The following is an interview with International Space Station Associate Program Scientist Tara Ruttley and Southwest Research Institute Associate Vice President for Research and Development Alan Stern as they discuss the benefits and differences between the space station and suborbital research platforms.

A Lab Aloft’s Jessica Nimon: Alan and Tara, thank you for joining me. Today we are talking about the topic of microgravity research platforms. I sometimes hear people treat suborbital and orbital laboratory options as synonymous. These options, however, offer distinctly different benefits. Alan, can you tell me what makes suborbital research unique?

Stern: Suborbital is special for a number of reasons. First of all, it offers low cost and more frequent spaceflight than we can currently achieve with orbital research. It also provides the space station with a great training and proving ground. So despite its many amazing capabilities, space station is highly constrained in terms of crew time, how much equipment you can get back and forth and room to place investigations. Naturally, only the most important experiments can go up to station and they receive limited crew time. This is part of why it is important for the station to have a proving ground—like suborbital—where you can test the equipment, the techniques and the science. This way selections for which experiments should go up to station can be made based on experience in research, not just theory.

My analogy for the relationship between the station and suborbital research is a baseball one: the major leagues rely on the minors as a feeder system and I think this is a similar relationship between station (i.e., the major leagues) and suborbital (i.e., the minors). Without the minor leagues, the majors would be crippled; they would not have the farm teams to develop techniques and players. I think the station can use suborbital in the same way and very cost effectively.

Ruttley: I agree with Alan that suborbital research can help to pare out the tests that investigators want to do. It could be a way for a scientist to get a good handle on a hypothesis prior to working with the space station. Once an investigator knows what might be seen in microgravity, a decision can be made on the next step.

One of the advantages of working with the space station is this ability for continuous testing. On the ground, scientists do one experiment, look at the results, and then repeat in a lab setting with controlled variables. The space station provides a researcher the ability to perform multiple trials to increase the data set, thereby offering longevity with a sustainable presence in space.

You have large opportunities for data and power, as well. These are huge resources for investigations like the Alpha Magnetic Spectrometer or AMS. This study could not sustain itself without the space station’s power and data capabilities. Space station also provides a human in the loop to help troubleshoot in real time and potentially move the investigation on to the next step.

The starboard truss of the International Space Station with the newly-installed Alpha Magnetic Spectrometer-2, or AMS,
visible at center left.
(NASA Image S134E007532)

Something else to consider is that the space station offers not only the U.S. laboratory, but also access to our international partner labs. Each partner module has its own range of facilities for investigators to potentially take advantage of. This includes external mounting for studies seeking exposure to the space environment. It is appealing to researchers that we have this massive, interdisciplinary, resupplied and fully-outfitted research laboratory on orbit.

A Lab Aloft’s Jessica Nimon:  Alan, you mentioned that suborbital research can feed into station investigations. I’m curious, does this ever occur in reverse? Have findings from station studies contributed to suborbital research?

Stern:  Not yet. I think that’s largely the outcome of limitations with the current suborbital program at NASA. For one, NASA’s current suborbital program does not fly very often and it’s very expensive. Secondly, it’s primarily a Science Mission Directorate program and station does not do a lot of planetary science, astrophysics or much Earth science—the mainstays of the Science Mission Directorate. These could be future areas, however, for the space station to expand into.

But I also think the new commercially reusable suborbital efforts are going to really change current paradigms and allow things to work in both directions. This is because the user community will vastly expand with daily flights—instead of monthly flights—and lower costs will enable more trial and error experimentation like in a regular lab. The people interested in commercial suborbital are not necessarily looking at the same goals at the Science Mission Directorate. They are looking instead at the things that fit better with station, in terms of the user base: microgravity, life sciences, technology tests.

Ruttley:  There are a few NASA research announcements sponsored by the Science Mission Directorate right now that encompass the use of the space station. These are the Research Opportunities in Space and Earth Sciences, or ROSES, and the Stand Alone Missions of Opportunity Notice, or SALMON.

Stern:  There are many places in the directorate portfolio that space station could assist with. Putting these things on the already existing station platform makes sense; it would allow many kinds of research to move forward faster. It is true, however, that while in many cases this will work, some kinds of research just aren’t compatible with station. For instance, since station is a human space facility—which by nature has a lot of outgassing—it is too dirty for some kinds of external investigations.

A Lab Aloft’s Jessica Nimon:  Do you see a difference in interest or a preference from users towards either platform?

Stern:  Most of what I’ve heard is that there are limited resources and too lengthy of a timeline for both station and suborbital research. Fixing this for both arenas would be a home run hit. I think users find that suborbital is easier to work with, due to the faster timescales. You could spend 5 to 10 years in the past getting something to fly on shuttle, and 2 or 3 years getting ready for a sounding rocket flight, but the commercial research and development cycle is usually less than a year—which is the very timescale the new suborbital vehicles are comfortable with for arranging flights.

If station can streamline its experiment manifesting and operations, with COTS [commercial off-the-shelf] and commercial cargo going back and forth, this may change. Now that we have great facilities aboard the space station, I’d like to see the use of existing hardware to get investigations going more swiftly. Otherwise, the timescale is too big a barrier to most users. The space station needs to adapt the customer’s needs, I think, to increase its user base.

Ruttley:  That has been the case in the past, Alan, but recent National Lab efforts have done a lot to improve the timeline. The National Lab has been successful in securing several agreements with government agencies, commercial users, and universities for the use of the space station. National Lab Manager Marybeth Edeen recently wrote a blog on this topic of improving the timeline to flight. Payload developers using existing hardware have been able to fly to station in as little time as six months . This is not the standard yet, but it is possible by pairing researchers with existing certified payload developers to really accelerate the process.

Stern:  I don’t think this is well known yet. With this changing for the positive, people need to know that the story has changed—let’s get the word out faster.

Ruttley:  That’s part of what we’re doing with this blog and with our other media efforts, like the stories we publish on our International Space Station Research and Technology Website. With the National Lab effort, over 50 percent of NASA’s assets are available to users. Perhaps the new non-profit management planned for National Lab will have additional ways to help get the word out.

Stern:  It’s good that the word is now starting to get out, but I think that more could be done to reach more users. Perhaps National Lab can send representatives to host workshops at the meetings and conferences scientists attend, whether industrial or academic. Just to talk to them and answer their questions on how to do business. Usually researchers are looking for money, too, since universities don’t usually have their own for investigations.

Ruttley:  I agree. I think the progress of communication and the streamlined process will continue to improve over the next few years. National Lab users do have to come up with their own research funding, but it’s been shown to be successful already. Just last year, the National Institutes of Health, or NIH, gave three awardees the money to do their research on the station; NASA will integrate and launch the investigations. While the National Lab and the Space Station Payloads Office are working on a streamlined process for launch and integration, research funding itself will always be the real issue for potential researchers.

A Lab Aloft’s Jessica Nimon:  Where do you see the future of suborbital research?

Stern:  Right now there are five firms building reusable suborbital systems: Virgin Galactic, XCOR, Armadillo Aerospace, Masten Space Systems and Blue Origin. Four carry people and payloads and one—i.e., Masten—carries only payloads. While the legacy NASA suborbital program flies infrequently, these commercial companies plan a far more frequent flight schedule. Between several times a week and daily, so we’ll go from roughly two dozen flights per year to hundreds per year. This will be a huge change to users’ access to space. It will be more affordable, too, maybe in the hundreds of thousands of dollars.

Ruttley:  The price of space station research is also coming down, because more and more experiment hardware can be reused. Companies such as BioServe or NanoRacks LLC offer excellent entry points for new experiments; you can do a lot on the space station in the hundreds of thousands range.

Dave Masten and Nadir Bagaveyev mounting the Ames payload rack onto the Xaero suborbital launch vehicle prior to a combined systems test.  
(Credit: Doug Maclise)

A Lab Aloft’s Jessica Nimon:  What is the operations duration for these experiments on suborbital flights?

Stern:  It’s really short. The typical time they have in microgravity is three to four minutes, which is the same as the current standard suborbital option. You can make a well thought-out experiment run in this timeframe, however, and then fly it again to get more data.

Keep in mind that there are multiple experiments running at once on a given flight. Each seat can hold racks capable of housing as many as 10 experiments—in just one seat! Virgin, for instance, plans to have six seats available on six vehicles, which they plan to fly on a daily basis. Add to this the other companies similar numbers and over time and with enough flights, suborbital has the potential to start returning many hours of research—if all the seats are full. The difference is that it comes in little blips, rather than all at once.

Currently the U.S. flies only one suborbital sounding rocket mission every two weeks. So as all of the various suborbital companies ramp up to full operations, we have a huge magnification of capability. We will have 10s of hours per week of available human research flight time, in addition to the onboard automated experiments. We are approximately four to five years away from full operations.

Ruttley:  This is a great way for short-duration experiments to get microgravity time, especially as demand for the space station’s long-duration capabilities grows. The suborbital option can potentially free up the station platform for investigations that need to run for longer than three minutes in a given flight. The two options really could work in concert, as they both meet different experiment needs, based on duration and capability.

I’d like to point out that the space station also uses racks, though of a different design and capability, to house multiple studies. These racks, which are housed in each module, can hold several investigations at once. As far as hands-on research, however, the space station at full operation gets 3,500 hours of crew time per year across the whole partnership. Our long-duration capabilities enable our investigations to run according to the needs of the research, whether in repeatable, short-duration experiments or in longer, ongoing operations. The crew can also replicate studies immediately, under the right circumstances, to look into unexpected phenomena.

A Lab Aloft’s Jessica Nimon:  Alan, can you comment on current funding for suborbital flights?

Stern:  There are two sources that come to mind. There’s a request for proposals from NASA’s Chief Technologist Bobby Braun’s office. In their flight opportunities program, they just completed final selection for suborbital payloads. It’s a very small program, but it’s a start. Along with that, they also did another request for proposals due June 24, 2011 to select launch service providers and integrators—and just announced IDIQ [indefinite-delivery, indefinite-quantity] contracts with seven flight provider firms.

A Lab Aloft’s Jessica Nimon:  Tara, turning to the space station now. Where do you see the future of station research going?

Ruttley:  When you look at where the space station is headed, there are really two areas to examine. The station as a whole and the National Lab. For the station at large, our international partners each have their own individual goals based on their governing agency and their scientific and political climates. NASA’s own space station research goals are dependent on our mission—currently this is driven by the NASA Authorization Act of 2010. So as a result, NASA focuses on areas of research that benefit space exploration, and relatively less fundamental physical and life sciences, though they are certainly not excluded.

The second piece is the U.S. National Laboratory, with a focus on Earth benefits. The combination of these elements drives the use of the space station as a whole. So the future of station is to continue to march towards these mission directives and goals. As more users engage in National Lab efforts, we will see more of those Earth benefits, as well. It is important to mention, however, that any research done on station can have Earth benefits, even if that is not the original focus of the investigation.

A Lab Aloft’s Jessica Nimon:  Where are your suborbital efforts headed next?

Stern:  We do a number of things related to suborbital flight at the Southwest Research Institute. We will launch our own payload specialists and payloads in this effort; currently we have nine launches funded and options on three more.

A Lab Aloft’s Jessica Nimon:  What do you hope to see ahead for orbital research?

Stern:  I think one of the things this decade will hopefully see—and which may amp up the space station program—is an effort to host commercial payload specialists. Whether in government or commercial taxis, these payload specialists could stay weeks or months on station using the National Lab. It’s hard to tell if this will happen, in the government world, but it would be a great program for the space station. We had something like this for shuttle and I think it would benefit station, as well.

Ruttley:  I think the real key is that efforts to have commercial companies flying people into space are going to be important for both research on the space station and other flight opportunities. With easy access to both station and abbreviated platforms like suborbital flights, scientists will finally be unconstrained and able to do experiments where they see fit. The discovery potential is amazing!

Tara Ruttley, Ph.D., is Associate Program Scientist for the International Space Station for NASA at Johnson Space Center in Houston. Dr. Ruttley previously served as the lead flight hardware engineer for the ISS Health Maintenance System, and later for the ISS Human Research Facility. She has a Bachelor of Science degree in Biology and a Master of Science degree in Mechanical Engineering from Colorado State University, and a Doctor of Philosophy degree in Neuroscience from the University of Texas Medical Branch. Dr. Ruttley has authored publications ranging from hardware design to neurological science, and also holds a U.S. utility patent.

Dr. Tara Ruttley
(NASA Image)

Alan Stern, Ph.D., is the Associate Vice President for Research and Development for Southwest Research Institute Boulder, Colo. He also served as NASA's associate administrator for the Science Mission Directorate in 2007-2008. Stern is a planetary scientist and an author who has published more than 175 technical papers and 40 popular articles. He has a long association with NASA, serving on the NASA Advisory Council and as the principal investigator on a number of planetary and lunar missions. Stern earned a doctorate in astrophysics and planetary science from the University of Colorado at Boulder in 1989.