JULY 17, 2021–On July 15, onlookers gathered in and around Port Canaveral, to welcome home the newest member of the rapidly evolving SpaceX oceanic fleet. The vessel, known as “A Shortfall Of Gravitas” (ASOG), is the third drone-ship built by SpaceX to propulsively land their Falcon 9 rocket on. ASOG, known by its official name, Marmac 302, was modified from its original configuration as a barge for SpaceX at facilities in Port Fourchon, LA. It recently underwent sea trials in the Gulf of Mexico before being towed 1,000mi (1600km) from Louisiana to Port Canaveral in Florida.
A Shortfall of Gravitas creates a new and very exciting chapter in SpaceX’s quest for rapid reusability. Currently, the process of landing and returning a Falcon 9 first stage to Port Canaveral has been problematic in SpaceX’s neverending efforts to reduce rocket turnaround times, the biggest factor being the returning sea journey, from landing to processing, which averages between 2-5 days.
The original two SpaceX drone-ships: Of Course I Still Love You (OCISLY) and Just Read the Instructions (JRTI) suffer from these turnaround issues due to their inherent design deficiencies. When OCISLY and JRTI were originally designed and constructed, 6 years ago, SpaceX’s launch and sea recovery rates were nowhere near the company’s current cadence. While they are commonly called “autonomous,” in reality, the two older drone-ships currently only possess the ability to achieve what is known as “station keeping,” in which the four thrusters on each drone-ship are used to maintain a precise latitude/longitude for the Falcon 9 to land on. Beyond small adjustments to its position, the trips to and from the landing zone are handled by one of SpaceX’s deep-sea tug boats. The tug, known as “Finn Falgout,” is frequently used to transport the drone-ships to and from the designated landing zones.
With the recent introduction of A Shortfall of Gravitas to the fleet, SpaceX has made strides in the reusability game once again. A video recently posted by Elon Musk on Twitter, showed off the drone-ship undergoing sea trials. While it may have the same Marmac barge base as the other drone-ships, ASOG is now known to possess two key modernizations: autonomy and propulsion.
At this time, A Shortfall Of Gravitas’ level of autonomy is not publicly known, however, it’s likely that SpaceX leveraged the expertise of Elon’s other company, Tesla, to develop some level of autonomy into ASOG, using hardware and software from their existing vehicle production. This cross-company collaboration has been documented before, with Tesla components seen in the construction of starship prototypes.
In addition to the drone-ship’s new autonomy, it now possesses a propulsion system. This update over OCISLY and JRTI will now facilitate the drone-ship to propel itself to and from the landing zone, without the need of a deep-sea tugboat. In the end, these modernizations will likely allow for faster recovery and transit times, hopefully meeting and exceeding SpaceX’s objectives. While it is clear that the end goal for SpaceX is to have a largely autonomous and streamlined method of recovering rockets, the effectiveness of these modernizations is yet to be determined.