Falcon 5

Falcon 5

Early Falcon 5 design
Function	Human-rated re-usable orbital launch vehicle
Manufacturer	SpaceX
Country of origin	United States
Size
Height	47 m (154 ft)
Diameter	3.65 m (12 ft)
Mass	155,000 kg (340,000 lb)
Stages	2
Capacity
Payload to LEO	4,200 kg (9200 lb) at 200 km orbit 28 degree inclination
Payload to Geosynchronous transfer orbit	1,250 kg (2,750 lb) 9 degree inclination
Launch history
Status	Cancelled
Launch sites	SLC-3W Vandenberg AFB Omelek Island SLC-36 Cape Canaveral Kodiak Island Wallops Island
First stage
Engines	5 Merlin
Thrust	1,890 kN (425,000 lbf)
Specific impulse	Sea level: 255 sec (2.6 kN/kg) Vacuum: 304 sec (3.0 kN/kg)
Burn time	200 seconds
Fuel	LOX/RP-1
Second stage
Engines	1 Merlin
Thrust	409 kN (93,000 lbf)
Specific impulse	Vacuum: 304 sec (3.0 kN/kg)
Burn time	265 seconds
Fuel	LOX/RP-1

The Falcon 5 was a proposed two-stage-to-orbit partially reusable launch vehicle designed by SpaceX, since canceled in preference of the larger, more powerful Falcon 9.^[1]

Overview

The first stage of Falcon 5 was to be powered by five Merlin engines and the upper stage by one Merlin engine, both burning RP-1 with a liquid oxygen oxidizer. Along with the Falcon 9, it would have been the world's only launch vehicle with all stages designed for reuse.^[2]

The Falcon 5 would have been the first American rocket since the Saturn V to have full engine out capability, meaning that with the loss of one engine, it can still meet mission requirements by burning the other four engines longer to achieve the correct orbit.^[3] In comparison, the Space Shuttle only had partial engine out capability, meaning it may not be able to achieve proper orbit by burning the remaining engines longer.^[3]

Launcher versions

In 2006, SpaceX stated that the Falcon 5 was a Falcon 9 with four engines removed.^[3] Since the launchers were being co-developed, work on the Falcon 9 was also applicable to the Falcon 5.^[3]

Sources for this table are from Space Launch Report and SpaceX and footnoted here. ^{[4] [5] [6] [7] [8]}

Payload capabilities

• LEO, 200 km (120 mi), 28 degrees:        4,100 kg (9,000 lb)^[1]
• GTO, 36,000 km (22,000 mi) 9 degrees: 1,050 kg (2,310 lb)^[3]

Related launch vehicle plans

Although an original Falcon 5 was never built, in December 2011 Stratolaunch Systems announced that they planned to develop a four- or five-engine Falcon 9-derivative two-stage liquid-fueled air-launched launch vehicle to be developed by SpaceX.^[9] The launch vehicle was planned to be "along the lines of the company's Falcon 4 [sic] or Falcon 5,"^[10] and was to have been capable of launching a 6,100 kilograms (13,500 lb) payload into low earth orbit.^[11]

The air-launched rocket concept was eventually named the Falcon 9 Air, and was being designed to have only four Merlin 1D engines. However, development was halted in late 2012 when SpaceX and Stratolaunch "amicably agreed to end [their] contractual relationship because the [Stratolaunch] launch vehicle design [had] departed significantly from the Falcon derivative vehicle envisioned by SpaceX and does not fit well with [SpaceX's] long-term strategic business model."^[12]

References

See also

• Falcon 1
• Falcon 9