While NASA is open to extending ISS operatons beyond 2020, at some point the station will need to be replaced—but with what? (credit: NASA) Replacing the ISS

The debates about the future of human spaceflight are focused on where we should go next: should it be the Moon? An asteroid? An asteroid moved to lunar orbit? An Earth-Moon Lagrange point? Mars? Or should we even go beyond low earth orbit? In the meantime, very little attention seems to be paid to the long-term future of human spaceflight in low earth orbit (LEO). The partner countries plan to extend the life of the International Space Station until at least 2020. There are discussions on possibly extending it until 2028. The ISS, though, can’t last forever. It wasn’t designed to. The questions are: How long can it last? How long should it be used? Should it be replaced? When should it be replaced? Why should it be replaced? And what should replace it? The ISS was designed for a number of purposes. It was designed to be a pathfinder on how to build and operate a station in LEO. It was designed to test new technology for further exploration. It was designed to be a laboratory to do research in microgravity. It was designed to spur collaboration among most of the spacefaring nations. It was designed to be a political tool for politicians across the globe. In part, it was designed to improve relations with Russia after the collapse of the Soviet Union and keep their engineers from applying their skills to weapons systems for countries with conflicts with the West. Whether the ISS lasts until 2020 or until 2028, planning for what comes next needs to get started now. In assessing if and how well the ISS has met its goals, you will probably get a variety of answers, depending upon people’s varying perspectives and interests. The ISS has served as a pathfinder allowing us humans to learn how to assemble and operate a station in LEO. There have been many lessons learned. One of the latest has been from the problem with a spacesuit on a recent EVA by ESA astronaut Luca Parmitano where he potentially could have drowned in his suit from a water leak. The biggest lesson from this incident should be that, as good as you think a design is, you don’t really know until it has significant experience in real operations. It is a lesson businesses learn about their products often when they hit the real world for the first time. Aboard the ISS there has been time to test life support equipment and find out how it will hold up over years of service. There have been improvements in recycling water that have reduced the need to haul water up from earth. There have been EVA procedures developed to maintain the physical health of the station. The work at maintaining the station has definitely been an international collaboration with, I’m sure, much knowledge gained on how to operate in space. There is very little that hits the mainstream media about the research done aboard the ISS. Part of the reason for that is that the research isn’t typically headline-making news. That doesn’t mean that the research can’t be valuable. An example is research done since 2001 that has been instrumental in finding a method to destroy a variant of staphylococcus aureus, also known as MRSA, using cold plasma. MRSA infections are a real problem especially for hospitals and athletic facilities. MRSA has been extremely difficult to remove from operating rooms and locker rooms and can lead to life-threatening infections. A friend of mine had a significant problem with a MRSA infection that was eating away at the flesh on his leg after an abrasion that happened in a karate match. Grant Hill of the NBA had a bad MRSA infection that, in his words, “nearly killed him”. I don’t know a lot about the other research that goes on aboard the ISS, but just because we don’t hear much about it doesn’t mean valuable research is not taking place. According to page 11 of NASA’s FY 2013 Budget Estimates for Space Operations the cost of operating the ISS for fiscal year 2013 is as follows: ISS Operations and Management: $1.4935 billion ISS Research: $229.3 million Crew and Cargo Transportation: $1.2848 billion Total: $3.0076 billion NASA wants to go beyond Earth orbit, but has limited funds to do so. With the ISS now costing more than $3 billion a year (not counting partner contributions) to operate, it begs the question of how much longer should it operate. On August 20, NASA released the latest update to their Global Exploration Roadmap. On page 10 of the document it shows in the line for LEO the ISS operating up to 2020. After 2020 it shows “Commercial or Government owned platforms” through 2030. I’m obviously not the only person wondering what comes after the ISS and when. Whether the ISS lasts until 2020 or until 2028, planning for what comes next needs to get started now. The first step in figuring out what should be built is figuring out who the potential customers are and deciphering the needs. If the next station or stations are commercial, the potential for opening up new commercial markets for space activities increases. Commercial stations wouldn’t have to be constrained by the needs of government space agencies. Commercial stations could provide everything the ISS currently does and more at hopefully at a significantly lower cost than operating the ISS. All sorts of ideas have been floated for commercial space stations over the years. They could be hotels for space tourism. They could host fuel depots for beyond Earth orbit vehicles. They could be orbital shipyards for assembling larger vehicles. They could be manufacturing facilities for products that can only be made in microgravity. They could be warehouses for all sorts of supplies needed in orbit. They can be transit ports for ships heading out deeper into space and back, carrying crew and cargo of all kinds. They can be test platforms for earth observing instruments. They can be research facilities taking advantage of both microgravity and ultra-hard vacuum. Turning over low Earth orbit to potentially more cost-effective business models would free up resources at NASA to develop payloads for beyond Earth orbit exploration. NASA’s efforts to develop capabilities for both commercial cargo and crew currently only have the ISS as a destination. When the ISS is finally splashed into the Pacific, there will be no destination and no market for Dragon, Dream Chaser, Cygnus, and CST-100 if no replacement is developed. If the replacement is another government-owned and -developed station, the growth potential for commercial cargo and crew will be limited. If commercial stations can be successful, commercial financing opportunities of space based businesses will have the potential for more rapid growth. All sorts of ideas for space-based businesses have often had a very big problem. Many of them require other space infrastructure elements to be developed by other commercial ventures to have a market or they require government space agencies to be their only customer. This is not a model investors are thrilled about and it makes them very reluctant to invest. Going to a commercial model for space stations has the potential to change this dynamic. While I don’t have any definite ideas of what the configurations of next-generation stations should look like or even what orbits they should be in, I do believe they should be planned for steady expansion and capable of incorporating continuously improving technology. A station doesn’t necessarily have to have all components physically connected. Components such as fuel depots and vibration-isolated research modules could fly in formation with each other. I don’t pretend to know which kinds of commercial space adventures will and will not succeed. I do believe that commercial stations in orbit would improve the odds for more to succeed. Commercial crew and cargo will need thriving and growing destinations to have any significant growth potential. Space tourism would be greatly helped with a destination that has some room for people to move and float around in. It isn’t going to grow unless launch costs decline with commercial suppliers competing to come up with better and more cost-effective launchers. For satellite servicing to emerge as a business, it could make use on-orbit storage of spare parts and fuel. For reusable commercial space tugs to carry cargo to destinations in cislunar space to succeed, an operating base with fuel depots would help. For a market to develop for commercial heavy lift to emerge, it would require a growing market, putting stress on the capacity of existing EELV-class launchers. If asteroid mining and space-based solar power are ever going to have a chance of succeeding, they will need a more affordable space infrastructure in place. When commercial real estate developers build a large office building, they usually don’t have to pre-sell all the space before they break ground. What they usually do is sign an anchor tenant to secure financing. It’s a model that I believe could work for commercial space stations. It would help to have both government and commercial tenants signed to get financing for a commercial station. Guaranteed revenue starts making these types of businesses interesting to the financial community. For commercial space stations to have a chance of being financially viable for the foreseeable future, they will need government agencies as major tenants. There still is no one else with pockets as deep. NASA wants to move beyond LEO. Turning over low Earth orbit to potentially more cost-effective business models would free up resources to develop payloads for beyond Earth orbit exploration. In other words, if the President and Congress could ever agree on a vision for NASA, even in this tight budget environment there could actually be significant human spaceflight exploration missions in the next decade. Turning over LEO to commercial entities could actually create new industries when the country could use them to create desperately needed jobs. So how could this vision happen? First of all, NASA could solicit proposals from industry on facilities that could host NASA’s needs while not limiting the ability to address other customers. Industry organizations could do market research on other potential customers to find out what their needs could be. Partnerships and consortia of aerospace companies could develop to finance and build these stations. These could turn into global ventures bringing in traditional and nontraditional sources of financing and technology development. For it to happen, though, it needs at least NASA and hopefully other space agencies to buy into the concept. If we are to advance in space capabilities, the next generation of stations needs to improve on the capabilities of the ISS. While NASA and its international partners are trying to figure out how to push the boundaries of human space exploration, it may be the right time to think about a commercial foundation in LEO that could make these missions more capable and affordable. The wildest dreams of the space community will not happen in a timely fashion if the foundation isn’t strengthened by making it more capable and affordable than it is now. I do believe now is the time to start making this happen. And I do believe commercial stations in LEO and, eventually, beyond could be the catalyst for a prosperous future in space. In this article I’m not going to answer where I think NASA should go next, but will offer my opinion on the remaining questions I posed. How long can the ISS last? It should be able to be maintained until well into the next decade if there is the will and the money available to keep it running. How long should it be used? The ISS should be used as long as it is safe, maintainable, and no replacement is yet available. Should it be replaced? Since it can’t last forever, if NASA wants to continue operating in LEO in the coming decades, it needs to be replaced. When should it be replaced? The ISS should be replaced by the middle of next decade before the ISS becomes significantly more expensive to maintain due to its age and the risks of major component failures become too great. Why should it be replaced? If humans want to be a spacefaring species, operating in LEO is something we need to do and the place to figure out more effective ways of operating in space. And what should replace it? If we are to advance in space capabilities, the next generation of stations needs to improve on the capabilities of the ISS. To me, this means they need to address both the needs of government markets and potential commercial markets. It is time to start planning. Home









