# Scaled Composites Stratolaunch
The Scaled Composites Stratolaunch, nicknamed **Roc**, is a twin-fuselage, six-engine composite carrier aircraft with a 385-foot (117 m) wingspan, the largest of any fixed-wing aircraft, built as an airborne launch platform for rockets and later for hypersonic test vehicles.[1](https://scaled.com/portfolio/stratolaunch/) • [2](https://apnews.com/article/37aafcd56883a4e0885a5861b30a197e) It was designed and built by Scaled Composites of Mojave, California, under a 2011 contract from [Stratolaunch Systems](https://www.edgepedia.org/stratolaunch-systems), the company founded by Microsoft co-founder Paul G. Allen.[3](https://scaled.com/2019/10/11/having-completed-the-stratolaunch-sow-were-handing-over-the-keys/) After Allen's death and the cancellation of the original space-launch business, the aircraft was repurposed as the launch platform for the Talon-A reusable hypersonic testbed.[2](https://apnews.com/article/37aafcd56883a4e0885a5861b30a197e)
| Key fact | Detail |
|---|---|
| Wingspan | 385 feet (117 m), the largest of any fixed-wing aircraft[1](https://scaled.com/portfolio/stratolaunch/) |
| Size and weight | Length 238 feet; maximum takeoff weight 1,300,000 pounds; payload capacity about 550,000 pounds[1](https://scaled.com/portfolio/stratolaunch/) |
| Propulsion | Six Pratt & Whitney PW4056 turbofans, the engines of the Boeing 747-400, producing 336,000 pounds of thrust combined[4](https://www.twz.com/how-to-land-the-worlds-biggest-aircraft-according-to-its-test-pilot) |
| Crew and registration | Crew of 3 (two pilots, one flight engineer); US registration N351SL[1](https://scaled.com/portfolio/stratolaunch/) |
| First flight | April 13, 2019, aloft for 149 minutes and landing back at Mojave[1](https://scaled.com/portfolio/stratolaunch/) |
| Current role | Air launch of the Talon-A, a reusable autonomous hypersonic vehicle that has completed more than 10 successful flights[5](https://www.stratolaunch.com/news/stratolaunch-achieves-major-milestone-10-successful-hypersonic-flights-with-reusable-fully-autonomous-talon-a-aircraft/) |
| Fleet context | Stratolaunch also operates the modified Boeing 747 Spirit of Mojave (acquired 2023) and, as of 2026, a Boeing 777-200ER being modified as an additional Talon-A carrier[6](https://www.stratolaunch.com/faq/) • [7](https://www.axios.com/2026/09/30/stratolaunch-boeing-777-talona-hypersonics-california) |
## Design and construction
[Scaled Composites](https://www.edgepedia.org/scaled-composites) founder [Burt Rutan](https://www.edgepedia.org/burt-rutan), the aircraft designer whose [SpaceShipOne](https://www.edgepedia.org/spaceshipone) had earlier proven private air-launch spaceflight with Allen's backing, had explored large carrier-aircraft concepts for over 20 years before Allen agreed in 2011 to fund the project.[3](https://scaled.com/2019/10/11/having-completed-the-stratolaunch-sow-were-handing-over-the-keys/) • [8](https://www.wired.com/story/stratolaunch-airplane-burt-rutan-paul-allen/) The internal codename was Maliboo, but the Scaled team called it Roc, after the giant bird of prey of Middle Eastern mythology.[8](https://www.wired.com/story/stratolaunch-airplane-burt-rutan-paul-allen/)
The airframe is all composite, with flat-sided fuselages and a mostly straight wing, a shape Scaled chose after building demonstration pieces to reduce fabrication cost per pound of material.[3](https://scaled.com/2019/10/11/having-completed-the-stratolaunch-sow-were-handing-over-the-keys/) A Scaled team of 300 engineers and fabricators designed, built, and assembled the twin-fuselage vehicle.[9](https://scaled.com/2017/05/31/scaled-completes-tow-test-worlds-largest-composite-aircraft-stratolaunch/) To hold down cost and schedule, the design reuses proven [Boeing 747](https://www.edgepedia.org/boeing-747) hardware: landing gear, engines, cockpit, and flight controls come from three 747s scavenged for parts.[10](https://quartus.com/resource-type/case-study/stratolaunch-airplane-project/) • [8](https://www.wired.com/story/stratolaunch-airplane-burt-rutan-paul-allen/) The largest single components were 285-foot wing spars, each weighing 18,000 pounds, around which the rest of the aircraft was built.[8](https://www.wired.com/story/stratolaunch-airplane-burt-rutan-paul-allen/) An early design placed the cockpit at the rear on a foil connecting the two fuselages; the designers abandoned it because the weight at the back of the aircraft was too high, leaving the two fuselages joined only by the main wing.[8](https://www.wired.com/story/stratolaunch-airplane-burt-rutan-paul-allen/)
The two fuselages serve different functions: the flight crew sits in the right fuselage and flight data systems occupy the left, while the reinforced center wing carries payloads and provides lift and stability.[11](https://www.aopa.org/news-and-media/all-news/2017/december/19/immense-mother-ship-stratolaunch-taxis) Ground testing proceeded through a tow test in May 2017, the first engine runs of all six Pratt & Whitney PW4056 engines in September 2017, and low-speed taxi tests in December 2017.[9](https://scaled.com/2017/05/31/scaled-completes-tow-test-worlds-largest-composite-aircraft-stratolaunch/) • [12](https://scaled.com/2017/09/21/scaled-composites-puts-spurs-worlds-largest-aircraft/) • [13](https://scaled.com/2017/12/16/scaled-compositestaxis-worlds-largest-aircraft/)
## First flight and the end of the space-launch plan
Roc flew for the first time on April 13, 2019, staying aloft 149 minutes before landing at Mojave.[1](https://scaled.com/portfolio/stratolaunch/) Allen had died in October 2018, months before the flight.[2](https://apnews.com/article/37aafcd56883a4e0885a5861b30a197e) In January 2019 the company canceled its own family of air-launched rockets, including a reusable space plane called Black Ice and new rocket engines, to concentrate on the aircraft and a demonstration launch of Northrop Grumman Pegasus XL rockets.[14](https://spaceflightnow.com/2019/10/11/stratolaunch-under-new-ownership/) In May 2019, Reuters reported that Vulcan Inc., Allen's holding company, was closing operations and exploring a sale of assets and intellectual property.[15](https://www.engadget.com/2019-05-31-paul-allen-stratolaunch-shutdown-report.html/)
In October 2019 the company announced that Stratolaunch LLC had transitioned ownership and was continuing operations, without naming the buyer; reporting later identified the purchaser as [Cerberus Capital Management](https://www.edgepedia.org/cerberus-capital-management).[14](https://spaceflightnow.com/2019/10/11/stratolaunch-under-new-ownership/) • [6](https://www.stratolaunch.com/faq/) The two purchased Pegasus XL launchers returned to [Northrop Grumman](https://www.edgepedia.org/northrop-grumman) control, and the new owners stated a near-term strategy of reusable rocket-powered testbed vehicles and flight services.[14](https://spaceflightnow.com/2019/10/11/stratolaunch-under-new-ownership/)
## Repurposing for hypersonic flight testing
Under the new owners, Stratolaunch shifted from commercial space launch to hypersonic flight testing.[6](https://www.stratolaunch.com/faq/) In May 2022, Roc flew for the fifth time, 4 hours and 58 minutes at up to 22,500 feet, debuting a new pylon on the center wing for carrying and releasing Talon-A vehicles. The pylon weighs about 8,000 pounds and occupies 14 feet of Roc's 95-foot center wingspan, and includes a winch system that loads Talon-A from the ground.[16](https://www.stratolaunch.com/news/stratolaunch-carrier-aircraft-completes-fifth-flight-with-new-pylon/)
The Talon-A is a rocket-powered, autonomous, reusable testbed about 28 feet (8.5 m) long with an 11.3-foot (3.4 m) wingspan, designed to fly at speeds above Mach 5, the threshold of hypersonic flight.[17](https://www.space.com/technology/double-digits-air-launched-talon-a-hypersonic-vehicle-notches-big-flight-milestone) On March 9, 2024, the expendable Talon-A1 made the first powered flight: Roc released it off the central California coast, the liquid-fueled vehicle reached high supersonic speeds approaching Mach 5, and it ended with a controlled ocean landing.[2](https://apnews.com/article/37aafcd56883a4e0885a5861b30a197e) In December 2024 and March 2025, a reusable Talon-A flew twice, launching from Roc, exceeding Mach 5 over the Pacific, and landing on a runway at [Vandenberg Space Force Base](https://www.edgepedia.org/vandenberg-space-force-base), the first reuse of the same autonomous hypersonic vehicle months apart.[18](https://www.axios.com/2025/05/07/hypersonic-talona-stratolaunch-machtb-northrop)
By July 2026 the company announced more than 10 successful hypersonic flights with Talon-A, all flown with no onboard crew and no human in the loop, with multiple flights performed by the same vehicle.[5](https://www.stratolaunch.com/news/stratolaunch-achieves-major-milestone-10-successful-hypersonic-flights-with-reusable-fully-autonomous-talon-a-aircraft/) The work is funded largely through the Pentagon's Multi-Service Advanced Capability Hypersonic Test Bed (MACH-TB) program: in November 2023 Stratolaunch received a flight test contract from Leidos, the MACH-TB prime contractor, funding five Talon-A flights, and the company counts the Air Force, Navy, Missile Defense Agency, and NASA among its customers.[19](https://www.stratolaunch.com/news/stratolaunch-awarded-flight-contract-mach_tb/) • [7](https://www.axios.com/2026/09/30/stratolaunch-boeing-777-talona-hypersonics-california)
## The carrier fleet
Roc is no longer the only launch platform. Stratolaunch acquired [Spirit of Mojave](https://www.edgepedia.org/spirit-of-mojave), a modified [Boeing 747-400](https://www.edgepedia.org/boeing-747-400), in 2023 and refurbished it as an operational Talon-A launch platform, adding worldwide deployability and what the company calls a proven 747 maintenance ecosystem.[6](https://www.stratolaunch.com/faq/) • [5](https://www.stratolaunch.com/news/stratolaunch-achieves-major-milestone-10-successful-hypersonic-flights-with-reusable-fully-autonomous-talon-a-aircraft/) In September 2026 the company bought a [Boeing 777](https://www.edgepedia.org/boeing-777)-200ER to modify with pylon stations for Talon-A air launch, an addition the chief executive said increases flight capacity by about 35 percent and moves the company toward multiple simultaneous hypersonic tests; the Pentagon has stated a goal of 50 hypersonic flights per year for MACH-TB.[7](https://www.axios.com/2026/09/30/stratolaunch-boeing-777-talona-hypersonics-california)
## Why air launch
The original rationale was operational: launching from altitude offers payload capacity in weight and volume, flexible launch locations, weather avoidance, and increased responsiveness, and a runway-based operation avoids the towers, sound suppression, and fixed infrastructure of a vertical launch pad.[6](https://www.stratolaunch.com/faq/) • [20](https://www.engineering.com/how-stratolaunch-soared-to-success-by-flying-a-little-lower/) The performance case is narrower. Rutan estimated at the 2011 announcement that for reaching orbit, air launch provides a performance advantage of only about five to ten percent, though he argued that a small advantage matters in a business where small margins are significant.[21](https://thespacereview.com/article/1994/1) The aircraft's size constrains operations: the original design called for a 3,650-meter (12,000-foot) runway and a range of 2,400 kilometers (1,500 miles), limiting the airports it could use while reaching a launch range.[21](https://thespacereview.com/article/1994/1)
For hypersonic testing the economics differ from orbital launch. A reusable, air-launched vehicle that lands on a runway can fly repeatedly at high cadence, which is what the MACH-TB program buys: rapid, affordable access to flight conditions above Mach 5 for government, commercial, and academic payloads, instead of the expensive, infrequent tests of traditional methods.[5](https://www.stratolaunch.com/news/stratolaunch-achieves-major-milestone-10-successful-hypersonic-flights-with-reusable-fully-autonomous-talon-a-aircraft/) • [19](https://www.stratolaunch.com/news/stratolaunch-awarded-flight-contract-mach_tb/)
## References
1. [Stratolaunch, Scaled Composites portfolio page](https://scaled.com/portfolio/stratolaunch/)
2. [Stratolaunch conducts first powered flight of new hypersonic vehicle off California coast, AP News (March 9, 2024)](https://apnews.com/article/37aafcd56883a4e0885a5861b30a197e)
3. [Having Completed the Stratolaunch SOW, We're Handing Over the Keys, Scaled Composites (October 11, 2019)](https://scaled.com/2019/10/11/having-completed-the-stratolaunch-sow-were-handing-over-the-keys/)
4. [How To Land The World's Biggest Aircraft According To Its Test Pilot, The War Zone](https://www.twz.com/how-to-land-the-worlds-biggest-aircraft-according-to-its-test-pilot)
5. [Stratolaunch Achieves Major Milestone: 10+ Successful Hypersonic Flights with Reusable, Fully Autonomous Talon-A Aircraft, Stratolaunch (July 2026)](https://www.stratolaunch.com/news/stratolaunch-achieves-major-milestone-10-successful-hypersonic-flights-with-reusable-fully-autonomous-talon-a-aircraft/)
6. [Stratolaunch Frequently Asked Questions](https://www.stratolaunch.com/faq/)
7. [Exclusive: Stratolaunch buys Boeing 777 to boost hypersonic testing, Axios (September 30, 2026)](https://www.axios.com/2026/09/30/stratolaunch-boeing-777-talona-hypersonics-california)
8. [Building Stratolaunch, The Largest Airplane Ever Created, WIRED](https://www.wired.com/story/stratolaunch-airplane-burt-rutan-paul-allen/)
9. [Scaled Completes Tow Test of World's Largest Composite Aircraft, Stratolaunch, Scaled Composites (May 31, 2017)](https://scaled.com/2017/05/31/scaled-completes-tow-test-worlds-largest-composite-aircraft-stratolaunch/)
10. [Stratolaunch Airplane Project, Quartus Engineering case study](https://quartus.com/resource-type/case-study/stratolaunch-airplane-project/)
11. [Immense mother ship Stratolaunch taxis, AOPA (December 19, 2017)](https://www.aopa.org/news-and-media/all-news/2017/december/19/immense-mother-ship-stratolaunch-taxis)
12. [Scaled Composites Puts the Spurs to the World's Largest Aircraft, Scaled Composites (September 21, 2017)](https://scaled.com/2017/09/21/scaled-composites-puts-spurs-worlds-largest-aircraft/)
13. [Scaled Composites Taxis World's Largest Aircraft, Scaled Composites (December 16, 2017)](https://scaled.com/2017/12/16/scaled-compositestaxis-worlds-largest-aircraft/)
14. [Stratolaunch under new ownership, Spaceflight Now (October 11, 2019)](https://spaceflightnow.com/2019/10/11/stratolaunch-under-new-ownership/)
15. [Paul Allen's Stratolaunch is reportedly shutting down, Engadget (May 31, 2019)](https://www.engadget.com/2019-05-31-paul-allen-stratolaunch-shutdown-report.html/)
16. [Stratolaunch Carrier Aircraft Completes Fifth Flight with New Pylon, Stratolaunch (May 4, 2022)](https://www.stratolaunch.com/news/stratolaunch-carrier-aircraft-completes-fifth-flight-with-new-pylon/)
17. [Double digits! Air-launched 'Talon-A' hypersonic vehicle notches big flight milestone, Space.com](https://www.space.com/technology/double-digits-air-launched-talon-a-hypersonic-vehicle-notches-big-flight-milestone)
18. [Stratolaunch goes hypersonic with reusable Talon-A vehicle, Axios (May 7, 2025)](https://www.axios.com/2025/05/07/hypersonic-talona-stratolaunch-machtb-northrop)
19. [Stratolaunch Awarded Flight Test Contract for the Navy's MACH-TB Hypersonic Program, Stratolaunch (November 28, 2023)](https://www.stratolaunch.com/news/stratolaunch-awarded-flight-contract-mach_tb/)
20. [How Stratolaunch soared to success by flying a little lower, Engineering.com](https://www.engineering.com/how-stratolaunch-soared-to-success-by-flying-a-little-lower/)
21. [Stratolaunch: SpaceShipThree or Space Goose?, The Space Review (2011)](https://thespacereview.com/article/1994/1)
---
*Topic: Encyclopedia › Technology and the built world › Transport and spaceflight › Spaceflight › Launch systems and rocketry › Spaceports and launch infrastructure › Major launch complexes and platforms › Air launch platforms*
*Initially written Sep 17, 2026 · Reviewed: Oct 15, 2026 · Edited: Oct 15, 2026 · Last review: Oct 15, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license