Defense bills, like those related to agriculture and manufacturing, tend to be filled with special carve-outs and privileges for individual firms.  The recently passed 2019 National Defense Authorization Act (NDAA) is no exception.  Among its many provisions is one that effectively protects SpaceX, Elon Musk's brainchild, from competition from other rocket-manufacturers.

The provision in question, Section 1603, requires the secretary of defense to submit written justification for utilizing "space launch services for which the use of reusable vehicles is not eligible."

In other words, by introducing obstacles to the Pentagon's future use of expendable rockets, Congress created for the military a default preference for reusable rockets.  The problem?  SpaceX is the sole domestic supplier of reusable rockets.

Given NASA's track record with reusable rockets and SpaceX's numerous budget and design issues, this preference isn't justified.  For Congress to make the most of this new layer of oversight, it should hold SpaceX to a much more exacting standard of quality and cost-effectiveness.

Though conceptually, reusable rockets are revolutionary, so far, their execution has been less than stellar, threatening both our national security and our budget.  NASA's partially reusable Space Shuttle was retired in 2011, but not before it delayed approximately 40% of its missions, ballooned costs by over 15,000 percent from original projections, and suffered two major disasters in which 14 astronauts died due to quality control failures.

So far, there is no reason to expect SpaceX's reusable rockets to fare any better.

SpaceX has delayed rocket launches on several occasions.  As one example, Falcon Heavy was intended to launch in 2013 or 2014, but the launch didn't occur until February of this year.

SpaceX's launches aren't without their problems, either.  In June 2015, after SpaceX received a $110-million contract, one of its Falcon rockets exploded while on a mission to resupply the International Space Station.

Then, in September 2016, after SpaceX received a $62-million grant from the government, the Falcon exploded and in the process destroyed a $205-million Facebook satellite.  The explosion was likely caused by SpaceX's dangerous "load and go" fueling strategy that some aerospace experts warn against – a strategy SpaceX uses to this day.

Several recent government audits of SpaceX raise additional concerns about the reliability of its rockets.  In a December 2017 report, the Department of Defense inspector general found that SpaceX had 33 major unconformities – 50% more than its leading competitor.  A Forbes summary of the report noted the company's failure to comply with requirements for everything from reviewing designs to calibrating their tools.  An additional January 2018 report released by the NASA Aerospace Advisory Panel echoed the findings, underscoring concerns about SpaceX's ability to safely transport astronauts to space.

The cost of SpaceX's reusable rockets also continue to grow.  NASA's inspector general released a report highlighting the 50% increase in the cost for some of SpaceX's launches.  With each new report, it becomes increasingly clear that SpaceX's reusable rocket technology is, for now, dubious at best and a suboptimal use of taxpayer dollars.

The trajectory of Elon's other major company, Tesla, provides a preview of one potential future for SpaceX.  Tesla too has missed numerous production targets despite receiving millions in subsidies and has yet to turn a profit.  Elon's recent antics have further alarmed Tesla's investors.  The SEC is currently investigating Musk's potential violation of securities law in a tweet – a move possibly caused by his public relationship drama.

Congress and the Pentagon have a responsibility to properly assess the safety and cost-effectiveness of SpaceX's rockets.  Before making any additional grants to SpaceX, it should press the company for its data.  The best available evidence suggests that Congress was premature to nudge the Pentagon to prefer reusable rockets.  To prove otherwise, it will need to, at the very least, subject SpaceX and reusable rockets broadly to a much greater level of scrutiny.

Tammy Winter is a freelance author and former program associate for the Mercatus Center at George Mason University.  She currently works at Stand Together and can be reached at tammy.a.winter@gmail.com.