When it comes to deciding the future of human spaceflight, a rational approach would be to begin with a vision and objectives, then determine policy guidelines, define a series of increasingly ambitious destinations, develop design reference missions and requirements, and develop candidate architectures that meet the requirements, perform apples-to-apples cost, reliability, safety, performance and risk analyses to allow a decision maker to make an informed decision.

This approach was largely followed in the 2004-2005 timeframe by the White House and NASA, through the Vision for Space Exploration and the Exploration Systems Architecture Studies, and the resulting decisions had bipartisan congressional support. Despite this purported support, annual and future NASA exploration budgets have been reduced every year since.

With the release of the final report of the Review of U.S. Human Space Flight Plans Committee — known as the Augustine committee after the panel’s chairman, former Lockheed Martin chief Norm Augustine — this process has begun again, but it has only just begun.

The Augustine committee report outlines a number of options and approximate budgets to support decisions that must be made by the White House, NASA and the Congress in the near future. Unfortunately, the Augustine committee and staff, by necessity, used vehicle cost and performance estimates from a variety of sources and did not even examine relative loss-of-crew probabilities. Development cost profiles for the Ares 5 heavy-lift rocket and the Orion Crew Exploration Vehicle were often stretched out over many years to fit within budget profiles without regard to the feasibility of the underlying program milestone phasing and added costs. Costs of some major elements, such as “commercial” crew systems, are understandably rough-order-of-magnitude estimates that are not based on bottoms-up costing of specific vehicles. Despite these shortcomings, the Augustine committee results provide a useful assessment of alternate visions, policy approaches, potential destinations and approximate budgets to support some of these alternatives. However, it was not, and did not purport to be, a technical effort that defined systems to perform specific mission requirements or that developed bottoms-up cost, safety or reliability, estimates that could credibly be used to select between specific architecture solutions.

This work remains to be done.

Based on the work done to date, the White House should immediately make decisions concerning:

  • International space station extension through 2020.
  • Space shuttle extension into 2011 and/or beyond 2011.
  • Beyond low Earth orbit (LEO) human mission destinations and time frames.
  • Out-year available budgets.
  • General policy toward commercial and international crew transport to the space station.
  • NASA should then be allowed to define design reference missions and requirements and perform an architecture study to:
  • Perform apples-to-apples cost, safety and risk comparison of Augustine-defined and additional options.
  • Revisit Evolved Expendable Launch Vehicle and shuttle-derived vehicle trade studies.
  • Perform definition and economic analysis of propellant depots.
  • Determine the true cost and risk of “commercial” crew transport.
  • Examine the work force impacts of the options.
  • Define more detailed budgets to support the 2011 budget cycle.

Making decisions about canceling or beginning multibillion dollar programs at this point based solely on the Augustine committee results without performing these additional analyses would be irresponsible.

Some options presented do not appear to actually fit within the assumed budget wedges, and many potentially attractive options were not included in the Augustine report. For example, options that include Ares 5 Lite, Orion, “commercial” crew and additional technology funding were made to fit within the budget by reducing the near-term budgets for Ares 5 Lite and Orion to unrealistic levels and stretching out the development over 15 years. The longest the Ares 5 and Orion development can reasonably be extended is about nine years — and even that adds additional costs. In addition, no options are presented that include Ares 1 and extending space station operations through 2020. If development of systems needed for mission beyond low Earth orbit is deferred, the Ares 1 and Orion budgets can actually fit within the worst-case constrained Augustine report budgets  with some margin. They certainly fit within the less-constrained Augustine report budgets with additional non-LEO exploration systems. A choice between Ares 1 and extending space station operations is not necessary.

Once a destination, mission and requirements are selected, the architecture options reduce to three basic families: Ares 1-based approaches, Ares 5-based approaches and non-shuttle-derived approaches.

Keeping Ares 1 enables the option of developing Ares 5 or other shuttle-derived vehicles, for exploration at a later date when the budget allows, since the space shuttle solid-rocket boosters, J-2X engine and ground systems are preserved. Although it was not presented to or considered by the Augustine committee, the Ares 1 upper stage can be re-fueled on orbit and deliver as much payload to non-LEO destinations as an Ares 5. Two re-fueled Ares 1 vehicles could be used to accomplish a human Near-Earth Object mission, and an Ares 5 could always be built later for human Mars missions.

Eliminating Ares 1 and accelerating the development of an Ares 5 Lite or other shuttle-derived vehicle could enable cost-effective exploration beyond low Earth orbit in a timeframe determined by the available budget, while preserving the NASA work force in the near term. However,  it is difficult to fund “commercial” crew, even in a less constrained budget — especially if a new technology program is desired. A choice between “commercial” crew and shuttle-derived vehicles will likely be necessary. This approach could allow the Ares 5 Lite, or another shuttle-derived vehicle, to transport crew to the space station once available and relies on the Russian Soyuz in the interim.

Eliminating Ares 1 and Ares 5 and all shuttle infrastructure could save NASA future costs that could eventually be applied toward exploration by significantly reducing the work force and fixed infrastructure costs. This approach would require “commercial” crew transportation for space station and exploration missions, and would likely require propellant depots to compensate for the smaller commercial launch vehicles. This was not politically feasible in 2005, but perhaps could be today. Additional detailed cost analysis is required, however, to determine the true cost of a procurement that would require paying for two human-rated capsules and launch vehicles — an undertaking the Augustine committee rather optimistically estimated would cost the government just $5 billion.


Douglas Stanley is a member of the research faculty at the Georgia Institute of Technology. He led NASA’s Exploration Systems Architecture Study in 2005.