Doug Bonderud

Jan 31st 2019

Sky’s the Limit? Proteus High Altitude Aircraft Begs to Differ


With all the recent attention on commercial space flight, it’s easy to overlook the innovative flight technologies that are changing the game right here on Earth. Take, for example, Scaled Composites’ Proteus high-altitude aircraft. Originally known as Scaled Composites Model 281 and designed for 100-150 flight hours, the craft has passed the 4,500-hour mark and continues to expand the limits of human aerospace knowledge.

Aviation Innovation

When the Wright brothers first took to the skies in 1903, they touched off a firestorm of aviation evolution. Less than 15 years later, propeller planes were valuable military assets and innovators like romance-novelist-turned-pilot Barbara Cartland developed new ways to launch, tow and precision-land unpowered gliders. In 1960, Pan Am launched the first Boeing 747, proving that large-scale commercial air travel was not just possible but also cost-effective, according to The Museum of Flight. 1998 saw the development of Scaled Composites’ Proteus, the brain child of then-president Burt Rutan. Originally designed as a telecommunications platform intended to provide high-speed internet over cities, Proteus evolved into a platform for research, including high-altitude environmental and telecommunications studies.

The Proteus Plan

According to Scaled Composites, the craft uses an all-composite airframe and graphite-epoxy sandwich construction. In addition, the tandem-wing Proteus has a wingspan of 77 feet, 7 inches expandable up to 92 feet with the use of optional wingtip assemblies. It is piloted by two crew members inside a pressurized cabin.

If that description sounds a little odd, rest easy knowing it’s a shared sentiment: The Experimental Aircraft Association (EAA) describes the Proteus aircraft as “a somewhat ungainly-looking bird.” But it’s all part of the plan. The craft’s name comes from the name of a Greek sea-god who could change forms at will and is the root of the English word “protean,” which means “ever-changing” — and the Proteus has proven itself versatile enough for use in NASA, DARPA, DOE, the International H20 Project (IHOP 2002) and Transformational Space Corp missions.

The changeable nature of Proteus’ design is also evident in payload handling. According to Scaled Composites’ bids and proposals manager Erik Hoffman, “‘you really decouple the payload from the plane,'” making it possible to switch between payloads in days rather than weeks or months. Bob Withrow, vice president of engineering at Scaled Composites, puts it simply: “‘It turns out that at Scaled, a lot of what we build are flying trucks. It doesn’t always start that way, but with ARES, Firebird, Proteus, all those aircraft were started with a specific mission in mind, and after we had done the demonstration, it turns out that they are really good at doing some other things.'”

Big Numbers

As noted by NASA, the high-altitude aircraft owns several world records for Federation Aeronautique Internationale Class C-1e vehicles including piloted altitude (63,245 ft), horizontal flight altitude (62,385 ft) and altitude with 1,000 kg of payload (55,994). According to the Aircraft Owners and Pilots Association (AOPA), meanwhile, the plane completed flight number 1,000 in June 2017 — not bad for a craft that took to the skies more than 19 years ago.

Multipurpose Mission

Over the last two decades, Proteus has been involved with multiple NASA research initiatives, including some of the original work on allowing unmanned aircraft to detect and avoid other airborne vehicles. In March 2001, the craft gathered data over the North Pole as part of the TRACE-P mission; in August of the same year, it did work for NASA’s Chesapeake Lighthouse & Aircraft Measurements for Satellites (CLAMS) program to measure ocean characteristics; and in 2006 it housed the development version of the Multi-Platform Radar Technology Insertion Program radar system.

It’s also important to remember the Proteus aircraft’s roots as a telecommunications relay — original plans called for a “fleet” of 100 Proteus-like aircraft providing high-altitude broadband communications. The advent of in-ground fiber optic technology shelved that idea, but Proteus’ original mission was ahead of its time, and other companies are studying similar missions today.

Protean Task

The unique nature of Scaled Composites’ high altitude aircraft makes it indispensable for airborne research missions. Over 19 years and 1,000 flights, the craft has shattered airborne records and helped scientists unlock new atmospheric data, and it may pave the way for ultra-high-speed air-to-ground telecommunications.

If you’re interested in the shaping the future of aviation, you’re in luck. Take a look at the latest job postings from Northrop Grumman and Scaled Composites.