If Space Exploration Technologies Corp's SpaceX (SPCX) Starship reaches space on Thursday, the headlines will likely call the mission a success. JPMorgan analyst Seth Seifman thinks investors should wait a little longer.

According to JPMorgan, the real test of Starship Flight 13 won't end when the rocket leaves the launch pad—or even when it returns to Earth. The bigger question is whether SpaceX is getting closer to flying the same rocket again, and again, and again.

That's the milestone that could ultimately determine whether Starship transforms from an engineering marvel into the economic engine behind SpaceX's long-term growth.

Launching Isn't The Hard Part

Flight 13 is expected to carry 20 Starlink V3 satellites, test improvements to the Super Heavy booster and attempt an in-flight relight of one of Starship's upper-stage engines. The mission also marks the second flight of the company's latest V3 configuration, which is expected to power future Starlink deployments, lunar missions and eventually next-generation AI satellite infrastructure.

Those are important milestones. But JPMorgan argues they're not the ones investors should focus on.

Instead, Seifman says one of the biggest questions remains how quickly SpaceX can inspect, refurbish and fly Starship's second stage again after surviving the extreme heat and stress of re-entry. That makes the performance of the vehicle's thermal protection system—and the time required to prepare it for another mission—arguably more important than whether Thursday's launch goes according to plan.

The Economics Of Reusability

SpaceX has never hidden its ambition.

The company wants to launch Starship dozens of times next year, hundreds of times in 2028 and eventually thousands of times annually. That vision depends less on building rockets than on rapidly reusing them.

The distinction matters for investors.

A rocket that flies once remains an expensive engineering project. A rocket that can be turned around quickly begins to resemble an airline fleet—capable of lowering launch costs, increasing capacity and dramatically improving the economics of satellite deployment.

That's why JPMorgan says future milestones such as catching Starship's upper stage with the Mechazilla launch tower will be impressive, but not necessarily the most important. The bigger question is how soon that same vehicle can fly again.

The Next Milestone To Watch

Flight 13 will provide plenty of data on Starship's technical progress, from engine performance to heat-shield durability.

But the next catalyst for investors may arrive well after the launch webcast ends.

If SpaceX can prove that Starship's upper stage can be recovered, refurbished and returned to service on increasingly shorter timelines, it would strengthen the business case behind one of the company's biggest long-term ambitions: making access to space as routine as commercial aviation.

That's the launch after the launch that Wall Street may ultimately care about most.