Jul 26,2023 _ News

Proteus Reaches 25 Years of Flight

Today marks 25 years from Proteus’ first flight on July 26, 1998!

In 1996, Scaled started working with customer Angel Technologies to investigate the use of an aircraft as a vehicle to provide high-altitude telecommunications transmissions to a populated area, developing a unique vehicle capable of carrying a large telecommunications dish underneath it. The concept involved a team of 4 aircraft, two flying at a time in a circular pattern for 12 hour shifts over a populated area – an idea that unfortunately got overshadowed as broadband access became widely accessible.

During development, there were many unique design decisions to make Proteus capable of supporting a 13 foot telecommunications dish for the intended mission. Long wings and canards provided a low wing loading needed for efficient high altitude loiter and the landing gear spread far apart between the booms and nose provide the space needed to carry a large dish. While the structure of the aircraft is mostly carbon composites, a plan had to be made to not interrupt signal when the aircraft is flying in an orbit – one of the wingtips is made of fiberglass to avoid blocking the telecommunications dish signal. For ease of operation, Scaled built the pressure vessel for the cabin with grid-stiffened structure to create a shirt-sleeve environment for the crew. All these design factors led to the constructions of a one-of-a-kind aircraft, Proteus!

As its original mission became no longer viable, Scaled was left with a unique aircraft on its hands: one that could fly at high altitudes, had a large underbody space that unique volumes could be externally attached to, and wings designed to not interfere with the volume beneath the fuselage. With these capabilities, Proteus has proven to be a versatile, high altitude, long-endurance research platform that has conducted over 1200 flights in the 25 years since it first flew.

In October of 2000, the team at Scaled wanted to prove out the max capabilities of Proteus, and during two flights on October 25th and 27th proceeded to set three World Records in the FAI Class C1-e, Group 2, Turbojet category – Altitude (63,245 ft), Altitude in Horizontal Flight (62,385 ft), and Altitude with a 1,000kg payload (55,994 ft) – none of which have been broken yet! Mike Melvill and Bob Waldmiller crewed the record breaking flights, wearing pressure suits loaned to Scaled from NASA Dryden.

If you’re familiar with Greek mythology, you’re aware of Proteus as the ‘old man of the sea’ whose nature continually changes. Scaled’s Proteus was named after this sea god because one of its original design features allowed it to be reconfigurable. Looking closely, you’ll see fasteners around its midsection, indicating the barrel of its fuselage is removable. Although the airplane has never had an opportunity to fly a mission with the mid-section removed, Proteus has been involved in over 30 significant research projects and missions and true to its shape-shifting name origin has had these payloads on all areas of the aircraft. In addition to the standard payload ‘pod’ slung underneath the fuselage, Scaled has installed payloads of all types to the wings, the canards, the booms, the top of the fuselage, the nose of the aircraft, the tail – even wing extensions have been added on to Proteus to support missions! The various programs Proteus has supported has allowed it to operate in 19 states and deploy to 8 countries including: France, Italy, Japan, Marshall Islands, Australia, Iceland, Papua New Guinea, and England.

Proteus has acted as a surrogate UAV in NASA ERAST “Detect, See, Avoid” missions, helped test the aerial refueling capabilities of the Global Hawk in the KQ-X program, tested the Multiple Altimeter Beam Experiment Lidar (MABEL) laser altimeter, carried the t/Space rocket booster model to test air launch capabilities, and more. To look closer at a smattering of Proteus’ missions over the years:

The NASA Transport And Chemical Evolution over the Pacific (TRACE P) missions took Proteus across the Pacific and over the North Pole, gathering atmospheric data to support development of Earth Observation Satellites and validate sensors.

One of Proteus’ longest running missions was testing out Multi-Platform Radar Technology Insertion Program (MP-RTIP) sensor – Proteus acted as a surrogate airplane for this Global Hawk radar to verify sensor performance. This mission had Proteus flying over 1000 hours, carrying one of the largest pods in its flight history.

Proteus recently flew in concert with Northrop Grumman’s Firebird to demonstrate an advanced data link for connecting aircraft in contested airspace. During this mission, the aircraft established a link, performed a simulated ISR mission, and connected back to a cloud-based 5G network testbed through a novel prototype multi-level security switch.

For 25 years Proteus has proven to be a unique aircraft with priceless capabilities to test out low TRL experiments in a flight environment, without the drastic configuration change that would be needed in other aircraft. Our talented team at Scaled takes the low TRL experiments our customers bring us and iterates them into flying equipment, designing what’s needed to work in a flying environment, testing out that everything will work in their new flight-style environment, and then entering flight test to operate and gather the data our customers need. Every mission Proteus has flown has been unique in what it needs from the aircraft, leading to many rapid design – build – test iterations by the Scaled team to adapt a customer’s equipment to the vehicle.

For our flight crew, Proteus gives a unique flying experience – as a one-of-a-kind aircraft, it is unconventional in both the way it looks and the way it flies. Taking off is unique as the tandem wing configuration results in no major rotation – from the ground it looks almost like the entirety of Proteus just rises without the nose drastically lifting. When at altitude, Proteus just wants to continue soaring, and landing gear need to lower to add enough drag to start descending. With its altitude capabilities, our pilots get to experience views from much higher than a standard commercial flight, routinely flying at 50,000 ft. At that altitude above most of the atmosphere, the Belt of Venus, responsible for the transition of pink and purple twilight, is no longer a factor, and sunset, instead goes from light to dark incredibly fast. In fact, the number of people who have flown in Proteus is less than the number who have flown in a Space Shuttle!

Scaled Composites has learned a lot during the many design – build – test iterations each Proteus payload brings us. The constant exciting new flight test programs that the aircraft has taken part in has let many employees over the years get hands-on in the maintenance, engineering, and flight operations. Proteus is a unique aircraft in all aspects, one our team is excited to fly, operate unique payloads for, and to see what it has coming next!

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