Autonomous spaceport drone ship


An autonomous spaceport drone ship is an ocean-going vessel derived from a deck barge, outfitted with station-keeping engines and a large landing platform and is controlled by an autonomous robot. Construction of such ships was commissioned by aerospace company SpaceX to allow for recovery of rocket first-stages at sea for missions which do not carry enough fuel to return to the launch site after boosting spacecraft onto an orbital or transplanetary trajectory.
SpaceX has two operational drone ships. Just Read the Instructions and Of Course I Still Love You, which both operate in the Atlantic for launches from Cape Canaveral. JRtI operated in the Pacific for Vandenberg launches from 2016 to 2019 before leaving the Port of LA in August 2019., 43 Falcon 9 flights have attempted to land on a drone ship, with 34 of them succeeding.
The ASDS are a key early operational component in the SpaceX objective to significantly lower the price of space launch services through "full and rapid reusability," and were developed as part of the multi-year reusable rocket development program SpaceX undertook to engineer the technology. Any Falcon flights going to geostationary orbit or exceeding escape velocity require landing at sea, encompassing about half of SpaceX missions.

History

In 2009, SpaceX CEO Elon Musk articulated ambitions for "creating a paradigm shift in the traditional approach for reusing rocket hardware." In October 2014, SpaceX publicly announced that they had contracted with a Louisiana shipyard to build a floating landing platform for reusable orbital launch vehicles. Early information indicated that the platform would carry an approximately landing pad and would be capable of precision positioning so that the platform could hold its position for launch vehicle landing. On 22 November 2014 Musk released a photograph of the "autonomous spaceport drone ship" along with additional details of its construction and size.
As of December 2014, the first drone ship used, the McDonough Marine Service's Marmac 300 barge, was based in Jacksonville, Florida, at the northern tip of the JAXPORT Cruise Terminal where SpaceX built a stand to secure the Falcon stage during post-landing operations. The stand consists of four, tall and wide pedestal structures bolted to a concrete base. A mobile crane lifted the stage from the ship and placed it on the stand. Tasks such as removing or folding back the landing legs prior to placing the stage in a horizontal position for trucking occurred there.
The ASDS landing location for the first landing test was in the Atlantic approximately northeast of the launch location at Cape Canaveral, and southeast of Charleston, South Carolina.
in April 2015
On 23 January 2015, during repairs to the ship following the unsuccessful first test, Musk announced that the ship was to be named Just Read the Instructions, with a sister ship planned for west coast launches to be named Of Course I Still Love You. On 29 January, SpaceX released a manipulated photo of the ship with the name illustrating how it would look once painted. Both ships are named after two General Contact Units, spaceships commanded by autonomous artificial intelligences, that appear in The Player of Games, a Culture novel by Iain M. Banks.
The first Just Read the Instructions was retired in May 2015 after approximately six months of service in the Atlantic, and its duties were assumed by Of Course I Still Love You. The former ASDS was modified by removing the wing extensions that had extended the barge surface and the equipment that had been added to refit it as an ASDS; these items were saved for future reuse.
In 2018, SpaceX announced plans for a fourth barge, A Shortfall of Gravitas to support east coast operations however the droneship has failed to materialize and instead JRtI was moved to the East Coast and began operations in June 2020.
By June 2020, SpaceX had received the ability to utilize "its own private AIS aids to navigation to mark the temporary exclusion areas it uses during rocket launches Cape Canaveral, Florida," the first such use of dynamic restricted area ever approved by the US Coast Guard.

The active ASDS fleet

In early 2015, SpaceX leased two additional deck barges—Marmac 303 and Marmac 304—and initiated refit to construct two additional autonomous-operation-capable ASDS ships, built on the hulls of these Marmac barges. These constitute the active ASDS fleet as of 2020.

''Of Course I Still Love You''

The second ASDS barge, Of Course I Still Love You, had been under construction in a Louisiana shipyard since early 2015 using a different hull—Marmac 304—in order to service launches on the east coast. It was built as a replacement for the first Just Read the Instructions and entered operational service for Falcon 9 Flight 19 in late June 2015. As of June 2015, its home port was Jacksonville, Florida, but after December 2015, it was transferred further south, at Port Canaveral.
While the dimensions of the ship are nearly identical to the first ASDS, several enhancements were made including a steel blast wall erected between the aft containers and the landing deck. The ship was in place for a first-stage landing test on the CRS-7 mission, which failed on launch on 28 June 2015.
On 8 April 2016 the first stage, which launched the Dragon CRS-8 spacecraft, successfully landed for the first time ever on OCISLY, which is also the first ever drone ship landing.
In February 2018, the central core of Falcon Heavy Test Flight exploded near OCISLY, which damaged two of the four thrusters on the drone ship. Two thrusters were removed from the Marmac 303 barge in order to repair OCISLY.
On 30 May 2020, the first stage of the Crew Demo-2 mission landed on OCISLY, with the Crew Demo-2 mission marking both the first launch of American astronauts, from American soil, on an American rocket since the final flight of the Space Shuttle in 2011, and the first launch of astronauts aboard a SpaceX rocket. This marked the first time in history that the first stage of a rocket launched a crew into space and then landed itself safely.

''Just Read The Instructions''

SpaceX first rocket landing barge, and also its third, were both named Just Read the Instructions ASDS barge.
The second JRTI vessel, using the Marmac 303 barge hull, was built during 2015 in a Louisiana shipyard. When the refit as an ASDS was complete, the barge transited the Panama Canal in June 2015 carrying its wing extensions—the same ones originally built for the first ASDS built, JRTI on Marmac 330)—as cargo on the deck because the ASDS, when complete, would be too wide to pass through the canal.
The home port for the Marmac 303 was initially the Port of Los Angeles at the AltaSea marine research and business campus in San Pedro's outer harbor. The landing platform and tender vessels began docking there in July 2015 in advance of the main construction of the AltaSea facilities.
SpaceX announced that the Marmac 303 would be the second ASDS to be named Just Read the Instructions in January 2016, shortly before its first use as a landing platform for Falcon 9 Flight 21.
On 17 January 2016, JRTI was put to first use in an attempt to recover a Falcon 9 first-stage booster from the Jason-3 mission from Vandenberg. The booster successfully landed on the deck; however, a lockout collet failed to engage on one of the legs causing the rocket to tip over, exploding on impact with the deck. On 14 January 2017, SpaceX launched Falcon 9 Flight 29 from Vandenberg and landed the first stage on the JRTI that was located about downrange in the Pacific Ocean, making it the first successful landing in the Pacific.
In August 2019, JRTI left the Port of Los Angeles to be towed to the Gulf of Mexico; it transited through the Panama Canal. JRTI arrived in Morgan City, Louisiana in late August and stayed there until December then moved to Cape Canaveral. JRTI began operations in the Atlantic in June 2020, supporting the first time a F9 would land after a 5th use.

''A Shortfall of Gravitas''

A fourth ASDS, A Shortfall of Gravitas, was announced in February 2018 and was planned to enter service in mid-2019, but never materialised. Like the rest of the fleet, its name is based on those used for ships in the Culture series.

Characteristics

The ASDS are autonomous vessels capable of precision positioning, originally stated to be within even under storm conditions, using GPS position information and four diesel-powered azimuth thrusters. In addition to the autonomous operating mode, the ships may also be telerobotically controlled.
The azimuth thrusters are hydraulic propulsion outdrive units with modular diesel-hydraulic-drive power units manufactured by Thrustmaster, a marine equipment manufacturer in Texas. The returning rocket must not only land within the confines of the deck surface but must also deal with ocean swells and GPS errors.
SpaceX equips the ships with a variety of sensor and measurement technology to gather data on the booster returns and landing attempts, including commercial off the shelf GoPro cameras.
At the center of the ASDS landing pads is a circle that encloses the SpaceX stylized "X" in an X-marks-the-spot landing point.

Naming

The two ASDS names used so far, Just Read the Instructions, and Of Course I Still Love You, pay homage to the works of the late science fiction author Iain M. Banks by being based on his Culture fictional universe. Both JRtI and OCISLY are names of enormous, sentient starships, which appeared in the novel The Player of Games. The third name that will be used for the fourth ASDS will be A Shortfall of Gravitas that is similarly drawn from the Culture-milieu of Iain M. Banks. The Culture series has a running gag on having some starships that include "Gravitas" within their names.

''Just Read the Instructions'' (''Marmac 300'')

The landing platform of the upper deck of the first barge named Just Read the Instructions was while the span of the Falcon 9 v1.1 landing legs was.

''Of Course I Still Love You'' (''Marmac 304'')

Of Course I Still Love You was built as a refit of the barge Marmac 304 for landings in the Atlantic Ocean. Its homeport is in Port Canaveral, Florida since December 2015, after being ported for a year at the Port of Jacksonville during most of 2015. Of Course I Still Love You worked successfully as a landing platform after the Falcon 9 rocket brought astronauts to space on the manned mission Launch America on May 30th, 2020.

''Just Read the Instructions'' (''Marmac 303'')

Just Read the Instructions, the second barge with that name, was built as a refit of the barge Marmac 303 in 2015 for landings in the Pacific Ocean. Its homeport was in the Port of Los Angeles, California from 2015 to 2019 but in August 2019 it was moved to the Gulf of Mexico.
In December 2019 it was moved to Cape Canaveral.

''A Shortfall of Gravitas'' (under construction)

The fourth ASDS named A Shortfall of Gravitas, was proposed in February 2018 to help east coast launch cadence but has yet to be built.

Operation

A tug is used to bring the ASDS to its oceanic position, and a support ship stands by some distance away from the crewless ASDS. The vessels initially used on the east coast were Elsbeth III and GO Quest. Following landing, technicians and engineers typically board the landing platform, and secure the rocket's landing legs to lock the vehicle in place for transport back to port. The rocket stage is secured to the deck of the drone ship with steel hold downs welded on to the feet of the landing legs. In June 2017, OCISLY started being deployed with a robot that drives under the rocket and grabs onto the hold-down clamps located on the outside of the Falcon 9's structure after landing. Fans call the robot "Optimus Prime" or "Roomba," the latter of which has been turned into a backronym for "Remotely Operated Orientation and Mass Balance Adjustment."

Vessel missions

The first flight test was 10 January 2015
when SpaceX conducted a controlled-descent flight test to land the first-stage of Falcon 9 Flight 14 on a solid surface after it was used to loft a contracted payload toward Earth orbit. SpaceX projected prior to the first landing attempt that the likelihood of successfully landing on the platform would be 50 percent or less. The landings went from being landing tests towards being routine parts of missions.
No.DateMissionASDS landing mission descriptionLanding resultImage
110 January 2015SpaceX CRS-5SpaceX attempted a landing during SpaceX CRS-5 on Just Read the Instructions on 10 January 2015. Many of the test objectives were achieved, including precision control of the rocket's descent to land on the platform at a specific point in the North Atlantic Ocean and a large amount of test data was obtained from the first use of grid fin control surfaces used for more precise reentry positioning. However, the landing was a hard landing. The SpaceX webcast indicated that the boostback burn and reentry burns for the descending first-stage occurred, and that the descending rocket then went "below the horizon," as expected, which eliminated the live telemetry signal. Shortly thereafter, SpaceX released information that the rocket did get to the drone spaceport ship as planned, but "landed hard... Ship itself is fine. Some of the support equipment on the deck will need to be replaced."
211 February 2015DSCOVRJust Read the Instructions was towed to sea for the Deep Space Climate Observatory satellite launch on 11 February 2015 but, it was not used for a landing attempt. Ocean conditions of -high waves interfered with the ASDS recovery duties for the landing, so the ship returned to port and no landing test occurred. SpaceX executed a soft landing in the sea to continue data gathering for future landing attempts. The soft landing was successful, Elon Musk tweeted that it landed with a lateral accuracy of away from the target and in a vertical position.No attempt
314 April 2015SpaceX CRS-6On 14 April 2015, SpaceX made a second attempt during SpaceX CRS-6 to land a Falcon first-stage on the Marmac 300 drone ship Just Read the Instructions. News from Elon Musk suggested that it made a hard landing. He later clarified that it appeared to have made a vertical landing on the ship, but then toppled over due to excessive remaining lateral momentum.
428 June 2015SpaceX CRS-7In order to prepare for SpaceX CRS-7 on 28 June 2015, the then new ASDS, Of Course I Still Love You, was towed out to sea to prepare for a third landing test. This was its first operational assignment. However, the Falcon launch rocket disintegrated before first-stage shutdown so the mission never progressed to the point where the controlled-descent test could happen.No attempt
517 January 2016Jason-3In January 2016, SpaceX indicated that there would be an attempt to land on the then new ASDS, reusing the name Just Read the Instructions, located on the west coast following the launch of Falcon 9 Flight 21 scheduled for 17 January 2016. JRtI was located about downrange from the launch site in the Pacific Ocean. Musk reported that the first stage did successfully soft-land on the ship, but a lockout latch on one of the landing legs failed to latch and the first stage fell over, causing a breach of the propellant tanks and a deflagration on impact with the drone ship. descending to the ASDS.
64 March 2016SES-9During a launch of a heavy communications satellite on Falcon 9 Flight 22 on 4 March 2016, SpaceX performed an experimental descent and landing attempt with very low propellant margins. For the first time, and in order to reduce the propellant required, SpaceX attempted the landing burn with three engines. SpaceX had indicated that the test was unlikely to result in a successful landing and recovery. In the event, one engine flamed out early, and the rocket hit Of Course I Still Love You 's deck surface with considerable velocity, destroying the rocket and causing damage to the drone ship's deck. By 21 March 2016, the deck of the drone ship was nearly repaired.
78 April 2016SpaceX CRS-8The Falcon 9 first-stage performed a successful landing on OCISLY in the Atlantic Ocean off the coast of Florida at T+9 minutes and 10 seconds after liftoff of SpaceX CRS-8, the first-ever successful landing of a first stage on an Autonomous Spaceport Drone Ship. The rocket was successfully affixed to the barge for the maritime transport portion of the journey back to port, and successfully completed its journey, entering Port Canaveral early in the morning on 12 April 2016.
86 May 2016JCSat-14SpaceX landed the first stage of the Falcon 9 on OCISLY during the JCSat-14 mission on 6 May 2016, its second time successfully landing on a drone ship at sea, and its first time recovering a booster from a high-velocity mission.
927 May 2016Thaicom 8SpaceX landed the first stage of a Falcon 9 on OCISLY during the Thaicom 8 mission, its third time successfully landing on a drone ship at sea.
1015 June 2016ABS-3A/Eutelsat 115 West BSpaceX failed to land the first stage of the Falcon 9 on OCISLY during the Asia Broadcast Satellite/Eutelsat mission. Elon Musk tweeted that one of the three engines had low thrust, and when the rocket was just off the deck, the engines ran out of oxidizer.
1114 August 2016JCSAT-16Falcon 9's 28th flight propelled the Japanese JCSAT-16 telecommunications satellite to a geosynchronous transfer orbit on 14 August 2016. The first stage re-entered the atmosphere and during the night landed vertically on OCISLY, positioned in the Atlantic Ocean nearly 400 miles from the Florida coastline; unlike previous successful landings, this landing-burn only used one engine, not three.
1214 January 2017Iridium NEXT-1The Falcon 9 first stage landed on the Pacific Ocean ASDS JRtI during the Iridium NEXT-1 mission. This marked the first successful landing on JRtI and the first landing in the Pacific Ocean.
1330 March 2017SES-10The Falcon 9 first stage landed on OCISLY during the SES-10 launch. This was the first successful launch and landing of a previously flown orbital booster.
1423 June 2017BulgariaSat-1The Falcon 9 first stage landed on OCISLY during the BulgariaSat-1 launch. This was the second successful launch and landing of a previously flown orbital booster. This was also the first booster to have landed on both active drone ships. While the landing was considered a success, the booster was "slammed sideways" and suffered a 'hard landing' which resulted in 'most of the emergency crush core being used'.
1525 June 2017Iridium NEXT-2The Falcon 9 first stage landed on JRtI during the Iridium launch.-
1624 August 2017FORMOSAT-5The Falcon 9 first stage landed on JRtI during the FORMOSAT-5 launch.
179 October 2017Iridium NEXT-3The Falcon 9 first stage landed on JRtI during the Iridium launch.
1811 October 2017SES-11The Falcon 9 first stage landed on OCISLY during the SES-11 launch.
1930 October 2017Koreasat 5AThe Falcon 9 first stage landed on OCISLY during the Koreasat 5A mission.-
206 February 2018Falcon Heavy Test FlightOn 6 February 2018, the central core from the Falcon Heavy Test Flight attempted a landing on OCISLY. There was not enough TEA-TEB igniter remaining and only the centermost of the three engines required ignited during the landing burn. The core hit the water near the drone ship at over 300 mph and was destroyed. The explosion of the central core upon impact also damaged two of the thrusters on the drone ship. The side boosters successfully landed at Landing Zones 1 and 2. The loss of the central core did not impact SpaceX operations since it was from an older generation of the Falcon 9 not intended to be reused.
216 March 2018Hispasat 30W-6On 6 March 2018, a Falcon 9 Full Thrust carrying the Hispasat 30W-6 communications satellite for Hispasat of Spain was originally supposed to attempt a landing, as the first stage was programmed to do the landing. However, due to sea conditions considered to be unfavorable, the drone ship was left at the port. The first stage did its pre-programmed maneuvers, but did not attempt to land.No attempt
2218 April 2018TESSThe Falcon 9 first stage landed on OCISLY during the TESS mission and was the 13th successful drone ship-based recovery.-
2311 May 2018Bangabandhu-1The Falcon 9 Block 5 first stage landed on OCISLY during the Bangabandhu-1 mission and was the first flight of a Block 5 booster and upper stage. It was the overall 25th successful recovery of a booster.-
2422 July 2018Telstar 19VThe Falcon 9 first stage landed on OCISLY during the Telstar 19V mission.-
2525 July 2018Iridium 7The Falcon 9 first stage landed on JRtI during the Iridium 7 mission.-
267 August 2018Merah PutihFalcon 9 first stage landed on OCISLY during the Merah Putih mission.
2715 November 2018Es'hail-2Falcon 9 first stage landed on OCISLY during the Es'hail-2 mission.
283 December 2018SSO-AFalcon 9 block 5 first stage landed on JRtI during the Spaceflight SSO-A mission and was the first time that a booster landed 3 times.
2911 January 2019Iridium 8Falcon 9 block 5 first stage B1049 landed on JRtI during the Iridium 8 mission.-
3022 February 2019Nusantara Satu/Beresheet/ S5Falcon 9 block 5 first stage B1048 landed on OCISLY during the Nusantara Satu, Beresheet & S5 mission.
312 March 2019SpX-DM1Falcon 9 block 5 first stage B1051.1 landed on OCISLY during the SpX-DM1.
3211 April 2019Arabsat-6AFalcon Heavy block 5 first stage's center booster B1055.1 landed on OCISLY. This was the first successful landing of a center booster used in a Falcon Heavy rocket. The side boosters also landed on their respective ground pads. However, the recovery team was unable to secure the center booster onto the drone ship due to rough seas and the core was lost at sea.
334 May 2019SpaceX CRS-17Falcon 9 first stage B1056.1 landed on OCISLY during the SpaceX CRS-17 mission. The landing was originally scheduled for Landing Zone 1, but was switched after an explosion in a test of a Crew Dragon capsule at LZ1. The launch of CRS-17 was delayed due to generator issues on the drone ship.
3424 May 2019Starlink L0Falcon 9 first stage B1049.3 landed on OCISLY during the Starlink mission to launch 60 satellites.
3525 June 2019Space Test Program Flight 2Falcon Heavy center core from the STP-2 mission failed to land on the OCISLY due to lack of control from a failure with the thrust vectoring control in the center engine; the side cores landed successfully on ground pads.
3611 November 2019Starlink L1Falcon 9 first stage B1048.4 landed on OCISLY during the second large batch Starlink mission to launch 60 satellites. This was the first time that a Falcon 9 booster made a fourth flight and landing.
375 December 2019SpaceX CRS-19Falcon 9 first stage B1059.1 successfully landed on OCISLY following the launch of the SpaceX CRS-19 commercial resupply mission. It was the first flight and landing for this booster.-
3816 December 2019JSAT-18Falcon 9 first stage B1056.3 successfully landed on OCISLY following the launch of the Kacific-1/JCSAT-18 communications satellite. It was the third flight and landing for this booster.-
397 January 2020Starlink L2Falcon 9 first stage B1049.4 successfully landed on OCISLY following the launch of Starlink L2, which was third large batch of Starlink satellites.-
4029 January 2020Starlink L3Falcon 9 first stage B1051.3 successfully landed third time on OCISLY following the launch of Starlink L3, which was fourth batch of 60 Starlink satellites launched from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida.-
4117 February 2020Starlink L4Falcon 9 first stage B1056.4 made a water landing following the launch of Starlink L4, which was the fifth batch of 60 Starlink satellites. The first stage booster failed to land on the drone ship making it the first landing failure of flight proven booster.-
4218 March 2020Starlink L5Falcon 9 first stage B1048.5 failed to land on OCISLY after an engine anomaly during launch. After a launch abort at T-0s due to out of family data during an engine power check on 15th March 2020, the launch was postponed until 18th March 2020. At T+2:22, an engine shutdown occurred, the second one to ever have happened on a Falcon 9 flight since CRS-1. It performed the entry burn nominally but then at T+7:30 the downlink feed cut out. It is presumed that the booster either broke up in the atmosphere or crashed into the ocean. It was later confirmed by Elon Musk on Twitter that a small amount of isopropyl alcohol was trapped in a sensor dead leg and was ignited during flight.-
4322 April 2020Starlink L6-
4430 May 2020Crew Dragon Demo-2Falcon 9 first stage B1058.1 successfully landed on OCISLY following the launch of Crew Dragon Demo-2. This was SpaceX's first crewed mission and the first Falcon 9 first stage to launch humans into orbit and successfully return to Earth.-
453 June 2020Starlink L7Falcon 9 first stage B1049.5 successfully landed on JRtI following the launch of Starlink L7. This marks only the second time a Falcon core has been able to fly five times.-
4613 June 2020Starlink L8Falcon 9 first stage B1059.3 successfully landed landed on OCISLY.