Past Projects - ERAST


In 1999, Scaled Composites' Proteus aircraft was adopted into NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. This unique tandem-wing, twin-engine aircraft was designed by famed aircraft designer Burt Rutan and built as a privately funded venture at Scaled's development facility at Mojave, Calif.

Proteus in flight over the Mojave Desert in CaliforniaProteus in flight over the Mojave Desert in California

The aircraft was named after the Greek mythological god Proteus, because like its namesake, the aircraft can be reconfigured to carryout a variety of missions. These include serving as a high altitude, long duration telecommunications relay platform, reconnaissance/surveillance, commercial imaging, launching of small space satellites, atmospheric sampling and Earth monitoring.

Flight testing of the Proteus began in September 1998 at Mojave Airport and continued through the end of 1999.

Under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project, NASA's Dryden Flight Research Center assisted Scaled Composites in developing a sophisticated station-keeping autopilot system and a satellite communications (SATCOM)-based uplink-downlink data system for Proteus' performance and payload data.

Flight testing included the installation and checkout of the autopilot system, including the refinement of the altitude hold and altitude change software. The SATCOM equipment, including avionics and antenna systems, was installed and checked out in several flight tests. The systems performed flawlessly during Proteus' deployment to the Paris Air Show in 1999.

In May 2000, the Proteus demonstrated continuous "over-the-horizon" (OTH) command and control capability from a remote ground control station at Mojave, Calif., while flying more than 200 miles north of where the station was located.

In October 2000, Proteus set three international aviation altitude records. The craft reached a peak altitude of 62,786 feet and sustained horizontal flight of 61,919 feet. On a second flight, Proteus reached a peak altitude of 55,878 feet while carrying a 1,000 kg (12,200 lb.) payload. All three records were set for aircraft with gross weights of 12,500 lbs. or less. NASA Dryden supported Proteus' altitude-expansion flights by providing full pressure suits for the pilots through the ERAST project and helped fund the effort as part of its evaluation of the Proteus as an airborne platform for high-altitude atmospheric science and remote sensing missions.

In recent years, NASA Dryden has contracted with Scaled Composites to fly Proteus as a testbed for a variety of technologies related to maturing unmanned air vehicles (UAVs) for use in civil applications.

Proteus on the runway at the Mojave airportProteus on the runway at the Mojave airport

A small Airborne Real-Time Imaging System (ARTIS) camera, developed by HyperSpectral Sciences, Inc., under ERAST, was demonstrated during the summer of 1999 when it took visual and near-infrared photos from Proteus while it was flying high over the Experimental Aircraft Association's "AirVenture 99" Airshow at Oshkosh, Wisc. The images were displayed on a computer monitor at the show only moments after they were taken.

In March 2002, Proteus served as a surrogate UAV controlled remotely from the ground during flight demonstrations of an active detect, see and avoid (DSA) system for potential application to UAVs out of Las Cruces, New Mexico. In each of 18 different scenarios, a Goodrich Skywatch HP Traffic Advisory System (TAS) on the Proteus detected approaching "cooperative" aircraft (those with operating transponders) on potential collision courses, including several scenarios with two aircraft approaching from different directions. The remote pilot then directed Proteus to turn, climb or descend as needed to avoid the potential threat.

In April 2003, a second series of flight demonstrations focusing on "non-cooperative" aircraft (those without operating transponders) was conducted near Mojave, Calif., again using the Proteus as a surrogate UAV. This time, Proteus was equipped with a small Amphitech OASys 35 Ghz primary radar system to detect intruder aircraft on simulated collision courses. The radar data was telemetered directly to the ground station as well as relayed through a satellite system installed on Proteus. A mix of intruder aircraft, ranging from a sailplane to a high-speed jet, flew 20 scenarios over a four-day period. In each case, the radar picked up the intruding aircraft at ranges from 2.5 to 6.5 miles, depending on the intruder's radar signature. Proteus' remote pilot on the ground was able to direct Proteus to take evasive action if needed.

Project Milestones

Date Milestone
Sept. 23, 1998 First flew publicly.
Feb. 2, 1999 Flew to 50,500 feet for the first time.
June 7, 1999 Made a 9-hour flight from Mojave airport to Bangor, Maine.
June 9, 1999 Lands in LeBourget airport in Paris, France for Air Show.
May 18, 2000 Demonstrated over-the-horizon satellite link command and control from remote ground station.
Oct. 2000 Set three world altitude records for aircraft in its weight class
March 2002 Served as testbed for UAV "detect, see and avoid" (DSA) flight demonstrations
July 2002 Proteus team was part of NASA's Crystal FACE science campaign involving six aircraft and hundreds of scientists.
April 2003 Served as testbed for second series of UAV DSA flight demonstrations

Proteus Links

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