the extent to which a leading, senior scientist can dominate scientific discussion on a topic. This can actually discourage or suppress truly novel thought at the junior levels. It turns out that there is actually a burst of new thought and work at the junior level following the death of leaders at the senior level.

We must come to some kind of agreement on this phenomena if we are to have a centuries-long, cumulative growth in human knowledge. Funding and tenure have the natural effect of concentrating influence in a few people at the top. This is not necessarily a bad thing! The potential detriment to progress comes when the powers that be deny this natural phenomenon as a process of growth and development.

This broad, diverse science community has a significant impact on the science priorities identified by NASA. This influence is deployed via a process called the Decadal Survey. Here is an example:

Every 10 years the various space scientific communities publish an extremely lengthy and detailed document called the Decadal Survey. The communities self-assemble along boundaries roughly parallel to NASA’s SMD structurestrucutre. There is a decadal community and report for Earth Science, Planetary Science (non-Earth planets) and Astrophysics. Each report summarizes the preceding decade’s work, its promising lines of inquiry, and other proceedings. If you were to choose one page from six hundred to look at, you might reasonably choose the list of mission priorities. Each Decadal Survey prioritizes missions and investigations that its respective community feels should be the priority for space exploration resources for the coming decade. For example, the 2012 Planetary Science Decadal Survey recommended a Uranus orbiter, Mars Sample Return mission, and… (need to look up.) Again, the primary audience of this report is NASA HQ itself, and the Capitol Hill feedback loop that ultimately gets congressional approval for very large missions that are beyond NASA’s ability to select internally. The Decadal input is not binding on NASA in any way; rather it is a list of suggestions based on the rough consensus of the scientific communities. Work has begun exploring mission concepts for a Uranus orbiter in response to the last Planetary Science decadal, for example, but there is no commitment to fund an actual mission (yet.) The steps ahead for the Uranus mission, for example, will be discussed in general in the rest of this book.

NASA “Announcements of Opportunity”

NASA is empowered to allocate part of its budget up to a certain level. The agency has tried various mechanisms of identifying the highest value missions over the decades. Our discussion will be limited to the current process, which is a competitive evaluation process of solicited mission concepts. This means that NASA publishes a document, called an “Announcement of Opportunity” that lays out the details of space mission opportunities and provides a framework within which interested proposers can submit a concept. AO documents are often hundreds of pages long and prescribe in great detail everything the review committee wishes to see. For example, an AO might describe a $100M opportunity to fly a single, small spacecraft in Earth orbit. That sets the constraints for any potential proposal. If you want to fly your camera to Mars, you are not going to get there with this AO. The AO schedules are relatively predictable, which enables institutions to invest their own resources internally between AO periods to mature concepts for future proposal to NASA. This is a strategic activity in itself, as people leave institutions, technologies advance, and other things change in the dynamic world of research. A researcher might spend twenty years developing a concept and never see it fly because the underlying technology might have become obsolete, or some other mission might make relevant observations, or the researcher might even leave their institution.

Let’s discuss a widely-known mission as an example: the Mars Rover, “Curiosity” that landed on Mars in 2012. The AO for this mission was published in 2004. In the case of this mission, NASA internally had already decided to send a rover, and so the AO was specifically asking for instruments and experiments to be performed on the surface of Mars. (An instrument is something as simple as camera to look at rocks, or something as complex as a miniaturize chemistry laboratory designed to break down material and determine its chemical composition.) As it happens, both of those examples are on the Curiosity rover. Prior to the publication of the AO, engineers had roughly determined the capabilities that they imagined could be possible with a rover. This “rough draft” of the rover design was sufficient for NASA to solicit experiment ideas with enough detail that research teams around the country and world could design to them. The rover design itself matured along with the instrument selections during the time between 2004 and launch in 2011, and ultimately the vehicle successfully landed on Mars on the author’s birthday in 2012.

What does it mean to “design” a space mission?

There is no single process by which a space mission is designed, but certain patterns repeat. Whether a Mars rover, an instrument on a spacecraft orbiting the Earth, or a probe entering the atmosphere of Jupiter, there is always a single person who is responsible for the success of the mission. That person is called the “Principal Investigator” and represents the mission to institutions, government, contractors, press, and more. This person serves as the primary point of contact for all activities relating to the mission. There is also usually a project scientist, who is the the main point of contact with the scientific community. The PI and PS may be the same person in smaller missions. Larger missions may have multiple “Co-Investigators” as well; usually other scientists that have contributed to the field under study. This science team is responsible for both defining the science goals of the mission early in formulation, and for ensuring that the day to day operations of the mission actually perform experiments that can address those science goals.

Let us now discuss the engineering side of mission. Engineering in this context is the process of actually designing, building, testing and operating the actual hardware of the mission. In very large missions the science team may be quite removed from actual engineering, as they only need to know that the systems perform as required. On small missions there is significant overlap between science and engineering roles. The top engineering role is “Flight System Engineer” or “Instrument Engineer” depending on whether the mission is a full spacecraft or an instrument. These roles have the responsibility of ensuring that the spacecraft or instrument perform according to the required specifications.

Somewhat in parallel to these science and engineering roles is the project manager, who is ultimately responsible to the involved institutions for cost, schedule, and other higher-level issues. An AO will often prescribe the roles required at the high level and leave it up to the team to propose sufficient management structures.

Science Traceability

The most important document early in the process of designing a mission is known as the “Science Traceability Matrix.” The purposes of this document is to both capture and communicate the scientific goals of the mission, the justification for the selection of those goals, the measurement requirements to capture data to address those goals, the performance of the intended instruments, and any particular mission requirements. To explore this lets create an example space mission with the goal of looking for Bigfoot, the fabled forest-dwelling primate.

The STM is intended to be read from left to right, row by row. The first column, Decadal Goals, represents the goals from the science community that NASA has chosen to prioritize. They are often expressed in slightly more specific form in the AO goals, which is the next column. These two columns’ data are provided by NASA. The rest of the columns represent the proposed mission. The Science Goals column represents questions to be addressed by the mission that the science team believes address the AO goals. These goals are the subject of significant debate among the science team, and generally emerge from the continuous process of science publishing. A strong set of science goals will both address the AO goals in a way that is acceptable broadly to the scientific community, but specific enough that the team and proposed mission are the only way, or the best way, to move the field forward. Recall that these materials will be evaluated as part of a competitive process, so the details of the mission must together make a compelling big picture. The next column, required observables, represent the transition from science-focused thought to engineering-focused thought. Real-life scientific instruments have strengths and weaknesses and the science goals are only as useful as the ability of instruments to observe the subject phenomena. This column will also include the idea of “margin”, which shows the reader how much better an instrument is than it really needs to be to make the required measurement. This gives NASA confidence that unpredictable changes through the development process will not degrade instrument performance to below the point at which the required observation cannot be reliably made. Finally, the mission requirements column expresses major drivers in the mission design; for example a requirement to observe at a certain time of day, or from a certain altitude.

The STM is much more than a wish list; it is the primary writing from which the entire mission design and proposal development activity flows. It is critical to finalize the STM as early as possible. Until this is done there is no actual mission concept; rather an incomplete set of ideas spread across busy minds. STMs are not usually created from scratch. Rather, they evolve over time as the field changes, as proposals are submitted and evaluated (with feedback) and as new opportunities emerge. It may, for example, be possible to study the same geologic feature from either a vehicle on the surface of Mars or from a vehicle orbiting the planet.

The next section will discussion spacecraft technical details at the conceptual level. This transition from scientific thinking to engineering parallels the mission development process. In the ideal process, engineering work for the spacecraft does not go into full speed until the majority of the science goal development is complete. In practice there are many factors that affect this, but it is generally preferable to start with science and use that to lead engineering.

Space(craft) Missions

This wonderful map shows 54 years worth of space missions and is required reading if you are interested in the subject.

Now that we have discussed the fundamental motivations of space missions, we can discuss some finer details. We will avoid deeply technical matters but some discussion of how these things work is necessary to see the big picture of how missions actually happen. First we will discuss the general subsystems of a spacecraft, and then to into more detail about the scientific instruments involved. The most relatable example might be the first spacecraft sent to take a photograph of Mars, in the 1960s. This mission was the first attempt to target another planet with enough accuracy to pass within a certain range of altitudes, in order to take photos. The space vehicle itself in this case is largely a camera with a handful of other systems attached. It, and many missions of its type and era, were not much more than an aluminum frame with a camera, simple computer, battery, radio transmitter, and satellite dish attached. Due to the distances involved the satellite dish had to be very large, and so one would be forgiven for referring to these spacecraft as satellite dishes with computers (and radios and batteries) attached.

Spacecraft Systems

Spacecraft in the modern era have more capabilities and are much more complex, but still adhere to the same overall feel of a satellite dish (or a box) with a bunch of equipment attached to it. All spacecraft require electric power, and so some kind of power system must be included. The options here vary from batteries alone for short missions, to solar panels, to nuclear-powerd generators. The choice of power system is usually first limited by the details of the mission and its distance from the sun, and second limited by strategy. For example, using a nuclear power system can give a mission access to electric power in places where the sun does not shine, but it also comes with a higher regulatory burden and a nerve-wracking approval process. The Cassini mission was entangled in regulatory battles nearly until the day of launch due to its nuclear power system. Protests were held at the launch site.

Communications

The next basic spacecraft system is communications. A spacecraft that gathers data is not very useful if that data cannot be transmitted back to Earth. These options vary widely again, ranging from simple omni-directional radios (used for some low-altitude spacecraft) to long-range, multiple node systems. The Mars Curiosity rover is an example of this; it has two ways to communicate. It has a small antenna that can communicate directly with Earth (when Earth is in above the horizon of Mars!) and it also has a larger, higher data rate antenna with which it can communicate with other spacecraft orbiting Mars, which then transmit that data across the gulf of space to Earth.

Attitude Control

Instruments and communication also require precise control of spacecraft pointing, also called “Attitude control.” This is exactly what it sounds like; as different things must be pointed in different directions at different times. There are two primary technologies used to accomplish this. The first are what you might expect; small thrusters mounted on the outside of the spacecraft. Their operation is relatively intuitive; when activated they thrust in a direction and rotate the spacecraft. The second option is less intuitive but operates on the same principle; the reaction wheel. We know that for every action there is an equal and opposite reaction. In the microgravity environment of space this means that rotating a wheel inside a spacecraft will make the entire spacecraft rotate in the opposite direction. This idea is used to enable spacecraft attitude control without external thrusters. A spacecraft might rotate itself to point its camera at a feature of interest, and then rotate to point its radio antenna back to Earth. Each of these actions has been carefully planned and rehearsed beforehand into the daily CONOPS (concept of operations) for the mission. This planning extends down to the level of turning specific spacecraft systems on and off. There is a legendary story from Russian space program: a spacecraft had two radios for redundancy. Each could turn the other on or off. One day ground control sent the command to shut radio A off, but had neglected to previously send the command to turn radio B on. Radio A was promptly shut off. Mission Over. It was not possible to turn either radio back on because both were off at the same time. Modern systems have protections to prevent this kind of human error, but it highlights the extremely detail required to successfully perform any kind of space mission.

Some spacecraft are able to propel themselves along under their own power. These vehicles have propulsion systems, which can be intuitively thought of as rocket engines. Some space mission do not require this kind of propulsion, if for example they only need to stay in a certain orbit or are not designed to last long enough to need to move themselves.

Thermal Management

One aspect of spacecraft and mission design that may not be immediately intuitive is that of thermal management. An object in space experiences a huge range of temperatures even in a benign situation. The side facing the sun can heat up to 300 degrees farenheit and the side facing away can cool down to -200. Add in a rotating spacecraft, and orbits that take the spacecraft over the night side of the Earth, and you have a very dynamic thermal environment. Certain spacecraft systems must be kept within a range of temperatures, and often the performance of scientific instruments depends on their temperature. In the most obvious case, the MESSENGER spacecraft that orbited Mercury had perhaps the most challenging thermal management ever seen. Being that close to the sun the spacecraft would fail in minutes if not for sufficient thermal management. The solution was to build all of the critical spacecraft systems behind a large ceramic heat shield that had to always face the sun. The only part of the spacecraft that extended beyond the edges of the heat shield were the solar panels, and even these needed a few tricks to remain safe. The solar panels were able to articulate like window shades in order to lower the amount of surface area exposed directly to the sun.

Spacecraft Instruments

The fundamental purpose of any space mission is to return data that cannot be gathered any other way. Thus the real function of the spacecraft is to bring the instruments to their sweet spot; the point in space at which they can best do their job. Instruments can range from the relatively simple digital camera (and in fact early digital camera products were enabled by NASA work on sensors for deep space cameras) to 20 meter long rods to measure Jupiter’s magnetic field, to elaborate miniaturized chemical laboratories that can replicate an entire building’s worth of equipment on the surface of Mars. The selection of instruments, and the design and planning of their activities, comprise the bulk of the initial stages of mission design.

Mission Cost

Mission cost estimation is an art and a science. AOs will usually refer to a NASA policy regarding cost estimation but the general idea is straightforward. A total mission cost is determined by adding up projected development costs for all parts of the mission, adding up projected labor costs according to institutional rates, and applying a percentage of the total cost to account for unexpected increases in cost. This also includes a strategic component, as NASA will accept cost margins within a certain range, but decreases in margin are not often reviewed favorably without a very good tradeoff. Such a tradeoff might be allocating more resources to a certain technology development, or adding more people to a particularly challenging period of the mission.

Heritage

Heritage, generally, represents the previous use of some spacecraft subsystem and the amount of work necessary to adapt it to the proposed mission. A proposed mission that is reusing something that has 1. Already flown on a previous mission, 2. To a similar destination, and 3. Worked properly is said to have high heritage. To be clear, this is not a reuse of the exact same system that flew (as space systems are not reused, with the recent exception of reusable launch vehicles) but rather a new device built identically to a previously flown device. Such a proposed subsystem is said to have high heritage. Heritage can be described in terms of risk and cost.

NASA evaluates proposed missions primarily on the basis of science and risk. We have discussed the science process already, and it follows a somewhat intuitive thought process: the proposed space mission should achieve improvements in scientific knowledge. The risk component is less intuitive. How can we hope to identify, much less mitigate, the risks involved in sending extremely complex, one-off pieces of equipment to hazardous environments?

Technology Readiness Level

One way NASA tries to manage this is with a concept called “Technology Readiness Level” or TRL. TRL is a scale from 1-9 that represents how mature and reliable a piece of technology is, and how much risk it would represent as part of a mission. It is equal parts tedious bureaucracy and invaluable tool. It was created in response to a need for a way to communicate effectively about risk across teams, projects, and time. TRLs are like taxes in that you have to tell NASA what your TRLs are and then justify those assertions. Like any system it can be gamed, and proposal development meetings can get bogged down in discussions about how to define the current TRL of a technology and the steps remaining to get it to an acceptable level.

The scale itself is displayed below, but the general idea is that a TRL of 1 or 0 even represents a brand new concept, perhaps expressed on a cocktail napkin. A TRL of 9 represents a system that has been built, flown, and successfully operated in a certain environment. Mission AOs will prescribe a certain minimum TRL for systems and sometimes an acceptable amount of development that can occur using mission funds. This tension between bringing high-TRL technologies to a mission versus using mission funds to advance technology is a highly charged issue. This ongoing difficulty resulted in the formation of the Space Technology Mission Directorate to, in theory, assume some of this risk independent of missions.

Source: NASA

One common discussion about TRLs emerges when a team wishes to propose, in a new mission, the use of a technology that has successfully flown to another destination. For example; the re-use of a camera design in Mars orbit that has successfully flown in Earth orbit. A proposal team may attempt to reduce cost and risk by including a previously-flown camera, and will have to identify a TRL for the camera in the proposal. This can become an extremely detailed conversation as any changes in design for Mars will be carefully (some would say excessively) scrutinized to determine whether they affect TRL or not. For example, if the Mars implementation requires a different set of lenses (but those lenses have already flown elsewhere) the team would probably conclude, and NASA would agree, that that change does not affect the TRL because it is an “engineering” development. However if the sensor that actually gathers the light inside the camera needs to be modified, that would likely rise to the level of a “technology” development and would negatively affect the TRL. It’s a fine line and many conference room tables have been banged on in frustration during such discussions. Misrepresenting a TRL is a very good way to get your mission proposal rejected out of hand.

“Valley of Death”

After this discussion of TRL, and our discussion of NASA’s low appetite for risk, the reader may be curious about how brand new technologies are introduced to missions. Technology developments are solicited in a somewhat parallel way to missions. There are AOs for technology developments, and some mission AOs contain incentives to use certain new technologies that have been prioritized by NASA. This introduces a highly political component to proposal development. After all, if your project becomes one of these priorities, you can expect greater visibility, more favorable reviews, and possibly even mandates or incentives to use your technology. This can skew mission development discussions away from the best technology for the job to the most favored technology for the job. I have seen this derail discussions for weeks or months. On the other hand, the laws of nature do make certain technologies unquestionably better in some cases. NASA does have a role to play in defining these technology areas as high-priority.

The net effect of these parallel technology and mission development activities is a system that prioritizes brand new concepts (that cost little to explore in a preliminary sense) and mature concepts (that add little risk to missions.) This leaves a relatively large gap in between the two that is affectionately known as the “valley of death.” Many promising technologies languish there because they have passed the point at which early phase funds are achievable, but have not yet found the mission demand that justifies funding the rest of the development. This outcome is not surprising in an agency of 100,000 minds but it does not make it less frustrating.

Bringing it all Together

I have the most fun at the intersection of science and mission engineering/design. It is like solving a giant puzzle with dozens of moving parts. It also involves soft skills such as empathy, communication, and conversation. Teams are incredibly diverse and highly geographically distributed. There is a wonderful feeling of satisfaction to contribute to the development of a concept that can advance human knowledge. It also feels great to be part of a process that creates completely new ideas that have never existed before and that few know are even possible.

Our next section will address the strategic component of this creative process.

Mission Development Strategy

Stream of missions

Space missions are not developed in isolation. It is more accurate to consider a possible mission as a pebble in a stream, with many missions before, ongoing, and not yet launched. This makes sense given the primary purpose of missions themselves as mechanisms to advance knowledge. All science builds on previous discoveries. In the space mission world this means that new missions build on previous ones, and missions in development change and even stop work based on other events in the larger world. For example it is not unheard of for a group of researchers to work on a mission concept for years only for their institution to cancel it when a different mission is selected that has significant science overlap. Another interesting phenomenon is when the leaders of a scientific sub-speciality (astrobiology for example) ends up split into two teams competing for NASA resources. This can happen because institutions have to make strategic choices for their hires, what internal projects they support, resulting in scientific leadership being somewhat clustered in a handful of places. These groups end up in direct competition not just for NASA resources but for individual scientists and institutional support. This is not necessarily a bad thing but it is an interesting duplication of effort.

Strategic Process

STM-, Capability-, or Instrument-driven

Another way to look at the process of developing missions is to examine what drives them. There are at least two major ways: mission pull and technology push. Mission pull referees to the situation where a certain mission that already has broad support is overwhelmingly better suited to using a certain technology. This results in medium or long term strategic investments by NASA in that technology’s development. For example a certain sensor technology that can be used for Earth and Mars observation will get priority from NASA, and might even be directly funded in order to mature it for use.

Technology push is the opposite, which is when NASA wants to fly a certain technology and so missions are conceived that require it. This is usually frustrating for most of us (except those who are working on that technology.) This can be done for political or, less often, strategic reasons. NASA is directly controlled by Congress which results in work being directed to certain districts, whether their technology is part of the bigger picture or not. This is frustrating due to both its actual cost and its opportunity cost. The major opportunity cost is actually time, not money. 10 years spent funding an inferior technology is 10 years that could have been spent funding a better one.

Impact on policy

What is the purpose of conducting science? For centuries it was to inform decision making and improve quality of life. This extends to the universe in ways that are not always intuitive. One might reasonably ask how the details of Jupiter’s atmosphere are relevant to our daily life on Earth, or why the details of the sun’s magnetic field, measured from the edge for the solar system, matter at all. The answer is we don’t always know exactly what we can gain in a practical sense from the advancement of knowledge. However, every single difference in our daily lives from that of our cave-dwelling ancestors is due to the scientific process or at least the process of inquiry and exploration.

Our challenge today is to keep that focus in a world of ever-increasing challenges.

Archimedes took a bath.

Isaac Newton lit two lamps separated by a few miles.

Galileo built a telescope out of junk.

Einstein worked on a notepad during his coffee break at the patent office.

All of these luminaries were able to make major discoveries at little to no cost, and with little to no support from the public. At the risk of calling their discoveries the “low hanging fruit of the universe”, they were able to make them because it cost little or nothing to conduct the experiment or think through the problem.

This is no longer possible. Modern experiments involve sending massively complex machines to other planets, or gathering data from a giant tank of water 1000 feet under the ground in Antarctica, or smashing gold atoms into each other at 99% of the speed of light in a 17 mile wide track. Modern science requires the public and society to participate.

These projects benefit society, of course! But the reward is now separated from the risk by many years and many dollars. Further, science only benefits society if it is involved in the policy process. We ignore it at our peril, and it is real whether we believe it or not.

Other Space Agency Structures

This section will briefly describe how other nations have configured their space activities. NASA is a civil space agency, meaning that is not formally part of the U.S. military. There are connections but NASA is a distinct agency. This is not the case everywhere.

Russia

Russia was the first nation to formally create a space program, even if it was non-public. The Sputnik launch in 1957 spurred the formation of NASA, or rather the evolution of NACA (the predecessor agency) to the NASA we would recognize today. Russia’s space program remains tied to the Russian military and is relatively opaque.

ESA

ESA stands for “European Space Agency” but that is a misnomer. ESA is not a singular agency in the way that NASA is. Rather, it is an agreement between national space programs of EU member states that funding that is contributed by the states will be returned to the states in the form of work on space projects.

India

India’s space agency is structured somewhat similar to NASA, except that it’s centers are each focused on specific applications of space research. For example, there is a center that is focused on improving agriculture with space-based work. There is no similar functional distinction between the NASA centers.

Japan and Korea

Japan and Korea each have space agencies that follow in the NASA model, albeit much smaller. JAXA is divided primarily into contributions to human spaceflight, and to science missions. This roughly approximates the HEOMD and SMD divisions of NASA.

China

China’s space program is highly secretive but appears to be full steam ahead to landing humans on the moon.

Relationship to NASA

NASA led the world in Space Exploration from the 1960s until the early 2000s. The ending of the Space Shuttle program, without a replacement system in place, will probably be remembered by future historians as the beginning of the downward slide of leadership and influence. NASA’s capabilities lead the world in some areas, and lag in others. There is still no domestic system for human space launch as of 2018. On the other hand, we still successfully and routinely launch robotic spacecraft much farther than any other nation has even attempted. NASA can still lead the world, but we need Congressional and Presidential leadership with the vision and will to implement long-term goals.

Challenges going Forward

Are we going to Mars or not?

Mars has been an alluring destination for human spaceflight since the beginning of the space age. So when are we going? The answer is a complex “not yet.” Putting humans on Mars is many orders of magnitude more challenging than the moon. Further, the geopolitical climate of the late 1950s and early 1960s was a major, if not the primary factor in JFK’s famous challenge to “put a man on the moon and return him to the Earth by the end of this decade.” We have since lost the capability to put people on the moon, and are only tangentially farther along the long path of putting people on Mars. This chapter will discuss this tragedy.

Enabling Apollo (unavoidable history section)

The Apollo program was a result of an amazing combination of factors.

The primary factor was the state of geopolitics at the time, and the leadership and personality of JFK. The mathematics enabling interplanetary travel had been worked out shortly after World War 1. The mechanization of combat for which WW1 has been credited led to a significant industrial capacity in the various nations involved in World War 2. Powered flight, itself only developed in the late 19th century, was first used in WW1 for mail delivery and primitive, exceedingly dangerous dogfighting. The militaries of the world came to see the air as a new warfighting domain, adding a new dimension to the land and sea domains of all of previous human history. Early tests of liquid fueled rockets, first attached to aircraft wings to reduce takeoff distance, led to short, medium and long range missiles capable of raining devastation on distant targets.

WW2’s unrivalled devastation came in large part from these airborne rocket capabilities (and the corresponding lack of effective defenses for them.) If you fire a rocket at the correct angle and speed, your rocket never comes back down. That small addition in thrust changed the world from an airborne to a spaceborne paradigm. This is the context in which Sputnik’s launch in 1957 occurred, and provided the lens of terror through which its simple orbit and radio transponder had to be viewed.

In this simpler world the public demonstration of strength that was Sputnik had to be countered. The US and Soviet Union took turns launching people into space, and in 1961 President Kennedy issued the single greatest technological and societal challenge in the history of the world. JFK was assassinated just two years later, and an effort already well underway defied cancellation at least partially due to the memory of his leadership and challenge. The Apollo program continued despite another tragedy; the Apollo 1 fire in 1967. Again, the memory of the deceased spurred the effort onward with even greater passion.

Assuming a successful moon landing would lead to a journey to Mars, NASA actually began preliminary work on a humans to Mars mission prior to the successful landing on the moon of Apollo 11. This mission would have occurred in the 1980s! Alas, one man would prevent this, and, intentionally or not, transform NASA into a very different beast.

Nixon

President Nixon lacked many qualities I would hope for in a leader. Among them is scientific vision. He cancelled the final three Apollo missions mostly because the previous ones had unquestionably shown America’s superiority in space and “won” the space race. Apollo was colossally expensive, at one time consuming 5% of the federal budget (compared to .5% or so today) but in shutting off the spigot he also transformed NASA. As an agency charged with space exploration, NASA has a long term investment horizon in new technology, capabilities, and benefits to society. This was not an issue during the Apollo heyday as the cash flowed easily, but the early 1970s saw a sort of reckoning within NASA. NASA suddenly had to compete for attention, funding and prioritization with other agencies that delivered much more short term, down-to-earth benefits such as education or other public works.

This change of structure and position led to NASA’s huge gamble known as the Space Shuttle.

The Shuttle Era

Part of NASA’s motivation in the creation of the Space Shuttle was to develop a system that could service multiple federal agencies. This resulted in the Air Force working with NASA on initial designs. The design process for something like the shuttle is very long. The Air Force provided input on the kind of capability a space shuttle would need to support their payloads, but backed out of the project at the worst time. This occurred before the Air Force would have committed to long term use (providing NASA with a major “customer” of their new expensive system) but after the point at which the design changes made for the Air Force could be reversed. As such the Space Shuttle was larger and heavier than NASA anticipated from day one. Every single shuttle and launch was more costly, risky, and complex because of this.

The Space Shuttle is also the first and last space vehicle designed to ferry large amounts of cargo and crew at the same time. It turns out it is exceptionally difficult to design a vehicle to do this well, as evidenced the Challenger and Columbia tragedies. This is because heavy cargo requires different kinds of support as living crew, and combining the different technologies for both into one vehicle results in the most complicated machine ever built. 

The International Space Station

The international space station is a fascinating project. Its costs to date are roughly at the level of the entire Apollo program. Its origin is another product of geopolitics. While being played to the public as a global partnership in science and exploration, the ISS was largely funded to give scientists and engineers from the other side of the Iron Curtain something to do after the fall of the Soviet Union. The concern was that these researchers would work for the highest bidder once the Soviet government no longer had projects to support. The ISS is a worthy project and a constructive use of global talent. It is a valuable laboratory for research that can be done nowhere else. It has enabled the deeper study of the effects of living in space on human health than was possible before. However, it was not ever more than a geopolitical maneuver justified to the public with a coat of scientific paint. It truly pains me to describe it as such but getting humans to Mars requires a realistic look at what we have accomplished so far.

NASA as a Jobs Program, and the Power of Infrastructure

Unfortunately, NASA has come to be treated as a jobs program by a handful of Congressmen and Senators. They exert enormous influence on the actual direction of the NASA Human spaceflight program, up to and including essentially telling NASA what projects to fund. This happened over the last few decades of the 20th century resulting in a series of partisan projects over the past 20 years. This was enabled by the rapid investment into infrastructure and NASA centers during the Apollo program, and has resulted in the maintenance of a large workforce that is very good at building technology that gets older and older every year. These centers represent a hundred thousand jobs or more and the representatives from these areas use those jobs as currency to control the direction of NASA human spaceflight. The Space Shuttle program was largely based on Apollo-era technology, and that preserved 1960s-era technology for almost four decades. This locked-in phenomenon persists even now as the major human spaceflight programs since about the year 2000 have still largely avoided reinvention and innovation and have settled on marginal improvement. The next few sections will discuss this trap and the hyper-partisan nature of its continued existence .

The Constellation Program

Constellation was a plan issued by the George W. Bush administration that in theory set NASA’s sights on a return to the moon. Work began on many projects including new rockets, lunar surface equipment, power systems, and more. Unfortunately, it was not funded to the level necessary and to reach its goal (some would say deliberately.) The project did maintain the influence of a group of Southern representatives in districts with NASA centers.

The Obama Mars “Plan”

The Obama administration redirected NASA to work on human missions to Mars. This did not come with a deadline, as Kennedy had issued for the moon, nor with the kind of budget increase necessary to actually get there. However the decision was met with excitement within NASA for several reasons. It appeared to try to balance the short-term nature of agency political leadership with the long-term nature of preparations for an interplanetary journey. It also did not jettison the constellation work entirely (though there were casualties). The NASA social media office made brief headlines in 2012 with a tweet along the lines of “Our journey to Mars begins today!” that had us all scratching our heads. We knew there was no actual plan or budget to go to Mars, just a directive to think about the kinds of technologies we’d need. That tweet symbolized the lack of direction within NASA.

Around the same time NASA was instructed by Congress to begin work on what would become known as the Space Launch System.

Space Launch System

The space launch system represents much of what is both right and wrong with the United States space program. The vehicle itself is an enormous rocket with incredible launch capacity. Its origins lie in back-room conversations on Capitol Hill near the end of the Space Shuttle program. If one were to design a rocket from scratch that scratches all the right backs, funnels money into powerful Senate districts, and maintains an enormous workforce, one could not do better than the SLS. Unfortunately this comes at an staggering cost due to the rocket’s non-reusable design; even more baffling in an era of successful reusable rocket designs from SpaceX. NASA cannot afford to both launch an SLS, and put a serious mission on top of it, in the same fiscal year. This results in an almost comical situation in which one can afford the delivery truck but the item that needs to be delivered, in the same year.

Meanwhile, SpaceX has demonstrated partial reusability in even a heavy lift launch vehicle, challenging the public justification for the SLS (the real, private reason being the maintenance of NASA jobs and power politics.)

Commercial Crew / SpaceX

“Commercial Crew” is an Obama-era NASA policy that attempts to push launch services to private industry, ostensibly to reduce NASA costs. Unfortunately, while SpaceX has shown promising capability, NASA itself is stuck funneling money to SLS that could be spent developing actual payloads for SpaceX rockets to launch into space. There are good reasons for NASA to have it’s own launch vehicles; primarily to avoid total reliance on private industry, but the SLS is unquestionably excessive for that justification.

ARM / Humans to Mars?

NASA has a problem. It is institutionally stuck spending money on excessive capability due to power politics. It also has an unspoken goal of “Sending humans to Mars” someday, but without funding, planning or commitment from Congress to make it happen. This bind results in odd things happening such as the Asteroid Redirect Mission, or ARM. ARM is a concept for a mission to travel away from the Earth with the mighty power of the SLS, “capture” an asteroid, and bring it back to near-Earth space for study by astronauts. While it is not without scientific value, it is mostly a make-work mission for the SLS itself. This is where the NASA human spaceflight program finds itself in 2018; half beholden to “The Swamp” and half adventurers trying to find a way to the next frontier.

Unfortunately, NASA will not send humans to Mars, or anywhere close to Mars, until this impasse is resolved. However, NASA is not the only player in the game anymore. China seems intent on sending humans to the Moon, even reproducing the Apollo playbook of incremental missions proving new technologies along the way to the lunar surface.

I believe humans will walk on Mars in my lifetime, but they may not be American.

2018

The Trump administration was very slow to nominate a new NASA administrator, so much of its policy has only come to light in 2018. There is no talk of sending humans to Mars, and much talk about sending humans back to the moon. ARM is effectively eliminated and the new “goal” is a space station orbiting the moon known as the “Deep Space Gateway.” Such a project would maintain the SLS status quo and feed the major aerospace contractors and further delay American boots on Mars. This administration is likely to have to make tough decisions about the future of the International Space Station, and as of May 2018 it appears that it will be sacrificed towards the middle of the 2020s to free up funding for the deep space gateway and related make-work projects.

Fortunately, the Science Mission Directorate has been more or less left alone and is pursuing exciting robotic missions to Jupiter’s moon Europa, another car-sized rover to Mars, and is in early stages of considering a flying rover on Saturn’s moon Titan. The latter’s ambition should warm the heart of all adventurers. Meaningful science around the Solar System continues.

Conclusion

I criticize NASA from deep well of hope and ambition. I think there is much to be proud of and excited by, and much to improve. The overall national leadership in space is still too beholden to the vagaries of changing administrations, but great capability remains. Still, we have built a great many wonders, with many more to come.