Dope on a Rope 2: Development of a Dream Chaser Aero Tow Simulation

Dope on a Rope 2: Development of a

Dream Chaser Aero Tow Simulation

Armstrong innovators have developed a lifting-body aero tow simulation to determine feasibility and procedures for towing the Dream Chaser Flight Test Vehicle (FTV) to an altitude of 30,000 feet. The Dream Chaser FTV is a full-scale, full-weight, single-seat, manned glide test spacecraft and was designed to conduct approach and landing tests. The aero tow concept calls for a large transport-size jet aircraft to tow a piloted commercial re-entry vehicle into the air with a long robust towline. At a predetermined altitude, the re-entry vehicle separates from the tow aircraft

and is landed by the astronaut on board. The tow concept was successfully demonstrated in the late 1990s in the Eclipse Project with F-106 and C-141 aircraft.

'Dope on a Rope' was the unofficial Eclipse Project name, a moniker developed in jest to teasingly poke fun at the intelligence of the project pilot. The name stuck, and 'Dope on a Rope 2' has been adopted as the unofficial project name for the follow-on work.

Work to date: The Armstrong team linked an existing simulation of the HL-20 lifting-body aircraft and a C-17 to determine feasibility. The simulation has been updated with models of the Dream Chaser FTV, and a cockpit with representative windows has been built. The simulation is now being used to develop tow profiles and procedures, evaluate control law changes, and determine potential tow vehicles. It is also being used to validate the rope model for stability and control analysis.

Looking ahead: An important role of the simulator is to evaluate different aircraft as Dream Chaser tow planes. Simulations of potential tow aircraft can be linked to evaluate performance and tow efficiency. When a tow aircraft is selected, the simulation will be used to develop tow techniques and procedures.

Partners: Sierra Nevada Corporation and U.S. Air Force

_' As a result of evaluations in the Aero Tow Simulator, Sierra Nevada Corporation has made Aero Tow the primary method of getting the Dream Chaser FTV to altitude for the approach and landing testing to be performed in 2015-2016. The Aero Tow Simulator will play a vital role in developing towing techniques and

procedures, tow mode flight control development, and astronaut training. _'

Bruce Cogan, PI

Engineering Successes

Armstrong's Research and Engineering Directorate is responsible for the overall engineering content of flight research projects. Our engineers provide technical expertise in aerodynamics; guidance, navigation, and control; propulsion; static and dynamic structures; flight hardware and software; flight and ground test instrumentation and data systems; and system engineering and integration. They apply their expertise across the spectrum of Armstrong's many activities and also support the development and continual evolution of engineering tools and test techniques. Here are highlights from a few recent and particularly notable engineering success stories.