![Falcon 9 first stage at LZ-1(two)](https://upload.wikimedia.org/wikipedia/commons/4/41/Falcon_9_first_stage_at_LZ-1%28two%29.jpg)
The Falcon 9 first-stage landing tests were a series of controlled-descent
flight test
Flight testing is a branch of aeronautical engineering that develops specialist equipment required for testing aircraft behaviour and systems. Instrumentation systems are developed using proprietary transducers and data acquisition systems. D ...
s conducted by
SpaceX
Space Exploration Technologies Corp. (SpaceX) is an American spacecraft manufacturer, launcher, and a satellite communications corporation headquartered in Hawthorne, California. It was founded in 2002 by Elon Musk with the stated goal of ...
between 2013 and 2016. Since 2017, the first stage of
Falcon 9
Falcon 9 is a partially reusable medium lift launch vehicle that can carry cargo and crew into Earth orbit, produced by American aerospace company SpaceX.
The rocket has two stages. The first (booster) stage carries the second stage and payl ...
missions has been routinely landed if the rocket performance allowed it, and if SpaceX chose to recover the stage.
The program's objective was to reliably execute controlled re-entry, descent and landing (
EDL) of the Falcon 9
first stage into Earth's atmosphere after the stage completes the boost phase of an
orbital spaceflight
An orbital spaceflight (or orbital flight) is a spaceflight in which a spacecraft is placed on a trajectory where it could remain in space for at least one orbit. To do this around the Earth, it must be on a free trajectory which has an altit ...
. The first tests aimed to touch down vertically in the ocean at zero velocity. Later tests attempted to land the rocket precisely on an
autonomous spaceport drone ship
An autonomous spaceport drone ship (ASDS) is an ocean-going vessel derived from a deck barge, outfitted with station-keeping engines and a large landing platform and is autonomously controlled when on station for a landing. Construction of ...
(a barge commissioned by SpaceX to provide a stable landing surface at sea) or at
Landing Zone 1
Landing Zone 1 and Landing Zone 2, also known as LZ-1 and LZ-2 respectively, are landing facilities on Cape Canaveral Space Force Station for recovering components of SpaceX's VTVL reusable launch vehicles. LZ-1 and LZ-2 were built on land lea ...
(LZ-1), a concrete pad at
Cape Canaveral
, image = cape canaveral.jpg
, image_size = 300
, caption = View of Cape Canaveral from space in 1991
, map = Florida#USA
, map_width = 300
, type =Cape
, map_caption = Location in Florida
, location ...
. The first ground landing at LZ-1 succeeded in December 2015, and the first landing at sea on a drone ship in April 2016. The second landed booster,
B1021
A Falcon 9 first-stage booster is a reusable rocket booster used on the Falcon 9 and Falcon Heavy orbital launch vehicles manufactured by SpaceX. The manufacture of first-stage booster constitutes about 60% of the launch price of a single exp ...
, was the first to fly again in March 2017, and was recovered a second time.
Landings of Falcon 9 first-stage boosters
Overview
The first landing test occurred in September 2013 on the
sixth flight of a Falcon 9 and maiden launch of the
v1.1 rocket version. From 2013 to 2016, sixteen test flights were conducted, six of which achieved a soft landing and recovery of the booster:
*
flight 20 (
Orbcomm OG2 M2) safely touching down on the
LZ-1 ground pad upon first attempt in December 2015;
*
flight 23 (
CRS-8) finally achieving a stable landing at sea in the
Atlantic
The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...
on the drone ship ''
Of Course I Still Love You
An autonomous spaceport drone ship (ASDS) is an ocean-going vessel derived from a deck barge, outfitted with station-keeping engines and a large landing platform and is autonomously controlled when on station for a landing. Construction of ...
'' in April 2016 after four previous attempts ended in destruction of the booster upon impact;
* flights
24 (
JCSAT-14
JCSAT-2B, known as JCSAT-14 before commissioning, is a geostationary communications satellite operated by SKY Perfect JSAT Group and designed and manufactured by SSL on the SSL 1300 platform. It had a launch weight of , a power production capaci ...
) and
25 (
Thaicom 8
THAICOM 8 ( th, ไทยคม 8) is a Thai satellite of the THAICOM series, operated by Thaicom Public Limited Company, a subsidiary of INTOUCH, and is considered to be the 8th THAICOM satellite headquartered in Bangkok, Thailand.
Overview ...
) returning at higher speed from
GTO missions at sea on a drone ship in May 2016;
*
flight 27
National Airlines Flight 27 was a scheduled passenger flight between Miami, Florida and San Francisco, California with intermediate stops at New Orleans, Louisiana; Houston, Texas; and Las Vegas, Nevada, in the United States.
On November 3, 1973 ...
(
CRS-9
SpaceX CRS-9, also known as SpX-9, is a Commercial Resupply Service mission to the International Space Station which launched on 18 July 2016. The mission was contracted by NASA and is operated by SpaceX using a Dragon capsule.
The cargo ...
) returning to LZ-1 in July 2016;
*
flight 28 Flight 28 may refer to:
*American Airlines Flight 28, crashed on 23 October 1942
*British Airtours Flight 28M
British Airtours Flight 28M (also known as Flight 328) was an international passenger flight which caught fire before takeoff at Man ...
(
JCSAT-16
JCSAT-16 is a geostationary communications satellite operated by SKY Perfect JSAT Group and designed and manufactured by SSL on the SSL 1300 platform. It has a launch weight of , a power production capacity of 8.5 kW and a 15-year design lif ...
) landing on a drone ship in August 2016;
Since the January 2017 return to flight, SpaceX has stopped referring to landing attempts as "experimental", indicating that they have become a routine procedure (se
Iridium-1an
CRS-10press kits of 2017, compared wit
CRS-9an
JCSAT-16of 2016). , 14 routine landings have been performed ( success) and three missions were launched in
expendable
''Expendable'' is a science fiction novel by the Canadian author James Alan Gardner, published in 1997 by HarperCollins Publishers under its various imprints.Avon Books; HarperCollins Canada; SFBC/AvoNova. Paperback edition 1997, Eos Books. It i ...
configuration, not attempting to land.
The first-stage descent tests were part of the larger
SpaceX reusable launch system development program
SpaceX is private spaceflight, privately funding the development of Orbital spaceflight, orbital spacecraft, launch systems that can be reusable launch vehicle, reused many times, in a manner similar to the reusability of aircraft. SpaceX has ...
, which included a large amount of
new technology development activities and earlier low-altitude test flights at the
SpaceX facility in
McGregor, Texas
McGregor is a city in McLennan and Coryell counties in the U.S. state of Texas. The population was 4,987 at the 2010 census.
McGregor lies in two counties, as well as two metropolitan areas. The McLennan County portion of the city is part of the ...
in preparation for the high-altitude high-velocity testing of landing test phase of the program. The overall objective of the program is to
privately develop reusable rockets using
vertical-landing technology so as to substantially reduce the cost of space access.
Traditionally, the first stages of orbital carrier rockets have been
discarded in the ocean once the ascent was complete. Achieving routine recovery and reuse of the launch vehicles could dramatically reduce the cost of access to space.
History
From the beginning, Elon Musk wanted the first stage of
SpaceX launch vehicles
SpaceX manufactures launch vehicles to operate its launch provider services and to execute its various exploration goals. SpaceX currently manufactures and operates the Falcon 9 Full Thrust family of medium-lift launch vehicles and the Falcon ...
to be recoverable, and all
Falcon 1
Falcon 1 was a small-lift launch vehicle that was operated from 2006 to 2009 by SpaceX, an American aerospace manufacturer. On 28 September 2008, Falcon 1 became the first privately-developed fully liquid-fueled launch vehicle to go into orbit ...
launches and the first two Falcon 9 launches had parachutes. However the boosters burned up on reentry, before the parachutes even deployed.
This meant a different approach had to be taken.
Experimental prototypes were built and flown during 2012 to 2014 to test the idea of propulsive landings and gain experience.
SpaceX first announced in March 2013 that it would instrument and equip subsequent Falcon 9 first stages as controlled-descent test vehicles, able to propulsively decelerate towards a soft touchdown over the water surface. The company expected to begin these flight tests in 2013, with an attempt to return the vehicle to the launch site for a powered landing no earlier than mid-2014.
In the event, SpaceX did perform their first controlled-descent test flight in 2013 but continued the over-water testing well into 2015. Following analysis of telemetry data from the first controlled descent in September 2013, SpaceX announced that a large amount of new technology passed their real-life test objectives, and that coupled with the technology advancements made on the
''Grasshopper'' prototype, they were now ready to test the full EDL process to recover the first stage. The rocket was "able to successfully transition from vacuum through
hypersonic
In aerodynamics, a hypersonic speed is one that exceeds 5 times the speed of sound, often stated as starting at speeds of Mach 5 and above.
The precise Mach number at which a craft can be said to be flying at hypersonic speed varies, since in ...
, through
supersonic
Supersonic speed is the speed of an object that exceeds the speed of sound ( Mach 1). For objects traveling in dry air of a temperature of 20 °C (68 °F) at sea level, this speed is approximately . Speeds greater than five times ...
, through
transonic
Transonic (or transsonic) flow is air flowing around an object at a speed that generates regions of both subsonic and supersonic airflow around that object. The exact range of speeds depends on the object's critical Mach number, but transonic ...
, and light the engines all the way and control the stage all the way through
he atmosphere
He or HE may refer to:
Language
* He (pronoun), an English pronoun
* He (kana), the romanization of the Japanese kana へ
* He (letter), the fifth letter of many Semitic alphabets
* He (Cyrillic), a letter of the Cyrillic script called ''He'' i ...
.
This second EDL test took place during the
third cargo resupply mission for NASA in April 2014. SpaceX attached
landing legs to the first stage, decelerated the stage through atmospheric re-entry and attempted a simulated landing over water, following the separation of the second stage carrying the Dragon capsule to the ISS. The first stage was slowed down sufficiently to perform a soft touchdown over the Atlantic Ocean.
SpaceX announced in February 2014 that they intended to continue over-water tests of the first stage until mastering precision control of the vehicle from hypersonic speed all the way through subsonic regimes.
Subsequent tests, starting with the
CRS-5
SpaceX CRS-5, also known as SpX-5, was a Commercial Resupply Service mission to the International Space Station (ISS), conducted by SpaceX for NASA, and was launched on 10 January 2015 and ended on 11 February 2015. It was the seventh flight ...
mission in January 2015, attempted to land the first stage on an
autonomous spaceport drone ship
An autonomous spaceport drone ship (ASDS) is an ocean-going vessel derived from a deck barge, outfitted with station-keeping engines and a large landing platform and is autonomously controlled when on station for a landing. Construction of ...
stationed off the Florida coastline or in the Pacific Ocean depending on launch site.
The ships were used for six landing attempts, two of which succeeded in April and May 2016. Meanwhile, the
first attempt to land on solid ground at Cape Canaveral occurred on December 21, 2015, and succeeded flawlessly.
Post-mission test plan
The post-mission Falcon 9 test plan for the earliest flight tests called for the first stage to perform a retro-propulsion burn in the upper atmosphere to slow it down and put it on a descent
ballistic trajectory
Projectile motion is a form of motion experienced by an object or particle (a projectile) that is projected in a gravitational field, such as from Earth's surface, and moves along a curved path under the action of gravity only. In the particu ...
to its target landing location, followed by a second burn in the lower atmosphere before the first stage reached the water.
SpaceX announced in March 2013 that it intended to conduct such tests on Falcon 9 v1.1 launch vehicles and would "continue doing such tests until they can do a return to the launch site and a powered landing". The company said it expected several failures before it could land the vehicle successfully.
In detailed information disclosed in the Falcon 9 flight 6
launch license
The Office of Commercial Space Transportation (generally referred to as FAA/AST or simply AST) is the branch of the United States Federal Aviation Administration (FAA) that approves any commercial rocket launch operations — that is, any laun ...
for the
CASSIOPE
Cascade, Smallsat and Ionospheric Polar Explorer (CASSIOPE), is a Canadian Space Agency (CSA) multi-mission satellite operated by the University of Calgary. The mission development and operations from launch to February 2018 was funded through CS ...
mission, SpaceX said it would fire three of the nine
Merlin 1D
Merlin is a family of rocket engines developed by SpaceX for use on its Falcon 1, Falcon 9 and Falcon Heavy launch vehicles. Merlin engines use RP-1 and liquid oxygen as rocket propellants in a gas-generator power cycle. The Merlin eng ...
engines initially to slow the horizontal velocity of the rocket and begin the attempt at a controlled descent.
Then, shortly before hitting the ocean, one engine would be relighted in an attempt to reduce the stage's speed so that it could be recovered. , SpaceX said the experiment had approximately a ten percent chance of success.
SpaceX did not perform controlled-descent tests on all Falcon 9 v1.1 flights, as payloads going to
GTO did not leave enough fuel margin.
In September 2013, SpaceX announced that the
CRS-3 mission of April 2014 (fourth flight of Falcon 9 v1.1)
would be the second test of the descent test profile.
Whereas the early tests restarted the engines only twice, by the fourth flight test, in September 2014, SpaceX was reigniting the engines three times to accomplish its EDL test objectives (although only three of the nine engines were used): a boost-back burn, a reentry burn, and a landing burn. The boost-back burn limits
downrange
Downrange, or down range, is the horizontal distance traveled by a spacecraft, or the spacecraft's horizontal distance from the launch site. More often, it is used as an adverb or adjective specifying the direction of that travel being measured ...
translation of the used stage; the reentry burn (from approximately altitude) is used to control the descent and deceleration profile at
atmospheric interface
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the ent ...
; and the landing burn completes the deceleration from
terminal velocity
Terminal velocity is the maximum velocity (speed) attainable by an object as it falls through a fluid (air is the most common example). It occurs when the sum of the drag force (''Fd'') and the buoyancy is equal to the downward force of gravit ...
to zero at the landing surface.
Test flights
Ocean touchdown attempts
Flight 6
The first
propulsive reentry, descent, and ocean-surface touchdown test occurred on September 29, 2013, on
Falcon 9 flight 6
Cascade, Smallsat and Ionospheric Polar Explorer (CASSIOPE), is a Canadian Space Agency (CSA) multi-mission satellite operated by the University of Calgary. The mission development and operations from launch to February 2018 was funded through CS ...
, the maiden launch of the
Falcon 9 rocket, version v1.1. After the three-minute boost phase and separation of the second stage with the
CASSIOPE
Cascade, Smallsat and Ionospheric Polar Explorer (CASSIOPE), is a Canadian Space Agency (CSA) multi-mission satellite operated by the University of Calgary. The mission development and operations from launch to February 2018 was funded through CS ...
and
nanosat
A small satellite, miniaturized satellite, or smallsat is a satellite of low mass and size, usually under . While all such satellites can be referred to as "small", different classifications are used to categorize them based on mass. Satellites ca ...
payloads, the rocket's first stage was
reoriented backwards and three of the nine
Merlin 1D
Merlin is a family of rocket engines developed by SpaceX for use on its Falcon 1, Falcon 9 and Falcon Heavy launch vehicles. Merlin engines use RP-1 and liquid oxygen as rocket propellants in a gas-generator power cycle. The Merlin eng ...
engines were reignited at high altitude to initiate a deceleration and controlled descent trajectory to the surface of the ocean. The first phase of the test "worked well and the first stage re-entered safely".
However, the stage began to roll because of aerodynamic forces during the atmospheric descent and the roll rate exceeded the capabilities of the first stage
attitude control system
Spacecraft attitude control is the process of controlling the orientation of a spacecraft (vehicle/satellite) with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, et ...
(ACS) to
null it out. The fuel in the tanks "centrifuged" to the outside of the tank and the single engine involved in the low-altitude deceleration maneuver shut down. SpaceX was able to retrieve some first-stage debris from the ocean.
The company did not expect to recover the first stage on this flight,
nor on the first several powered-descent tests, as predicted in their March 2013 announcement.
This first experimental descent was considered successful, achieving substantial test milestones and collecting a great deal of engineering data, despite losing the stage into the ocean.
SpaceX tested a large amount of new technology on this flight, and, combining those results with the advances made on the Grasshopper demonstrator, the company now believed it had "all the pieces of the puzzle".
Flight 9
The second test of controlled-descent hardware and software on the first stage
occurred on April 8, 2014,
and became the first successful controlled ocean soft touchdown of a liquid-rocket-engine orbital first stage.
The first stage included landing legs for the first time which were extended to simulate a landing upon touchdown, and the test utilized more powerful gaseous Nitrogen
control thrusters to control the aerodynamic-induced rotation that had occurred on the first test flight. The first stage successfully approached the water surface with no spin and at zero vertical velocity, as designed.
During the second test, the first stage was traveling at a velocity of
at an altitude of
at the time of the high-altitude turn-around maneuver, followed by ignition of three of the nine main engines for the initial deceleration and placement onto its descent trajectory.
The "first stage executed a good re-entry burn and was able to stabilize itself on the way down. ...
helanding in
heAtlantic
ceanwas good! ... Flight computers continued transmitting
elemetry datafor eight seconds after reaching the water" and stopped only after the first stage went horizontal.
The major modifications for the second first stage controlled-descent test flight included changes to both the reentry burn and the landing burn as well as adding increased
attitude control system
Spacecraft attitude control is the process of controlling the orientation of a spacecraft (vehicle/satellite) with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, et ...
(ACS) capabilities.
SpaceX had projected a low probability of stage recovery following the flight test due to complexity of the test sequence and the large number of steps that would need to be carried out perfectly.
The company was careful to label the entire flight test as "an experiment".
In a press conference at the
National Press Club
Organizations
A press club is an organization for journalists and others professionally engaged in the production and dissemination of news. A press club whose membership is defined by the press of a given country may be known as a National Press ...
on April 25, Elon Musk said that the first stage achieved a soft touchdown on the ocean but due to rough seas, the stage was destroyed.
Flight 10
The third test flight of a returned first stage was July 14, 2014, on
Falcon 9 flight 10
Falcon 9 flight 10 was a Falcon 9 space launch that occurred on July 14, 2014. It was the fifth launch of the Falcon 9 v1.1 launch vehicle and carried six Orbcomm-OG2 telecommunication satellites. All six satellites were successfully deployed.
F ...
. Whereas the previous test reached a target landing area some hundreds of kilometers off the Florida coast, this flight aimed for a boost-back trajectory that would attempt the ocean touchdown much nearer the coast, and closer to the original launch location at Cape Canaveral. Following the third controlled-descent test flight, SpaceX expressed confidence in their ability to successfully land in the future on a "
floating launch pad or back at the launch site and refly the rocket with no required refurbishment."
Following the first stage loft of the second stage and payload on its orbital trajectory, SpaceX conducted a successful
flight test
Flight testing is a branch of aeronautical engineering that develops specialist equipment required for testing aircraft behaviour and systems. Instrumentation systems are developed using proprietary transducers and data acquisition systems. D ...
on the spent first stage. The first stage successfully
decelerated from
hypersonic speed
In aerodynamics, a hypersonic speed is one that exceeds 5 times the speed of sound, often stated as starting at speeds of Mach 5 and above.
The precise Mach number at which a craft can be said to be flying at hypersonic speed varies, since i ...
in the upper atmosphere, made a successful
reentry
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the entr ...
, landing burn, and deployment of its
landing legs, and touched down on the ocean surface. The first stage was not recovered for analysis as the hull integrity was breached, either upon touchdown or on the subsequent "tip over and body slam".
Results of the post-landing analysis showed that the hull integrity was lost as the -tall first stage fell horizontally, as planned, onto the ocean surface following the landing.
Flight 13
![SupersonicRetropropulsion-Falcon9 first stage on SpaceX CRS4, 21 September 2014](https://upload.wikimedia.org/wikipedia/commons/9/9d/SupersonicRetropropulsion-Falcon9_first_stage_on_SpaceX_CRS4%2C_21_September_2014.jpg)
The fourth test flight of a returned first stage, with a planned ocean touchdown, occurred on
Falcon 9 flight 13 which was launched on September 21, 2014.
and the first stage flew a profile approaching a zero-velocity at zero-altitude simulated landing on the sea surface.
SpaceX made no attempt to recover the first stage, since earlier tests had confirmed that the 14-
story
Story or stories may refer to:
Common uses
* Story, a narrative (an account of imaginary or real people and events)
** Short story, a piece of prose fiction that typically can be read in one sitting
* Story (American English), or storey (British ...
tall first stage would not survive the tip-over event into the sea. The booster did run out of liquid oxygen.
One month later, detailed
thermal imaging
Infrared thermography (IRT), thermal video and/or thermal imaging, is a process where a thermal camera captures and creates an image of an object by using infrared radiation emitted from the object in a process, which are examples of infrared i ...
infrared sensor data and video were released of the controlled-descent test. The data was collected by NASA in a joint arrangement with SpaceX as part of research on
retropropulsive deceleration technologies in order to develop new approaches to
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...
atmospheric entry
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the ent ...
. A key problem with propulsive techniques is handling the
fluid flow
In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids— liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) an ...
problems and
attitude control
Attitude control is the process of controlling the orientation of an aerospace vehicle with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc.
Controlling vehicle ...
of the descent vehicle during the supersonic retropropulsion phase of the entry and deceleration. All phases of the night-time flight test on the first stage were successfully imaged except for the final landing burn, as that occurred below the clouds where the
IR data was not visible.
The research team is particularly interested in the altitude range of the SpaceX "reentry burn" on the Falcon 9 Earth-entry tests as this is the "powered flight through the Mars-relevant retropulsion regime" that models Mars entry and descent conditions.
Flight 15
![Falcon 9 1st stage re-entry with grid fins; DSCOVR mission (16849254595)](https://upload.wikimedia.org/wikipedia/commons/5/53/Falcon_9_1st_stage_re-entry_with_grid_fins%3B_DSCOVR_mission_%2816849254595%29.png)
SpaceX had planned to make the sixth controlled-descent test flight and second
landing attempt on their drone ship no earlier than February 11, 2015. Landing a returning rocket at sea would have been a "potentially historic rocket launch and landing", as such a feat "was unheard of" five years earlier.
According to regulatory paperwork filed in 2014, SpaceX plans had called for the sixth test flight to occur on a
late January 2015 launch attempt. However, after the completion of the fifth test flight, and with some damage being incurred by the drone ship in the botched landing, it was not clear whether the sixth test would still be feasible only a few weeks later.
This issue was resolved within days of the ship's return to Jacksonville, and by January 15, SpaceX was unambiguous about its plans to attempt a landing of the first stage following the boost phase of the
Deep Space Climate Observatory
Deep Space Climate Observatory (DSCOVR; formerly known as Triana, unofficially known as GoreSat) is a National Oceanic and Atmospheric Administration (NOAA) space weather, space climate, and Earth observation satellite. It was launched by Space ...
mission.
However, in a statement by SpaceX, the drone ship was in conditions "with waves reaching up to three stories in height crashing over the decks". Additionally, one of the four thrusters that keep the barge in a constant position had malfunctioned, making station-keeping difficult. For these reasons, the post-launch flight test did not involve the barge, but instead attempted a soft touchdown over water.
The test was successful, and the first stage of the Falcon 9 landed "nicely vertical" with an accuracy of 10 meters from the target location in the ocean.
Therefore, this test represented the fifth ocean touchdown, and the sixth overall Falcon 9 first stage controlled-descent test.
Flight 46 and 48
Flight 46 and 48 were both boosters on their second flight that were not recovered due to the older Block 3 design only being capable of two flights. Instead of having an uncontrolled descent, SpaceX softly landed both boosters in the water to test high energy landing techniques without the risk of damaging a drone ship. On flight 48, the booster survived landing and stayed intact after tipping over. Unplanned recovery was discussed but the booster broke up before it could be attempted.
Landing attempts
![Falcon 9 First Stage Reusability Graphic](https://upload.wikimedia.org/wikipedia/commons/c/c1/Falcon_9_First_Stage_Reusability_Graphic.jpg)
, SpaceX has attempted 47 landings of a first stage on a solid surface, 40 of which have succeeded.
In July 2014, SpaceX announced that the fifth and sixth controlled-descent test flights would attempt to land on a solid surface, merging the lessons from the high-altitude
envelope expansion of the first four controlled-descent flights over water with the low-altitude lessons of the
F9R Dev
Falcon 9 prototypes were experimental flight test reusable rockets that performed vertical takeoffs and landings. The project was privately funded by SpaceX, with no funds provided by any government until later on. Two prototypes were built, a ...
testing in Texas.
At that time, the "solid surface" was not further described, and was later revealed to be a seafaring barge dubbed an
autonomous spaceport drone ship
An autonomous spaceport drone ship (ASDS) is an ocean-going vessel derived from a deck barge, outfitted with station-keeping engines and a large landing platform and is autonomously controlled when on station for a landing. Construction of ...
.
Many of the test objectives were achieved on the first attempt, including bringing the stage to the specific location of the floating platform and collecting a large amount of test data with the first use of
grid fin
Grid fins (or lattice fins) are a type of flight control surface used on rockets and bombs, sometimes in place of more conventional control surfaces, such as planar fins. They were developed in the 1950s by a team led by and used since the 197 ...
control surfaces for more precise reentry positioning. However the touchdown on the corner of the barge was a
hard landing
A hard landing occurs when an aircraft or spacecraft hits the ground with a greater vertical speed and force than in a normal landing.
Landing is the final phase in flight, in which the aircraft returns to the ground. The average vertical sp ...
and most of the rocket body fell into the ocean and sank; SpaceX published a short clip of the crash.
It would take four more attempts to achieve the first barge landing at sea on
flight 23.
Meanwhile, ground landing succeeded on the first attempt with
flight 20 on December 21, 2015.
In October 2014, SpaceX clarified that the "solid surface" would be a
floating platform constructed from a barge in Louisiana, and confirmed that they would attempt to land the first stage of the
fourteenth Falcon 9 flight on the platform.
For the landing to succeed, the -wide span of the rocket
landing legs must not only land within the -wide barge deck, but would need to also deal with
ocean swell
A swell, also sometimes referred to as ground swell, in the context of an ocean, sea or lake, is a series of mechanical waves that propagate along the interface between water and air under the predominating influence of gravity, and thus are oft ...
and
GPS errors.
In late November, SpaceX revealed that the landing barge would be capable of
autonomous operation and would not need to be anchored or moored;
it was hence called an
autonomous spaceport drone ship
An autonomous spaceport drone ship (ASDS) is an ocean-going vessel derived from a deck barge, outfitted with station-keeping engines and a large landing platform and is autonomously controlled when on station for a landing. Construction of ...
. three of these ships had been built, two of which were operational.
Flight 14
This fifth controlled-descent test flight was anticipated by the specialized press as a historic core return attempt.
It incorporated for the first time in an orbital mission the
grid fin
Grid fins (or lattice fins) are a type of flight control surface used on rockets and bombs, sometimes in place of more conventional control surfaces, such as planar fins. They were developed in the 1950s by a team led by and used since the 197 ...
aerodynamic control surfaces
Aircraft flight control surfaces are aerodynamic devices allowing a pilot to adjust and control the aircraft's flight attitude.
Development of an effective set of flight control surfaces was a critical advance in the development of aircraft. E ...
that had previously been tested only during a low-altitude, low-speed test with the
F9R Dev1
Falcon 9 prototypes were experimental flight test reusable rockets that performed vertical takeoffs and landings. The project was privately funded by SpaceX, with no funds provided by any government until later on. Two prototypes were built, a ...
prototype vehicle in early 2014.
The addition of grid fins, with continuation of the control authority obtained from gimbaling the engines as on previous test flights, was projected to improve the
landing accuracy to , a thousand-fold improvement over the four previous test flights which landed within of their target coordinates.
Prior to the flight, SpaceX projected that the likelihood of success on the first try was 50 percent or less.
The first test flight for this new hardware occurred on January 10, 2015, on the
CRS-5 mission for NASA. The controlled-descent flight started approximately three minutes after launch, following the second stage separation event,
when the first stage was approximately high and moving at a velocity of .
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, so that the
retropropulsive landing
Vertical takeoff, vertical landing (VTVL) is a form of takeoff and landing for rockets. Multiple VTVL craft have flown. The most widely known and commercially successful VTVL rocket is SpaceX's Falcon 9 first stage.
VTVL technologies were deve ...
attempt was not shown live. Shortly thereafter, SpaceX released information that the rocket did get to the drone ship as planned, but "landed hard ... Ship itself is fine. Some of the support equipment on the deck will need to be replaced."
Musk later elaborated that the rocket's flight-control surfaces had exhausted their supply of hydraulic fluid prior to impact.
Musk posted photos of the impact while talking to
John Carmack
John D. Carmack II (born August 20, 1970) is an American computer programmer and video game developer. He co-founded the video game company id Software and was the lead programmer of its 1990s games ''Commander Keen'', ''Wolfenstein 3D'', ''Doo ...
on Twitter. SpaceX later released a video of the impact on
Vine
A vine (Latin ''vīnea'' "grapevine", "vineyard", from ''vīnum'' "wine") is any plant with a growth habit of trailing or scandent (that is, climbing) stems, lianas or runners. The word ''vine'' can also refer to such stems or runners themselv ...
.
Flight 17
A seventh test flight of the first stage controlled-descent profile occurred on April 14, 2015, on Falcon 9 flight 17, which carried
CRS-6
SpaceX CRS-6, also known as SpX-6, was a Commercial Resupply Services, Commercial Resupply Service mission to the International Space Station, contracted to NASA. It was the eighth flight for SpaceX's uncrewed SpaceX Dragon, Dragon Comparison ...
to the
International Space Station
The International Space Station (ISS) is the largest modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos (Russia), JAXA ...
. This was SpaceX's second attempt to land on a floating platform. The first stage was fitted with grid fins and landing legs to facilitate the post-mission test.
An early report from Elon Musk suggested that the first stage made a hard landing on the drone ship.
Musk later clarified that the
bipropellant
The highest specific impulse chemical rockets use liquid propellants (liquid-propellant rockets). They can consist of a single chemical (a monopropellant) or a mix of two chemicals, called bipropellants. Bipropellants can further be divided into ...
valve was stuck, and therefore the control system could not react rapidly enough for a successful landing.
On April 15, SpaceX released a video of the terminal phase of the descent, the landing, the tip over, and the resulting
deflagration
Deflagration (Lat: ''de + flagrare'', "to burn down") is subsonic combustion in which a pre-mixed flame propagates through a mixture of fuel and oxidizer. Deflagrations can only occur in pre-mixed fuels. Most fires found in daily life are diffu ...
as the stage broke up on the deck of the ASDS.
Flight 20: first landing on ground pad
The first attempt to land the first stage of Falcon 9 on a ground pad near the launch site occurred on
flight 20, the maiden flight of the
Falcon 9 Full Thrust
Falcon 9 Full Thrust (also known as Falcon 9 v1.2, with variants Block 1 to Block 5) is a partially reusable medium-lift launch vehicle, designed and manufactured by SpaceX. Designed in 2014–2015, Falcon 9 Full Thrust began launch operations ...
version, on the evening of December 21, 2015. The landing was successful and the first stage was recovered.
This was
the first time in history that a rocket first stage returned to Earth after propelling an orbital launch mission and achieved a controlled
vertical landing.
SpaceX applied to the
Federal Aviation Administration
The Federal Aviation Administration (FAA) is the largest transportation agency of the U.S. government and regulates all aspects of civil aviation in the country as well as over surrounding international waters. Its powers include air traffic m ...
(FAA) US regulatory authority to perform its eighth booster controlled-descent test culminating with a landing attempt at the ''
Landing Zone 1
Landing Zone 1 and Landing Zone 2, also known as LZ-1 and LZ-2 respectively, are landing facilities on Cape Canaveral Space Force Station for recovering components of SpaceX's VTVL reusable launch vehicles. LZ-1 and LZ-2 were built on land lea ...
'' facility (formerly
Launch Complex 13
Launch Complex 13 (LC-13) was a launch complex at Cape Canaveral Space Force Station, the third-most southerly of the original launch complexes known as Missile Row, lying between LC-12 and LC-14. In 2015, the LC-13 site was leased by SpaceX ...
) that SpaceX had recently built at
Cape Canaveral Air Force Station
Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida.
Headquartered at the nearby Patrick Space Force Base, the statio ...
.
The FAA cleared SpaceX to attempt this landing after assessing that it would inflict minimal damage on the environment.
Additionally, NASA planned to close the
NASA Causeway
NASA Parkway, also known as NASA Causeway, is an east-west expressway in Brevard County, Florida, containing two causeways. The first causeway connects the Florida mainland to Merritt Island and later, over the private second causeway, connects ...
near the launch and landing site and significantly increase the size of exclusion zones during the launch and landing attempt.
Both options to attempt landing on the ground pad or on the drone ship at sea remained open until the day of the launch. The final decision to return the booster to Cape Canaveral was made based on a number of factors, including weather at the potential landing sites.
Flight 20 took off at 20:29
EST on December 21, 2015 (01:29
UTC on December 22, 2015). About 9 minutes and 45 seconds later, the first stage landed vertically on the pad.
SpaceX does not plan to fly the Falcon 9 flight 20 first stage again. Rather, the rocket was inspected and moved back to the launch pad a few miles north to perform a
static fire
Launch vehicle system tests assess the readiness of a launch system to safely reach orbit. Launch vehicles undergo system tests before they launch. A wet dress rehearsal (WDR) and a more extensive static fire tests a fully assembled launch vehicl ...
test. After the hot fire test, the vehicle was evaluated in detail by SpaceX to assess capabilities for reflight of the launch vehicle design after future landings.
On December 31, SpaceX announced that no damage had been found on the stage and that it was ready to fire again.
On January 15, 2016, SpaceX conducted the static fire test on the recovered booster and reported a good overall outcome, except for some thrust fluctuations in one of the outer engines (engine 9). Elon Musk reported that this may have been due to debris ingestion.
This booster has been on display outside of SpaceX headquarters in Hawthorne, California since August 20, 2016.
Flight 21
Flight 21, the final launch of a
Falcon 9 v1.1
Falcon 9 v1.1 was the second version of SpaceX's Falcon 9 orbital launch vehicle. The rocket was developed in 2011–2013, made its maiden launch in September 2013, and its final flight in January 2016. The Falcon 9 rocket was fully designed ...
, carried the
Jason 3
Jason-3 is a satellite altimeter created by a partnership of the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) and National Aeronautic and Space Administration (NASA), and is an international cooperative mis ...
payload. At one point this was the first possible opportunity for an attempt to land the first stage on land,
but the launches were reordered following the loss of
Falcon 9 flight 19
SpaceX CRS-7, also known as SpX-7, was a private American Commercial Resupply Service mission to the International Space Station, contracted to NASA, which launched and failed on June 28, 2015. It disintegrated 139 seconds into the flight aft ...
in June 2015. Jason-3 was successfully launched on January 17, 2016, and while the first stage managed to slow down towards a soft landing, the lockout
collet
A collet is a segmented sleeve, band or ''collar''. One of the two radial surfaces of a collet is usually tapered (i.e a truncated cone) and the other is cylindrical. The term ''collet'' commonly refers to a type of chuck that uses collets t ...
on one of the landing legs did not latch correctly, which caused the rocket to fall over and explode after touching down.
Elon Musk noted that ice buildup on the collet from the high-humidity launch conditions may have led to the failure of the latch.
Flight 22
On March 4, 2016, Falcon 9 flight 22 launched the heavy
SES-9
SES-9 is a geostationary communications satellite operated by SES S.A. It was launched from Cape Canaveral SLC-40 by a Falcon 9 Full Thrust launch vehicle on 4 March 2016.
Satellite description
SES-9 is a large communications satellite operat ...
communications satellite
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. C ...
,
the rocket's largest payload yet targeting a
highly-energetic geosynchronous transfer orbit
A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellites that are destined for geosynchronous (GSO) or geostationary orbit (GEO) are (almost) always put into a GTO as an intermediate step f ...
(GTO). Consequently, the Falcon 9 first stage followed a
ballistic trajectory
Projectile motion is a form of motion experienced by an object or particle (a projectile) that is projected in a gravitational field, such as from Earth's surface, and moves along a curved path under the action of gravity only. In the particu ...
after separation and re-entered the atmosphere at high velocity with very little fuel to mitigate potential aerodynamic damage.
Therefore, SpaceX did not expect to successfully land its Falcon 9 booster on its sea barge, the ''
Of Course I Still Love You
An autonomous spaceport drone ship (ASDS) is an ocean-going vessel derived from a deck barge, outfitted with station-keeping engines and a large landing platform and is autonomously controlled when on station for a landing. Construction of ...
,'' positioned in the Atlantic Ocean. Elon Musk confirmed in a tweet that the landing attempt had failed.
Flight 23: first landing on a drone ship
On April 8, 2016, Falcon 9 flight 23, the third flight of
the full-thrust version, delivered the
SpaceX CRS-8
SpaceX CRS-8, also known as SpX-8, was a Commercial Resupply Service mission to the International Space Station (ISS) which was launched on April 8, 2016, at 20:43 UTC. It was the 23rd flight of a Falcon 9 rocket, the tenth flight of a ...
cargo on its way to the
International Space Station
The International Space Station (ISS) is the largest modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos (Russia), JAXA ...
while the first stage conducted a boostback and re-entry maneuver over the Atlantic Ocean. Nine minutes after liftoff,
the booster landed vertically on the drone ship ''Of Course I Still Love You'', from the Florida coastline, achieving a long-sought-after milestone for the
SpaceX reusability development program.
This stage, serial number
B1021
A Falcon 9 first-stage booster is a reusable rocket booster used on the Falcon 9 and Falcon Heavy orbital launch vehicles manufactured by SpaceX. The manufacture of first-stage booster constitutes about 60% of the launch price of a single exp ...
, was refurbished and flown again in March 2017 for the
SES-10
SES-10, is a geostationary communications satellite awarded in February 2014, owned and operated by SES S.A. and designed and manufactured by Airbus Defence and Space on the Eurostar-3000 satellite bus. It is positioned at the 67° West posi ...
mission, setting another milestone in the development of reusable rockets.
Flight 24: first return from GTO mission
On May 6, 2016, Falcon 9 flight 24 delivered the
JCSAT-14
JCSAT-2B, known as JCSAT-14 before commissioning, is a geostationary communications satellite operated by SKY Perfect JSAT Group and designed and manufactured by SSL on the SSL 1300 platform. It had a launch weight of , a power production capaci ...
satellite on a
geostationary transfer orbit
A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellite, Satellites that are destined for geosynchronous orbit, geosynchronous (GSO) or geostationary orbit (GEO) are (almost) always put into ...
(GTO) while the first stage conducted a re-entry burn under ballistic conditions without prior boostback. Following the controlled descent through the atmosphere, the booster executed a short landing burn as it approached the drone ship ''Of Course I Still Love You'', and succeeded in landing vertically. This second landing at sea was more difficult than the previous one because the booster at separation was traveling about compared to on the CRS-8 launch to
low Earth orbit
A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never mor ...
.
Pursuing their experiments to test the limits of the
flight envelope
In aerodynamics, the flight envelope, service envelope, or performance envelope of an aircraft or spacecraft refers to the capabilities of a design in terms of airspeed and load factor or atmospheric density, often simplified to altitude. The t ...
, SpaceX opted for a shorter landing burn with three engines instead of the single-engine burns seen in earlier attempts; this approach consumes less fuel by leaving the stage in free fall as long as possible and decelerating more sharply, thereby minimizing the amount of energy expended to counter gravity.
Elon Musk indicated this first stage may not be flown again and will instead be used as a life leader for ground tests to confirm future first stage rockets are good.
Flight 25
On May 27, 2016, Falcon 9 flight 25 delivered
THAICOM 8
THAICOM 8 ( th, ไทยคม 8) is a Thai satellite of the THAICOM series, operated by Thaicom Public Limited Company, a subsidiary of INTOUCH, and is considered to be the 8th THAICOM satellite headquartered in Bangkok, Thailand.
Overview ...
to a supersynchronous transfer orbit; despite high re-entry speed, the first stage again landed successfully on the SpaceX drone ship.
The landing crushed a "crush core" in one leg, leading to a notable tilt to the stage as it stood on the drone ship.
Flight 26
On June 15, 2016,
Falcon 9 flight 26
Falcon 9 flight 26 was the 26th Falcon 9 space launch by SpaceX, which launched both ABS's ABS-2A and Eutelsat's Eutelsat 117 West B (formerly Satmex 9) to geostationary transfer orbit, that occurred on 15 June 2016 at 14:29 UTC (10:29am loc ...
successfully delivered the
Eutelsat
Eutelsat S.A. is a French satellite operator. Providing coverage over the entire European continent, the Middle East, Africa, Asia and the Americas, it is the world's third-largest satellite operator in terms of revenues.
Eutelsat's satellit ...
117W B and
ABS 2A satellites into GTO. The first stage conducted a re-entry burn and successfully deployed its grid fins, before attempting a landing on the barge. The landing failed in its final moments due to low thrust on one of the first stage engines, caused by the exhaustion of its liquid oxygen fuel supply. That caused the engines to shut down early while the first stage was just above the drone's deck, causing a landing failure.
Flight 27
In the early hours of July 18, 2016, Falcon 9 flight 27, carrying the
Dragon spacecraft
American private space transportation company SpaceX has developed and produced several spacecraft named Dragon. The first family member, now referred to as Dragon 1, flew 23 cargo missions to the ISS between 2010 and 2020 before being retired ...
for the
CRS-9
SpaceX CRS-9, also known as SpX-9, is a Commercial Resupply Service mission to the International Space Station which launched on 18 July 2016. The mission was contracted by NASA and is operated by SpaceX using a Dragon capsule.
The cargo ...
mission was followed by a successful landing of the first stage at
Landing Zone 1
Landing Zone 1 and Landing Zone 2, also known as LZ-1 and LZ-2 respectively, are landing facilities on Cape Canaveral Space Force Station for recovering components of SpaceX's VTVL reusable launch vehicles. LZ-1 and LZ-2 were built on land lea ...
,
Cape Canaveral
, image = cape canaveral.jpg
, image_size = 300
, caption = View of Cape Canaveral from space in 1991
, map = Florida#USA
, map_width = 300
, type =Cape
, map_caption = Location in Florida
, location ...
.
Flight 28
On August 14, 2016, the Falcon 9 flight 28 successfully propelled the Japanese
JCSAT-16
JCSAT-16 is a geostationary communications satellite operated by SKY Perfect JSAT Group and designed and manufactured by SSL on the SSL 1300 platform. It has a launch weight of , a power production capacity of 8.5 kW and a 15-year design lif ...
telecommunications satellite to a
geosynchronous transfer orbit
A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellites that are destined for geosynchronous (GSO) or geostationary orbit (GEO) are (almost) always put into a GTO as an intermediate step f ...
. The first stage
re-entered the atmosphere and landed vertically on the ''Of Course I Still Love You'' drone ship that was located in the Atlantic Ocean.
Transition to routine reuse
SpaceX continued to return a number of first stages in both ground and sea landings to clarify the procedures needed to re-use flown boosters. The company had hoped to begin offering pre-flown Falcon 9 rocket stages commercially by the end of 2016,
but the first re-used booster eventually took off on March 30, 2017, with the
SES-10
SES-10, is a geostationary communications satellite awarded in February 2014, owned and operated by SES S.A. and designed and manufactured by Airbus Defence and Space on the Eurostar-3000 satellite bus. It is positioned at the 67° West posi ...
mission. The booster performed well and was recovered a second time.
In January 2016 Musk evaluated the likelihood of success to approximately 70 percent for landing attempts in 2016, hopefully rising to 90 percent in 2017; he also cautioned that the company expected "a few more RUDs", referring to the term ''
Rapid Unscheduled Disassembly'', a humorous euphemism for destruction of the vehicle.
Musk's prediction were close to the actual numbers, as five out of eight flown boosters () were recovered in 2016, and 14 out of 14 () in 2017. Three GTO missions for heavy payloads were flown in an
expendable
''Expendable'' is a science fiction novel by the Canadian author James Alan Gardner, published in 1997 by HarperCollins Publishers under its various imprints.Avon Books; HarperCollins Canada; SFBC/AvoNova. Paperback edition 1997, Eos Books. It i ...
configuration, not equipped for landing. Five boosters were flown a second time in 2017, marking the beginning of routine reuse of boosters. In 2018 and 2019, more than half of the missions were flown with reused boosters.
File:Falcon 9 first stage attempts landing on ASDS after CRS-6 (17170624412).jpg, Falcon 9 first-stage attempts landing on the Autonomous spaceport drone ship
An autonomous spaceport drone ship (ASDS) is an ocean-going vessel derived from a deck barge, outfitted with station-keeping engines and a large landing platform and is autonomously controlled when on station for a landing. Construction of ...
, the landing legs are in the midst of deploying
File:CRS-6 first stage booster landing attempt.jpg, Falcon 9 Flight 17's first-stage attempting a controlled landing on the drone ship following the successful launch of CRS-6
File:ORBCOMM-2 First-Stage Landing (23271687254).jpg, Falcon 9 flight 20's first-stage moments before touchdown on Landing Zone 1
File:Falcon 9 Flight 20 OG2 first stage post-landing (23273082823) cropped.jpg, Falcon 9 flight 20's first-stage after landing
File:First stage of Jason-3 rocket (24382360351).jpg, Falcon 9 flight 21's landing approach before it soft-landed and tipped over due to a leg lock failure
File:CRS-8 first stage landing (26366878046).jpg, Falcon 9 flight 23's first-stage was the first successful landing on the drone ship
File:JCSAT-14 first stage on droneship (26820653346).jpg, Falcon 9 flight 24's first stage on the drone ship
File:THAICOM 8 first-stage landing (27387436926).jpg, Falcon 9 flight 25 first-stage approached the drone ship with a tilt
See also
*
SpaceX reusable launch system development program
SpaceX is private spaceflight, privately funding the development of Orbital spaceflight, orbital spacecraft, launch systems that can be reusable launch vehicle, reused many times, in a manner similar to the reusability of aircraft. SpaceX has ...
*
List of Falcon 9 and Falcon Heavy launches
Since June 2010, rockets from the Falcon 9 family have been launched times, with full mission successes, one partial failure and one total loss of the spacecraft. In addition, one rocket and its payload were destroyed on the launch pad durin ...
*
List of Falcon 9 first-stage boosters
A Falcon 9 first-stage booster is a reusable rocket booster used on the Falcon 9 and Falcon Heavy orbital launch vehicles manufactured by SpaceX. The manufacture of first-stage booster constitutes about 60% of the launch price of a single expe ...
References
External links
* Video of CRS-3 first-stage landing test, April 2014:
low quality, corrupted dataan
higher quality, after video frames recovered by open-source recovery effort by NSF team
* On-board camera video of ORBCOMM Mission-1 first-stage landing test
Falcon 9 First Stage Return : ORBCOMM Mission SpaceX-released video of the controlled descent test, July 2014.
* Chase-plane camera video of ORBCOMM Mission-1 first-stage landing test
Falcon 9 First Stage Reentry Footage from Plane SpaceX-released video of the controlled descent test, released August 14, 2014.
{{SpaceX
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Articles containing video clips
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