On-orbit propellant depots have multiple potential uses — enabling exploration, increasing orbital lifetimes of satellites, developing more capable robotic missions, enabling other enterprises in space like debris clearing, and enhancing capability for national security assets. And fuel depots are absolutely essential for the long-term human settlement of space. If that is our goal, and I believe that it is, then we must pursue such depot technology with vigor, and we must do it now.

It seems that a proper, in-depth comparison between a super-heavy-lift exploration architecture and one of propellant depots and existing commercial launch vehicles would be an appropriate and critical step to selecting an affordable, sustainable and capable manned space exploration architecture. But it seems like the analysis may not have been done at NASA; otherwise it should be easy and straightforward to produce it and share it with Congress and the American people.

The announced super-heavy-lift system will be able to launch only once every four years, with the first crewed test flight 10 years from now, in 2021. Cost estimates range all over the map, from $25 billion to more than $60 billion over that same time period. And there is still no talk of the other parts of the spacecraft needed for deep-space human exploration, such as landers or space transport vehicles. On top of that, NASA does not have the best track record with keeping the actual costs of programs low.

Freeing up funds that would be spent on building a monster rocket, the biggest in history, would enable new, cutting-edge technologies to be developed. Projects that we have postponed for far too long, such as orbital debris removal and near-Earth object mitigation, would be within our grasp if we have the courage to reach for them.

The personnel at Johnson Space Center’s mission control and at Kennedy Space Center cannot wait. If we wish to make use of their knowledge, we must get them involved today by making NASA the primary customer for a robust commercial launch industry; otherwise they will retire or leave for other industries.

Kennedy Space Center launches rockets. Commercial-based solutions generate more launches, spreading out fixed costs, creating efficiencies and improving reliability. The monster rocket-based solution will generate two launches in the next decade. Johnson Space Center plans, practices and manages missions. Commercial-based solutions generate more missions, enabling iterative task performance to increase capabilities and confidence, and to routinize on-orbit operations. The monster rocket-based solution will generate two missions in the next decade.

Instead of fully funding the development work needed for NASA to be comfortable putting astronauts on our commercial rockets, we are wasting our borrowed money on monster rocket designs that incorporate narrow parochial political factors with a stubborn refusal to learn the lessons of the past.

Another plan is needed, and NASA provided a roadmap that can help us create an affordable, sustainable and flexible system. But now the agency seems to have lost that drive for greatness, and that trust in itself that can help create a truly remarkable future.

At the end of our July 12 House Science, Space, and Technology Committee hearing, “A Review of NASA’s Space Launch System,” I asked NASA Administrator Charles Bolden about the relative cost of using the technology of on-orbit propellant depots instead of relying on new large heavy-lift launch vehicles. He replied that he believed the studies had been done, and the fuel depot solution proved to be more expensive, and promised to get me the full answer.

As of this writing, I am still waiting for that answer. It has been more than three months, and NASA has not provided any analysis, or any data at all, that shows why depots are not a good solution or why they are more expensive.

New technologies have always given those who develop and implement them a distinct advantage. NASA has shown this time and again, overcoming seemingly insurmountable obstacles by creating and implementing ingenious solutions that are literally out of this world. We must trust ourselves to be bold once again.

In May 2010, at the NASA Exploration Enterprise Workshop in Galveston, Texas, Doug Cooke, associate administrator for NASA’s Exploration Systems Mission Directorate, presented NASA’s initial plans for meeting the human space exploration goals. The presentation included propellant depots and related technologies as a critical component of the architecture, which could potentially reduce mass requirements for a human Mars mission by 50 percent. That is an astounding number. This one technology could be the difference between an architecture that works and one that doesn’t.

NASA is, in fact, pursuing this technology right now on a small scale. In September, it selected the Boeing Co. of Huntington Beach, Calif., for the Composite Cryotank Technologies Demonstration effort, which is a follow-up to the August selection of four companies to develop concepts for storing and transferring cryogenic propellants in space. NASA stated that “[t]hese capabilities are important for the agency’s future deep space human exploration missions.”

Earlier this year I became aware of an outside analysis performed by Alan Wilhite and Douglas Stanley, whom then-NASA Administrator Michael Griffin selected to head up the NASA Exploration Systems Architecture Study in April 2005. This analysis showed very clearly that while there are some technical issues to overcome, a propellant depot exploration architecture, rather than a monster rocket architecture, would result in:

  • Tens of billions of dollars in cost savings, including lower up-front costs that fit within the revised budget profile.
  • Launches every two or three months, increasing the experience and focus of the work force, enhancing safety and improving launch reliability.
  • Multiple competitors for propellant delivery, driving down costs, ensuring available alternatives should a launch failure occur, and enabling noncritical-path international participation.
  • Reduction of critical path complexity, thus reducing potential delays and cost overruns.
  • Increased mission flexibility.
  • Sharing of fixed costs between programs, and other commercial customers.
  • Stimulated U.S. commercial launch industry.

It would, however, require a loss of some of the NASA control and oversight of launches — but that shouldn’t be a problem since the cargo is easily replaceable propellant.

It is clear that propellant depots promise a paradigm shift in space transportation. Instead of loading up all the supplies on the ground, we can pull up to the orbital gas station and refuel before our journey beyond Earth orbit.

It has been reported that NASA’s Human Architecture Team is actively working this issue. I hope that does not mean the agency is performing the initial analysis now, but even that is better than having done nothing, or hiding the information it already has in hand. We still have time to make a bold, smart decision before we waste billions of dollars digging another hole.

I look forward to reviewing NASA’s complete and balanced analysis of alternatives that contrasts super-heavy-lift with propellant depots plus commercial launch vehicles.

Ultimately, the use of depots is a path toward leveraging private resources — those of the commercial companies and their other customers — to help meet national goals. By spreading the risk between launches, and spreading the costs between multiple users, we can create the future that we all want — long-term human settlement of space under the banner of freedom.


Rep. Dana Rohrabacher (R-Calif.) has served on the U.S. House Science, Space and Technology space and aeronautics subcommittee since 1989 and was its chairman for eight years.