SpaceX is gearing up for Starship's 13th test flight later this week

This flight will put Starship under higher pressure and test out new Starlink satellites in orbit.

The next test flight of SpaceX’s Starship spacecraft and Super Heavy booster could take off as soon as Thursday, and much of the hour-long mission will look a lot like the last Starship flight in May.

But there are a few key differences for this launch, set to occur during a launch window that opens at 5:45 pm CDT (22:45 UTC) on Thursday. The most notable change is the inclusion of real, functioning Starlink satellites inside Starship’s cargo bay. SpaceX previously tested the ship’s payload deployment mechanism using simulators mimicking the mass and dimensions of the company’s next-generation Starlink Version 3 broadband satellites.

This time—Starship’s 13th full-scale test flight and the second to use SpaceX’s newest version of Starship—technicians have installed 20 Starlink V3 satellites into the ship’s deployer, a system of pulleys and cables designed to eject a stack of satellites one at a time through an opening on the side of the spacecraft. The satellites will not be part of SpaceX’s operational network, but engineers will attempt to briefly establish laser communication links between the Starlink V3s and other spacecraft flying in low-Earth orbit. If successful, these links will validate Starlink V3’s interoperability with SpaceX’s previous generation of Starlink satellites.

As with all of SpaceX’s previous Starship test flights, the more than 400-foot-tall rocket will fly on a long suborbital trajectory arcing halfway around the world from the launch site at Starbase, Texas, to a predetermined location in the Indian Ocean. The flight of Starship and the 20 Starlink satellites will last a little more than an hour before they fall back into the atmosphere. The ship will target a controlled splashdown northwest of Australia, while the Starlink satellites will burn up during reentry.

A new ingredient

The flight plan for this week’s mission has just enough time in space for the Starlink satellites to extend their solar arrays and antennas. The satellites will also attempt to connect with ground stations in South Africa as they soar nearly more than 100 miles overhead.

What’s more, some of the Starlink V3s will host cameras to scan Starship’s heat shield and transmit the imagery down to engineers on the ground, according to SpaceX. The imagery will allow ground teams to “continue testing methods of analyzing Starship’s heat shield readiness for return to launch site on future missions,” SpaceX said in a post on its website.

Two of the Starlink mockups carried cameras for external imaging on the last Starship mission, returning views of the ship set against the ghostly darkness of space. This time, SpaceX has affixed cameras to six of the Starlink satellites. The imaging opportunity on this week’s mission will occur during nighttime, just as it did on the last flight.

The presence of Starlink V3s on the next Starship test flight is a harbinger for what’s to come. Fully-loaded Starships will be capable of launching up to 60 Starlink V3s on a single flight, unlocking a dramatic expansion of the network’s capacity. Each Falcon 9 launch with V2 satellites adds about 2.6 Tbps to the constellation. Pairing Starship with a full stack of V3 satellites will add 60 Tbps to the network.

Starship is designed to carry other kinds of satellites, too, including customer payloads and massive platforms for SpaceX’s proposed orbital data center network. The rocket is also designed for flights to the Moon and Mars. Starship is a core part of NASA’s Artemis program to land astronauts at the Moon’s south pole. But the first real operational missions for Starship will begin fielding SpaceX’s third-generation Starlink constellation, perhaps later this year if all goes according to plan.

Lessons learned

SpaceX must send Starship into low-Earth orbit before achieving any these lofty objectives. A near-perfect test flight Thursday would put the company on the cusp of an orbital launch. That, in turn, would allow Starship to move toward several important milestones, such bona fide satellite launches, in-orbit refueling demos, and the first return of Starship to Starbase, Texas, for future reuse.

One reason SpaceX isn’t attempting an orbital flight this week is Starship’s failure to complete one of its test objectives on the last launch, when the spacecraft was supposed to ignite one of its six Raptor engines for a brief burn in space. The spacecraft skipped the burn after a Raptor engine shut down prematurely during the launch sequence.

The rest of the ship’s flight went according to plan, culminating in a pinpoint splashdown in the Indian Ocean. It was the first flight of SpaceX’s Starship V3 debuting new, more powerful Raptor engines. But officials need confidence in the Raptor engine’s ability to reignite in the airless vacuum of space before proceeding to an orbital flight. In a worst-case scenario, a failed Raptor engine relight would strand Starship in orbit, leaving the enormous stainless steel vehicle to an unguided reentry that could become a risk to public safety.

The flight plan for this week’s mission includes the Raptor restart objective left unaccomplished in May. In an update posted to its website over the weekend, SpaceX did not address what caused the premature shutdown of the Raptor engine on Flight 12.

“The vehicle was able to demonstrate its engine out capability and reach its planned suborbital trajectory,” the company wrote on its website. “Several hardware and operational modifications have been made to address the interconnected causes with additional reliability improvements planned in upcoming versions of the Raptor engine.”

The other goal left incomplete on Starship’s last flight involved the splashdown of the rocket’s Super Heavy booster, or first stage, which lost control moments separating from the ship, or upper stage, a few minutes after liftoff. SpaceX intended for the booster to fly itself to a water landing in the Gulf of Mexico downrange from its launch base in South Texas.

“At stage separation on Flight 12, slight differences in engine startup on the ship caused the directional flip of the booster to be off by approximately 90 degrees,” SpaceX wrote. “The startup sequence has been modified to be more robust to timing variability and more reliably flip in the desired direction, which is done to increase overall performance.

“After stage separation and the flip, the Super Heavy booster attempted its boostback burn,” SpaceX continued. “Five of its 33 engines experienced issues when attempting to relight causing the boostback burn to end early. The Super Heavy on this upcoming flight has hardware modifications to improve relight reliability along with updates to engine alarms and aborts to match the conditions seen in the multi-engine flight environment.”

SpaceX will also use Flight 13 to continue experimenting with Starship’s heat shield, one of the most daunting technical challenges on the program. If the full rocket is to become rapidly reusable, as SpaceX intends, the heat shield’s thousands of ceramic tiles must not only protect the ship once. They have to be robust enough to handle the extreme heating of reentry over and over again without refurbishment or replacement.

“What’s single biggest remaining problem for Starship? It’s having the heat shield be reusable,” Musk said in February on the Dwarkesh Podcast. “No one has ever made a reusable orbital heat shield. The heat shield’s got to make it through the ascent phase without shucking a bunch of tiles, and then it’s got to come back in and also not lose a bunch of tiles or overheat the main airframe.”

“We have brought the ship back and had it do a soft landing in the ocean. We’ve done it a few times, but it lost a lot of tiles, and it … would not have been reusable without a lot of work,” Musk said. “If you want to be able to land it, refill propellant and fly again, you can’t do this laborious inspection of 40,000 tiles type of thing.”

On this flight, SpaceX will test out modified tiles and attachment mechanisms to gather flight data on different heat shield options. The shield will also have “load sensing tiles” to take measurements as the vehicle experiences higher dynamic pressure during ascent than on previous flights. This higher dynamic pressure will put “added stress on the tile attachments in exchange for increased payload to orbit capability,” SpaceX said.