With construction of the international space station (ISS) complete, 2011 is supposed to usher in full-scale scientific utilization of the $100 billion outpost. But uncertainties abound.

Congress has yet to approve NASA’s 2011 budget request, which includes some $80 million for space station utilization, for example. Meanwhile, the space shuttle is slated to retire this year and Congress and the White House lack a shared vision for what comes next.

U.S. President Barack Obama is seeking to nurture commercially operated space station crew taxis, an effort that, if fully funded, could come to fruition by 2016, advocates say. But lawmakers are insisting that NASA lay the groundwork for deep space exploration by building its own multipurpose crew capsule and heavy-lift rocket, and funding for that effort could come at the expense of the commercial crew initiative.

Mark Uhran is responsible for mapping out and implementing a research agenda for the U.S. part of the space station. Fifty percent of that capacity has been set aside as a national laboratory for non-NASA experiments, and Uhran is overseeing a competition to select a nonprofit entity to manage and operate that lab, with a contract award expected this summer.

Uhran spoke with Space News staff writer Amy Svitak.

How is space station utilization being affected by the fact that NASA’s 2011 budget request remains stalled in Congress?

The president proposed $50 million a year in both 2011 and 2012 for space station utilization, but the situation in Congress is preventing us from moving forward this year, so we’re exploring all options. It’s important that we make this transition as we move from assembly to utilization and we do it decisively. This is not the time to be hesitant or it could send the wrong signal that we’re not getting the return on assets from our $60 billion investment in the space station.

We also have $15 million a year that the president has proposed with this cooperative agreement with the nonprofit organization and roughly $15 million that the president proposed in functionality enhancements to the space station that will enable research.

Is there a percentage of station capacity set aside for commercial experiments?

It’s any organization other than NASA. Half of the U.S. capacity is set aside for the national laboratory uses. Those national laboratory uses will be a mix and that mix will be determined using a value-based process. Value is measured in two dimensions: For scientific research that value is measured in terms of citations to published reports. In the case of economic value it is measured in terms of the intellectual property produced. But they are of equal emphasis.

What does exclusive reliance on Soyuz for space station crew transport through at least 2016 mean for utilization?

The fact that Soyuz delivers the crew has no implications whatsoever on the progress of the research program or the crew time for the research program. Recall that the space station crews operate as a multinational crew, not as national members. So the crew time that’s available can be allocated against the uses, the requirements, of any one of the partners.

Can we expect to see a resumption of crewed U.S. flights to the international space station in 2016?

I don’t know the answer to that. I think that is a subject that is still being determined. Somewhere around the middle of the decade we hope to complete a transition to U.S.-provided crew vehicles and do that in a manner that overlaps with the existing Soyuz services until the new generation of U.S. crew vehicles is available.

What is the space station’s potential as a test bed for some of the so-called game-changing technologies the president hopes will change the economics of human exploration of deep space?

We have 24 pressurized sites for payloads inside and 25 outside in the unpressurized environment. We’re beginning to populate those sites with demonstrations that cut across technology areas. In communications we’re planning to deploy the CoNNeCT payload, which is designed to advance software-defined radio. We just launched Robonaut 2 and plan to conduct a robotic refueling demonstration using the Canadian special purpose dexterous manipulator, perhaps later this year or early next year. We’ll be looking at further improvements to the environmental control and life support system (ECLSS). We’re looking at a variety of visible and hyperspectral imagers because we have very high spatial resolution for remote sensing applications. We’re negotiating right now to add another propulsion test bed to station, this one potentially in the area of nitrous oxide fuel blends. And of course we have the ongoing discussions with Ad Astra Corp. on the Variable Specific Impulse Magnetoplasma Rocket. I think we can see a propulsion test bed in the future.

As NASA adopts a commercial model for station crew transport, are you reconsidering the six-month standard crew rotation?

If we were to shorten the durations from six months to three months, for instance, then the cost would double because we’d be putting twice as many crew in orbit. So we have to be very sensitive to the total program cost associated with the crew exchanges. That’s what you’re trying to balance, the degree to which you’re subsidizing the commercial model by increasing the flight rate of the vehicles vs. the increased cost to the agency of having to purchase the extra flights.

Other than cost are there downsides to more frequent flights to station?

It’s a busy spacecraft. Keep in mind we have Russian Progress and Soyuz vehicles, the European Automated Transfer Vehicle, the Japanese H-2 Transfer Vehicle, and in the next six months, the Dragon and Cygnus space capsules. So the traffic model, the density of the vehicles coming and going is an important consideration, as are the number of docking ports that are on the spacecraft. It’s a fairly complex problem to solve and not all the information is available yet to really solve that problem.

Space Exploration Technologies (SpaceX) is pushing to combine two of its three planned space station cargo-delivery demonstration flights this year. Do you support the proposal?

Those discussions are still under way. We’re very optimistic that the commercial cargo providers will be able to maintain their schedules to begin the commercial resupply service (CRS) missions to station. I believe the current projected schedule for SpaceX is to have the first CRS flight in December 2011. I certainly wouldn’t want to see anything compromise their ability to meet that schedule, and if there were any slippage to that schedule we would certainly want to see that it was minimized. The future use of the space station as a national lab is entirely dependent on the availability of both of the CRS vehicles. So we will ramp up our national lab program as those CRS services come on line.

Will the space station accommodate tourists if one of the commercial spaceflight hopefuls succeeds in lining up such a mission?

The space station’s ECLSS capacity will allow up to seven crew. Current vehicles, because of the three-seat nature of the Soyuz, limit us to six crew. Perhaps by the middle of the decade we’ll have a vehicle that allows four crew. Our requirements for crew time to support research and development are one of our most constraining requirements. So if any tourist proposals are received during that period they will have to compete directly against research and development requirements.

How serious is NASA about attaching a Bigelow Aerospace inflatable module to the space station?

We’re still in discussions with Bigelow Aerospace about deploying a subscale demonstrator of one of their inflatable modules on the station. The purpose of this discussion period is to understand what utilities will be provided at the interface and to manage the expectations of both NASA and Bigelow Aerospace so that we both succeed. We’re looking to do the demonstration as a test bed that will allow our crews to interact directly with the inflatable structure and conduct a variety of demonstrations and experiments related to inflatable structures.

Can you elaborate on plans by the National Science Foundation to deploy nano-satellites from station?

All of the non-NASA uses will transition to this new organization. If the National Science Foundation interest matures for deploying nano-sats on station, or from station or from visiting vehicles en route to station, then this would end up being managed by the nonprofit organization. We already do deployments from station for disposal. It’s definitely viable, but there are many issues that go with it. For instance we have a micrometeoroid and orbital debris environment that we don’t want to contribute to so we have to be sensitive to that. We also want to be sure that any deployments take place without any threats to the station itself. But this is all technically feasible.