Unmanned floating landing platform

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Aerial view of the first Autonomous spaceport drone ship after it was named Just Read the Instructions in honor of Iain Banks
Graphical representation of the entire process from the launch of the Falcon 9 rocket to the landing of the first stage on the Spaceport drone ship
Recording of the failed landing attempt on April 14, 2015
Recording of the second ASDS Of Course I Still Love You , a conversion based on the Marmac 304

Unmanned floating landing platforms are special ships that are used in space travel for the controlled landing of reusable rocket stages and their return transport.

The first platform of this type was developed by the American space company SpaceX and put into service in 2014, the second in 2015. A third is under construction. SpaceX calls this class of ship the Autonomous spaceport drone ship . Similar landing platforms for the missile New Glenn from Blue Origin and the Chinese CZ-8 planned. The ships are part of the strategy to greatly reduce the cost of space travel by reusing rockets and spacecraft.

After several unsuccessful attempts, the first undamaged landing of a Falcon 9 rocket stage on an autonomous spaceport drone ship succeeded on April 8, 2016 . It was the first stage of the SpaceX mission CRS-8 , the eighth supply flight with the spacecraft Dragon to the International Space Station on behalf of NASA . The platforms have been in regular use since then.

The first three ships and their names

The first ship put into service in the Atlantic in 2014 , a conversion of the 87.8 meter long and 30.5 meter wide cargo ship Marmac 300, originally only bore the name Autonomous spaceport drone ship . In January 2015, SpaceX CEO Elon Musk announced in a tweet that the first ship will be called Just Read the Instructions in the future and has now used the previous name to denote the ship class.

The background to this name change became clear when he announced on the same day that in addition to the first ship stationed on the east coast of the USA, another drone ship would be built on the west coast of the USA, i.e. for the Pacific Ocean . This was later named Of Course I Still Love You .

Both names are taken from the science fiction story The Game Azad by Scottish author Iain Banks .

In the course of 2015, SpaceX decided to replace the first ASDS Just Read the Instructions with the structurally improved ship Of Course I Still Love You, originally intended for the west coast . The first mission was supposed to be SpaceX's seventh supply flight to the ISS on June 28, 2015, but this did not happen because the rocket exploded while climbing. For the west coast, a conversion of the Marmac 303 barge, which was named Just Read the Instructions , was to be used.

The home port of the ASDS Of Course I Still Love You (conversion of Marmac 304) on the US east coast is Jacksonville , the home port of ASDS Just Read the Instructions (conversion of Marmac 303) on the west coast of Los Angeles , there the AltaSea campus, San Pedro.

In February 2018, Musk announced that a third drone ship called A Shortfall of Gravitas was under construction. It is to be stationed in Florida to enable a higher landing rate of Falcon 9 first stages and a synchronous water landing of the two side boosters of the Falcon Heavy . The name of the ship is a reference to Experiencing A Significant Gravitas Shortfall , name of a spaceship in Iain Banks' Culture universe.

Ship concept, design and mode of operation

SpaceX's long-term goal is to land both stages of a rocket back on the launch site. With the use of a landing platform floating on the ocean in the test phase of the technology, the endangerment to people that would have to be feared if a controlled return over inhabited land failed. The founder and CEO of SpaceX, Elon Musk , estimated in advance the probability of success of the first attempt at landing at 50 percent, and in the first year of testing at 80 percent.

Since a landing rocket stage with the engine jet directed downwards would pose a considerable risk to the crew of the platform during deceleration and it was to be assumed that the platform would fail or even crash, the platform was carried out unmanned.

When the Marmac 300 was converted, the first autonomous spaceport drone ship was given a landing deck that is around 90 meters long and 50 meters wide. Since then, it has also been able to hold around 15,000 cubic meters of ballast water, which stabilizes the position of the platform.

To land, the Falcon 9 needs an area approx. 22 meters wide, so that very precise control of both the rocket and the ship is required when touching down on the floating platform. That is why the Autonomous spaceport drone ship is equipped with four diesel-powered propeller pods (Portable Dynamic Positioning System) from the US company Thrustmaster. With the help of GPS positioning, it can keep its position independently against wind and water currents. Even in a storm, the landing platform should not deviate more than 3 meters from the intended position. In addition, the ship does not have its own drive and is towed to its place of use.

After a storm that caused major damage, the platform was rebuilt in March and April 2015. Among other things, two thrust units were replaced by stronger ones (now around 1000 HP each) and a breakwater wall was installed.

First landing tests

Photo of the failed landing attempt on April 14, 2015 from the deck of the Just Read the Instructions

For the tests, SpaceX used rocket stages that had already been launched for commercial satellite launches or for the supply flights it carried out on behalf of NASA to the International Space Station (ISS) . These rockets, paid for by the client, were also equipped with landing controls and extendable landing legs. Subsequently, at that time (around 2014), it was planned to try to refuel and restart rocket stages that had landed in the future.

Already in advance, e.g. B. in April and July 2014, SpaceX had launched two commercial satellite missions, e.g. B. for Orbcomm , let the first stage land in a controlled manner on a trial basis. At that time, however, it was simply directly on the surface of the ocean, where the steps then sank.

First attempt: SpaceX CRS-5

For the first attempt at landing on a ship, SpaceX's fifth supply flight with the cargo spacecraft Dragon to the ISS (SpaceX CRS-5) was selected, which took place on January 10, 2015; 9:47 UTC started. During the attempt, the ship was stationed about 320 km northeast of the launch site of Cape Canaveral Air Force Station at 30.8 degrees north and 78.1 degrees west.

After the separation, the first rocket stage could be steered back into the atmosphere as intended and also reached the landing ship. However, it shattered on landing. According to Elon Musk, there was not enough hydraulic fluid on board by 10% , so that the four grid fins mounted on top of the rocket lost their stabilization and control functions. The landing platform was only slightly damaged.

2nd attempt: launch of the Deep Space Climate Observatory

On February 11, 2015, SpaceX launched the NASA and NOAA project Deep Space Climate Observatory with a Falcon 9 rocket on behalf of the USAF and wanted to make the second attempt to land. However, a strong storm in the landing area did not allow the drone ship to be used. However, it was possible to steer the rocket with a deviation of only 10 meters from the originally intended position.

3rd attempt: SpaceX CRS-6

On the sixth supply flight to the ISS, the Falcon 9 took off on April 14, 2015 at 20:10:41 UTC. As in the first test, the first stage was reached by the autonomous spaceport drone ship with the new name Just Read the Instructions . The first step came up at an angle and shattered after an approach in which it staggered strongly around the vertical.

4th attempt: SpaceX CRS-7 (failed)

During the planned seventh supply flight to the ISS, the Falcon 9 deployed exploded on June 28, 2015 shortly after take-off. The return attempt, in which the second ASDS, Of Course I Still Love You , was to be used for the first time, was thus omitted .

5th attempt: Jason-3

On January 17, 2016, the last version 1.1 Falcon 9 took off with the Jason 3 earth observation satellite on board from Vandenberg Air Force Base . The satellite was successfully launched into orbit. In principle, the launch parameters would have allowed the first stage to return to the launch site, but the responsible environmental authority did not issue a permit for the land landing in good time. Therefore a ship landing on the Pacific was planned. On landing, one of the four landing legs gave way, presumably it was not locked in the open position. As a result, the rocket stage tipped over on the landing platform and was largely destroyed. Pictures showed that the engine block had remained lying on the deck.

6th attempt: SES-9

For the launch of SES-9 on March 4, 2016, SpaceX predicted a very low probability of success due to the launch parameters. In contrast to previous attempts with one engine, three engines were used to brake. The landing failed and Of Course I Still Love You returned damaged, u. a. back to port with a hole in the deck and some wreckage from the missile on the deck.

7th attempt: CRS-8

On April 8, 2016, a Falcon 9 was launched on a supply mission to the ISS. 9 minutes and 10 seconds after the successful start, the first level sat on Of Course I Still Love You . For the first time, a successful and safe landing of a first stage on an autonomous spaceport drone ship was achieved.

After the successful landing, a troop of welders was placed on the landing platform, who welded the folding supports onto the steel platform so that the almost 50 meter high rocket would not tip over in rough seas.

  • CRS-8 (25728668373) .jpg
  • CRS-8 (26265214251) .jpg
  • CRS-8 (26239020092) .jpg

Other selected missions

  • May 6, 2016: Successful night landing of the first stage at the start of JCSAT-14 on Of Course I Still Love You . The landing took place with three engines due to the launch parameters.
  • May 27, 2016: Another successful landing of the first stage at the start of Thaicom-8 on Of Course I Still Love You . The landing took place with three engines due to the launch parameters. There were minor difficulties on landing. The crumple zone of the Falcon 9 first stage was so used on one side that the rocket tilted on deck. For this purpose, video material was published from a camera on board the Falcon 9.
  • June 15, 2016: Crash landing of the first stage after the start of Eutelsat 117 West B / ABS 2A on Of Course i still love you . The landing was supposed to take place again with three engines, however, the underperformance of one engine resulted in a hard impact and the destruction of the stage. The three engines went too early to maximum power until the stage almost came to a standstill. The fuel ran out, then the rocket overturned because an external engine was initially undersupplied and fell onto the drone ship from a height of around 20 meters.
  • January 14, 2017: Successful landing of the first stage when launching Iridium Next 1 on Just Read the Instructions . When decelerating from 2000 to 1000 m / s before entering the atmosphere, 3 engines were ignited, but only one engine was ignited for landing in order to achieve slower braking.
  • June 23, 2017: Successful landing of the first stage at the launch of BulgariaSat-1 on Of Course I Still Love You . This landing took place with three engines due to the launch parameters. In addition, after successfully reusing a first stage at the start of SES-10, it was the second reuse of a first stage and thus the second landing of the same. It was previously used on the mission on January 14, 2017 and is therefore the first stage to land on both drone ships.
  • June 25, 2017: Successful landing of the first stage when launching Iridium Next 2 on Just Read the Instructions . When decelerating from 2000 to 1000 m / s before entering the atmosphere, 3 engines were ignited, but only one engine was ignited for landing in order to achieve slower braking.
  • August 24, 2017: Successful landing of the first stage when starting FORMOSAT-5 on Just Read the Instructions .
  • October 9, 2017: Successful landing of the first stage when launching Iridium Next 3 on Just Read the Instructions .
  • October 11, 2017: Successful landing of the first stage at the start of SES-11 / EchoStar 105 on Of Course I Still Love You .
  • October 30, 2017: Successful landing of the first stage at the start of Koreasat 5A on Of Course I Still Love You .
  • February 6, 2018: Crash of the center core of the first Falcon Heavy next to the Of Course I Still Love You. Wreckage from the center core also damaged parts of the spaceport ship.
  • April 11, 2019: First successful landing of the center core of the second Falcon Heavy on the Of Course I Still Love You .

The list of Falcon missile launches contains details of all landing sites and ships.

First successful use of a recycled first stage: Mission SES-10 on March 30, 2017

The launch of the SES-10 mission was the first ever launch with a recycled first stage rocket. Picture by Steve Jurvetson taken on March 30, 2017 at 3:29 PM Eastern Time

With the refurbished first stage of the Falcon 9 of the SpaceX CRS-8 mission from April 8, 2016, both the second stage and the payload, the eponymous communication satellite SES-10, were successfully transported into space on March 30, 2017 on the SES-10 mission, as well as a new landing on one of SpaceX's two autonomous spaceport drone ships, the Of Course I Still Love You in the Atlantic Ocean. The rocket was previously launched from the Kennedy Space Center Launch Complex 39a .

Patent dispute

In August 2014, SpaceX attacked a patent held by its competitor Blue Origin , owned by Amazon founder Jeff Bezos , in which the company describes the concept of landing a rocket stage on a ship. SpaceX referred in its legal attack on designs for sea-based landing platforms for missiles that are older than Blue Origin's patent from 2009. What Blue Origin describes as a complex development is old hat at best. The challenge was ultimately successful.

See also

Web links

Videos of the first successful landing

Links to ship engineering and SpaceX strategy

on SpaceX's strategy, which is being pursued with the landing platform.

Links to the operations in the development phase of the return technique

for the first time on January 10, 2015

for the third attempt on April 14, 2015

Individual evidence

  1. ↑ https://twitter.com/SpaceX/status/718542763545899008 , accessed April 9, 2016.
  2. ↑ http://boatdb.net/boat/marmac-300-1063184.htm
  3. ↑ https://twitter.com/elonmusk/status/558665265785733120
  4. ↑ This linguistic usage has been consistently continued since then, for example in the press release by SpaceX for the start of the CRS-6 mission on April 14, 2015
  5. ↑ https://twitter.com/elonmusk/status/558703223909781505
  6. ↑ Stubby the Rocket: Elon Musk Names SpaceX Drone Ships in Honor of Iain M. Banks, January 23, 2015; Retrieved April 19, 2015
  7. ↑ Jesse Smedley: SpaceX Augments and Upgrades Drone Ship Armada , nasaspaceflight.com from June 18, 2015
  8. ↑ losangeles.cbslocal.com: SpaceX Planning To Base Rocket, Spacecraft Retrieval At Port Of Los Angeles , June 18, 2015
  9. ↑ Donna Littlejohn: Groundbreaking partnership announced between SpaceX, AltaSea in San Pedro redlandsdailyfacts.com, June 18, 2015
  10. ↑ Elon Musk: A Shortfall of Gravitas. In: @elonmusk. February 12, 2018, accessed February 13, 2018 .
  11. ↑ Stephen Clark: New drone ship under construction for SpaceX rocket landings . In: Spaceflight Now , February 14, 2018.
  12. ↑ Chris Bergin: SpaceX's Autonomous Spaceport Drone Ship ready for action. nasaspaceflight.com, November 24, 2014, accessed May 9, 2015 .
  13. ↑ SpaceX: X marks the spot: Falcon 9 attempts ocean platform landing. December 16, 2014, accessed December 30, 2014 .
  14. ↑ a b Kevin Bullis: SpaceX Plans to Start Reusing Rockets Next Year. October 25, 2014, accessed December 5, 2014 .
  15. ↑ Jeff Foust: Next Falcon 9 Launch Could See First-stage Platform Landing. Spacenews, October 24, 2014, accessed December 5, 2014 .
  16. ↑ SpaceX: SpaceX Soft Lands Falcon 9 Rocket First Stage. July 22, 2014, accessed December 5, 2014 .
  17. ↑ Danielle Haynes (UPI): SpaceX delays resupply flight to ISS , spacedaily.com, December 18, 2014, accessed December 21, 2014
  18. ↑ a b Stephen Clark: Ships deployed into the Atlantic for experimental rocket landing , spaceflightnow.com, January 5, 2015, accessed January 18, 2015
  19. ↑ http://www.spacex.com/webcast/ . See post below the start video
  20. ↑ http://www.manager-magazin.de/unternehmen/artikel/spacex-rakete-zerschellt-auf-landeplatz-musk-keine-zigarre-heute-a-1012341.html
  21. ↑ http://www.spacex.com/missions
  22. ↑ Overview of the landing attempt
  23. ↑ Close-up of the landing attempt from the landing platform
  24. ↑ Jesse Smedley: SpaceX Augments and Upgrades Drone Ship Armada , nasaspaceflight.com, June 18, 2015
  25. ↑ http://www.raumfahrer.net/news/raumfahrt/17012016220630.shtml , accessed on January 17, 2016
  26. ↑ Christian Davenport: https://www.washingtonpost.com/news/the-switch/wp/2016/04/08/elon-musks-spacex-nails-landing-at-sea/ , Washington Post, April 8, 2016 , accessed the same day.
  27. ↑ Horst Rademacher: SpaceX. The falcon has landed. Frankfurter Allgemeine, April 10, 2016, accessed April 10, 2014 .
  28. ↑ Space X Falcon9 rocket tumbles after landing on ship http://www.golem.de/news/spacex-falcon-9-rakete-kippelt-nach-landung-auf-schiff-1605-121150-rss.html
  29. ^ First-stage landing | Onboard camera. Space X, May 27, 2016, accessed May 28, 2016 .
  30. ↑ Elon Musk: Ascent phase & satellites look good, but booster rocket had a RUD on droneship. Twitter, June 15, 2016, accessed June 15, 2016 .
  31. ↑ Elon Musk: Looks like thrust was low on 1 of 3 landing engines. High g landings v sensitive to all engines operating at max. Twitter, June 15, 2016, accessed June 15, 2016 .
  32. ^ Bob Taylor: Eutelsat / ABS: SpaceX landing. June 17, 2016, accessed January 21, 2017 .
  33. ↑ Emily Shanklin: Iridium-1 Mission in Photos . In: SpaceX . January 14, 2017 ( spacex.com [accessed January 21, 2017]).
  34. ^ SpaceX: Iridium-1 Hosted Webcast. January 14, 2017. Retrieved January 21, 2017 .
  35. ↑ https://spaceflightnow.com/2017/10/12/spacex-launches-its-15th-mission-of-the-year/ , accessed on October 12, 2017
  36. ^ SpaceX confirms it lost the center core of the Falcon Heavy . In: Engadget . ( engadget.com [accessed February 7, 2018]).
  37. ↑ SpaceX: Falcon Heavy's center core has landed on the Of Course I Still Love You droneship! Pic.twitter.com/pNqwMWr50d. In: @SpaceX. April 11, 2019, accessed April 13, 2019 .
  38. ↑ SES-10 Hosted Webcast by SpaceX March 30, 2017.
  39. ↑ Todd Bishop: Blue Origin's rocket-landing patent canceled in victory for SpaceX. In: Geekwire. September 1, 2015, accessed May 2, 2019 .