| AeroVironment | |
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HW100 - 45000
UAW55 - 105000 RRW100 - 175000 PKRR - 7500 |
AeroVironment AeroVironment, Inc. Type - Public Traded as - Nasdaq: AVAV / S&P 600 component Industry - Aerospace industry, Energy industry Founded - 1971; 51 years ago Headquarters - Arlington, Virginia, United States Key people - Paul B. MacCready Jr., Founder Revenue - Increase US$ 394.912 million (2021) Operating income - Increase US$ 43.538 million (2012) Net income - Decrease US$ 14 million (estd.) (2021) Total assets - Decrease US$ 401.6 million (2021) Total equity - Increase US$ 978.4 million (2020) Website - www.avinc.com AeroVironment, Inc. is an American defense contractor headquartered in Arlington, Virginia, that designs and manufactures unmanned aerial vehicles (UAVs). Dr. Paul B. MacCready Jr., a designer of human-powered aircraft, founded the company in 1971. The company is best known for its lightweight human-powered and solar-powered vehicles. The company is the US military's top supplier of small drones - notably the Raven, Switchblade, Wasp and Puma models. Vehicles Among the vehicles the company built are: Gossamer Condor - The first successful human-powered airplane. The Gossamer Condor is on display at the US National Air and Space Museum (NASM), since it won the first Kremer Prize in 1977. Gossamer Albatross - In 1979 this human-powered plane flew 23 miles (37 km) across the English Channel and claimed the largest prize in aviation history. Another of these planes is displayed at the National Air and Space Museum. Gossamer Penguin - A solar-powered variant of the Gossamer Albatross. Solar Challenger - This plane flew 163 miles (262 km) from Paris, France, to England on solar power. High Altitude Solar (HALSOL) - This solar-powered unmanned aircraft was sponsored by the CIA in the 1980s as the first unmanned solar-powered aircraft prototyped for national security missions. It was declassified and transferred to the Ballistic Missile Defense Organization (BMDO) in 1993 where it was modified as a high altitude, long endurance (HALE) UAV technology demonstrator capable of becoming weaponized to destroy boost-phase theater ballistic missiles (Boost Phase Intercept).The goal was to develop the world's first "fly forever" HALE UAV that could be configured for national security missions. The program was cancelled in 1995 due to budget reductions in the Clinton Administration at which time the aircraft, called Pathfinder, was transferred to NASA. Pathfinder flew flight test missions at NASAs Dryden Flight Research Center before the transfer. NASA Pathfinder and Pathfinder Plus - This unmanned plane, built by AeroVironment as a part of the NASA Environmental Research Aircraft and Sensor Technology (ERAST) Program, demonstrated that an airplane could stay aloft for extended periods fueled by solar power. After initial successes, the Pathfinder was rebuilt into the larger Pathfinder Plus, which is on display at NASM. NASA Centurion - The Centurion was an expansion of the Pathfinder concept, designed to achieve the ERAST Program goal of sustained flight at 100,000 feet (30,000 m) altitude. NASA Helios Prototype - Derived from the Centurion, this solar cell and fuel cell powered UAV set a world record for flight at 96,863 feet (29,524 m). It was intended to be the prototype for the production Helios aircraft, envisioned as an "atmospheric satellite". The ERAST program was terminated in 2003, and as of 2008 Helios has not entered production. In actuality, it has been reborn in the form of the Global Observer UAS, currently in development under a Joint Concept Technology Demonstration led by United States Special Operations Command (USSOCOM]). The key technology shift was switching from solar power to liquid hydrogen power. Global Observer - The Los Angeles Times reported first flight of Global Observer in the Mojave Desert in January, 2011. The aircraft was powered by hydrogen. It appears to have 4 motors with twin-bladed props, a 175-foot (53 m) wingspan, 65,000-foot (20,000 m) maximum altitude, airspeed greater than 120 mph (190 km/h), and 5 to 7 day maximum flight duration. Sunraycer - This solar-powered car won the first world's first solar car race in Australia in 1987. The next fastest car finished two days later. This car is at the Smithsonian National Museum of American History. GM Impact - This was an electric car, developed as a prototype for a mass-production consumer car. RQ-11 Raven - A small military UAV. It is hand launched with a wingspan of 4.5 feet (1.4 m) and a weight of 4.2 pounds (1.9 kg), providing color and infrared video to its handheld ground control and remote viewing stations. Over 9,000 Ravens had been delivered or were on order as of June 2008. Wasp III - A miniature, hand-launched UAV that provides aerial observation at line-of-sight ranges up to 3.1 miles (5.0 km). In 2007, the Wasp was selected by the US Air Force as the choice for their BATMAV Program. As of 2008, over 1,000 Wasp aircraft had been delivered. RQ-20 Puma - A small lightweight, battery powered, hand-launched production UAV that provides aerial observation at line-of-sight ranges up to 6.2 miles (10.0 km). Puma's avionics enable autonomous flight via GPS navigation. It was designed to demonstrate advanced propulsion technologies. It flew in June 2007 for five hours, powered by an onboard "fuel cell battery hybrid energy storage system". A flight in November 2007 lasted more than seven hours. On July 2, 2008, USSOCOM selected the Puma AE variant as its All Environment Capable Variant (AECV) solution. Nano Hummingbird - Announced in 2011, a hummingbird look-alike drone equipped with a camera, it could fly at speeds of up to 11 miles (18 km) per hour. It could climb and descend vertically, fly sideways, forward and backward, as well as rotate clockwise and counter-clockwise by remote control for about eight minutes. SkyTote - A vertical take-off and landing (VTOL)-fixed wing hybrid UAV, which offered VTOL takeoff capability and decreased energy usage. Switchblade - A miniature, electrically powered, armed unmanned drone kamikaze weapon, for field use. Now deployed in two configurations, the 300 for attacking personnel and the 600 for attacking armor. FQM-151 Pointer RQ-14 Dragon Eye Puma LE (Long Endurance) VAPOR Helicopter Snipe - A quadrotor design small enough to be deployed by an individual to collect surveillance. It weighs 5 oz (0.14 kg), can reach speeds of 20 mph (32 km/h) with a range of more than 0.6 mi (0.97 km). It has flight times of 15 minutes, can withstand winds of 15 mph (24 km/h), and is equipped with EO/IR. It is low light-capable and includes long-wave infrared sensors to take photos or video in day or night conditions. In May 2017, the first 20 Snipes were delivered to an undisclosed U.S. military customer. Programs As of 2007 AeroVironment held a five-year, $4.7 million IDIQ (indefinite-delivery, indefinite-quantity) contract from the U.S. Air Force Research Laboratory to develop UAV propulsion technologies. The contract also provided for specific tasks such as integration of solar cells into aircraft wings, electric motor efficiency improvement, and hydrogen storage systems. HAPSMobile HAPSMobile is a subsidiary of SoftBank planning to operate High Altitude Platform Station (HAPS) networks, with AeroVironment as a minority owner. HAPSMobile develops the Hawk30 solar-powered unmanned aircraft for stratospheric telecommunications, and has a strategic relationship with Loon LLC, a subsidiary of Google's parent Alphabet Inc. Subsidiaries AeroVironment owns Skytower, Inc., which was formed in 2000 to develop the technologies and government approvals to use high altitude UAVs as "atmospheric satellites", or high altitude communications relay platforms. In July 2002 the NASA/AeroVironment UAV Pathfinder Plus carried commercial communications relay equipment developed by Skytower to test using the aircraft as an "atmospheric satellite". Skytower, in partnership with NASA and the Japan Ministry of Telecommunications used the aircraft to transmit both an HDTV signal as well as an IMT-2000 wireless communications signal from 65,000 ft (20,000 m). It was the equivalent of a 12 mi (19 km) tall transmitter tower. Because of the aircraft's high angle, the transmission utilized only one watt of power, or 1/10,000 that required by a terrestrial tower to provide the same signal. According to SkyTower's Stuart Hindle, "SkyTower platforms are basically geostationary satellites without the time delay." Hindle said that such platforms flying in the stratosphere, as opposed to actual satellites, can achieve much higher levels of frequency use. "A single SkyTower platform can provide over 1,000 times the fixed broadband local access capacity of a geostationary satellite using the same frequency band, on a bytes per second per square mile basis." In January 2021, the company acquired Arcturus UAV, the manufacturer of the Arcturus T-20 UAV for US$405m. AeroVironment SkyTote SkyTote Role - Unmanned aerial vehicle Manufacturer - AeroVironment Designer - AeroVironment Retired - 2010 Status - Retired Primary user - Air Force Research Laboratory The SkyTote is an unmanned aerial vehicle (UAV), tail-sitter Vertical Take-Off and Landing (VTOL)-fixed wing hybrid plane, which attains the advantages of both airplane designs (respectively VTOL takeoff capability and decreased energy usage). In order to control the vehicle when transitioning between vertical take-off to forward flight, an adaptive neural network controller was designed by Guided Systems Technologies and used on the vehicle. The vehicle was developed by AeroVironment, under a contract given by the Air Force Research Laboratory, and its primary purpose is cargo-delivery. The SkyTote is special as it features a fly-by-wire system with remote control. As of August 2010, the SkyTote appears as a past product on the company websites, not as a current. NASA Centurion Centurion Role - Remote controlled UAV Manufacturer - AeroVironment First flight - November 10, 1998 Primary user - NASA ERAST Program Number built - 1 Developed from - NASA Pathfinder Developed into - NASA Helios The NASA Centurion was the third aircraft developed as part of an evolutionary series of solar- and fuel-cell-system-powered unmanned aerial vehicles. AeroVironment, Inc. developed the vehicles under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. They were built to develop the technologies that would allow long-term, high-altitude aircraft to serve as atmospheric satellites, to perform atmospheric research tasks as well as serve as communications platforms. It was developed from the NASA Pathfinder Plus aircraft and was developed into the NASA Helios. Centurion Centurion, originally built for the 100,000 feet (30,000 m) altitude on solar power milestone specified by the ERAST project, was the third generation aircraft in the NASA Pathfinder series of electrical-powered flying wing unmanned aircraft. The ERAST program managers had determined that an aircraft based on the Pathfinder/Pathfinder Plus concept would be the lowest risk approach of achieving the altitude goal. Initially, a quarter-scale model of the Centurion was test flown at El Mirage Dry Lake on March 4, 1997. The full-size Centurion's maiden flight took place at Rogers Dry Lake on November 10, 1998, and lasted a total of 1 hr and 24 minutes. At the time, it weighed in at 1,385 pounds (628.2 kg) (including a 150 pounds (68.0 kg) steel anvil hanging on its centerline to simulate a payload) for its first flight. The flight was nearly flawless and was followed by a second similar performance on November 19, this time before a crowd of VIPs and Media. It lasted 1 hr and 29 minutes. The third and final flight of the low altitude test series took place on December 3. On this flight the vehicle was loaded down to its maximum gross weight of 1,806 pounds (819.2 kg) to test its weight carrying capability. Total flight time on this flight was 30 minutes, as it was shortened because high winds were anticipated by mid-morning. All of these flights took place on battery power and verified the design's handling qualities, performance, and structural integrity. Following these three flights, NASA decided to expand the aircraft into the Helios Prototype, with work starting in January, 1999. Aircraft description The design of Centurion resulted in an aircraft that looked very much like the Pathfinder, but with a much longer wingspan of 206 feet (63 m). Although the Centurion shape resembled the Pathfinder, the structure was designed to be stronger and capable of carrying numerous payloads (up to 600 pounds (272.2 kg)) more efficiently. Its wing incorporated a redesigned high-altitude airfoil and the span was increased to 206 feet (63 m). The number of motors was increased to 14 and the number of underwing pods to carry batteries, flight control system components, ballast, and landing gear rose to four. Specifications - Pathfinder - Pathfinder-Plus - Centurion - Helios HP01 - Helios HP03 Length ft(m) - 12 (3.6) - 12 (3.6) - 12 (3.6) - 12 (3.6) - 16.5 (5.0) Chord ft(m) - 8 (2.4) - 8 (2.4) - 8 (2.4) - 8 (2.4) - 8 (2.4) Wingspan ft(m) - 98.4 (29.5) - 121 (36.3) - 206 (61.8) - 247 (75.3) - 247 (75.3) Aspect ratio - 12 to 1 - 15 to 1 - 26 to 1 - 30.9 to 1 - 30.9 to 1 Glide ratio - 18 to 1 - 21 to 1 - ? - ? - ? Airspeed kts(km/h) - ? - ? - 15-18 (27-33) - 16.5-23.5 (30.6-43.5) - ? Max altitude ft(m) - 71,530 (21,802) - 80,201 (24,445) - n/a - 96,863 (29,523) - 65,000 (19,812) Empty Wt lb(kg) - ? - ? - ? - 1,322 (600) - ? Max. weight lb(kg) - 560 (252) - 700 (315) - ±1,900 (±862) - 2,048 (929) - 2,320 (1,052) Payload lb(kg) - 100 (45) - 150 (67,5) - 100-600 (45-270) - 726 (329) - ? Engines - electric, 2 hp (1.5 kW) each - electric, 2 hp (1.5 kW) each - electric, 2 hp (1.5 kW) each - electric, 2 hp (1.5 kW) each - electric, 2 hp (1.5 kW) each No. of engines - 6 - 8 - 14 - 14 - 10 Solar pwr output (kW) - 7.5 - 12.5 - 31 - ? - 18.5 Supplemental power - batteries - batteries - batteries - Li batteries - Li batteries, fuel cell The prehistory of endurance UAVs / Electric vehicle / Electric aircraft / QinetiQ Zephyr / Pegasus UAV / Regenerative fuel cell / Scaled Composites Proteus / Solar Impulse project AeroVironment Helios Prototype (NASA Helios) Helios Prototype Role - Unmanned aerial vehicle Manufacturer - AeroVironment First flight - September 8, 1999 Status - Destroyed in 2003 Primary user - NASA ERAST Program Number built - 1 Developed from - NASA Pathfinder, Pathfinder Plus and NASA Centurion The Helios Prototype was the fourth and final aircraft developed as part of an evolutionary series of solar- and fuel-cell-system-powered unmanned aerial vehicles. AeroVironment, Inc. developed the vehicles under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. They were built to develop the technologies that would allow long-term, high-altitude aircraft to serve as atmospheric satellites, to perform atmospheric research tasks as well as serve as communications platforms. It was developed from the NASA Pathfinder and NASA Centurion aircraft. Helios Prototype The NASA Centurion was modified into the Helios Prototype configuration by adding a sixth 41 feet (12 m) wing section and a fifth landing gear and systems pod, becoming the fourth configuration in the series of solar-powered flying wing demonstrator aircraft developed by AeroVironment under the ERAST project. The larger wing on the Helios Prototype accommodated more solar arrays to provide adequate power for the sun-powered development flights that followed. The aircraft's maiden flight was on September 8, 1999. The ERAST program had two goals when developing the Helios Prototype: 1) sustained flight at altitudes near 100,000 feet (30,000 m) and 2) endurance of at least 24 hours, including at least 14 of those hours above 50,000 feet (15,000 m). To this end, the Helios Prototype could be configured in two different ways. The first, designated HP01, focused on achieving the altitude goals and powered the aircraft with batteries and solar cells. The second configuration, HP03, optimized the aircraft for endurance, and used a combination of solar cells, storage batteries and a modified commercial hydrogen-air fuel cell system for power at night. In this configuration, the number of motors was reduced from 14 to ten. Using the traditional incremental or stairstep approach to flight testing, the Helios Prototype was first flown in a series of battery-powered development flights in late 1999 to validate the longer wing's performance and the aircraft's handling qualities. Instrumentation that was used for the follow-on solar-powered altitude and endurance flights was also checked out and calibrated during the initial low-altitude flights at NASA Dryden. Aircraft description Helios Prototype flying wing moments after takeoff, beginning its first test flight on solar power from the U.S. Navy's Pacific Missile Range Facility on Kauai, Hawaii, July 14, 2001. The Helios Prototype is an ultra-lightweight flying wing aircraft with a wingspan of 247 feet (75 m), longer than the wingspans of the U.S. Air Force C-5 military transport (222 feet (68 m) or the Boeing 747 (195 or 224 feet (59 or 68 m), depending on the model), the two largest operational aircraft built in the United States. The electrically powered Helios was constructed mostly of composite materials such as carbon fiber, graphite epoxy, Kevlar, Styrofoam, and a thin, transparent plastic skin. The main tubular wing spar was made of carbon fiber. The spar, which was thicker on the top and bottom to absorb the constant bending motions that occur during flight, was also wrapped with Nomex and Kevlar for additional strength. The wing ribs were also made of epoxy and carbon fiber. Shaped Styrofoam was used for the wing's leading edge and a durable clear plastic film covered the entire wing. The Helios Prototype shared the same 8-foot (2.4 m) wing chord (distance from leading to trailing edge) as its Pathfinder and Centurion predecessors. The 247-foot (75 m) wingspan gave the Helios Prototype an aspect ratio of almost 31 to 1. The wing thickness was the same from tip to tip, 11.5 inches (29 cm) or 12 percent of the chord, and it had no taper or sweep. The outer panels had a built-in 10-degree dihedral to give the aircraft more lateral stability. A slight upward twist at the tips of the trailing edge helped prevent wing tip stalls during the slow landings and turns. The wing area was 1,976 sq ft (183.6 m2)., which gave the craft a maximum wing loading of only 0.81 lb./sq. ft. when flying at a gross weight of 1,600 lb. The all-wing aircraft was assembled in six sections, each about 41 feet (12 m) long. An underwing pod was attached at each panel joint to carry the landing gear, the battery power system, flight control computers, and data instrumentation. The five aerodynamically shaped pods were made mostly of the same materials as the wing itself, with the exception of the transparent wing covering. Two wheels on each pod made up the fixed landing gear-rugged mountain bike wheels on the rear and smaller scooter wheels on the front. The only flight control surfaces used on the Helios Prototype were 72 trailing-edge elevators that provided pitch control. Spanning the entire wing, they were operated by tiny servomotors linked to the aircraft's flight control computer. To turn the aircraft in flight, yaw control was applied using differential power on the motors - speeding up the motors on one outer wing panel while slowing down motors on the other outer panel. A major test during the initial flight series was the evaluation of differential motor power as a means of pitch control. During normal cruise the outer wing panels of Helios were arched upward and give the aircraft the shape of a shallow crescent when viewed from the front or rear. This configuration placed the motors on the outer wing panels higher than the motors on the center panels. Speeding up the outer-panel motors caused the aircraft to pitch down and begin a descent. Conversely, applying additional power to the motors in the center panels caused Helios to pitch up and begin climbing. From 2000 to 2001, the HP01 received a number of upgrades, including new avionics, high-altitude environmental control systems and SunPower solar array composed of more than 62,000 solar cells installed on the upper wing surface. These cells featured a rear-contact cell design that placed wires on the underside of the cells, so as not to obstruct the cells' exposure to solar radiation. Records On August 13, 2001, the Helios Prototype piloted remotely by Greg Kendall reached an altitude of 96,863 feet (29,524 m), a world record for sustained horizontal flight by a winged aircraft. The altitude reached was more than 11,000 feet (3,400 m) - or more than 2 miles (3.2 km) - above the previous altitude record for sustained flight by a winged aircraft. In addition, the aircraft spent more than 40 minutes above 96,000 feet (29,000 m). Crash On June 26, 2003, the Helios Prototype broke up and fell into the Pacific Ocean about ten miles (16 km) west of the Hawaiian Island Kauai during a remotely piloted systems checkout flight in preparation for an endurance test scheduled for the following month. On the morning of the accident, weather forecasts indicated that conditions were inside the acceptable envelope, although during the preflight go/no-go review, the weather forecaster gave it a "very marginal GO." One of the primary concerns was a pair of wind shear zones off the island's coast. After a delayed take off, due to the failure of the winds to shift as predicted, Helios spent more time than expected flying through a zone of low-level turbulence on the lee side of Kauai, because it was climbing more slowly than normal, since it had to contend with cloud shadows and the resultant reduction in solar power. As the aircraft climbed through 2,800 feet (850 m) 30 minutes into the flight, according to the subsequent mishap investigation report "the aircraft encountered turbulence and morphed into an unexpected, persistent, high dihedral configuration. As a result of the persistent high dihedral, the aircraft became unstable in a very divergent pitch mode in which the airspeed excursions from the nominal flight speed about doubled every cycle of the oscillation. The over-speed condition was exacerbated when the pilot turned off the airspeed hold loop instead of executing the correct emergency procedure and increasing the airspeed hold loop gain. The aircraft’s design airspeed was subsequently exceeded and the resulting high dynamic pressures caused the wing leading edge secondary structure on the outer wing panels to fail and the solar cells and skin on the upper surface of the wing to rip off. The aircraft impacted the ocean within the confines of the Pacific Missile Range Facility test range and was destroyed. Most of the vehicle structure was recovered except the hydrogen-air fuel cell pod and two of the ten motors, which sank into the ocean." The investigation report identified a two-part root cause of the accident: "Lack of adequate analysis methods led to an inaccurate risk assessment of the effects of configuration changes leading to an inappropriate decision to fly an aircraft configuration highly sensitive to disturbances." "Configuration changes to the aircraft, driven by programmatic and technological constraints, altered the aircraft from a spanloader to a highly point-loaded mass distribution on the same structure significantly reducing design robustness and margins of safety." Specifications - Pathfinder - Pathfinder-Plus - Centurion - Helios HP01 - Helios HP03 Length ft (m) - 12 (3.6) - 12 (3.6) - 12 (3.6) - 12 (3.6) - 16.5 (5.0) Chord ft (m) - 8 (2.4) - 8 (2.4) - 8 (2.4) - 8 (2.4) - 8 (2.4) Wingspan ft (m) - 98.4 (29.5) - 121 (36.3) - 206 (61.8) - 247 (75.3) - 247 (75.3) Aspect ratio - 12 to 1 - 15 to 1 - 26 to 1 - 30.9 to 1 - 30.9 to 1 Glide ratio - 18 to 1 - 21 to 1 - ? - ? - ? Airspeed kts (km/h) - ? - ? - 15-18 (27-33) - 16.5-23.5 (30.6-43.5) - ? Max altitude ft (m) - 71,530 (21,802) - 80,201 (24,445) - n/a - 96,863 (29,523) - 65,000 (19,812) Empty Wt lb (kg) - ? - ? - ? - 1,322 (600) - ? Max. weight lb (kg) - 560 (252) - 700 (315) - ±1,900 (±862) - 2,048 (929) - 2,320 (1,052) Payload lb (kg) - 100 (45) - 150 (67,5) - 100-600 (45-270) - 726 (329) - ? Engines - electric, 2 hp (1.5 kW) each - electric, 2 hp (1.5 kW) each - electric, 2 hp (1.5 kW) each - electric, 2 hp (1.5 kW) each - electric, 2 hp (1.5 kW) each No. of engines - 6 - 8 - 14 - 14 - 10 Solar pwr output (kW) - 7.5 - 12.5 - 31 - ? - 18.5 Supplemental power - batteries - batteries - batteries - Li batteries - Li batteries, fuel cell History of unmanned aerial vehicles . Electric aircraft . Regenerative fuel cell . QinetiQ Zephyr . Pegasus UAV . Scaled Composites Proteus . Solar Impulse project NASA Pathfinder Pathfinder / Pathfinder Plus Role - Remote controlled UAV Manufacturer - AeroVironment Primary user - NASA ERAST Program Number built - 1 Developed into - NASA Centurion / NASA Helios The NASA Pathfinder and NASA Pathfinder Plus were the first two aircraft developed as part of an evolutionary series of solar- and fuel-cell-system-powered unmanned aerial vehicles. AeroVironment, Inc. developed the vehicles under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. They were built to develop the technologies that would allow long-term, high-altitude aircraft to serve as atmospheric satellites, to perform atmospheric research tasks as well as serve as communications platforms. They were developed further into the NASA Centurion and NASA Helios aircraft. Pathfinder AeroVironment initiated its development of full-scale solar-powered aircraft with the Gossamer Penguin and Solar Challenger vehicles in the late 1970s and early 1980s, following the pioneering work of Robert Boucher, who built the first solar-powered flying models in 1974. As part of the ERAST program, AeroVironment built four generations of long endurance unmanned aerial vehicles (UAVs) under the leadership of Ray Morgan, the first of which was the Pathfinder. Development In 1983, AeroVironment obtained funding from an unspecified US government agency to secretly investigate a UAV concept designated "High Altitude Solar" or HALSOL. The HALSOL prototype first flew in June 1983. Nine HALSOL flights took place at Groom Lake in Nevada. The flights were conducted using radio control and battery power, as the aircraft had not been fitted with solar cells. HALSOL's aerodynamics were validated, but the investigation led to the conclusion that neither photovoltaic cell nor energy storage technology were mature enough to make the idea practical for the time being, and so HALSOL was put into storage. In 1993, after ten years in storage, the aircraft was brought back to flight status for a brief mission by the Ballistic Missile Defense Organization (BMDO). With the addition of small solar arrays, five low-altitude checkout flights were flown under the BMDO program at NASA Dryden in the fall of 1993 and early 1994 on a combination of solar and battery power. In 1994 the aircraft transferred to the NASA ERAST Program to develop science platform aircraft technology. It was renamed "Pathfinder" because it was "literally the pathfinder for a future fleet of solar-powered aircraft that could stay airborne for weeks or months on scientific sampling and imaging missions". A series of flights were planned to demonstrate that an extremely light and fragile aircraft structure with a very high aspect ratio (the ratio between the wingspan and the wing chord) can successfully take-off and land from an airport and can be flown to extremely high altitudes (between 50,000 feet (15,000 m) and 80,000 feet (24,000 m)) propelled by the power of the sun. In addition, the ERAST Project also wanted to determine the feasibility of such a UAV for carrying instruments used in a variety of scientific studies. On October 21, 1995, the aircraft's fragility was aptly demonstrated when it was severely damaged in a hangar accident, but was subsequently rebuilt. Aircraft description Pathfinder was powered by eight electric motors - later reduced to six - which were first powered by batteries. It had a wing span of 98.4 feet (30.0 m). Two underwing pods contain the landing gear, batteries, triple-redundant instrumentation system, and dual-redundant flight control computers. By the time the aircraft was adopted into the ERAST project in late 1993, solar cells were being added, eventually covering the entire upper surface of the wing. The solar arrays provide power for the aircraft's electric motors, avionics, communications and other electronic systems. Pathfinder also had a backup battery system that can provide power for between two and five hours to allow limited-duration flight after dark. Pathfinder flies at an airspeed of only 15 miles per hour (24 km/h) to 25 miles per hour (40 km/h). Pitch control is maintained by the use of tiny elevators on the trailing edge of the wing Turn and yaw control is accomplished by slowing down or speeding up the motors on the outboard sections of the wing. Flight testing and records Major science activities of Pathfinder missions have included detection of forest nutrient status, forest regrowth after damage caused by Hurricane Iniki in 1992, sediment/algal concentrations in coastal waters and assessment of coral reef health. Science activities are coordinated by the NASA Ames Research Center and include researchers at the University of Hawaii and the University of California. Pathfinder flight tested two ERAST-developed scientific instruments, a high spectral resolution Digital Array Scanned Interferometer (DASI) and a high spatial resolution Airborne Real-Time Imaging System (ARTIS), both developed at Ames. These flights were conducted at altitudes between 22,000 feet (6,700 m) and 49,000 feet (15,000 m) in 1997. On September 11, 1995, Pathfinder set an unofficial altitude record for solar powered aircraft of 50,000 feet (15,000 m) during a 12-hour flight from NASA Dryden. This and subsequent records claimed by NASA for Pathfinder remain unofficial, as they were not validated by the FAI, the internationally recognized aviation world record sanctioning body. The National Aeronautic Association presented the NASA-industry ERAST team with an award for one of the "10 Most Memorable Record Flights" of 1995. After further modifications, the aircraft was moved to the U.S. Navy's Pacific Missile Range Facility (PMRF) on the Hawaiian island of Kauai. On one of seven flights there in the spring and summer of 1997, Pathfinder raised the altitude record for solar-powered aircraft - as well as propeller-driven aircraft - to 71,530 feet (21,800 m) on July 7, 1997. During those flights, Pathfinder carried two lightweight imaging instruments to learn more about the island's terrestrial and coastal ecosystems, demonstrating the potential of such aircraft as platforms for scientific research. Pathfinder-Plus During 1998, the Pathfinder was modified into the longer-winged Pathfinder-Plus configuration. It used four of the five sections from the original Pathfinder wing, but substituted a new 44 feet (13 m) long center wing section that incorporated a high-altitude airfoil designed for the follow-on Centurion/Helios. The new section was twice as long as the original, and increased the overall wingspan of the craft from 98.4 feet (30.0 m) to 121 feet (37 m). The new center section was topped by more-efficient silicon solar cells developed by SunPower Corporation of Sunnyvale, California, which could convert almost 19 percent of the solar energy they receive to useful electrical energy to power the craft's motors, avionics and communication systems. That compared with about 14 percent efficiency for the older solar arrays that cover most of the surface of the mid- and outer wing panels from the original Pathfinder. Maximum potential power was boosted from about 7,500 watts on Pathfinder to about 12,500 watts on Pathfinder-Plus. The number of electric motors was increased to eight, and the motors used were more powerful units, designed for the follow-on aircraft. The Pathfinder-Plus development flights flown at PMRF in the summer of 1998 validated power, aerodynamic, and systems technologies for its successor, the Centurion. On August 6, 1998, Pathfinder-Plus, piloted by Derek Lisoski, proved its design by raising the national altitude record to 80,201 feet (24,445 m) for solar-powered and propeller-driven aircraft. Atmospheric satellite tests In July 2002 Pathfinder-Plus carried commercial communications relay equipment developed by Skytower, Inc., a subsidiary of AeroVironment, in a test of using the aircraft as a broadcast platform. Skytower, in partnership with NASA and the Japan Ministry of Telecommunications, tested the concept of an "atmospheric satellite" by successfully using the aircraft to transmit both an HDTV signal as well as an IMT-2000 wireless communications signal from 65,000 feet (20,000 m), giving the aircraft the equivalence of a 12 miles (19 km) tall transmitter tower. Because of the aircraft's high lookdown angle, the transmission utilized only one watt of power, or 1/10,000 of the power required by a terrestrial tower to provide the same signal.[6] According to Stuart Hindle, Vice President of Strategy & Business Development for SkyTower, "SkyTower platforms are basically geostationary satellites without the time delay." Further, Hindle said that such platforms flying in the stratosphere, as opposed to actual satellites, can achieve much higher levels of frequency use. "A single SkyTower platform can provide over 1,000 times the fixed broadband local access capacity of a geostationary satellite using the same frequency band, on a bytes per second per square mile basis." Ray Morgan, president of AeroVironment, has described the concept as, "What we're trying to do is create what we call an 'atmospheric satellite,' which operates and performs many of the functions as a satellite would do in space, but does it very close in, in the atmosphere". Specifications - Pathfinder - Pathfinder-Plus - Centurion - Helios HP01 - Helios HP03 Length ft(m) - 12 (3.6) - 12 (3.6) - 12 (3.6) - 12 (3.6) - 16.5 (5.0) Chord ft(m) - 8 (2.4) - 8 (2.4) - 8 (2.4) - 8 (2.4) - 8 (2.4) Wingspan ft(m) - 98.4 (29.5) - 121 (36.3) - 206 (61.8) - 247 (75.3) - 247 (75.3) Aspect ratio - 12 to 1 - 15 to 1 - 26 to 1 - 30.9 to 1 - 30.9 to 1 Glide ratio - 18 to 1 - 21 to 1 - ? - ? - ? Airspeed kts(km/h) - ? - ? - 15-18 (27-33) - 16.5-23.5 (30.6-43.5) - ? Max altitude ft(m) - 71,530 (21,802) - 80,201 (24,445) - n/a - 96,863 (29,523) - 65,000 (19,812) Empty Wt lb(kg) - ? - ? - ? - 1,322 (600) - ? Max. weight lb(kg) - 560 (252) - 700 (315) - ±1,900 (±862) - 2,048 (929) - 2,320 (1,052) Payload lb(kg) - 100 (45) - 150 (67,5) - 100-600 (45-270) - 726 (329) - ? Engines - electric, 2 hp (1.5 kW) each - electric, 2 hp (1.5 kW) each - electric, 2 hp (1.5 kW) each - electric, 2 hp (1.5 kW) each - electric, 2 hp (1.5 kW) each No. of engines - 6 - 8 - 14 - 14 - 10 Solar pwr output (kW) - 7.5 - 12.5 - 31 - 35 - 18.5 Supplemental power - batteries - batteries - batteries - Li batteries - Li batteries, fuel cell (Electric aircraft / Electric vehicle / History of unmanned aerial vehicles / Pegasus UAV / Qinetiq Zephyr / Regenerative fuel cell / Scaled Composites Proteus / Solar Impulse) MacCready Solar Challenger (Solar Challenger) Solar Challenger Role - Experimental aircraft National origin - United States Manufacturer - AeroVironment Designer - Paul MacCready First flight - 6 November 1980 Status - Museum piece Number built - 1 Developed from - Gossamer Penguin The Solar Challenger was a solar-powered electric aircraft designed by Paul MacCready's AeroVironment. The aircraft was designed as an improvement on the Gossamer Penguin, which in turn was a solar-powered variant of the human-powered Gossamer Albatross. It was powered entirely by the photovoltaic cells on its wing and stabilizer, without even reserve batteries, and was the first such craft capable of long-distance flight. In 1981, it successfully completed a 163-mile (262 km) demonstration flight from France to England. History The Solar Challenger was designed by a team led by Paul MacCready as a more airworthy improvement on the Gossamer Penguin, directly incorporating lessons learned from flight testing the earlier aircraft. As with the Gossamer Penguin, construction was sponsored by DuPont in exchange for publicity for the company's patented materials incorporated in the design. AstroFlight, Inc. supplied the motors and solar panels, designed by Robert Boucher. The plane's wings carried 16,128 solar cells yielding a maximum solar power of 3,800 watts. It was flight tested in Western USA in winter 1980-1981. On July 7, 1981, the aircraft flew 163 miles from Pontoise - Cormeilles Aerodrome, north of Paris, France to Manston Royal Air Force Base in Manston, United Kingdom, staying aloft 5 hours and 23 minutes, with pilot Stephen Ptacek at the controls. Currently the plane is owned by the Smithsonian Institution's Air and Space Museum. Design The Solar Challenger was designed to be sturdier, more powerful, and more maneuverable than the Gossamer Penguin so as to be able to withstand sustained high-altitude flight and normal turbulence. It was over three times as heavy (without pilot) as the Gossamer Penguin and had a shorter wingspan, but was proportionately more powerful, with electricity supplied by 16,128 solar cells powering two three-horsepower motors. The solar panels were directly affixed to the wing and large horizontal stabilizer, both of which had to be flat on top to accommodate them. The two motors, each 3 inches wide and 17 inches long and incorporating samarium-cobalt permanent magnets, operated in tandem on a common shaft to drive a single, controllable-pitch propeller. The design incorporated advanced synthetic materials with very high strength to weight ratios, including Kevlar, Nomex, Delrin, Teflon, and Mylar, all supplied by the aircraft's sponsor, Dupont. Specifications Data from General characteristics Crew: One Capacity: One Length: 29 ft 0 in (8.8 m) Wingspan: 47 ft 0 in (14.3 m) Empty weight: 205 lb (90 kg) Gross weight: 350 lb (159 kg) Powerplant: 1 × solar-powered electric motor , 2.75 hp (2 kW) Performance Maximum speed: 40 mph (64 km/h, 35 kn) Range: 400 mi (645 km, 350 nmi) (projected) Endurance: 11 hours (projected) Service ceiling: 14,300 ft (4,360 m) demonstrated, 35,000 ft (11,000 m) calculated at summer solstice g limits: +6, -3 Rate of climb: 150 ft/min (0.765 m/s) Related development Sunrise II, whose solar cells were used on this project Gossamer Penguin Aircraft of comparable role, configuration, and era Solair Solar Impulse Solar-Powered Aircraft Developments Solar One Sunseeker I Solar Impulse Solar Impulse Role - Experimental solar-powered aircraft National origin - Switzerland Manufacturer - Solar Impulse First flight - 3 December 2009 Primary user - André Borschberg and Bertrand Piccard Produced - 2009-present Number built - 2 (including prototype) Solar Impulse is a Swiss long-range experimental solar-powered aircraft project, and also the name of the project's two operational aircraft. The privately financed project is led by Swiss engineer and businessman André Borschberg and Swiss psychiatrist and balloonist Bertrand Piccard, who co-piloted Breitling Orbiter 3, the first balloon to circle the world non-stop. The Solar Impulse project's goals were to make the first circumnavigation of the Earth by a piloted fixed-wing aircraft using only solar power and to bring attention to clean technologies. The aircraft is a single-seated monoplane powered by photovoltaic cells; it is capable of taking off under its own power. The prototype, often referred to as Solar Impulse 1, was designed to remain airborne up to 36 hours. It conducted its first test flight in December 2009. In July 2010, it flew an entire diurnal solar cycle, including nearly nine hours of night flying, in a 26-hour flight. Piccard and Borschberg completed successful solar-powered flights from Switzerland to Spain and then Morocco in 2012, and conducted a multi-stage flight across the US in 2013. A second aircraft, completed in 2014 and named Solar Impulse 2, carries more solar cells and more powerful motors, among other improvements. On 9 March 2015, Piccard and Borschberg began to circumnavigate the globe with Solar Impulse 2, departing from Abu Dhabi in the United Arab Emirates. The aircraft was scheduled to return to Abu Dhabi in August 2015 after a multi-stage journey around the world. By June 2015, the plane had traversed Asia, and in July 2015, it completed the longest leg of its journey, from Japan to Hawaii. During that leg, the aircraft's batteries sustained thermal damage and took months to replace. A battery cooling system was installed and Solar Impulse 2 resumed the circumnavigation in April 2016, when it flew on to California. It continued across the US until it reached New York City in June 2016. Later that month, the aircraft crossed the Atlantic Ocean to the city of Seville. It stopped in Egypt before returning to Abu Dhabi on 26 July 2016, more than 16 months after it had left, completing the approximately 42,000-kilometre (26,000-mile) first circumnavigation of the Earth by a piloted fixed-wing aircraft using only solar power. In 2019 the Solar Impulse 2 aircraft was sold to Skydweller, a Spanish-American company that is developing autonomous unmanned aerial vehicles capable of continuous flight. It plans to use the plane for research and development flights, after which the Solar Impulse 2 is planned to be on permanent display at the Swiss Museum of Transport. Project development and funding Bertrand Piccard initiated the Solar Impulse project in November 2003 after undertaking a feasibility study in partnership with the École Polytechnique Fédérale de Lausanne (EPFL).[20] As a mechanical engineer, co-founder André Borschberg directed the construction of each aircraft and oversees the preparation of the flight missions. By 2009, they had assembled a multi-disciplinary team of 50 engineers and technical specialists from six countries, assisted by about 100 outside advisers and 80 technological partners. The project is financed by a number of private companies and individuals, as well as receiving around CHF 6 million (US$6.4 million) in funding from the Swiss government. The project's private financial backers include Omega SA, Solvay, Schindler, ABB and Peter Diamandis. The EPFL, the European Space Agency and Dassault have provided technical expertise, while SunPower provided the aircraft's photovoltaic cells. Piccard stated that the entire project from its beginnings in 2003 until mid-2015 had cost ˆ150 million. It raised another ˆ20 million in late 2015 to continue the round-the-world flight. Timeline 2002: Feasibility study at the École Polytechnique Fédérale de Lausanne 2004-2005: Development of the concept 2006: Simulation of long-haul flights 2006-09: Construction of first prototype (HB-SIA; Solar Impulse 1) 2009: First flight of Solar Impulse 1 2009-11: Manned test flights 2011-12: Further test flights through Europe and North Africa 2011-13: Construction of second prototype (HB-SIB; Solar Impulse 2) 2013: Continental flight across the US by Solar Impulse 1 2014: First flight of Solar Impulse 2 2015-2016: Circumnavigation of the Earth by Solar Impulse 2, conducted in seventeen stages over 16-1/2 months Solar Impulse 1 (HB-SIA) The first Solar Impulse aircraft, registered as HB-SIA, was primarily designed as a demonstration aircraft. It has a non-pressurized cockpit and a single wing with a wingspan similar to that of the Airbus A340 airliner. Under the wing are four nacelles, each with a set of lithium polymer batteries, a 7.5 kW (10 hp) electric motor and one twin-bladed propeller. To keep the wing as light as possible, a customised carbon fibre honeycomb sandwich structure was used. 11,628 photovoltaic cells on the upper wing surface and the horizontal stabilizer generate electricity during the day to power the electric motors and to charge the batteries allowing flight at night, theoretically enabling the single-seat plane to stay in the air indefinitely. The aircraft's major design constraint is the capacity of the lithium polymer batteries. Over an optimum 24-hour cycle, the motors can deliver a combined average of about 6 kW (8 hp), roughly the power used by the Wright brothers' Flyer, the first successful powered aircraft, in 1903. In addition to the charge stored in its batteries, the aircraft uses the potential energy of height gained during the day to power its night flights. Specifications Data from Solar Impulse Project and Diaz General characteristics Crew: 1 Length: 21.85 m (71 ft 8 in) Wingspan: 63.4 m (208 ft 0 in) Height: 6.40 m (21 ft 0 in) Wing area: 200 m2 (2,200 sq ft) covered with 11,628 photovoltaic cells rated at 45 kW peak Aspect ratio: 19.7 Gross weight: 1,600 kg (3,500 lb) Max takeoff weight: 2,000 kg (4,400 lb) Fuel capacity: 21 kW⋅h (76 MJ) lithium-ion battery Take-off speed: 35 km/h (22 mph) Powerplant: 4 × 7.5 kW (10 hp) electric motors Propellers: single blade, 3.5 m (11 ft 0 in) diameter Performance Cruise speed: 70 km/h (43 mph, 38 kn) Endurance: approximately 36 hours Service ceiling: 8,500 m (27,900 ft) with a maximum altitude of 12,000 m (39,000 ft) Operational history Maiden flight and other early flights On 26 June 2009, Solar Impulse 1 was first presented to the public at the Dübendorf Air Base, Switzerland. Following taxi testing, a short-hop test flight was made on 3 December 2009,[38] piloted by Markus Scherdel. Borschberg, co-leader of the project team, said of the flight: "It was an unbelievable day. The airplane flew for about 350 metres (1,150 ft) and about 1 metre (3 ft 3 in) above the ground ... The aim was not to get high but to land on the same runway at a speed to test its controllability and get a first feeling of its flying characteristics ... the craft behaved just as the engineers had hoped. It is the end of the engineering phase and the start of the flight testing phase." On 7 April 2010, the plane conducted an 87-minute test flight, piloted by Markus Scherdel. This flight reached an altitude of 1,200 m (3,937 ft). On 28 May 2010, the aircraft made its first flight powered entirely by solar energy, charging its batteries in flight. First overnight flight On 8 July 2010, Solar Impulse 1 achieved the world's first manned 26-hour solar-powered flight. The airplane was flown by Borschberg, and took off at 06:51 Central European Summer Time (UTC+2) on 7 July from Payerne Air Base, Switzerland. It returned for a landing the following morning at 09:00 local time. During the flight, the plane reached a maximum altitude of 8,700 m (28,500 ft). At the time, the flight was the longest and highest ever flown by a manned solar-powered aircraft; these records were officially recognized by the Fédération Aéronautique Internationale (FAI) in October 2010. International and intranational flights Belgium and France (2011) On 13 May 2011 at 21:30 local time, the plane landed at Brussels Airport, after completing a 13-hour flight from its home base in Switzerland. It was the first international flight by the Solar Impulse, which flew at an average altitude of 1,800 m (6,000 ft) for a distance of 630 km (391 mi), with an average speed of 50 km/h (31 mph). The aircraft's slow cruising speed required operating at a mid-altitude, allowing much faster air traffic to be routed around it.[50] The aircraft was piloted by Borschberg. The project's other co-founder, Piccard, said in an interview after the landing: "Our goal is to create a revolution in the minds of people...to promote solar energies - not necessarily a revolution in aviation." A second international flight to the Paris Air Show was attempted on 12 June 2011, but the plane turned back and returned to Brussels because of adverse weather conditions.[53] In a second attempt on 14 June, Borschberg successfully landed the aircraft at Paris' Le Bourget Airport after a 16-hour flight. First intercontinental flight (2012) On 5 June 2012, the Solar Impulse successfully completed its first intercontinental flight, a 19-hour trip from Madrid, Spain, to Rabat, Morocco. During the first leg of the flight from Payerne Air Base to Madrid, the aircraft broke several further records for solar flight, including the longest solar-powered flight between pre-declared waypoints (1,099.3 km or 683 mi) and along a course (1,116 km or 693 mi). United States (2013) On 3 May 2013, the plane began its cross-US flight with a journey from Moffett Field in Mountain View, California, to Phoenix Goodyear Airport in Arizona. Successive legs of the flight ended at Dallas-Fort Worth airport, Lambert–St. Louis International Airport, Cincinnati Municipal Lunken Airport to change pilots and avoid strong winds, and Washington Dulles International Airport. On 6 July 2013, following a lengthy layover in Washington, Solar Impulse completed its cross-country journey, landing at New York City's JFK International Airport at 23:09 EDT. The landing occurred three hours earlier than originally intended, because a planned flyby of the Statue of Liberty was cancelled as a result of damage to the covering on the left wing. Each flight leg took between 14 and 22 hours. The aircraft's second leg of its trip on 23 May to Dallas-Fort Worth covered 1,541 kilometres (958 mi) and set several new world distance records in solar aviation. Solar Impulse 1 was placed on public display at JFK after its landing. In August 2013, it was disassembled, then transported via a Cargolux B-747-400F to Dübendorf Air Base, where it was placed in storage in a hangar. Detailed route Source: Leg - Start[63] - Stop - Origin - Destination - Distance - Flight time - Avg. speed - Pilot 1 - 3 May 14:12 - 4 May 08:30 - Moffett Field, California (KNUQ) - Phoenix, Arizona (KGYR) - 984 km - 18 h 18 min - 53 km/h - Bertrand Piccard 2 - 22 May 12:47 - 23 May 07:08 - Phoenix, Arizona (KGYR) - Dallas, Texas (KDFW) - 1541 km - 18 h 21 min - 84 km/h - André Borschberg 3 - 3 Jun 10:06 - 4 Jun 07:28 - Dallas, Texas (KDFW) - Saint Louis, Missouri (KSTL) - 1040 km - 21 h 22 min - 49 km/h - Bertrand Piccard 4 - 14 Jun 11:01 - 15 Jun 02:15 - Saint Louis, Missouri (KSTL) - Cincinnati, Ohio (KLUK) - - 15 h 14 min - - André Borschberg 5 - 15 Jun 15:10 - 16 Jun 05:15 - Cincinnati, Ohio (KLUK) - Washington, DC (KIAD) - - 14 h 5 min - - Bertrand Piccard 6 - 6 July 09:56 - 7 July 05:15 - Washington, DC (KIAD) - New York City, New York (KJFK) - - 19 h 19 min - - André Borschberg Aircraft on display In March 2015, the plane was transported by truck to Paris to be part of the permanent exhibition at Cité des Sciences et de l'Industrie. Solar Impulse 2 (HB-SIB) Construction history Construction started in 2011 on the second aircraft, known as Solar Impulse 2, which carries the Swiss registration HB-SIB. Completion was initially planned for 2013, with a 25-day circumnavigation of the globe planned for 2014. A structural failure occurred on the aircraft's main spar during static tests in July 2012, leading to delays in the flight testing schedule to allow repairs. Solar Impulse 2's first flight took place at Payerne Air Base on 2 June 2014. Design The wingspan of Solar Impulse 2 is 71.9 m (236 ft), slightly less than that of an Airbus A380, the world's largest passenger airliner, but compared with the 500-ton A380, the carbon-fibre Solar Impulse weighs only about 2.3 tonnes (5,100 lb), little more than an average SUV. It features a non-pressurized cockpit 3.8 cubic metres (130 cu ft) in size and advanced avionics, including limited functionality of an autopilot that allows the pilot to sleep for up to 20 minutes at a time, enabling multi-day transcontinental and trans-oceanic flights. Supplemental oxygen and various other environmental support systems allow the pilot to cruise up to an altitude of 12,000 metres (39,000 ft). Specifications Data from Solar Impulse Project General characteristics Crew: 1 Length: 22.4 m (73 ft 6 in) Wingspan: 71.9 m (236 ft 0 in) Height: 6.37 m (20 ft 11 in) Gross weight: 2,300 kg (5,100 lb) Take-off speed: 36 km/h (22.4 mph) Wing area: 17,248 photovoltaic solar cells cover the top of the wings, fuselage and tailplane for a total area of 269.5 m2 (2,901 sq ft) (rated at 66 kW peak) Powerplant: 4 × electric motors with 4 x 41 kW⋅h (150 MJ) lithium-ion batteries (633 kg or 1,396 lb), providing , 13.0 kW (17.4 hp) each Propellers: 4.0 m (13 ft 1 in) diameter Performance Maximum speed: 140 km/h (87 mph, 76 kn) Cruise speed: 90 km/h (56 mph, 49 kn) 60 km/h (37 mph) at night to save power Service ceiling: 8,500 m (27,900 ft) with a maximum altitude of 12,000 m (39,000 ft) Operational history Solar Impulse 2 was first publicly displayed on 9 April 2014. Its inaugural flight took place on 2 June 2014, piloted by Markus Scherdel. The aircraft averaged a ground speed of 30 knots (56 km/h), and reached an altitude of 1,700 metres (5,500 ft). The first night flight was completed on 26 October 2014, and the aircraft reached its maximum altitude during a flight on 28 October 2014. 2015-16 circumnavigation of the Earth The repair work to the aircraft's main spar delayed Solar Impulse 2's circumnavigation of the Earth from 2012 to 2015. The aircraft was delivered to Masdar City in Abu Dhabi for the World Future Energy Summit in late January 2015, and it began the journey from Al Bateen Executive Airport on 9 March 2015. It was scheduled to return to the same location in August 2015. A mission control centre for the circumnavigation was established in Monaco, using satellite links to gather real-time flight telemetry and remain in constant contact with the aircraft and the support team. The route followed by Solar Impulse 2 was entirely in the Northern Hemisphere. It left Abu Dhabi, then it headed east to nearby Oman and India. Twelve stops were originally planned along the route, with pilots Borschberg and Piccard alternating; at each stop, the crew awaited good weather conditions along the next leg of the route. For most of its time airborne, Solar Impulse 2 cruised at a ground speed of between 50 and 100 kilometres per hour (31 and 62 mph), usually at the slower end of that range at night to save power. Legs of the flight crossing the Pacific and Atlantic oceans were the longest stages of the circumnavigation, taking up to five days and nights. On multi-day flights, the pilots took 20-minute naps and used yoga or other exercises to promote blood flow and maintain alertness. By the end of May 2015, the plane had traversed Asia. It made an unscheduled stop in Japan to await favourable weather over the Pacific, increasing the expected number of legs of the journey to 13. The aircraft began the flight from Japan to Hawaii on 28 June 2015 (29 June, Japan local time). With Borschberg in the cockpit, it reached Hawaii on 3 July, setting new records for the world's longest solar-powered flight both by time (117 hours, 52 minutes) and distance (7,212 km; 4,481 mi). The flight's duration was also a record for longest solo flight, by time, for any aircraft. During that leg the plane's batteries were damaged by overheating because they were packed in too much insulation. New parts had to be ordered, and as it was late in the season, with days shortening in the northern hemisphere, the plane was grounded in Hawaii. The US Department of Transportation stored the aircraft in a hangar at Kalaeloa Airport on Oahu. New batteries were made and installed in the plane. Test flights began in February 2016 to prepare for resumption of the circumnavigation once northern hemisphere days lengthened enough to permit multi-day solar-powered flights. A favourable weather window opened in April 2016, and the plane resumed its journey, landing at Moffett Field, in California, on 23 April. During that flight, Piccard, via a live videolink, spoke with Ban Ki-Moon and Doris Leuthard before the General Assembly of the United Nations, from the cockpit of Solar Impulse 2, commenting on that day's historic signing of the Paris Agreement and discussing how using clean technologies can create jobs and fight global warming.[89] Additional legs of the flight were added in the US as Solar Impulse 2 flew to Phoenix, Arizona, Tulsa, Oklahoma, Dayton, Ohio, Lehigh Valley, Pennsylvania and New York City, arriving there on 11 June 2016. Piccard piloted the aircraft across the Atlantic Ocean, arriving in Seville, Spain, on 23 June. The aircraft next stopped in Cairo, Egypt, on 13 July, and landed in Abu Dhabi on 26 July, completing the around-the-world trip in a total of 17 stages and 16-1/2 months; it was the first circumnavigation of the Earth by a piloted fixed-wing aircraft using only solar power. Detailed route Leg - Start[95] - Origin - Destination - Flight time - Distance - Avg. speed - Max. altitude - Pilot 1 - 9 March 2015 03:12 - United Arab Emirates Abu Dhabi, UAE (OMAD) - Oman Muscat, Oman (OOMS) - 13 h 1 min - 417 nmi (772 km) - 32.0 kn (59.2 km/h) - 20,942 ft (6,383 m) - A. Borschberg 2 - 10 March 02:35 - Oman Muscat, Oman (OOMS) - India Ahmedabad, India (VAAH) - 15 h 20 min - 860 nmi (1,593 km)[97] - 56.1 kn (103.9 km/h) - 29,114 ft (8,874 m) - B. Piccard 3 - 18 March 01:48 - India Ahmedabad, India (VAAH) - India Varanasi, India (VEBN) - 13 h 15 min - 630 nmi (1,170 km) - 47.7 kn (88.3 km/h) - 17,001 ft (5,182 m) - Borschberg 4 - 18 March 23:52 - India Varanasi, India (VEBN) - Myanmar Mandalay, Myanmar (VYMD) - 13 h 29 min - 829 nmi (1,536 km) - 61.5 kn (113.9 km/h) - 27,000 ft (8,230 m) - Piccard 5 - 29 March 21:06 - Myanmar Mandalay, Myanmar (VYMD) - China Chongqing, China (ZUCK) - 20 h 29 min - 883 nmi (1,636 km) - 43.1 kn (79.9 km/h) - 28,327 ft (8,634 m) - Piccard 6 - 20 April 22:06 - China Chongqing, China (ZUCK) - China Nanjing, China (ZSNJ) - 17 h 22 min - 747 nmi (1,384 km) - 43.0 kn (79.7 km/h) - 14,010 ft (4,270 m) - Piccard 7 - 30 May 18:39 - China Nanjing, China (ZSNJ) - Japan Nagoya, JapanN1 (RJNA) - 44 h 9 min - 1,589 nmi (2,942 km) - 36.0 kn (66.6 km/h) - 28,327 ft (8,634 m) - Borschberg 8 - 28 June 18:03 - Japan Nagoya, Japan (RJNA) - United States Kalaeloa, Hawaii, US (PHJR) - 117 h 52 min - 4,819 nmi (8,924 km) - 40.9 kn (75.7 km/h) - 28,327 ft (8,634 m) - Borschberg 9 - 21 April 2016 16:15 - United States Kalaeloa, Hawaii, US (PHJR) - United States Mountain View, CA, US (KNUQ) - 62 h 29 min - 2,206 nmi (4,086 km) - 35.3 kn (65.4 km/h) - 28,327 ft (8,634 m) - Piccard 10 - 2 May 12:03 - United States Mountain View, CA, US (KNUQ) - United States Phoenix, AZ, US (KGYR) - 15 h 52 min - 601 nmi (1,113 km) - 37.9 kn (70.2 km/h) - 22,001 ft (6,706 m) - Borschberg 11 - 12 May 11:05 - United States Phoenix, AZ, US (KGYR) - United States Tulsa, OK, US (KTUL) - 18 h 10 min - 850 nmi (1,570 km) - 46.7 kn (86.4 km/h) - 22,001 ft (6,706 m) - Piccard 12 - 21 May 09:22 - United States Tulsa, OK, US (KTUL) - United States Dayton, OH, US (KDAY) - 16 h 34 min - 647 nmi (1,199 km) - 39.1 kn (72.4 km/h) - 21,001 ft (6,401 m) - Borschberg 13 - 25 May 08:02 - United States Dayton, OH, US (KDAY) - United States Lehigh Valley, PA, US (KABE) - 16 h 49 min - 564 nmi (1,044 km) - 33.6 kn (62.2 km/h) - 15,000 ft (4,572 m) - Piccard 14 - 11 June 03:18 - United States Lehigh Valley, PA, US (KABE) - United States New York, NY, US (KJFK) - 4 h 41 min - 143 nmi (265 km) - 30.6 kn (56.6 km/h) - 3,002 ft (915 m) - Borschberg 15 - 20 June 06:30 - United States New York, NY, US (KJFK) - Spain Seville, Spain (LEZL) - 71 h 8 min - 3,653 nmi (6,765 km) - 50.9 kn (94.3 km/h) - 27,999 ft (8,534 m) - Piccard 16 - 11 July 04:20 - Spain Seville, Spain (LEZL) - Egypt Cairo, Egypt (HECA) - 48 h 50 min - 2,022 nmi (3,745 km) - 41.4 kn (76.7 km/h) - 27,999 ft (8,534 m) - Borschberg 17 - 23 July 2016 23:28 - Egypt Cairo, Egypt (HECA) - United Arab Emirates Abu Dhabi, UAE (OMAD) - 48 h 37 min - 1,455 nmi (2,694 km) - 29.9 kn (55.4 km/h) - 27,999 ft (8,534 m) - Piccard Total - - - - 558 h 7 min (23.25 d) - 22,915 nmi (42,438 km) - 41.0 kn (76.0 km/h) - 29,114 ft (8,874 m) - Notes: ^N1 - Leg 7 was planned as a 144-hour flight from Nanjing, China to Hawaii (4,931 nmi or 9,132 km). Deteriorating weather forced a diversion to Nagoya, Japan. Post-flight sale In September 2019 the Solar Impulse 2 aircraft was sold to Skydweller, a Spanish-American company that is developing autonomous unmanned aerial vehicles capable of continuous flight and “carrying radar, electronic optics, telecommunications devices, telephone listening and interception systems”. As part of this sale, the Solar Impulse 2 aircraft was transferred from Switzerland to Spain though once Skydweller completes its research and development flights the Solar Impulse 2 will be transferred back to Switzerland for permanent display at the Swiss Museum of Transport. Honours In 2016, the Swiss Post edited a special stamp to honour the achievement of Solar Impulse 2. World Alliance for Clean Technologies During the final flight of their circumnavigation of the globe, Borschberg and Piccard announced the creation of a World Alliance for Clean Technologies (later renamed World Alliance for Efficient Solutions). The aim of this non-governmental organisation is to promote green energy and sustainable technologies by bringing together for-profit companies creating green solutions. World Alliance was launched in November 2017. Patrons of the initiative included Albert II, Prince of Monaco and actor Arnold Schwarzenegger. Piccard said that he and his organization, Solar Impulse Foundation, formed the World Alliance to help draw investors' and businesses' attention to new cleantech startups. Piccard does not receive a salary for his leadership of the alliance, which is funded by donors including Air Liquide, Nestle and Solvay. In November 2017 at COP23, Piccard tasked the World Alliance with a project to identify 1,000 technological solutions that are both profitable and good for the planet, with the goal to bring environmentalists and industrialists together. He noted in a 2018 Smithsonian article that technologies developed for the solar-powered flight were already being repurposed in new ways, including new ceiling fans based on the solar airplane engines and refrigerators using the cockpit insulation. When speaking to government leaders, Piccard said he was consistently told that they wanted to protect the environment but it was too expensive. To provide reassurance, in May 2018 Piccard and the Solar Impulse Foundation announced the Efficient Solutions Label, a certification involving a rigorous Ernst and Young-certified evaluation by independent experts to assess each solution's quality and ability to turn a profit. According to Piccard, any Solar Impulse labeled solution must be the best in its class: the most environmentally friendly as well as economically viable and available for purchase today. In 2021 in a Reuters interview Piccard stated that his organization had assembled a portfolio of 910 vetted and labeled solutions and expected to reach 1000 by mid-April 2021. Piccard told Reuters he plans to discuss the solutions with businesses and governments, especially those in the process of funding the global economic recovery from COVID-19. |