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Just Read the Instructions


Just Read the Instructions arrives at the Port of Los Angeles – Pauline Acalin

Just Read the Instructions (JRTI) is a SpaceX autonomous spaceport droneship (ASDS) operating out of Port Canaveral, Florida. The droneship is built upon a modified barge – Marmac 303 – and is named after a spacecraft of the same name from the novel ‘The Player of Games‘, from author Iain M. Banks’s Culture series.

JRTI droneship is a modified barge that is outfitted with a large landing platform, station-keeping thrusters, and other equipment to allow SpaceX to land Falcon boosters at sea on high-velocity missions that cannot carry enough fuel to allow for a return-to-launch-site landing.

Just Read the Instructions was originally based in California from 2015 to 2019 to support missions landing in the Pacific Ocean. In 2019 JRTI sailed through the Panama Canal and transferred to Port Canaveral to support the increasing number of missions launched from Cape Canaveral. There was a two-year gap between 2019 and 2021 when SpaceX did not operate a droneship in the Pacific Ocean.

Just Read the Instructions is the second SpaceX droneship to use the same name. The original pilot SpaceX droneship which operated for two experimental landings in the Atlantic Ocean in early 2015, was the first droneship to use the name but was retired and replaced in June 2015. The JRTI name was then given to the new droneship at the time that was due to operate in the Pacific Ocean.

JRTI was constructed in a Louisiana shipyard alongside Of Course I Still Love You droneship. To reach its new home in California the ship had to pass through the Panama Canal. The droneship was too wide to fit through the canal locks in its full design so the extra wing extensions – designed to provide a larger landing pad – had to be placed on deck to be installed upon final arrival in California.

Wing extensions being carried on deck during journey to LA – Unknown

Just Read the Instructions is designed in a similar fashion to Of Course I Still Love You and A Shortfall of Gravitas. Four azimuth thruster engines give the droneship the capability to maintain position at sea. Cameras and sensors record the landings for analysis and a series of Starlink dishes and other communications antennae up-link this data and allow for communication with the incoming booster.

Although SpaceX is known to be actively working to make its droneship fleet fully autonomous, Just Read the Instructions droneship is yet to be confirmed to possess this capability, instead only using the technology to maintain position during a landing attempt. To reach the downrange landing zones, JRTI is towed by a support ship from Port Canaveral. The exact location of the landing zone is dependent on mission requirements and regulatory changes.

JRTI will typically leave Port Canaveral up to five days in advance of the launch date, with other accompanying support ships leaving later. After traveling to the landing zone the thrusters and other equipment are engaged. Support vessels will retreat or sail away to complete other recovery operations and JRTI will operate autonomously during the landing. Just Read the Instructions is uncrewed during all landings.

Once the landing is complete, the Octagrabber robot will be deployed to secure the booster and SpaceX technicians will disengage the thrusters and prepare the droneship for the return journey. A support vessel will then tow JRTI back to port.

West Coast Departure and Upgrade

Just Read the Instructions was towed away from Los Angeles, California, on August 1st, 2019 – destined for Morgan City, Louisiana. The droneship passed through the Panama Canal on August 18th. Because of the limited width of the Panama Canal locks, the wing extensions of Just Read the Instructions had to be cut off and placed on the deck for the transit.

Just Read the Instructions arrived in Louisiana on August 27th, 2019. JRTI spent about four months there whilst the side wings were reinstalled and the barge received a general refurbishment. JRTI was then towed to Port Canaveral, Florida arriving on December 11th, 2019. A large amount of equipment was loaded onto the droneship for the journey to Florida which was later installed onto the droneship as part of upgrade work.

Just Read the Instructions crossing the Panama Canal – Oswaldo Sira

Between January and May 2020, SpaceX workers upgraded JRTI for service in the Atlantic Ocean. The old azimuth retractable thrusters were replaced with electrically-driven fixed thrusters that remain permanently submerged underwater.

To power the new thrusters, six diesel generators were installed alongside other supporting equipment. Just Read the Instructions also gained an Octagrabber robot, something it did not have during Pacific Ocean operations.

Just Read the Instructions upgraded thruster – US Coast Guard Sector Jacksonville

Design overview of JRTI. photo KimptonColorado, labels added by

Last Known Location

Track the last known AIS position received from Just Read the Instructions. When the ship is far offshore, this service will not update regularly. Follow @SpaceOffshore across social media for updates!

Vital Statistics

Operator: SpaceX 

Length: 90 m / 295 ft

Breadth: 46m / 150 ft

Joined SpaceX Fleet: 2015

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