Falcon 1 was a two-stage small-lift launch vehicle that was operated from 2006 to 2009 by SpaceX, an American aerospace manufacturer. On September 28, 2008, Falcon 1 became the first privately developed fully liquid-fueled launch vehicle to successfully reach orbit.
The Falcon 1 used LOX/RP-1 for both stages, the first stage powered by a single pump-fed Merlin engine, and the second stage powered by SpaceX's pressure-fed Kestrel vacuum engine.
The vehicle was launched a total of five times. After three failed launch attempts, Falcon 1 achieved orbit on its fourth attempt in September 2008 with a mass simulator as a payload. On July 14, 2009, Falcon 1 made its second successful flight, delivering the Malaysian RazakSAT satellite to orbit on SpaceX's first commercial launch (fifth and final launch overall).
While SpaceX had announced an enhanced variant, the Falcon 1e, following this flight, the Falcon 1 was retired in favor of the Falcon 9 v1.0, the first version of the company's successful and long-running Falcon 9 launch vehicle.
History
Private funding The Falcon 1 rocket was developed with private funding. The only other orbital launch vehicles to be privately funded and developed were the Conestoga in 1982; and Pegasus, first launched in 1990, which uses a large aircraft as its launch platform.
The total development cost of Falcon 1 was approximately US$90 million to US$100 million.
While the development of Falcon 1 was privately funded, the first two Falcon 1 launches were purchased by the United States Department of Defense under a program that evaluates new US launch vehicles suitable for use by DARPA.Graham Warwick and Guy Norris, "Blue Sky Thinking: DARPA at 50," Aviation Week & Space Technology, Aug 18–25, 2008, p. 18.
Cancelled launches As part of a US$15 million contract, Falcon 1 was to carry the TacSat-1 in 2005. By late May 2005, SpaceX stated that Falcon 1 was ready to launch TacSat-1 from Vandenberg. But the Air Force did not want the launch of an untested rocket to occur until the final Titan IV flew from nearby SLC 4E. Subsequent and repeated delays due to Falcon 1 launch failures delayed TacSat-1's launch. After TacSat-2 was launched on an Orbital Sciences Minotaur I on December 16, 2006, the Department of Defense re-evaluated the need for launching TacSat-1. In August 2007, the Department of Defense canceled the planned launch of TacSat-1 because all of the TacSat objectives had been met.
An August 2005 update on SpaceX's website showed 6 launches planned for Falcon 1, with customers including MDA Corp (CASSIOPE, which eventually launched in 2013 on Falcon 9), Swedish Space Corp and US Air Force.
Design According to SpaceX, the Falcon 1 was designed to minimize price per launch for low-Earth-orbit satellites, increase reliability, and optimize flight environment and time to launch. It also was used to verify components and structural design concepts that would be reused in the Falcon 9. SpaceX started with the idea that the smallest useful orbital rocket was the minimum viable product (Falcon 1 with about to orbit), instead of building something larger and more complicated, and then running out of money and going bankrupt.Dead link: First stage The first stage was made from friction-stir-welded 2219 aluminum alloy. It employs a common bulkhead between the LOX and RP-1 tanks, as well as flight pressure stabilization. It can be transported safely without pressurization (like the heavier Delta II isogrid design) but gains additional strength when pressurized for flight (like the Atlas II, which could not be transported unpressurized). The parachute system, built by Irvin Parachute Corporation, uses a high-speed drogue chute and a main chute.
For the first two launches, the Falcon 1 used a Merlin 1A engine. An improved version of the Merlin 1A, the Merlin 1B, was supposed to fly on later flights of the Falcon 1, although it was further improved to create the Merlin 1C, which was first flown on the third Falcon 1 flight, and on the first 5 flights of the Falcon 9. The Falcon 1 first stage was powered by a single pump-fed Merlin 1C engine burning RP-1 and liquid oxygen providing of sea-level thrust and a specific impulse of 245 s (vacuum Isp 290 s). The first stage burns to depletion, taking around 169 seconds to do so.
Second stage The second stage Falcon 1 tanks were built with a cryogenic-compatible 2014 aluminum alloy, with the plan to move to aluminum-lithium alloy on the Falcon 1e. The helium pressurization system pumps propellant to the engine, supplies heated pressurized gas for the attitude control thrusters, and is used for zero-g propellant accumulation prior to engine restart. The Kestrel engine includes a titanium heat exchanger to pass waste heat to the helium, thereby greatly extending its work capacity. The pressure tanks are composite overwrapped pressure vessels made by Arde corporation with inconel alloy and are the same as those used in the Delta III.
The second stage was powered by a pressure-fed Kestrel engine with of vacuum thrust and a vacuum specific impulse of 330 s.
Reusability The first stage was originally planned to return by parachute to a water landing and be recovered for reuse, but this capability was never demonstrated. The second stage was not designed to be reusable.
Launch sequence At launch, the first stage engine (Merlin) is ignited and throttled to full power while the launcher is restrained and all systems are verified by the flight computer. If the systems are operating correctly, the rocket is released and clears the tower in about seven seconds. The first-stage burn lasts about 2 minutes and 49 seconds. Stage separation is accomplished with explosive bolts and a pneumatically actuated pusher system. The second stage Kestrel engine burns for about six minutes, inserting the payload into a low Earth orbit. It is capable of multiple restarts.
Pricing SpaceX quoted Falcon 1 launch prices as being the same for all customers.SpaceX, Falcon 1 Overview: Pricing and Performance (website viewed August 31, 2010) In 2005 Falcon 1 was advertised as costing $5.9 million ($9.5 million when adjusted for inflation in 2025). In 2006 until 2007 the quoted price of the rocket when operational was $6.7 million. In late 2009 SpaceX announced new prices for the Falcon 1 and 1e at $7 million and $8.5 million respectively, with small discounts available for multi-launch contracts, and in 2012 announced that payloads originally selected as flying on the Falcon 1 and 1e would fly as secondary payloads on the Falcon 9.
Historically, the Falcon 1 was originally planned to launch about to low-Earth orbit for but later declined to approximately as the price increased to approximately . It was SpaceX's offering intended to open up the smallsat launch market to competition. The final version of the Falcon 1, the Falcon 1e,Jessy Xavier, "Europes First Vega Rocket Blasts Off Successfully ," Oregon Herald, February 13, 2012 was projected to provide approximately for US$11 million. Several years ago, SpaceX was going to open up the smallsat launch market with the Falcon 1, which originally was to launch about 600 kilograms to LEO for $6 million; the payload capacity later declined to about as the price increased to around $9 million. Later, the Falcon 1e was to provide approximately for $11 million, but the company withdrew the vehicle from the market, citing limited demand.
Launch sites
All flights were launched from Kwajalein Atoll using the SpaceX launch facility on Omelek Island and range facilities of the Reagan Test Site.
Vandenberg AFB Space Launch Complex 3W was the original launch site for Falcon 1, but it was abandoned at the test-fire stage due to persistent schedule conflicts with adjacent launch pads. Cape Canaveral Air Force Station Space Launch Complex 40 (the Falcon 9 pad) was considered for Falcon 1 launches but never developed before Falcon 1 was retired.
Variants
Falcon 1 Versions Merlin A; 2006–2007 Merlin C; 2007–2009 Falcon 1e (proposed) Stage 1 1 × Merlin 1A 1 × Merlin 1C 1 × Merlin 1C Stage 2 1 × Kestrel 1 × Kestrel 1 × Kestrel Height(max; m) 21.3 22.25 26.83 Diameter 1.7 (5.57743 ft) 1.7 (5.57743 ft) 1.7 (5.57743 ft) Initial thrust(kN) 318 (71489.2 lbf) 343 (77109.5 lbf) 454 (102063 Takeoff weight(tonnes) 27.2 33.23 38.56 Fairing diameter(Inner; m) 1.5 1.5 1.71 Payload(LEO ; kg) 420 470 (290 to polar) 1,010 (430 to polar) Price(Mil. USD) 6.7 7 10.9 minimal Price/kg(LEO ; USD) ~14,000 ~14,000 ~8400 (~20,000 to polar) Success ratio(successful/total) 0/2 2/3 —
Launches Falcon 1 made five launches. The first three failed, however the subsequent two flights were successful, the first successful launch making it the first privately funded and developed liquid-propellant rocket to reach orbit. The fifth launch was its first commercial flight, and placed RazakSAT into low Earth orbit. + Launch attemptsFlight No.Date / time (UTC)Launch sitePayloadPayload massOrbitCustomersLaunch outcomeLaunch video1March 24, 2006, 22:30Omelek IslandFalconSAT-219.5 kgLEO (Planned)DARPAEngine failure at T+33 seconds. Loss of vehicle. FalconSAT-2 landed on a storage shed near the launch site.2March 21, 2007, 01:10Omelek IslandDemoSatLEO (Planned)DARPASuccessful first-stage burn and transition to second stage, maximal altitude 289 km. Harmonic oscillation at T+5 minutes. Premature engine shutdown at T+7 min 30 s. Failed to reach orbit.3August 3, 2008, 03:34Omelek IslandTrailblazer PRESat NanoSail-D Explorers4 kgLEO (Planned)ORS NASA NASA Celestis Residual stage-1 thrust led to collision between stage 1 and stage 2.4September 28, 2008, 23:15Omelek IslandRatSat165 kgLEOSpaceXInitially scheduled for Sep 23–25, carried dummy payload – mass simulator, 165 kg (originally intended to be RazakSAT).5July 14, 2009, 03:35Omelek IslandRazakSAT180 kgLEOATSBOnly commercial contract launch of Falcon 1.
First flight
Launch sequence (maiden flight example);time scale is in seconds.
The maiden flight of the Falcon 1 was postponed several times because of various technical issues with the new vehicle. Scheduling conflicts with a Titan IV launch at Vandenberg AFB also caused delays and resulted in the launch moving to the Reagan Test Site in the Kwajalein Atoll. The maiden launch was scheduled for October 31, 2005,SpaceX reveals Falcon 1 Halloween date, NASASpaceFlight.com, October 10, 2005, accessed January 31, 2019. but was held off, then rescheduled for November 25,SPACEX set maiden flight – goals, NASASpaceFlight.com, November 18, 2005, accessed January 31, 2019. which also did not occur. Another attempt was made on December 19, 2005, but was scrubbed when a faulty valve caused a vacuum in the first stage fuel tank, causing the walls of the tank to sunk inward, resulting in structural damage. After replacing the first stage, Falcon 1 launched Saturday, March 25, 2006, at 09:30 local time. The DARPA payload was the United States Air Force Academy's FalconSAT–2, which would have measured space plasma phenomena.
The launch took place on Saturday, March 24, 2006, at 22:30 UTC, from the SpaceX launch site on Omelek Island in the Marshall Islands. It ended in failure less than a minute into the flight because of a fuel line leak and subsequent fire. The vehicle had a noticeable rolling motion after liftoff, as shown on the launch video, rocking back and forth a bit, and then at T+26 seconds rapidly pitched over. Impact occurred at T+41 seconds onto a dead reef about 250 feet from the launch site. The FalconSAT–2 payload separated from the booster and landed on the island, with damage reports varying from slight to significant. SpaceX initially attributed the fire to an improperly tightened fuel-line nut. A later review by DARPA found that the nut was properly tightened, since its locking wire was still in place, but had failed because of corrosion from saltwater spray.