This month’s Captain’s Corner is brought to you by LCDR Marc Montemerlo, Chief of the Inspections Division. Please enjoy, and as always, we appreciate your input regarding future topics or recommendations. See you in the Port!
– CAPT Tom Allan
SPACEX – The World’s First Rocket Recovery Vessel
By LCDR Marc Montemerlo, Chief of the Inspections Division
In an attempt to reduce the high costs associated with space exploration, SpaceX, a spacecraft design and manufacturing company located in Hawthorne, CA, first approached Sector Jacksonville in October 2014 with the novel idea of landing one of their F9 rockets onto a stationary barge. At first, it was unclear what type of regulatory and design requirements would apply to the dynamically-controlled vessel since for safety reasons, it would need to be unmanned when underway. In the end, SpaceX, Sector Jacksonville and the Coast Guard Marine Safety Center (MSC) were able to agree upon design standards and a regulatory scheme that would ultimately transform a typically uninspected, non certified freight barge into the world’s first Coast Guard inspected rocket recovery vessel named the MARMAC 300.
Labeled an “autonomous spaceport drone ship” by Elon Musk, the CEO and founder of SpaceX, the MARMAC 300 is now a 170 ft by 300 ft certified oceanographic research vessel. Outfitted with specialized equipment installed while at a shipyard in Morgan City, LA and then towed to Jacksonville, FL, the MARMAC 300 is truly unlike any other inspected vessel operating in the U.S. When operating as a rocket recovery platform, the vessel is completely unmanned and remotely controlled through a satellite link or WiFi connection. The vessel is able to maintain a steady position and heading through the use of a computer-controlled dynamic positioning system and four azimuth thrusters. Each azimuth thruster is individually powered by 300 horsepower Thrustmaster hydraulic power units, which help maintain the vessels position to within three meters. In addition to the MARMAC’s unique propulsion system, the vessel is also outfitted with two remotely controlled fire suppression systems, and a backup uninterrupted power supply unit that provides power to vital systems for up to two hours.
Given all of its unique operating requirements, the certification and inspection of the vessel went remarkably smooth. Working closely with MSC, local inspectors from Sector Jacksonville experienced several “first time” vessel design type situations. In particular, inspectors spent several days offshore assessing the dynamic positioning system and certifying that all of the remote actuated safety controls worked properly; tests not typically required on vessels that operate in Sector Jacksonville’s area of responsibility. When initially proposed, representatives from SpaceX speculated the probability of success would be 50 percent at best. However, on Jan. 9, 2015 those odds were drastically improved when, according to SpaceX, a “less than nominal” landing occurred, and that “while the rocket made it to the drone ship, it landed hard.” A preliminary causal analysis revealed that the four deployable grid fins, responsible for controlling lift and orientation of the rocket, ran out of hydraulic fluid. While not optimal, recovering almost 80 percent of the rockets fuel tank was considered a huge success. In addition, damage to the barge was primarily to one of the thruster units and deck plating; nothing that adversely impacted the stability of the vessel.
Assuming a successful landing operation in the future, SpaceX personnel would be transferred from their mobile mission control center on board an offshore supply vessel to the MARMAC 300 to secure the 155 ft tall rocket and its landing legs before towing it into port. The next landing attempt is tentatively scheduled later this month.
Featured images courtesy of SpaceX Press Room