Nov 26, 2016 @ 16:25 |
Tern, a joint program between DARPA and the U.S. Navy’s Office of Naval Research (ONR), seeks to greatly increase the effectiveness of forward-deployed small-deck ships such as destroyers and frigates by enabling them to serve as mobile launch and recovery sites for specially designed unmanned air systems (UASs).
Effective 21st-century warfare requires the ability to conduct airborne intelligence, surveillance, and reconnaissance (ISR) and strike mobile targets anywhere, around the clock. Current technologies, however, have their limitations. Helicopters are relatively limited in their distance and flight time. Fixed-wing manned and unmanned aircraft can fly farther and longer but require either aircraft carriers or large, fixed land bases with runways often longer than a mile. Moreover, establishing these bases or deploying carriers requires substantial financial, diplomatic, and security commitments that are incompatible with rapid response.
Tern is an advanced technology development program that seeks to design, develop, and demonstrate a medium-altitude long-endurance (MALE) unmanned aircraft system and related technologies that enable future launch, recovery, and operations from small ships. The program seeks to develop systems and technologies to enable a future air vehicle that could provide persistent ISR and strike capabilities beyond the limited range and endurance provided by existing helicopter platforms.
Tern is an evolution of DARPA’s Tactically Exploited Reconnaissance Node (TERN) program, which culminated in successful Conceptual Design Reviews in summer 2014. In May 2014, DARPA and the Office of Naval Research (ONR) signed a Memorandum of Agreement making the program a joint effort named Tern. In October 2015, the Tern program passed a significant milestone with the successful completion Phase II preliminary design, culminating in a successful Preliminary Design Review.
Currently in Phase 3, the program is moving towards completion of detailed design activities. In this phase, DARPA plans to build a full-scale demonstrator system. Initial on-land testing, if successful, will progress to at-sea demonstrations of takeoff, transition to and from horizontal flight, and landing—all from a test platform with a deck size similar to that of a destroyer or other small surface-combat vessel.
“DARPA has been thinking about building a second Tern test vehicle for well over a year,” said Dan Patt, DARPA program manager. “Adding the second technology demonstrator enhances the robustness of the flight demonstration program and enables military partners to work with us on maturation, including testing different payloads and experimenting with different approaches to operational usage.”
Tern phase 3 Concept Video:
Tern seeks to enable on-demand, ship-based unmanned aircraft system (UAS) operations without extensive, time-consuming, and irreversible ship modifications. It would provide small ships with a “mission truck” that could transport ISR and strike payloads long distances from the host vessel. A modular architecture would enable field-interchangeable mission packages for both overland and maritime missions. It would be able to operate from multiple ship types in elevated sea states.
The Tern Phase 3 design is a tailsitting, flying-wing aircraft with a twin contra-rotating, nose-mounted propulsion system. The aircraft would lift off like a helicopter and then perform a transition maneuver to orient it for wing-borne flight for the duration of a mission. Upon mission completion, the aircraft would return to base, transition back to a vertical orientation, and land. The system is sized to fit securely inside a ship hangar for maintenance operations and storage.
Tern has accomplished the following technical milestones for its test vehicle in 2016:
- Wing fabrication: Since Phase 3 work started at the beginning of 2016, Tern has finished fabricating major airframe components and anticipates final assembly in the first quarter of 2017. Once complete, the airframe will house propulsion, sensors, and other commercial off-the-shelf (COTS) systems to make up the full-scale technology demonstration vehicle.
- Engine tests: In Phases 2 and 3, Tern has successfully tested numerous modifications to an existing General Electric engine to enable it to operate in both vertical and horizontal orientations. This type of engine was chosen because it is mature and powers multiple helicopter platforms currently in use.
- Software integration: This summer, Tern opened its Software Integration Test Station (SITS), part of the System Integration Lab that supports software development for the program. The test station includes vehicle management system hardware and software, and uses high-fidelity simulation tools to enable rapid testing of aircraft control software in all phases of flight. The SITS is helping ensure the technology demonstration vehicle could fly safely in challenging conditions such as launch, recovery, and transition between horizontal and vertical flight.
Additional tests are about to start. A 1/5th-scale version of the approved vehicle model is in testing in the 80’ x 120’ wind tunnel at the NASA Ames Research Center’s National Full-Scale Aerodynamics Complex (NFAC). Data collected during this test will be used to better characterize aircraft aerodynamic performance and validate aerodynamic models.
“We’re making substantial progress toward our scheduled flight tests, with much of the hardware already fabricated and software development and integration in full swing,” said Brad Tousley, director of DARPA’s Tactical Technology Office, which oversees Tern. “As we keep pressing into uncharted territory—no one has flown a large unmanned tailsitter before—we remain excited about the future capabilities a successful Tern demonstration could enable: organic, persistent, long-range reconnaissance, targeting, and strike support from most Navy ships.”
Tern is currently scheduled to start integrated propulsion system testing in the first part of 2017, move to ground-based testing in early 2018, and culminate in a series of at-sea flight tests in late 2018.
DARPA and the Navy have a Memorandum of Agreement (MOA) to share responsibility for the development and testing of the Tern demonstrator system. The Marine Corps Warfighting Laboratory (MCWL) has also expressed interest in Tern’s potential capabilities and is providing support to the program
- Keywords: DARPA, TERN, UAV, ISR
- Image: Tern, a joint program between DARPA and the U.S. Navy’s Office of Naval Research (ONR), has made significant advances during Phase 3 on numerous fronts, including commencement of wing fabrication (above) and completion of successful engine testing for its test vehicle, and funding of a second test vehicle. Click below for high-resolution image. (DARPA)
- Source: DARPA