SpaceX’s Rocket Engine Test Sees Stream of Sparks Fly Out As Testing Continues In Texas

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With two months left until 2024, the pace of Starship testing at SpaceX’s multiple facilities throughout Texas has increased. SpaceX seems to be testing upgrades to its Raptor 2 engine for the world’s most powerful rocket, while at the same time, a new test has taken place at the Starship launch pad in Boca Chica, Texas. Footage gathered by local media shows that the fire suppression system, installed earlier this year, was tested at a higher power level to meet the full brunt of the 33 Raptor 2 engine firing at launch.

Simultaneously, footage from SpaceX’s facilities in McGregor shows that Raptor engine development is in full flow. During the third week of October, SpaceX tested a Raptor 2 engine multiple times, and based on the footage, it could be possible that the tests are part of a process to improve the engine’s key performance parameters, build materials or subcomponent systems.

Testing Activity Picks Up The Pace In Boca Chica, Texas as SpaceX Tests Multiple Starship Vehicles

SpaceX’s development approach for its Starship program has allowed the firm to have multiple rockets in production and testing simultaneously. The full Starship stack comprises two rockets, the first stage Super Heavy booster and the second stage Starship spacecraft. One test conducted late last week saw SpaceX fire up a second stage Starship Raptor engine to demonstrate a key capability for NASA’s lunar landing system.

A couple of days later, SpaceX fired up its water deluge system more than two months after an initial test. This time, the test featured an extra storage tank and saw more water flow out to match the scale required to protect the launch pad from damage during a Starship launch.

SpaceX has had to follow a tedious process for its launch site to ensure rocket launch activity does not affect the ecosystem surrounding the launch pad. Cooling the pad and diverting the force of the engines away from the concrete and steel structures requires thousands of gallons of water, and even though this gets converted into steam, an excessive flow of water to the surrounding areas during the full life cycle of the Starship program should carry some risks to wildlife.

This latest launch site fire suppression system test follows a visit by the Fish and Wildlife Service officials to the test site, where they spent some time evaluating the areas surrounding Starshp’s launch pad. Getting approval from the government launch agencies has been a key bottleneck for the Starship program, and SpaceX has spent months waiting for agencies such as the FWS and the FAA to get environmental clearance for launch activities.

The FWS evaluation is part of a broader environmental assessment overseen by the FAA, and even though FAA officials were optimistic earlier this year in stating that the second Starship flight could have taken place by November at the very least, chances remain that it gets delayed to 2024.

However, this hasn’t stopped SpaceX from moving forward with developing all components of its rocket. Starship’s most important part, its engine, saw significant upgrades after the April test flight, and some recent Raptor tests from McGregor show that SpaceX might be busy upgrading the performance of its rocket engines.

Fresh footage from the rocket engine test stands shows sparks flying out from the engine’s nozzle bell as it pumps out thousands of pounds of thrust. These sparks are met by the characteristic green flames in another test, indicating that SpaceX might be pushing the engine to its performance limits once again.

Sparks fly out during engine testing or flight operations for several reasons. While they are not a characteristic of SpaceX’s engine systems, including the Merlin engine powering the Falcon 9 rocket, they are common on other engines, such as the Rutherford for Rocket Lab’s Electron rocket. According to Rocket Lab’s chief, Peter Beck, sparks are normal and generally result from carbon buildup on a rocket engine’s igniters.

Igniters work together with the combustion chamber on an engine to set its propellant mixture on fire,  and for the Raptor engine, the Raptor 1 and Raptor 2 feature significant igniter upgrades. For the Raptor 2,the igniters are  a “secret sauce,” which is located inside the rocket engine, according to SpaceX’s CEO Elon Musk. Torch igniters typically generate a spark to light the propellants, and while the Raptor 2 does not use them for its combustion chamber, they were still present in its oxygen and methane powerheads as of July 2022.

The powerheads are responsible for pressurizing the fuel and oxygen at levels necessary for their combustion in the chamber, and they achieve this by igniting some propellant mixture to drive turbines. Green flames during a test typically indicate that the engine’s chamber has melted due to excessive heat. Higher chamber pressures lead to higher thrust per unit of propellant, which allows engineers to save on weight as less propellants are needed to generate more power.

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