Why NASA linked launch affordability to space solar power in 2015

What the work claims

The presentation claims that large space programs, including space solar power, are blocked less by physics than by economics. Zapata asserts that both Mars exploration and space solar power need more affordable space transportation and more affordable spacecraft, and that neither is likely to arrive under the budget trajectory NASA was on in 2015.¹ The 2015 Human Exploration and Operations budget is shown as $8,185 million, with the NASA budget growing at an average compound rate of 1.535 percent per year since 2003.

The central argument is that NASA should act as an investor and partner rather than as a traditional cost-plus contractor manager. Zapata cites the Commercial Orbital Transportation Services and Commercial Resupply Services programs as an existence proof: the partnership structure, he says, aligned incentives, spread risk to the private sector, and produced launch services at a small fraction of the cost predicted for business-as-usual procurement.¹

How it works

The mechanism is a shift in acquisition architecture, not a propulsion or power technology. Zapata's proposed partnership model includes several linked features: milestone-based fixed payments rather than cost-plus contracts; early commitment to buy future services in block contracts; selection of at least two competing providers to preserve pressure through operations; a small government management office; and bundling of spacecraft and launch services so that the private partner internalizes system-level tradeoffs.¹ The goal is to move risk from the government to the contractor and to give the contractor a non-government market to amortize development costs.

The COTS/CRS example is the load-bearing evidence. Zapata's slide states that traditional business-as-usual development of Falcon 9 was predicted to cost $4.0 billion to $1.7 billion, while the actual COTS/CRS investment was roughly $300 million, inclusive of private investment and excluding Dragon.¹ The comparison comes from a 2011 Commercial Market Assessment for Crew and Cargo Systems prepared under the NASA Authorization Act of 2010.

Applied to space solar power, the argument is that modular assembly, power transmission, and launch services can be matured through similar partnerships without waiting for a single massive government program. Zapata quotes John Mankins' "The Case for Space Solar Power" to the effect that many technology and system-level demonstrations can be accomplished without new space transportation.¹ The presentation therefore treats launch cost as a binding constraint but not as an absolute prerequisite for early technology maturation.

The strongest case

The strongest case for the argument is that the COTS/CRS model did produce operational cargo launch services at costs well below historical NASA-developed vehicles, and that the 2015 launch market was already showing signs of the same pressure with Falcon 9 and emerging reusable-vehicle efforts. If launch and spacecraft costs are the dominant terms in any space solar power life-cycle cost model, then lowering them is the highest-leverage policy action NASA can take, more so than funding incremental improvements in solar cell efficiency or beaming hardware.

The presentation is also careful to avoid a pure technology-development framing. By separating the near-term maturation of assembly, transmission, and modularity from the long-term need for cheap launch, Zapata offers a politically realistic path: NASA can invest in demonstrations that do not require a fully reusable heavy-lift fleet, while market competition drives launch costs down in parallel.¹

Where a skeptic should push

The most important pushback is that the COTS/CRS cost comparison is not a controlled experiment. The predicted $4.0 billion to $1.7 billion business-as-usual figure is an estimate of what a traditional program might have cost, not an observed alternative history. The roughly $300 million actual figure is also partial: it excludes Dragon, includes private money, and is taken from a 2011 market assessment rather than an audited cost account.¹ The ratio is striking, but the exact savings to the government are less certain than the slide implies.

A second issue is selection bias. COTS worked for ISS cargo because there was a near-term, well-defined customer with predictable demand and a willingness to accept fixed-price risk. Space solar power in 2015 had no such customer. The private market for space solar power services did not exist, so the mechanism that aligned SpaceX incentives, a guaranteed service contract, would not operate in the same way for an SBSP partnership.

Third, the presentation treats launch cost as a single lever, but space solar power has multiple cost-sensitive links: on-orbit assembly, power beaming, ground rectenna construction, and operations at geostationary orbit. Even dramatic launch-cost reductions leave the other terms in the levelized-cost equation.¹ The argument that Mars and SBSP face the same barrier is rhetorically useful, but the technical and market risks differ.

What it means for power in space

The non-obvious implication is that space power economics depend on the structure of the buyer-seller relationship as much as on hardware performance. Zapata's presentation frames NASA's role as investor and anchor customer, not as system architect.¹ For power-in-space programs, this means the procurement model is itself a design variable. A fixed-price milestone contract for a modular power-transmission demonstration, for example, may advance the technology more effectively than a cost-plus study because the contractor bears integration risk and has an incentive to reach flight status.

The genuine threat is that the COTS analogy can be overstated. Space solar power is not ISS cargo: it lacks a committed buyer, a clear regulatory path for power-beaming spectrum, and a revenue stream to amortize private investment. If policymakers treat partnership structure as a substitute for technology maturation, they could fund contracts that produce vehicles or platforms without producing a credible path to grid-competitive electricity.¹ The specific risk is that the government pays for capability demonstrations that no utility will buy.

The opportunity is that the 2015 framing is compatible with a staged approach to space power. Near-term demonstrations of wireless power transmission, modular assembly, and power management can be funded through partnerships even while launch costs remain high. Each demonstration reduces technical risk and, if successful, builds the case for later investment in the launch infrastructure needed for a full system.¹ The opportunity is real only if the staged work is bounded and measured against metrics that are independent of the partnership savings claim.

The bottom line

What is established is that a NASA analyst argued in 2015, with budget data and the COTS/CRS precedent, that launch and spacecraft affordability are the binding constraints on space solar power and that public-private partnerships are the most viable policy response. What is not established is that the COTS model would produce comparable savings for SBSP, because SBSP lacks the near-term customer demand and fixed-price risk environment that made COTS work. Confidence in the diagnostic part, that launch cost dominates space solar power economics, is moderate to high. Confidence in the prescription, that partnership structure alone can replicate the COTS cost reduction, is low to moderate. The claim would be strengthened by audited comparisons of government and private investment in COTS and by a specific SBSP demonstration program designed with fixed-price milestones. It would be undercut if launch costs failed to fall or if SBSP demonstrations continued to require cost-plus government funding.