Why SpaceX Is Confident Starship’s Next Launch Will Be Different
The first integrated test flight of Starship lasted just under 4 minutes before the flight termination system activated and destroyed both the booster and upper stage. This cut the flight test short, however, the vehicle had managed to clear the pad and provide minutes of invaluable flight data to teams at SpaceX. It also revealed a few problems that would need to be addressed before the next attempt.
This leads us to today as a new booster and upper stage are stacked on the launch pad patiently waiting for FAA approval. This being said, in the time since the last flight, changes have been made to every aspect of the launch process. This includes Stage 0 infrastructure, physical test article upgrades, new hardware, and even alterations to the flight profile.
On that first flight, one of the biggest mission objectives was successfully completing stage separation. While the vehicle couldn’t complete that mission event, SpaceX is confident this time around things will be different. Here I will go more in-depth into all these changes, what SpaceX learned between the first flight and now, how much longer until FAA approval, and more.
Different Outcome
During the first flight, there were a few issues that stuck out as the main reasons for failure. The Raptor engines, for example, experienced multiple problems throughout the test. Multiple engines were disabled during the launch sequence and even more failed during the flight. Eventually, the spacecraft also lost thrust vectoring control of the Raptor engines, which led to the rocket starting an out of control tumbling motion.
The next issue had to do with the stage separation method. On the first flight, SpaceX had a unique stage separation design connecting Starship and Super Heavy. Here in order for the two to disconnect, a flip maneuver was necessary using the inertia of the launch vehicle. In other words, there was no pusher separation mechanism like the Falcon 9 where springs push the second stage away. During the flight attempt, the two vehicles never separated and eventually were destroyed while still attached to one another. The vehicle also sustained fires from leaking propellant in the aft end of the Super Heavy booster, which eventually severed connection with the vehicle’s primary flight computer.
The final main issue was the pad which we saw shoot debris in the air and carve out a significant crater under the Orbital Launch Mount. Prior to the launch, SpaceX had completed static fires on the special FONDAG concrete. These static fires were partial thrust and gave the company the confidence that it would survive at least one launch attempt. In addition to damage under the mount, debris also hit surrounding infrastructure. Interstingly, likely the worst result of the pad damage was delays in FAA approval due to environmental concerns from a few agencies.
With all this in mind, SpaceX managed to determine these different issues either immediately following the launch or relatively soon after. This gave them months to fix and change any details that they belive would increase the chances of Starship completing the next integrated flight test. In an update earlier last month, the company specifically addressed some of the main problems that occurred on the first flight.
Here they are quoted saying, “SpaceX has built and tested a hot-stage separation system, in which Starship’s second stage engines will ignite to push the ship away from the booster. Additionally, SpaceX has engineered a new electronic Thrust Vector Control (TVC) system for Super Heavy Raptor engines. Using fully electric motors, the new system has fewer potential points of failure and is significantly more energy efficient than traditional hydraulic systems.”
For stage separation, as mentioned in the statement, the method has changed completely from the first flight. SpaceX has added a relatively small ring between the upper stage and booster that acts as a flame diverter when the upper stage ignites its engines. The company also made significant upgrades to the orbital launch mount and pad system in order to prevent a recurrence of the pad foundation failure observed during the first flight test. These upgrades include significant reinforcements to the pad foundation and the addition of a flame deflector, which SpaceX has already tested multiple times.
Even the flight profile will be just a little different than the first. Not long after the first Starship launch Elon was quoted saying, “For the next flight, “we’re going to start the engines faster and get off the pad faster.” From engine start to moving Starship “was around 5 seconds, which is a really long time to be blasting the pad.” Going to try to cut that time in half” he said. This means we can expect to see Starship ignite its engines and be off the ground in only seconds. This in combination with the pad changes should help avoid any pad damage. All of these changes are why Starship’s second test flight is expected to have very different results than the first.
FAA Approval
At the same time as SpaceX has been making these various changes and upgrades, the company has also been working closely with the FAA to try and get launch approval. Yesterday SpaceX tweeted saying, “Starship stacked at Starbase ahead of flight, team continues to work with the FAA on a launch license.” The last news we heard in regard to this process was not the best.
Specifically, a new statement revealed the FAA has given the Fish & Wildlife Service (FWS) 135 days to review changes that SpaceX made to determine if they are acceptable. In relation to SpaceX, they said in a statement, “For SpaceX reinitiation with FAA we are considering the operation of a water deluge system. The Service is currently discussing the project details with FAA staff to understand the extent of the new effects. Once the Service reviews the FAA’s final biological assessment and deems it complete, a consultation will be reinitiated. We have 135 days to issue a final biological opinion. At any time the FAA and the Service can agree to extend that time if for some reason we need to gather further information or new information is presented” they said.
After the first launch, the U.S. Fish and Wildlife Service was not happy with the result. They were quoted saying that “a 3.5-acre fire started south of the pad site on Boca Chica State Park land”. They also said that “Impacts from the launch include numerous large concrete chunks, stainless steel sheets, metal and other objects hurled thousands of feet away along with a plume cloud of pulverized concrete that deposited material up to 6.5 miles northwest of the pad site.”
While not ideal, it’s possible that a launch license will be granted relatively soon. In early September, the acting head of the Federal Aviation Administration said that the agency could advance a launch license as early as next month for Starship. She was quoted saying, “We’re working well with them and have been in good discussions. Teams are working together and I think we’re optimistic sometime next month” she said. Obviously approval this month would be a big deal and allow SpaceX to get this upgraded vehicle off the ground.
In terms of what SpaceX still needs to do before launch day, the list is practically empty. For the most part, the only pre-launch requirements left don’t happen until right before the launch. Installing the FTS for example is a relatively last-minute task as you don’t want explosives tied to the rocket for longer than they need to. This is also an area that SpaceX will be paying extra attention to as it experienced some issues on the first launch. During flight, the Autonomous Flight Safety System (AFSS) automatically issued a destruct command, which fired all detonators as expected, after the vehicle deviated from the expected trajectory, lost altitude and began to tumble. There was however an unexpected delay in the termination system which they have since addressed.
In reality, there were far more changes to Starhip and its supporting systems than I mentioned. A few weeks ago we saw the list released by SpaceX which showed 57 out of 63 corrective actions that the company had completed. Some of the biggest include booster leak mitigation, Raptor leak mitigation, booster reliability improvement, safety system, and pad design/process. For the most part this all matches up with what SpaceX has said and been working on for the past couple of months. Some of the corrective actions listed were especially interesting such as “90+ cameras added to detect leakage during operations.”
At the end of the day, these integrated test flights are quite ambitious are allow SpaceX to quickly find and fix issues with the Starship system. In a statement, SpaceX said, “Testing development flight hardware in a flight environment is what enables our teams to quickly learn and execute design changes and hardware upgrades to improve the probability of success in the future. We learned a tremendous amount about the vehicle and ground systems during Starship’s first flight test. Recursive improvement is essential as we work to build a fully reusable launch system capable of carrying satellites, payloads, crew, and cargo to a variety of orbits and Earth, lunar, or Martian landing sites” they said.
Conclusion
SpaceX is closing in on the second launch of Starship. While we are still waiting for FAA approval, teams have been very busy changing everything from the physical rocket to the pad and even the fight profile. We will have to wait and see how it progresses and the impact it has on the space industry.