AstroFlight Sunrise

Last updated
AstroFlight Sunrise
Role Experimental aircraft
National origin United States
Manufacturer AstroFlight
DesignerRoland Boucher
First flight4 November 1974
StatusRetired
Number built2

The AstroFlight Sunrise was an uncrewed experimental electric aircraft technology demonstrator and the first aircraft to fly on solar power. [1]

Contents

First conceived in November 1970, the Sunrise first flew on 4 November 1974 from Bicycle Lake, a dry lakebed on the Fort Irwin Military Reservation, California, United States. The first prototype was destroyed on its 28th flight by turbulence. The improved Sunrise II flew the following year. [1] [2] [3] [4]

Development

While working as an engineer at Hughes Aircraft, Roland Boucher began design work on an electric-powered aircraft concept in November 1970, calculating that the contemporary nickel-cadmium batteries available would be sufficient to sustain flight using a radio-control model glider. Early experimental projects proved the concept sound and in 1973 Boucher turned his attention to the creation of a high-altitude solar-powered aircraft that would have unlimited endurance. [1]

Boucher explained the project to his superiors at Hughes Aircraft in 1972 and after reviewing it, the company released the project to Boucher in 1973. Boucher took a leave of absence from Hughes to pursue the project and joined his brother, Bob Boucher, at AstroFlight, a small model airplane manufacturer in Venice, California. After successfully flying an electric drone carrying a 5 lb (2 kg) payload on a DARPA project for Northrop Corporation, they then moved onto Project Sunrise. [5]

Using commercially available off-the-shelf solar cells producing only 10% efficiency, Boucher calculated that his project would need to be able to fly on about 0.5 kW (0.7 hp). The aircraft was envisioned as an uncrewed sailplane that would have an operating altitude of 73,000 ft (22,250 m), powered by a single Samarium–cobalt magnet electric motor, the first motor of its kind in the world. The aircraft would use no batteries and, instead, would descend at night from its operating altitude to about 10,000 ft (3,048 m) at dawn, before solar energy was once again available for climb. [6] [7] [8]

Boucher saw the Sunrise as a proof of concept for a follow on aircraft that would be capable of remaining aloft for months at an altitude of 100,000 ft (30,480 m). [5] [9]

Project Sunrise was funded by DARPA commencing in January 1974 and administered by Lockheed Aircraft Corporation of Sunnyvale, California, with the contract specifying a "proof of concept aircraft powered solely by incident sunlight on the wing surfaces." [9]

Roland Boucher took on the task of the structural design, aerodynamics, telemetry, control and navigation. He also designed the integration of the solar panel, electric motors, gearbox and the propeller. He selected an Eppler 387 airfoil for the wing. The solar cells were 5 cm (2.0 in) round commercial units provided by Heliotech. The actual airframe was constructed by a team under expert model builder Phil Bernhardt. [5]

The Sunrise's wing span was 32 ft (10 m) and the aircraft had a gross weight of 22 lb (10 kg). The wing loading was a very low 4 ounces per square foot (0.011 kg/sq m). The aircraft structure was built from spruce, balsa and maple. Due to their roughness the solar cells were only mounted on the aft two-thirds of the wing's upper surface. [9]

The wing spars were built from spruce spar caps with maple doublers at all attachment points and two 3⁄32 in (2 mm) balsa shear webs attached to 1⁄8 to 3⁄8 in (3 to 10 mm) balsa strips on the wing spars. The ribs were made from 3⁄32 in (2 mm) balsa. This construction resulted in a balsa spar box with tapered spruce caps. The leading edge was covered with 1⁄32 in (0.8 mm) balsa to form a leading edge D spar. The trailing edge was formed by two 2 in (51 mm) wide 1⁄32 in (0.8 mm) sheets forming a triangle with 1⁄8 to 3⁄8 in (3 to 10 mm) vertical spar sections in between the ribs. The covering was 1/2 mil Mylar. The 32 ft (10 m) span wing weighed 5 lb (2 kg) and was capable of loads up to 100 pounds. [10]

Control was via an S & O Radio designed and built telemetry transmitter and receiver. The standard S&O six channel radio had channels for elevator, rudder, motor on and off and solar cell operating mode. The solar cells could be set for either series or parallel operation. The telemetry functions provided gave data on motor current, motor voltage, motor RPM, airspeed and two heading references from a sun compass for navigation. [8]

Operational history

Flight testing commenced in 1974 at Bicycle Lake, California. The first flights were conducted on battery power, using a bungee cord launch to 20 ft (6 m). On its first flight the aircraft reached 500 feet, before returning for a landing. [2]

A lack of sunny days delayed flight testing, but in all, 28 flights were made. The Sunrise would climb slowly at first until its solar cells cooled down and their efficiency increased. On its 28th flight the aircraft was destroyed when it was flown too close to a cumulus cloud at about 8,000 ft (2,438 m) and the associated turbulence broke the aircraft's structure. [2]

Aftermath

The success of the flights that had been completed allowed Boucher to state:

Project Sunrise had demonstrated the feasibility of solar powered flight to extreme altitudes". [2]

DARPA and Lockheed proposed a follow-on design to the Sunrise to be powered at night by batteries instead of just gliding. Roland Boucher designed the second aircraft using higher efficiency solar panels that were more aerodynamically smooth. [11]

Roland Boucher had become physically exhausted from his work on the initial Sunrise and he suffered from congestive heart failure. He was admitted to intensive care at Santa Monica Hospital. While in hospital he resigned from AstroFlight and sold his interests in the company to his brother Bob Boucher who continued work on the second Sunrise aircraft. After recuperating, Roland Boucher returned to work at Hughes Aircraft on classified military programs. [11]

The Sunrise II first flew on 27 September 1975 from Nellis AFB, near Las Vegas, Nevada. [3] [4]

Variants

Project Sunrise Prototype #1 (Sunrise I)
Initial aircraft first flown in 1974 [1]
Project Sunrise Prototype #2 (Sunrise II)
1975 improved version for high altitude flight demonstration [12]

Specifications (Sunrise I)

Data from Project Sunrise website [9] [10]

General characteristics

Performance

See also

Aircraft of comparable role, configuration, and era

Related Research Articles

<span class="mw-page-title-main">NASA Pathfinder</span> Unmanned solar powered aircraft

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.

<span class="mw-page-title-main">Solar Impulse</span> Long-range solar-powered aircraft

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.

<span class="mw-page-title-main">Electric aircraft</span> Aircraft powered directly by electricity, with no other engine needed

An electric aircraft is an aircraft powered by electricity. Electric aircraft are seen as a way to reduce the environmental effects of aviation, providing zero emissions and quieter flights. Electricity may be supplied by a variety of methods, the most common being batteries. Most have electric motors driving propellers or turbines.

<span class="mw-page-title-main">Powered hang glider</span> Foot-launched powered hang glider

A foot-launched powered hang glider (FLPHG), also called powered harness, nanolight, or hangmotor, is a powered hang glider harness with a motor and propeller in pusher configuration. An ordinary hang glider is used for its wing and control frame, and the pilot can foot-launch from a hill or from flat ground, needing a length of about a football field to get airborne, or much less if there is an oncoming breeze and no obstacles.

Astroflight, Incorporated is a manufacturer of products for electric-powered radio controlled aircraft, unmanned aerial vehicles (UAV), brushless industrial motors, the world's first solar-powered aircraft and the world's first practical electric radio controlled model airplane. The company is based in Irvine, California, USA.

<span class="mw-page-title-main">MacCready Solar Challenger</span> Type of aircraft

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.

<span class="mw-page-title-main">Airbus Zephyr</span> Series of lightweight solar-powered UAV

The Zephyr is a series of high-altitude platform station aircraft produced by Airbus. They were designed originally by QinetiQ, a commercial offshoot of the UK Ministry of Defence. In July 2010, the Zephyr 7 flew during 14 days. In March 2013, the project was sold to Airbus Defence and Space. In the summer of 2022, the Zephyr 8/S flew during 64 days.

MacCready <i>Gossamer Penguin</i> Type of aircraft

The Gossamer Penguin was a solar-powered experimental aircraft created by Paul MacCready's AeroVironment. MacCready, whose Gossamer Condor in 1977 won the Kremer prize for human-powered flight, told reporters two weeks in June, 1980 that "The first solar-powered flight ever made took place on May 18." The testing ground was at Minter Field outside of Shafter, California.

<span class="mw-page-title-main">High-altitude platform station</span> Aircraft that provides common satellite services

A high-altitude platform station or atmospheric satellite is a long endurance, high altitude aircraft able to offer observation or communication services similarly to artificial satellites. Mostly unmanned aerial vehicles (UAVs), they remain aloft through atmospheric lift, either aerodynamic like airplanes, or aerostatic like airships or balloons. High-altitude long endurance (HALE) military drones can fly above 60,000 ft over 32 hours, while civil HAPS are radio stations at an altitude of 20 to 50 km above waypoints, for weeks.

<span class="mw-page-title-main">AeroVironment Helios Prototype</span> Type of aircraft

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.

<span class="mw-page-title-main">Pipistrel Taurus</span> Type of aircraft

The Pipistrel Taurus is a Slovenian self-launched two-seat microlight glider designed and built by Pipistrel.

The Solar-Powered Aircraft Developments Solar One is a British mid-wing, experimental, manned solar-powered aircraft that was designed by David Williams and produced by Solar-Powered Aircraft Developments under the direction of Freddie To. On 13 June 1979 it became one of the first solar-powered aircraft to fly, after the unmanned AstroFlight Sunrise and the manned Mauro Solar Riser, and the first successful British solar-powered aircraft.

<span class="mw-page-title-main">Mauro Solar Riser</span> First manned solar-powered aircraft

The Mauro Solar Riser is an American biplane ultralight electric aircraft that was the first crewed aircraft to fly on solar power. It was also only the second solar-powered aircraft to fly, after the uncrewed AstroFlight Sunrise, which had first flown 4+1⁄2 years earlier.

<span class="mw-page-title-main">Diamond HK36 Super Dimona</span> Austrian motor glider, 1989

The Diamond HK36 Super Dimona is an extensive family of Austrian low-wing, T-tailed, two-seat motor gliders that were designed by Wolf Hoffmann and currently produced by Diamond Aircraft Industries.

The Aviastroitel AC-5M is a Russian mid-wing, single-seat, T-tailed motor glider and unmanned aerial vehicle that is produced by Aviastroitel, now Glider Air Craft.

<span class="mw-page-title-main">Alisport Silent 2 Electro</span> Italian motor glider

The Alisport Silent 2 Electro is an Italian mid-wing, single-seat motor glider, designed and produced by Alisport of Cremella and provided as a complete ready-to-fly aircraft. The aircraft was introduced at the Aero show held in Friedrichshafen in 2011.

<span class="mw-page-title-main">AirStrato</span> Type of aircraft

AirStrato is a solar powered medium-sized unmanned aerial vehicle that was being developed by ARCAspace. There were two variants planned, AirStrato Explorer with a target flight ceiling of 18,000 m and AirStrato Pioneer with a target flight ceiling of 8000 m. It was planned to carry a 45 kg payload consisting of surveillance equipment, scientific instruments or additional battery pods for extended autonomy. The first prototype maiden flight took place on February 28, 2014. It was equipped with a fixed landing gear. Two more prototypes were constructed that lacked a landing gear. Instead ARCA opted for a pneumatic catapult as a launcher and landing skids and a recovery parachute for landing. Both prototypes performed take-off and landing testing and low altitude flights.

<span class="mw-page-title-main">SolarStratos</span> Aeronautical project

SolarStratos is an aeronautical project aimed at flying a solar-powered airplane for the first time to the stratosphere. The SolarStratos airplane is equipped with solar cells but is not able to fly directly on solar power, thus is accurately described as a battery powered electric airplane that is equipped with solar cells; it is planned to be the first crewed solar-equipped aircraft to enter the stratosphere.

<span class="mw-page-title-main">Facebook Aquila</span> Type of aircraft

The Facebook Aquila is an experimental solar-powered drone developed by Facebook for use as an atmospheric satellite, intended to act as relay stations for providing internet access to remote areas. The Aquila first flew on 28 June 2016 with a second aircraft successfully flying in 2017. Internal development of the Aquila aircraft was stopped in June 2018.

References

  1. 1 2 3 4 Boucher, Roland (n.d.). "Project Sunrise pg 1" . Retrieved 2009-09-23.
  2. 1 2 3 4 Boucher, Roland (n.d.). "Project Sunrise pg 13" . Retrieved 2009-09-23.
  3. 1 2 Newcome, Laurence R. (2004). Unmanned aviation: a brief history of unmanned aerial vehicles . Retrieved 2009-09-23.
  4. 1 2 Curry, Marty (March 2008). "Solar-Power Research and Dryden". Archived from the original on 28 October 2009. Retrieved 2009-09-15.
  5. 1 2 3 Boucher, Roland (n.d.). "Project Sunrise pg 9" . Retrieved 2009-09-23.
  6. ↑ Boucher, Roland (n.d.). "Project Sunrise pg 2" . Retrieved 2009-09-23.
  7. ↑ Boucher, Roland (n.d.). "Project Sunrise pg 4" . Retrieved 2009-09-23.
  8. 1 2 Boucher, Roland (n.d.). "Project Sunrise pg 11" . Retrieved 2009-09-23.
  9. 1 2 3 4 Boucher, Roland (n.d.). "Project Sunrise pg 8" . Retrieved 2009-09-23.
  10. 1 2 Boucher, Roland (n.d.). "Project Sunrise pg 10" . Retrieved 2009-09-23.
  11. 1 2 Boucher, Roland (n.d.). "Project Sunrise pg 16" . Retrieved 2009-09-23.
  12. ↑ AIAA-84-1429 History of Solar Flight Robert J. Boucher
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.