After the most recent integrated flight test and Super Heavy splashdown in the ocean, we started to hear about the possibility of a booster catch attempt on the next flight. This mainly came from Musk through different interviews and general comments. Just yesterday, however, the FCC revealed a permit for Flight 5 which mentioned a possible catch attempt on the next flight.
Comments from Musk are one thing, but while still not confirmed, this filing is even more official and suggests the company is very serious about bringing this booster back to the launch site for a landing in the near future. Here I will go more in-depth into the new permit, the dates provided, the catch process, and more.
FCC Permit
Yesterday, the Federal Communications Commission (FCC) not to be confused with the FAA, released the application for Special Temporary Authority (STA). In this report, they are first quoted saying, the STA “is necessary to authorize Starship Test Flight 5 vehicle communications launching from Starbase TX. Application includes a sub-orbital first stage booster and a second stage. Trajectory data will be provided directly to NTIA, USAF, and NASA. Launch licensing authority is FAA Office of Commercial Space Transportation.”
More importantly, within the purpose of operation section, they say, “Launch vehicle communications for test flight mission launching from Starbase TX. The first stage booster will either return to the launch site or perform a controlled water landing.” Obviously, based on that statement it’s clear that there are still options in the booster’s trajectory and plan however this is a good sign in favor of a catch attempt. Even though these FCC permits are usually quite broad and issued on just about a regular basis, they do partially factor in the company’s plans regarding both the flight profile and even the launch date.
By now, Musk has mentioned multiple times on different platforms that he believes SpaceX could definitely attempt a catch on IFT-5. More realistically, in an interview, he said, “I need to regroup with the team and confirm that there aren’t any other known issues, but I think given that the booster came to a precise location, came to a potentially zero velocity landing in the ocean, I think we should probably try to catch it with the tower arms on the next flight.” With this in mind, it comes down to the team’s confidence in the booster’s capability and even the timeline of relevant infrastructure and future Starships. Not far from the main launch tower, a second is under construction. Some think that SpaceX won’t attempt the catch until this second tower is done which likely won’t be until after the next flight. While logical, SpaceX is quite ambitious with their testing and willing to take on certain risks.
You also have to consider some of the features of a booster catch attempt that could help control the process and minimize damage. For one, Super Heavy is capable of hovering which gives time for it to properly position itself and make contact with the catch arms. The added engine out capability as partially demonstrated in the last flight also helps its odds when performing its landing burn. At the same time, it’s a massive metal booster that could easily cause some significant damage to the tower, OLM, or the surrounding infrastructure if it suffered a major failure. The various outcomes and probabilities is what SpaceX needs to consider as they decide whether or not to go through with it on the next flight. The mention of a catch attempt in the FCC report showcases a serious interest and consideration.
In regard to the timeline, the report shows an operation state date of July 19th and an end date of January 19th of next year. A 6-month period which is common and basically guarantees enough time for the next launch. That being said, SpaceX plans to launch in the near future. With the earliest date in this report being the 19th of next month, a launch around then or early August is likely what the company is aiming for. At the same time, besides the first available opportunity, these FCC filings don’t also provide the most insight. On the last launch for example, the date range went from late April until late October. IFT-4 didn’t end up happening until early June so about a month and a half after the earliest opportunity. SpaceX has been decreasing the time between Starship launches going back from IFT-1 to IFT-4. The last gap was less than 3 months and SpaceX is confident they can beat that for IFT-5.
With all this in mind, it’s important to clarify that nothing has been fully confirmed yet. We do however have Musk continually talking about catching the booster and now some official documents listing the catch attempt as an option. In only the next month or so SpaceX should be close enough to the flight that a decision will have been made and announced. At that point, we could start to see the final preparation and work on whatever decision is made.
The Landing Process
Assuming they do end up trying to catch Starship’s booster on the next flight, they have to do a few things perfectly. Looking at the external footage of the booster splashdown in the most recent flight gives a good perspective. Based on how well it went in general, and especially when compared to IFT-3, SpaceX is likely going to jettison the hot stage ring again. From there the control and even the orientation of the booster needs to be perfect as it approaches the ground.
When it’s right around 1km high it will ignite 13 engines, the center and innermost ring, burning off the majority of its speed. Then just the inner 3 engines will provide the final however and minute control of the booster. The combination of camera placement along with comments from Musk made it clear that the booster touched down in the water at a precise location.
While impressive, a catch attempt requires an incredible amount of precision, to the point where there is very little margin for error. For example, not only do obvious things like the speed and altitude of the stage matter, but much more precise factors like its exact rotation/orientation to position catching points in line with the arms. Combine that with the fact that the entire launch complex is static with the exception of the chopsticks and it will be an incredibly difficult process.
A landing animation provided by SpaceX helps put this process into perspective. It starts with the booster flying toward the launch site at very high speeds. As it approaches it gets uncomfortably close to the ground without lighting any of its engines yet. At this point, the catch arms are toward the top of the tower and in an open configuration. Finally, the booster ignites its engines slowing it rapidly and helping orient it vertically rather than its diagonally approach. Only a few seconds in and it would begin making its way closer to the tower both horizontally and vertically. It does this until it’s positioned between the arms and almost hovering in place. The arms would then need to come together under the catch points on either side of the booster.
If successful, this would mark a major milestone for the Starship program. Landing a booster out at sea has significant benefits, but landing one at the launch site offers incredible potential for rapid reusability. However, SpaceX still has quite a bit of work left before that point.
It’s also worth noting that during IFT-4, there were a few Raptor engine issues during liftoff and the relight of engines for the landing burn. Specifically, just a few seconds in one of the Raptor engines on the outer ring shut off and would remain that way for the rest of the flight. In addition, as Super Heavy was falling toward the water, it attempted to relight all 13 engines but one did not. You could also see some debris from what looked like an explosion likely related to that specific engine.
Even though these two instances during the mission didn’t have any significant negative effect on either the launch or landing thanks to all the additional engines, it means there is still some work to do with the Raptor engines. Super Heavy can operate without all 33 engines but that doesn’t mean SpaceX can afford to have engines going out on each mission. When talking about catching the booster on the next attempt, the company probably wants to be more confident in the system and the Raptor’s ability. Even though SpaceX is in the process of building a second launch tower next to the first, for the time being, that is their only tower. If a failed booster catch attempt were to take place it could cause some major damage to the Stage 0 infrastructure, delaying future launches.
A risk the company may be willing to take in order to try and gather some invaluable flight data and attempt a new mission milestone. On the last flight, besides the booster landing burn and splashdown, they also mentioned a small test with the chopsticks. Specifically, they pointed out that during the flight they would position them as if the catch were planned to happen. This would provide some extra confidence in the catch arms and its general operations. Considering the booster didn’t even make it to the water (at least in one piece) on IFT-3, going from that to a catch attempt at the launch site in two flights would be quite the spectacle. Something we should hear more about in the next few weeks as SpaceX makes up its mind and begins preparing for whatever IFT-5s mission profile ends up being.
Conclusion
A new FCC report mentions the possibility of catching Super Heavy on the next Starship flight. While not confirmed, it’s a promising sign that SpaceX is genuinely considering the operation and wants to try and advance this vehicle is a timely manner. We will have to wait and see how it progresses and the impact it has on the space industry.