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

Just Read the Instructions is named after a spacecraft from ‘The Player of Games‘, a novel from author Iain M. Banks’s Culture series.

Just Read the Instructions was originally based in California from 2015 to 2019 to support missions launching from Vandenburg Air Force Base. The droneship was then repositioned to Florida to support the increasing number of missions launched from Cape Canaveral. There was a two-year gap with no droneship available on the US West Coast before OCISLY was itself repositioned to take the role in 2021.

Just Read the Instructions is the second SpaceX droneship to use the name. The original pilot SpaceX droneship, operated for two experimental landings in the Atlantic Ocean in early 2015, used the same name but was retired and replaced by Of Course I Still Love You droneship in June 2015. The JRTI name was then given to the new droneship operating from California.

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 droneships. Four azimuth thruster engines give the droneship the capability to maintain position at sea to within 3 meters using GPS. 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.

Just Read the Instructions en-route to the LZ. – Tony Cacciarelli

ASOG droneship is the only SpaceX droneship with the known ability to autonomously sail rather than just maintain position. Although speculated to have this ability too, JRTI is towed to landing sites by a support vessel and only runs autonomously during landing operations.  The exact position of the droneship is dependent on mission requirements.

JRTI and the tugboat will leave Port Canaveral up to 7 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 required for the landing will be activated. Support vessels and the tugboat will then retreat to a safe distance to observe the landing. Just Read the Instructions is unmanned 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 – this same equipment was later installed onto the droneship for the upgrade.

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 (Estimate)

Width: 30m / 98 ft (Estimate)

Joined SpaceX Fleet: 2015

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