SpaceX Falcon 9 Overview


The Falcon launch vehicle family is designed to provide breakthrough advances in reliability, cost, flight environment and time to launch. The primary design driver is and will remain reliability, as described in more detail below. We recognize that nothing is more important than getting our customer’s spacecraft safely to its intended destination.

Like Falcon 1, Falcon 9 is a two stage, liquid oxygen and rocket grade kerosene (RP-1) powered launch vehicle. It uses the same engines, structural architecture (with a wider diameter), avionics and launch system.

Length: 54.9 m (180 ft)
Width: 3.6 m (12 ft)
Mass (LEO, 5.2m fairing): 333,400 kg (735,000 lb)
Mass (GTO, 5.2m fairing): 332,800 kg (733,800 lb)
Thrust (vacuum): 4.94 MN (1,110,000 lbf)
Data reflects the Falcon 9 Block 2 design.


Quarter section of the 5.2 m Falcon 9 fairing at SpaceX’s Hawthorne, CA headquarters.

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First Stage

The Falcon 9 tank walls and domes are made from aluminum lithium alloy. SpaceX uses an all friction stir welded tank, the highest strength and most reliable welding technique available. Like Falcon 1, the interstage, which connects the upper and lower stage for Falcon 9, is a carbon fiber aluminum core composite structure. The separation system is a larger version of the pneumatic pushers used on Falcon 1.

Nine SpaceX Merlin engines power the Falcon 9 first stage with 125,000 lbs-f sea level thrust per engine for a total thrust on liftoff of just over 1.1 Million lbs-f. After engine start, Falcon is held down until all vehicle systems are verified to be functioning normally before release for liftoff.

Falcon 9 Engines Close Up

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Second Stage

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 results in significant cost savings in vehicle production.

A single Merlin engine powers the Falcon 9 upper stage with an expansion ratio of 117:1 and a nominal burn time of 345 seconds. For added reliability of restart, the engine has dual redundant pyrophoric igniters (TEA-TEB).

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SpaceX Merlin Engine

Merlin Engine

The main engine, called Merlin, was developed internally at SpaceX, but draws upon a long heritage of space proven engines. The pintle style injector at the heart of Merlin was first used in the Apollo Moon program for the lunar module landing engine, one of the most critical phases of the mission.

Propellant is fed via a single shaft, dual impeller turbo-pump operating on a gas generator cycle. The turbo-pump also provides the high pressure kerosene for the hydraulic actuators, which then recycles into the low pressure inlet. This eliminates the need for a separate hydraulic power system and means that thrust vector control failure by running out of hydraulic fluid is not possible. A third use of the turbo-pump is to provide roll control by actuating the turbine exhaust nozzle (on the second stage engine).

Combining the above three functions into one device that we know is functioning before the vehicle is allowed to lift off means a significant improvement in system level reliability.

Sea Level Thrust : 556 kN (125,000 lbf)
Vacuum Thrust: 617 kN (138,800 lbf)
Sea Level Isp: 275s
Vacuum Isp: 304s

With a vacuum specific impulse of 304s, Merlin is the highest performance gas generator cycle kerosene engine ever built, exceeding the Boeing Delta II main engine, the Lockheed Atlas II main engine and the Saturn V F-1.

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Designed for Maximum Reliability

The vast majority of launch vehicle failures in the past two decades can be attributed to three causes: engine, stage separation and, to a much lesser degree, avionics failures. An analysis of launch failure history between 1980 and 1999 by Aerospace Corporation showed that 91% of known failures can be attributed to those subsystems.

Engine Reliability

Falcon 9 has nine Merlin engines clustered together. This vehicle will be capable of sustaining an engine failure at any point in flight and still successfully completing its mission. This actually results in an even higher level of reliability than a single engine stage. The SpaceX nine engine architecture is an improved version of the architecture employed by the Saturn V and Saturn I rockets of the Apollo Program, which had flawless flight records despite losing engines on a number of missions.

Another notable point is the SpaceX hold-before-release system — a capability required by commercial airplanes, but not implemented on many launch vehicles. After first stage engine start, the Falcon is held down and not released for flight until all propulsion and vehicle systems are confirmed to be operating normally. An automatic safe shut-down and unloading of propellant occurs if any off nominal conditions are detected.

Avionics Reliability

Falcon 9 will have triple redundant flight computers and inertial navigation, with a GPS overlay for additional orbit insertion accuracy. We have gone the extra mile in building a first class avionics system to provide medium and intermediate class satellites with the same avionics quality enjoyed by multi-billion dollar large satellites.

NASA’s Choice to Resupply the Space Station

In December 2008, NASA announced the selection of SpaceX’s Falcon 9 launch vehicle and Dragon Spacecraft to resupply the International Space Station (ISS) when the Space Shuttle retires in 2010. The $1.6 billion contract represents a minimum of 12 flights, with an option to order additional missions for a cumulative total contract value of up to $3.1 billion.

NASA cited SpaceX’s significant strengths as follows:

  • First stage engine-out capability
  • Dual redundant avionics system
  • Structural safety factor in excess of industry standards
  • Enhanced schedule efficiencies
  • Reduced overall technical risk to ISS cargo supply

Fairing Volume

Below are the standard fairing dimensions for Falcon 9. Dimensions are in meters and in inches inside the brackets. Custom fairings are available at incremental cost.



Falcon 9 – 5.2 meter diameter fairing



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Pricing and Performance

Falcon 9 will offer the lowest cost per pound/kilogram to orbit, despite providing breakthrough improvements in reliability.


SpaceX offers open and fixed pricing that is the same for all customers, including a best price guarantee. Modest discounts are available for contractually committed, multi-launch purchases. A half bay flight of Falcon 9 is available to accommodate customers with payloads in between Falcon 1 and 9.

Mission Type Price*
LEO (s/c<80% capacity to the customer orbit) $45.8M
LEO (s/c>80% capacity to the customer orbit) $51.5M
GTO (s/c<3,000 kg)** $45.8M
GTO (s/c up to 4,680 kg) $51.5M

*Standard Launch Services Pricing through 4/30/10.

Standard prices assumes standard services (see User Guide) and payment in full within the noted calendar period.

Payments made over time subject to LIBOR +2.5% financing rate. Contact SpaceX for standard payment plan.

Standard price includes a SpaceX-developed and produced payload adapter and tension-band separation system. Other systems can be accommodated or provided — contact SpaceX for more information.

Reflight insurance offered at 8.0% of Standard Launch Services Price.

**SpaceX reserves the right to seek a non-interference co-passenger

Rebates to Standard Launch Services Pricing are considered on a case-by case basis to address (i) inaugural launches, (ii) short turn around opportunities and (iii) multiple launch service procurements.


Launch Site: Cape Canaveral AFS Kwajalein
Mass to Low Earth Orbit (LEO): 10,450 kg (23,050 lb) 8,560 kg (18,870 lb)
Inclination: 28.5 degree 90 degree (polar orbit)
Mass to Geosynchronous Transfer Orbit (GTO): 4,540 kg (10,000 lb) 4,680 kg (10,320 lb)
Inclination: 28.5 degree 9.1 degree

For further information, contact us at


One thought on “SpaceX Falcon 9 Overview

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