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Falcon 9 v1.1

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Falcon 9 v1.1

Falcon 9 v1.1

Launch of the 10th Falcon 9 v1.1 with the Deep Space Climate Observatory on February 11, 2015. This rocket was installed with landing legs and grid fins.[1]
Function Orbital launch vehicle[2]
Manufacturer SpaceX[2]
Country of origin United States[3]
Cost per launch $61.2M[4]
Size
Height 68.4 m (224 ft)[3]
Diameter 3.66 m (12.0 ft)[3]
Mass 505,846 kg (1,115,200 lb)[3]
Stages 2[3]
Capacity
Payload to LEO 13,150 kg (28,990 lb)[4][3]
Payload to
GTO
4,850 kg (10,690 lb)[4][3]
Launch history
Status Active
Launch sites Cape Canaveral SLC-40
Vandenberg SLC-4E[4]
Total launches 14[5]
Successes 13[5]
Failures 1[5]
First flight September 29, 2013[6]
First stage
Engines 9 Merlin 1D[3]
Thrust 5,885 kN (1,323,000 lbf)[7]
Specific impulse Sea level: 282 s[8]
Vacuum: 311 s[9]
Burn time 180 seconds[3]
Fuel LOX/RP-1[10]
Second stage
Engines Merlin Vacuum (1D)[3]
Thrust 801 kN (180,000 lbf)[9]
Specific impulse Vacuum: 340 s[3]
Burn time 375 seconds[3]
Fuel LOX/RP-1[10]

Falcon 9 v1.1 is the second version of [12]

Falcon 9 v1.1 is a significantly redesigned version of the Falcon 9 v1.0, with 60 percent more thrust and weight. It flew for the first time on a demonstration mission on the sixth overall launch of any Falcon 9 on September 29, 2013.[13]

Both stages of the two-stage-to-orbit vehicle use liquid oxygen (LOX) and rocket-grade kerosene (RP-1) propellants.[10] The Falcon 9 v1.1 can lift payloads of 13,150 kilograms (28,990 lb) to low Earth orbit, and 4,850 kilograms (10,690 lb) to geostationary transfer orbit,[14] which places the Falcon 9 design in the medium-lift range of launch systems.[15]

The Falcon 9 v1.1 and Dragon capsule combination is being used, beginning in April 2014, to resupply the International Space Station under a contract with NASA.[16] SpaceX is developing the Falcon 9 v1.1 to be able to carry humans. In late 2014, NASA awarded at least two crewed missions to SpaceX with the Falcon 9 v1.1 and Crew Dragon, with the potential for up to six.[12]

The launch of the first Falcon 9 v1.1 from SLC-4, Vandenberg AFB (Falcon 9 Flight 6) 29 September 2013.
A Falcon 9 v1.1 rocket launching the SpaceX CRS-3 Dragon spacecraft in April 2014.

Design

The base Falcon 9 v1.1 is a two-stage, LOX/RP-1–powered launch vehicle.[10]

Changes from Falcon 9 v1.0

The Falcon 9 v1.1 ELV is a 60 percent heavier rocket with 60 percent more thrust than the v1.0 version of the Falcon 9.[17] It includes realigned first-stage engines[18] and 60 percent longer fuel tanks, making it more susceptible to bending during flight.[17] The engines have been upgraded to the more powerful Merlin 1D engines. These improvements increase the payload capability to LEO from 10,454 kilograms (23,047 lb)[19] to 13,150 kilograms (28,990 lb).[14] The stage separation system has been redesigned and reduces the number of attachment points from twelve to three,[17] and the vehicle has upgraded avionics and software as well.[17]

The v1.1 booster version arranges the engines in a structural form SpaceX calls Octaweb, aimed at streamlining the manufacturing process.[20] Later v1.1 vehicles include four extensible landing legs,[21] used in the controlled-descent test program.[22][23]

Following the first launch of the Falcon 9 v1.1 in September 2013, the second-stage igniter propellant lines were insulated to better support in-space restart following long coast phases for orbital trajectory maneuvers.[24]

Falcon 9 Flight 6 was the first launch of the Falcon 9 configured with a jettisonable payload fairing.[25]

First stage

Falcon 9 v1.0 (left) and v1.1 (right) engine configurations

The Falcon 9 v1.1 uses a first stage powered by nine Merlin 1D engines.[26][27] Development testing of the v1.1 Falcon 9 first stage was completed in July 2013.[28][29]

The v1.1 first stage has a total sea-level thrust at liftoff of 5,885 kilonewtons (1,323,000 lbf), with the nine engines burning for a nominal 180 seconds, while stage thrust rises to 6,672 kilonewtons (1,500,000 lbf) as the booster climbs out of the atmosphere.[30] The nine first-stage engines are arranged in a structural form SpaceX calls an Octaweb. This change from the v1.0 Falcon 9's square arrangement is aimed at streamlining the manufacturing process.[20]

Selected flights include four extensible landing legs.[21] Additionally, some flights contain grid fins which deploy during descent to maintain control authority. Fins were first tested on the F9R Dev-1 reusable test vehicle.[31] Grid fins were implemented on the Falcon 9 v1.1 on the CRS-5 mission,[32] but ran out of hydraulic fluid before a planned landing.[33] These are part of SpaceX's effort to develop a reusable rocket launching system. Later F9R flights will have, when the technology is sufficiently developed, full vertical-landing capability.[22][23]

SpaceX intends to ultimately produce both Reusable Falcon 9 and Reusable Falcon Heavy launch vehicles. Initial atmospheric testing of prototype vehicles is being conducted on the Grasshopper experimental technology-demonstrator reusable launch vehicle (RLV), in addition to the booster controlled-descent and landing tests described above on some Falcon 9 launches.[34]

The v1.1 first stage uses a pyrophoric mixture of triethylaluminium-triethylborane (TEA-TEB) as a first-stage ignitor, the same as was used in the v1.0 version.[35]

Like the Falcon 9 v1.0 and the Saturn series from the Apollo program, the presence of multiple first-stage engines can allow for mission completion even if one of the first-stage engines fails mid-flight.[36][37]

The main propellant supply tubes from the RP-1 and liquid oxygen tanks to the nine engines on the first stage are 10 cm (4 in) in diameter.[38]

Second stage

The upper stage is powered by a single Merlin 1D engine modified for vacuum operation.[39]

The interstage, which connects the upper and lower stage for Falcon 9, is a carbon fiber aluminum core composite structure.[40] Separation collets and a pneumatic pusher system separate the stages.[41] The Falcon 9 tank walls and domes are made from aluminium-lithium alloy.[42] SpaceX uses an all-friction stir welded tank, a technique which minimizes manufacturing defects and reduces cost, according to a NASA spokesperson.[43] The second-stage tank of Falcon 9 is simply a shorter version of the first-stage tank and uses most of the same tooling, material and manufacturing techniques. This saves money during vehicle production.[36]

Payload fairing

The fairing design was completed by SpaceX, with production of the 13 m (43 ft)-long, 5.2 m (17 ft)-diameter payload fairing in Hawthorne, California.[44]

Testing of the new fairing design was completed at NASA's Plum Brook Station facility in spring 2013 where acoustic shock, mechanical vibration, and electromagnetic electrostatic discharge conditions were simulated. Tests were done on a full-size test article in vacuum chamber. SpaceX paid NASA US$581,300 to lease test time in the $150M NASA simulation chamber facility.[45]

The first flight of a Falcon 9 v1.1 (CASSIOPE, September 2013) was the first launch of the Falcon 9 v1.1 as well as the Falcon 9 family configured with a payload fairing. The fairing separated without incident during the launch of CASSIOPE as well as the two subsequent GTO insertion missions.[45] In Dragon missions, the capsule protects any small satellites, negating the need for a fairing.[46]

Control

SpaceX uses multiple redundant flight computers in a fault-tolerant design. Each Merlin engine is controlled by three voting computers, each of which has two physical processors that constantly check each other. The software runs on Linux and is written in C++.[47]

For flexibility, commercial off-the-shelf parts and system-wide "radiation-tolerant" design are used instead of rad-hardened parts.[47] Falcon 9 v1.1 continues to utilize the triple redundant flight computers and inertial navigation—with GPS overlay for additional orbit insertion accuracy—that were originally used in the Falcon 9 v1.0.[36]

Falcon 9 v1.1 Full Thrust

SpaceX is making a number of changes to the existing Falcon 9 v1.1 rocket in 2015. Changes will include a new propellant mix, changes to the launch vehicle thrust structure, a higher-performance engine—the Merlin 1D has completed a substantive round of additional qualification testing since it was initially used in late-2013 on the early Falcon 9 v1.1 missions—and several size and volume changes to the first stage and second stage propellant tanks as well as several small mass reduction efforts.[48] SpaceX plans to use the upgraded Falcon 9 first stage as boosters for the Falcon Heavy, which will use a different design for the core stage. Although the name for the upgraded vehicle is not officially released, the new Falcon 9 is internally known as Falcon 9 v1.1 Full Thrust.[49] Other names include Enhanced Falcon 9, Falcon 9 v1.2, and Full-Performance Falcon 9.[50]

A principal objective of the new design is to facilitate booster reusability on a larger set of payloads, including allowing reusability on the typical large commsats launched to geosynchronous orbit.[51]

Several of the specific design details for the Falcon 9 v1.1 Full Thrust were released by Elon Musk on 1 March 2015. The modifications include increasing engine thrust by 15 percent, increasing tank volume by 10 percent, and subcooling the cryogenic oxygen to obtain greater density. [52]

In order to support the upgrades, SpaceX President Gwynne Shotwell noted that minor structural modifications would be made to the Falcon 9 vehicle.[53] As of March 2015, SpaceX had finished development on the higher thrust Merlin 1D rocket engines. In an interview with Shotwell, she noted:

So, we got the higher thrust engines, finished development on that, we're in qual. What we're also doing is modifying the structure a little bit. I want to be building only two versions, or two cores in my factory, any more than that would not be great from a customer perspective. It's about a 30% increase in performance, maybe a little more. What it does is it allows us to land the first stage for GTO missions on the drone ship.[50]

According to a SpaceX statement, Falcon 9 v1.1 Full Thrust will likely not require a recertification to launch for United States government contracts. Shotwell stated that "It is an iterative process [with the agencies]" and that "It will become quicker and quicker to certify new versions of the vehicle."[54]

SES S.A., a satellite owner and operator, announced plans in February 2015 to launch its SES-9 satellite on the first flight of the Falcon 9 with upgraded engines.[55] Moreover, the other planned upgrades to the Falcon 9—including increased second stage tank volume; larger Merlin 1D vacuum engine nozzle; larger and stronger interstage with revised stage-separation mechanism; revised grid fin design; upgraded structure in the landing legs, first stage structure, and octaweb engine support structures; plus liquid oxygen subcooling—will be implemented on the SES-9 flight.[56]

However, SpaceX has decided to move SES-9 to the second flight of the Falcon 9 and launch Orbcomm OG2's second constellation for the first flight of the Falcon 9 v1.1 Full Thrust. According to Chris Bergin of NASASpaceFlight, SES-9 requires a more complicated second stage burn profile involving one restart of the second stage engine. Therefore, SpaceX will launch Orbcomm's payload first because the mission profile "will allow for the Second Stage to conduct additional testing ahead of the more taxing SES-9 mission."[57] According to a spokesperson from SES S.A., SpaceX proposed the swap because of the high-risk nature of the first in-space restart of an upgraded second stage engine. The spokesperson added that the company is aiming for "a late December launch", with Orbcomm's mission targeted for a late November launch.[58]

Falcon 9 v1.1 Full Thrust's maiden first stage began acceptance testing at SpaceX's McGregor facility in September 2015. Two static fire tests are planned, with a full-duration firing scheduled to occur after a short-duration test firing of all nine Merlin 1D engines.[49] The first of two static fire tests was completed on 21 September 2015, which included the densified propellant and the higher-thrust Merlin 1D engines.[59] The rocket reached full throttle during the static fire. According to Spaceflight Now, the rocket that completed the test will launch no earlier than 17 November 2015.[60]

Development and production

From left to right, Falcon 1, Falcon 9 v1.0, three versions of Falcon 9 v1.1, and two versions of Falcon Heavy. (All three v1.1 versions have flown; neither Falcon Heavy version has yet flown.)

A test of the ignition system for the Falcon 9 v1.1 first stage was conducted in April 2013.[61] On 1 June 2013, a ten-second firing of the Falcon 9 v1.1 first stage occurred; a full-duration, 3-minute firing was expected a few days later.[62][63]

By September 2013, SpaceX total manufacturing space had increased to nearly 1,000,000 square feet (93,000 m2) and the factory had been configured to achieve a production rate of up to 40 rocket cores per year, for both the Falcon 9 v1.1 and the tri-core Falcon Heavy.[64] The November 2013 production rate for Falcon 9 vehicles was one per month. The company has stated that this will increase to 18 per year in mid-2014, and will be 24 launch vehicles per year by the end of 2014.[24]

As launch manifest and launch rate increases in 2014–2016, SpaceX is looking to increase their launch processing by building dual-track parallel launch processes at the launch facility. As of March 2014, they project they will have this in operation sometime in 2015, and are aiming for a 2015 launch pace of about two launches per month.[65]

Other launcher versions

There have been two versions of the Falcon 9. The original Falcon 9 flew five successful orbital launches in 2010–2013, all carrying the Dragon spacecraft or a test version of the spacecraft.[25]

The Falcon 9 v1.1 is a 60 percent heavier rocket with 60 percent more thrust than the v1.0 version of the Falcon 9.[17] It includes realigned first-stage engines[18] and 60 percent longer fuel tanks. The engines themselves were upgraded to the more powerful Merlin 1D. These improvements have increased the payload capability from 9,000 kilograms (20,000 lb) on the Falcon 9 v1.0 to 13,150 kilograms (28,990 lb).[14]The stage separation system was redesigned and reduced the number of attachment points from twelve to three.[17] The avionics and software have been upgraded in the v1.1 version as well.[17] The v1.1 first stage will also be used as side boosters on the Falcon Heavy launch vehicle.[66]

A third version of the rocket is under development. The Falcon 9-R, a reusable variant of the Falcon 9 family, is being developed using systems and software technology being developed as part of the SpaceX reusable launch system development program by SpaceX to facilitate rapid reusability of both the first and second stages.[67] Various technologies are being tested on the Grasshopper technology demonstrator, as well as some flights of the Falcon 9 v1.1 on which post-mission booster controlled-descent tests are being conducted.[68]

Future reusability

The Falcon 9 v1.1 includes several aspects of reusable launch vehicle technology included in its design, as of the initial v1.1 launch in September 2013 (throttleable and restartable engines on the first stage, a first-stage tank design that can structurally accommodate the future addition of landing legs, etc.). The Falcon 9 v1.1's launch occurred two years after SpaceX committed to a privately funded development program with the goal to obtain full and rapid reusability of both stages of the launch vehicle.[69]

Design was complete on the system for "bringing the rocket back to launchpad using only thrusters" in February 2012.[70] The reusable launch system technology is being considered for both the Falcon 9 and the Falcon Heavy, and is considered particularly well suited to the Falcon Heavy where the two outer cores separate from the rocket much earlier in the flight profile, and are therefore moving at slower velocity at stage separation.[70]

A reusable first stage is now being flight tested by SpaceX with the suborbital Grasshopper rocket.[71] By April 2013, a low-altitude, low-speed demonstration test vehicle, Grasshopper v1.0, had made seven VTVL test flights from late-2012 through August 2013, including a 61-second hover flight to an altitude of 250 metres (820 ft).

In March 2013, SpaceX announced that, beginning with the first flight of the stretch version of the Falcon 9 launch vehicle (Falcon 9 v1.1)—which flew in September 2013—every first stage would be instrumented and equipped as a controlled descent test vehicle. SpaceX intends to do propulsive-return over-water tests and "will continue doing such tests until they can do a return to the launch site and a powered landing. ... [They] expect several failures before they 'learn how to do it right.'"[22] SpaceX completed multiple water landings that were successful and they now plan to land the first stage of the flight CRS-5 on an Autonomous drone port in the ocean.[23]

Photos of the first test of the restartable ignition system for the reusable Falcon 9—the Falcon 9-R— nine-engine v1.1 circular- engine configuration were released in April 2013.[61]

In March 2014, SpaceX announced that GTO payload of the future reusable Falcon 9 (F9-R), with only the booster reused, would be approximately 3,500 kg (7,700 lb).[48]

Post-mission high-altitude launch vehicle testing of Falcon 9 v1.1 boosters

Falcon 9 Flight 17's first stage attempting a controlled landing on the Autonomous Spaceport Drone Ship following the launch of CRS-6 to the International Space Station. The stage landed hard and tipped over after landing.

The post-mission test plan calls for the first-stage booster on the sixth Falcon 9 flight, and several subsequent F9 flights, to do a burn to reduce the rocket's horizontal velocity and then effect a second burn just before it reaches the water. SpaceX announced the test program in March 2013, and their intention to continue to conduct such tests until they can return to the launch site and perform a powered landing.[22]

Falcon 9 Flight 6's first stage performed the first propulsive-return over-water tests on 29 September 2013.[10] Although not a complete success, the stage was able to change direction and make a controlled entry into the atmosphere.[10] During the final landing burn, the ACS thrusters could not overcome an aerodynamically induced spin, and centrifugal force deprived the landing engine of fuel leading to early engine shutdown and a hard splashdown which destroyed the first stage. Pieces of wreckage were recovered for further study.[10]

The next test, using the first stage from SpaceX CRS-3, led to a successful soft ocean landing, however it presumably broke up in heavy seas before it could be recovered.[72]

After further ocean landing tests, the first stage of the CRS-5 launch vehicle attempted a landing on a floating landing platform, the Autonomous spaceport drone ship. The rocket landed too hard for survival but guided itself to the ship successfully.[73] The first stage of the CRS-6 mission managed a soft landing on the platform; however, excess lateral velocity caused it to quickly tip over and explode.[74] SpaceX CEO Elon Musk indicated that a throttle valve for the engine was stuck and did not respond quickly enough for a landing.[75]

Launch sites

SpaceX is using both Launch Complex 40 at Cape Canaveral Air Force Station and Launch Complex 4E at Vandenberg Air Force Base for launching Falcon 9 v1.1 rockets. The Vandenberg site was first used by SpaceX for the first v1.1 launch, on 29 Sep 2013.[10][76]

SpaceX is currently building an additional launch site in Florida for crewed missions on land leased from NASA at Kennedy Space Center. Architectural and engineering design work on the pad modifications began in 2013, the contract to lease the pad from NASA was signed in April 2014, with construction commencing later in 2014,[77] including the building of a large Horizontal Integration Facility (HIF) in order to house both Falcon 9 v1.1 and Falcon Heavy launch vehicles with associated hardware and payloads during processing.[78]

An additional Puerto Rico.[80][81]

Launch prices

As of October 2015, the Falcon 9 v1.1 commercial launch price is US$61.2 million,[4] competing for commercial launches in an increasingly competitive market.[82]

NASA resupply missions to the ISS—which include the provision of the space capsule payload, a new Dragon cargo spacecraft for each flight—have an average price of $133 million.[83] The first twelve cargo transport flights contracted to NASA were done at one time, so no price change is reflected for the v1.1 launches as opposed to the v1.0 launches. The contract was for a specific amount of cargo carried to, and returned from, the Space Station over a fixed number of flights.

SpaceX stated that due to mission assurance process costs, launches for the U.S. military would be priced about 50% more than commercial launches, so a Falcon 9 launch would sell for about $90 million to the US government, compared to an average cost to the US government of nearly $400 million for current non-SpaceX launches.[84]

Secondary payload services

Falcon 9 payload services include secondary and tertiary payload connection via an ESPA-ring, the same interstage adapter first utilized for launching secondary payloads on US DoD missions that utilize the Evolved Expendable Launch Vehicles (EELV) Atlas V and Delta IV. This enables secondary and even tertiary missions with minimal impact to the original mission. As of 2011, SpaceX announced pricing for ESPA-compatible payloads on the Falcon 9.[85]

Launch history

As of June 2015, SpaceX had made 14 launches of the Falcon 9 v1.1, and 19 total launches of any Falcon 9 rocket since 2010. 18 of 19 launches have successfully delivered their primary payloads to either Low Earth orbit or Geosynchronous Transfer Orbit. The only failed launch of the Falcon 9 v1.1 is SpaceX CRS-7, which was lost during first stage operation. This was due to an overpressure event in the second stage oxygen tank. [86] The return to flight launch following the failure will be Falcon 9 Flight 20, with the Falcon 9 v1.1 Full Thrust vehicle carrying the second Orbcomm OG2 constellation.[58]

The first launch of the substantially upgraded Falcon 9 v1.1 vehicle successfully flew on 29 September 2013,[10][87]

The maiden Falcon 9 v1.1 launch included a number of "firsts":[6][88]

See also

References

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  35. ^ Mission Status Center, June 2, 2010, 1905 GMT, SpaceflightNow, accessed 2010-06-02, Quotation: "The flanges will link the rocket with ground storage tanks containing liquid oxygen, kerosene fuel, helium, gaserous nitrogen and the first stage ignitor source called triethylaluminum-triethylborane, better known as TEA-TAB."
  36. ^ a b c
  37. ^ Behind the Scenes With the World's Most Ambitious Rocket Makers, Popular Mechanics, 2009-09-01, accessed 2012-12-11. "It is the first since the Saturn series from the Apollo program to incorporate engine-out capability—that is, one or more engines can fail and the rocket will still make it to orbit."
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External links

  • Falcon 9 official page
  • Falcon Heavy official page
  • Test firing of two Merlin 1C engines connected to Falcon 9 first stage, Movie 1, Movie 2 (January 18, 2008)
  • Press release announcing design (September 9, 2005)
  • SpaceX hopes to supply ISS with new Falcon 9 heavy launcher (Flight International, September 13, 2005)
  • SpaceX launches Falcon 9, With A Customer (Defense Industry Daily, September 15, 2005)
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