Results for “Reentry” — Page 91

NASA NTRS1992

Structural mechanics simulations

Sandia National Laboratory has a very broad structural capability. Work has been performed in support of reentry vehicles, nuclear reactor safety, weapons systems and components, nuclear waste transport, strategic petroleum reserve, nuclear waste storage, wind and solar energy, drilling technology, and submarine programs. The analysis environment contains both commercial and internally developed software. Included are mesh generation capabilities, structural simulation codes, and visual codes for examining simulation results. To effectively simulate a wide variety of physical phenomena, a large number of constitutive models have been developed.

Biffle, Johnny H.↗

NASA NTRS1992

A high angle of attack inviscid shuttle orbiter computation

As a preliminary step toward predicting the leeside thermal environment for winged reentry vehicles at flight conditions, a computational solution for the flow about the Shuttle Orbiter at wind tunnel conditions was made using a point-implicit, finite volume scheme known as the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA). The surface pressures resulting from the computational solution are compared with wind tunnel data. The results indicate that the dominant inviscid flow features are being accurately predicted on the leeside of the Shuttle Orbiter at a moderately high angle of attack.

Kleb, William L.↗

NASA NTRS1992

Rarefied-flow aerodynamics

Means for relatively simple and quick procedures are examined for estimating aerodynamic coefficients of lifting reentry vehicles. The methods developed allow aerospace designers not only to evaluate the aerodynamics of specific shapes but also to optimize shapes under given constraints. The analysis was also studied of the effect of thermomolecular flow on pressures measured by an orifice near the nose of a Space Shuttle Orbiter at altitudes above 75 km. It was shown that pressures corrected for thermomolecular flow effect are in good agreement with values predicted by independent theoretical methods. An incidental product was the insight gained about the free molecular thermal accommodation coefficient applicable under 'real' conditions of high speed flow in the Earth's atmosphere. The results are presented as abstracts of referenced papers. One reference paper is presented in its entirety.

Potter, J. Leith↗

NASA NTRS1992

History of oxygen and carbon escape from the Martian atmosphere

A fraction of the oxygen in the Martian atmosphere continually escapes to space because dissociative recombination of the O2(+) ions in the ionosphere can impart sufficient energy to the product O atoms. In addition, ionization of the extended atomic oxygen corona resulting from the above process adds to escape since the solar wind can carry away O(+) ions born above a few hundred km altitude. A further by-product of this ion-pickup by the solar wind is an additional population of escaping oxygen atoms that are sputtered from the atmosphere near the exobase by pickup ions that are on reentry rather than escaping trajectories. This sputtering process can also remove carbon in the form of intact or dissociated CO2 since all atoms and molecules in the 'target' gas are subject to the collisional energy transfer that characterizes sputtering. We have estimated the present rates of escape of oxygen and carbon due to these mechanisms, as well as the rates at several epochs in the history of the solar system.

Luhmann, J. G.↗

NASA NTRS1992

Performance of uncoated AFRSI blankets during multiple Space Shuttle flights

Uncoated Advanced Flexible Reusable Surface Insulation (AFRSI) blankets were successfully flown on seven consecutive flights of the Space Shuttle Orbiter OV-099 (Challenger). In six of the eight locations monitored (forward windshield, forward canopy, mid-fuselage, upper wing, rudder/speed brake, and vertical tail) the AFRSI blankets performed well during the ascent and reentry exposure to the thermal and aeroacoustic environments. Several of the uncoated AFRSI blankets that sustained minor damage, such as fraying or broken threads, could be repaired by sewing or by patching with a surface coating called C-9. The chief reasons for replacing or completely coating a blanket were fabric embrittlement and fabric abrasion caused by wind erosion. This occurred in the orbiter maneuvering system (OMS) pod sidewall and the forward mid-fuselage locations.

Sawko, Paul M.↗

NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 4. Attachment B: Flight STS-35 report, section B

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume present spectra graphs of the reentry of flight STS-35.

Wright, Willie↗

NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 5. Attachment B: Flight STS-35 report, section C

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, and STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume presents spectral graphs of the reentry of flight STS-35.

Wright, Willie↗

NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 6. Attachment B: Flight STS-35 report, section D

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume presents spectral graphs of the reentry of flight STS-35.

Wright, Willie↗

NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 7. Attachment B: Flight STS-35 report, section E

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume presents data from the reentry of flight STS-35 in tabular and graphical format.

Wright, Willie↗

NASA NTRS1992

Support activities to maintain SUMS flight readiness, volume 8. Attachment B: Flight STS-35 report, section F

The Shuttle Upper Atmosphere Mass Spectrometer (SUMS), a component experiment of the NASA Orbital Experiments Program (OEX), was flown aboard the shuttle Columbia (OV102) mounted at the forward end of the nose landing gear well with an atmospheric gas inlet system fitted to the lower fuselage (chin panel) surface. The SUMS was designed to provide atmospheric data in flow regimes inaccessible prior to the development of the Space Transportation System (STS). The experiment mission operation begins about 1 hour prior to shuttle de-orbit entry maneuver and continues until reaching 1.6 torr (about 86 km altitude). The SUMS flew a total of three missions, 61C, STS-35, STS-40. Between flights, the SUMS was maintained in flight ready status. The flight data has been analyzed by the NASA LaRC Aerothermodynamics Branch. Flight data spectrum plots and reports are presented in the Appendices to the Final Technical Report for NAS1-17399. This volume presents tabular and graphical spectral data of the reentry of flight STS-35.

Wright, Willie↗

NASA NTRS1992

An approximate local thermodynamic nonequilibrium radiation model for air

A radiatively coupled viscous shock layer analysis program which includes chemical and thermal nonequilibrium is used to calculate stagnation point flow profiles for typical aeroassisted orbital transfer vehicle conditions. Two methods of predicting local thermodynamic nonequilibrium radiation effects are used as a first and second order approximation to this phenomena. Tabulated results for both nitrogen and air freestreams are given with temperature, species, and radiation profiles for some air conditions. Two body solution results are shown for 45 and 60 degree hyperboloid bodies at 12 km/sec and 80 km altitude. The presented results constitute an advancement in the engineering modeling of radiating nonequilibrium reentry flows.

Gally, Thomas A.↗

NASA NTRS1992

Common manned module

An economic analysis examines a reusable single crew module to reduce the cost of Moon to stay exploration by 5 billion dollars. Topics covered in viewgraph format include the following: aerodynamics, weight, runway landing, technology support, and common module reentry requirements.

Andrews, Dana↗

NASA NTRS1991

Consort and Joust sounding rocket missions

The two suborbital rocket programs are described in terms of their common objective of examining commercial applications of materials processing under microgravitational conditions. The sounding rocket programs have unique launch-service capabilities but provide essentially interchangeable payload accommodations. Major differences include longer low gravity times and larger payload volume for the Joust rocket, spin stabilization and land recovery for the Consort rocket, and faster ascent and reentry accelerations for the Joust rocket. A summary of previous and planned experiments for the rocket programs is given which includes studies of the morphology and strength of elastomer-modified epoxy resins, electrodeposition studies, the demixing of immiscible polymers, foam formation, and polymer experiments. These and other experiments can be facilitated by the microgravity time available on flights of the two sounding rockets.

Wessling, Francis C.↗

NASA NTRS1992

An approximate local thermodynamic nonequilibrium radiation model for air

A radiatively coupled viscous shock layer analysis program which includes chemical and thermal nonequilibrium is used to calculate stagnation point flow profiles for typical aeroassisted orbital transfer vehicle conditions. Two methods of predicting local thermodynamic nonequilibrium radiation effects are used as a first and second order approximation to this phenomena. Tabulated results for both nitrogen and air freestreams are given with temperature, species, and radiation profiles for some air conditions. Two body solution results are shown for 45 and 60 degree hyperboloid bodies at 12 km/sec and 80 km altitude. The presented results constitute an advancement in the engineering modeling of radiating nonequilibrium reentry flows.

Gally, Thomas A.↗

NASA NTRS1992

Langley 20-inch hypersonic CF4 tunnel - A facility for simulating real-gas effects

The Langley hypersonic CF4 tunnel is described focusing on the basic components, instrumentation, and operational capabilities. This tunnel is the only operational hypersonic facility which simulates an important aspect of dissociative real-gas phenomena associated with the reentry of blunt vehicles, i.e., the increase in density ratio across a normal shock or the decrease in the ratio of specific heats (gamma) that occurs within the shock layer of the vehicle. Particular attention is given to detailed pilot-pressure surveys for a new axisymmetric Mach 6 nozzle which were measured at the nozzle exit and downstream of the exit for reservoir pressures from 100 to 2000 psia and reservoir temperatures from 1100 to 1350 R.

Micol, John R.↗

NASA NTRS1992

Reusable ultralight personnel carrier (RUPC)

Attention is given to a personnel-carrying space vehicle concept developed to minimize the cost of access to LEO. The RUPC could provide alternate access to Space Station Freedom (SSF) for six passengers per flight. It can also bring and return small amounts of cargo, up to and including one SSF double rack. These capabilities are ideal for utilization flights during man-tended operations at SSF and for crew rotation during permanently manned periods. The RUPC is a reusable conical reentry vehicle and disposable adapter with propulsion and power subsystems. Avionics subsystem benefit from advanced low-power high-performance microelectronics developed for both the civilian and military space sectors. The RUPC core cabin concept has growth potential for other applications, including assured crew return, ground-launched crew rescue, delivery and retrieval of SSF cargo, and crew cabin for flights to the moon.

Clark, B. C., III↗

NASA NTRS1993

Improved Composite Flexible Blanket Insulation

Improved composite flexible blanket insulation is quilt of layers of advanced lightweight insulating materials. Each layer designed to optimize contribution to inhibition of radiative, conductive, and/or convective transfer of heat from hot side to cold side. Intended to protect spacecraft against heating during reentry into atmosphere, used on Earth where requirements for lightweight, flexible, highly efficient insulating materials protect people and equipment against temperatures up to about 1,650 degrees C. Such as, furnace curtains and insulating layers on firefighting equipment and protective clothing.

Kourtides, D. A.↗

NASA NTRS1993

Programs To Optimize Simulated Trajectories (POST\6DPOST)

Designed for optimizing simulated trajectories, POST is point mass, three degrees-of-freedom program while extended 6DPOST permits rigid-body six degrees-of-freedom models. Handles sophisticated problems such as ascent, orbital maneuvers, and reentry.

Brauer, Garry L.↗