Search NASA⌕ Search

Engineering topics

Siemers, P. M., III

Publications and source records attributed to Siemers, P. M., III.

26 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Shuttle Entry Air Data System

The SEADS system (Shuttle Entry Air Data System) is being developed to provide research quality hypersonic (M greater than 3.5) air data. SEADS will accomplish this through the instrumentation of the orbiter's baseline nose cap. The SEADS development program consists of (1) the design and testing program required to define a reinforced carbon-carbon (RCC) nose cap penetration concept which will not degrade nose cap performance, (2) the definition of analytical techniques and design criteria for array definition and flight data analysis, (3) the verification of these analytical techniques and array criteria through a comprehensive wind-tunnel test program, (4) the demonstration of the system concept through detailed testing, and (5) the analyses and tests required to flight-certify the SEADS system.

Siemers, P. M., III↗
NASA NTRS1978

The Space Shuttle Orbiter and aerodynamic testing

The concept of utilizing the Space Shuttle Orbiter as an aerodynamic flight research vehicle is discussed. The orbiter's planned flight frequency and its complex flight control system provide an unprecedented flight research potential. This paper defines the orbiter's flight environment and applicable baseline systems, their capabilities and limitations, as well as those instrument systems required to augment the baseline capability. These required systems, which are being developed under NASA's Orbiter Experiments Program (OEX) are the Aerodynamic Coefficient Identification Package (ACIP), Shuttle Entry Air Data System (SEADS), and the Shuttle Upper Atmosphere Mass Spectrometer (SUMS). Finally, the need for and capability of launching payloads from the orbiter to extend the research potential beyond the orbiter configuration and/or environment is defined.

Siemers, P. M., III↗
NASA NTRS1975

Shuttle launched flight tests - Supporting technology for planetary entry missions

The feasibility of conducting Space Shuttle-launched earth entry flight tests to enhance the technology base for second generation planetary entry missions is examined. Outer planet entry environments are reviewed, translated into earth entry requirements and used to establish entry test system design and cost characteristics. Entry speeds up to those needed to simulate radiative heating levels of more than 30 kW/sq cm are shown to be possible. A standardized recoverable test bed concept is described that is capable of accommodating a wide range of entry technology experiments. The economic advantage of shared Shuttle launches are shown to be achievable through a test system configured to the volume constraints of a single Spacelab pallet using existing propulsion components.

Vetter, H. C.↗
NASA NTRS1975

Shuttle entry technology payloads

The flight frequency of the Space Transportation System (STS) coupled with its large payload-carrying capability will provide an unprecedented opportunity for conducting aerothermodynamic/entry technology research. This STS research opportunity can be characterized into two distinct categories: (1) that research which will utilize the STS orbiter as the test vehicle, and (2) that research which will utilize a vehicle launched from the orbiter for entry. To date, on-going studies have defined experiments as well as the support systems required for the shuttle launched research program. The proposed Entry Technology Program will provide a flight data base from which accurate correlations can be performed relative to ground test and analysis data. These correlations will result in optimized designs for future flight systems.

Siemers, P. M., III↗
NASA NTRS1973

Development of the Viking parachute configuration by wind tunnel investigation.

Several experimental investigations to obtain the drag performance of 10% scale-model disk-gap-band-type parachute assemblies trailing in the Viking forebody wake were conducted over the range of Mach 0.2 to 2.6. The wind-tunnel tests varied both the canopy trailing distance and ratio of suspension line length to canopy diameter. The data obtained permitted optimization of both parameters. Parachute drag performance in the forebody wake is markedly degraded transonically beginning at Mach 0.6, reaching a minimum value at Mach 1.0, then approaches the subsonic value for the selected configuration as Mach number is increased to 1.4. Further increase in Mach number causes the drag coefficient to again decline. A 20% increase in parachute-alone transonic drag coefficient was obtained by increasing suspension-line length ratio from 1.16 to 1.73.

Steinberg, S.↗
NASA NTRS1972

Viking configuration pitch damping derivatives as influenced by support interference and test technique at transonic and supersonic speeds.

Experimental studies to determine the 140-deg spherically-blunted cone configuration single degree-of-freedom damping derivative included model sting interference effects at M = 1.76 to 3.0. Minimal sting influences are noted with sting/model diameter ratios of 0.183 and effective sting lengths of 3.55 of the reference length. Increasing the ratio of sting diameter to reference length to 0.53 influences damping considerably at angles of attack from 0 to 3 deg at all Reynolds numbers but shows little or no effect at higher angles. Free-flight model wake geometries (wake neck position and size) correlate well with those from captive model tests with the small diameter sting; this adds confidence to obtaining damping derivatives through captive model testing. The damping characteristics of an early Viking configuration obtained on 11.23 and 4.35% scale models using forced and free oscillation test methods, respectively, in two different test facilities are compared. The agreement is quite good under test conditions.

Steinberg, S.↗
NASA NTRS1972

Parameters influencing dynamic stability characteristics of Viking-type entry configurations at Mach 1.76.

Free-oscillation tests of three Viking-type blunt conical configurations were conducted in a wind tunnel to determine the important variables influencing their dynamic stability characteristics at Mach 1.76. The effects of sting geometry are shown to be significant at low angles of attack, while the effects of cross plane motions and tunnel vibration characteristics appear to be negligible. Variation of the reduced-frequency parameter and model base geometry caused significant effects in the data. An approximate technique was developed for converting effective data from either forced-oscillation or free-oscillation tests to values based on the instantaneous angle of attack.

Whitlock, C. H.↗