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Tewell, J. R.

Publications and source records attributed to Tewell, J. R..

12 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Wind tunnel test evaluation of a Shuttle derived launch system

The Shuttle Derived Vehicle (SDV) is a proposed unmanned launch system configured using Shuttle elements. The SDV incorporates two solid rocket boosters, an external tank and three Space Shuttle main engines identical to those used in the present Space Transportation System. Two new elements, a recoverable propulsion/avionics module housing the main engines and an expendable payload module, complete the SDV configuration. This paper describes the activities and results of wind tunnel tests conducted to validate the aerodynamic and controllability characteristics of SDV configurations. The configuration variables consisted of the payload module diameter, length and nose shape. The tests were conducted in the NASA/Marshall Space Flight Center 14 inch trisonic wind tunnel. Aerodynamic force and moment data were obtained over a Mach number range of 0.6 to 4.96. The attack and sideslip angles were varied + or - 8.0 deg. Forces and moments were measured by a sting-supported six component strain gage balance.

Tewell, J. R.↗
NASA NTRS1985

Shuttle derived launch vehicle wind tunnel tests

Studies are being conducted regarding new launch vehicle configurations which may effectively and economically share the delivery of payloads to orbit with the present Space Transportation System (STS). The role envisaged for these launch vehicles is related to the execution of missions whose requirements exceed the STS Shuttle capabilities, taking into account the delivery of much heavier or larger payloads. One class of advanced launch vehicles is configured to take advantage of the existing Shuttle hardware and facilities. Such vehicles are referred to as Shuttle Derived Vehicles (SDV). One version of an SDV consists of two STS elements, including the external tank (ET) and solid rocket boosters, and a cargo carrier. Attention is given to wind tunnel tests, which are being conducted with SDV sidemount configurations incorporating various size payload modules.

Tewell, J. R.↗
NASA NTRS1982

A Shuttle Derived Vehicle launch system

This paper describes a Shuttle Derived Vehicle (SDV) launch system presently being studied for the NASA by Martin Marietta Aerospace which capitalizes on existing Shuttle hardware elements to provide increased accommodations for payload weight, payload volume, or both. The SDV configuration utilizes the existing solid rocket boosters, external tank and the Space Shuttle main engines but replaces the manned orbiter with an unmanned, remotely controlled cargo carrier. This cargo carrier substitution more than doubles the performance capability of the orbiter system and is realistically achievable for minimal cost. The advantages of the SDV are presented in terms of performance and economics. Based on these considerations, it is concluded that an unmanned SDV offers a most attractive complement to the present Space Transportation System.

Tewell, J. R.↗
NASA NTRS1978

Dual-action expanded-latch mechanism

Single drive actuator operates novel mechanism that expands, attaches to object, and withdraws to latch object firmly to another part. Packaging is extremely simple and compact, and eliminates need for machined parts or close tolerances.

Spencer, R. A.↗
NASA NTRS1977

Docking and retrieval mechanism

An engineering prototype docking and retrieval mechanism (DRM) is described which enables two spacecraft to dock and be structurally joined on-orbit. The joining of two spacecraft or payloads on-orbit supports future planned space activities such as payload servicing, deployment and retrieval, and assembly of large space systems. The DRM, as developed, provides advantages over prior approaches because it is a nonimpact docking mechanism, does not require impact absorbing mechanisms or attitude stabilization on the target spacecraft, is capable of docking to a spinning spacecraft, and can spin up and deploy a spinning spacecraft or payload.

Tewell, J. R.↗
NASA NTRS1977

Docking and retrieval mechanism

An engineering prototype docking and retrieval mechanism (DRM) which enables two spacecraft to dock and be structurally joined on-orbit is described. The joining of two spacecraft or payloads on-orbit supports future planned space activities such as payload servicing, deployment and retrieval, and assembly or large space systems. Advantages of the DRM include: it is a nonimpact docking mechanism; does not require impact absorbing mechanisms or attitude stabilization on the target spacecraft; is capable of docking to a spinning spacecraft; and can spin up and deploy a spinning spacecraft or payload.

Tewell, J. R.↗
NASA NTRS1974

Configuration and design study of manipulator systems applicable to the free flying teleoperator. Volume 1: Executive summary

A preliminary design of a manipulator system, applicable to a free flying teleoperator spacecraft operating in conjunction with the shuttle or tug, is presented. A new control technique is proposed for application to the manipulator system. This technique, a range/azimuth/elevation rate-rate mode, was selected based upon the results of man-in-the-loop simulations. Several areas are identified in which additional emphasis must be placed prior to the development of the manipulator system. The study results in a manipulator system which will provide an effective method for servicing, maintaining, and repairing satellites to increase their useful life.

Tewell, J. R.↗
NASA NTRS1974

A manipulator system designed for Free-Flying Teleoperator Spacecraft

A preliminary design of a manipulator system, applicable to a Free-Flying Teleoperator Spacecraft operating in conjunction with the Shuttle or Tug, is presented. The manipulator arm incorporates two 4-ft segments to the wrist with actuators located at the shoulder, elbow, and wrist. The wrist provides three degrees-of-freedom through pitch, yaw and continuous roll joints. An interchangeable end effector provides multiple task performance and satellite worksite versatility. A tip force of 10 lbs and a torque of 15 ft-lbs is provided. Man-in-the-loop simulations, using both unilateral and bilateral control techniques, were conducted. Based upon the simulation, a new, but relatively simple, control technique was proposed for the manipulator system.

Tewell, J. R.↗
NASA NTRS1966

Gemini orbital tracking.

Simulation testing pilot performance in orbiting Gemini spacecraft based on tracking rate errors and fuel consumption

ASTRONAUT PERFORMANCE↗