O(1S) 557.7 nm and O(1D) 630 nm emissions in shuttle thruster plumes

Viereck, R. A.; Murad, Edmond; Pike, C. P.; Mende, S. B.; Swenson, G.; Elgin, James B.; Bernstein, Lawrence S.; Lucid, Shannon W.

doi:10.1029/94ja03371

Cited by 9 publications

(6 citation statements)

References 17 publications

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“…The collisional excitation of O by H20 has been identified and described by BroadfoOt et al. [1992a, b] and Viereck et al [1995]. In addition, it is speculated that raw fuel may react with O, but this is not well documented.…”

Section: Nh In the Excited State Emission From Nh (A 31i I •-> X 3•--)mentioning

confidence: 99%

The interaction of the atmosphere with the space shuttle thruster plume: The NH(A‐X) 336‐nm emission

Viereck¹,

Murad²,

Knecht³

et al. 1996

J. Geophys. Res.

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Observations of the optical emissions from the space shuttle's thrusters have been examined. Particular attention has been paid to the interaction of the thruster plume with the atmosphere. Emissions from CN, CH, C2, HNO, and NO 2 have been observed near the nozzle of the thruster in the vacuum core region of the plume, but these emissions are the direct result of the combustion process. Other emissions including OI and NH have been observed in the downstream region of the plume, where the plume effluents interact with the atmosphere. The NH emission is one of the most dominant UV/ visible wavelength emissions observed in the plumes. This emission was observed to extend several thousand meters from the shuttle, and detailed analysis shows that the total intensity of the emission depends on the ram angle (angle in the shuttle reference frame between the plume effluents and the ramming atmosphere) and altitude, indicating an interaction process with the atmosphere. Data from two observational experiments are presented. The Air Force Maui Optical Site (AMOS) experiment includes ground-based spectral and spatial measurements of the shuttle plumes as the thrusters were fired over the AMOS site on top of Haliakala Volcano on the island of Maui in the mid-Pacific. The GLO experiment was flown in the payload bay of the space shuttle and also includes spectral and spatial measurements of the shuttle plumes. During both of these experiments, the primary reaction control system (PRCS) engines (870 lb (394 kgf) thrust) and Vernier reaction control system (VRCS) engines (25 lb (11 kgf) thrust) were fired at various angles relative to the ram, thus providing a range of collision velocities (4.5-11 km/s) between the thruster plume and the atmosphere. In this report the dependence of the NH emission on ram angle, thruster size, and distance from the shuttle is presented and analyzed using a three-dimensional Monte Carlo simulation of the plume-atmosphere interactions called spacecraft/orbiter contamination representation accounting for transiently emitted species (SOCRATES). The chemical reactions deemed most likely involve collisions of the plume products HNC, HNCO, and CH2NH with atmospheric O, and all of these processes are examined. The ram-angle dependence is used to determine a threshold energy required for the reaction that leads to the NH emission and to conclude that the most likely reaction involves CH2NH collisions with O. orbit (-200-500 km) undergo complex interactions with the atmosphere because of the rarefied and reactive nature of the atmosphere at these altitudes. These interactions lead to the generation of local atmospheres that are quite different from the ambient atmosphere. The rarefied atmosphere and the relatively high orbit velocity also produce a unique opportunity to study high-velocity one-step and twostep chemical processes. The large scale lengths provide an environment where it is possible to study extremely long lived metastable species. The state of the local spacecraft environ-Paper number 95JA...

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Section: Nh In the Excited State Emission From Nh (A 31i I •-> X 3•--)mentioning

confidence: 99%

The interaction of the atmosphere with the space shuttle thruster plume: The NH(A‐X) 336‐nm emission

Viereck¹,

Murad²,

Knecht³

et al. 1996

J. Geophys. Res.

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“…Emissions ranging from the IR to the vuv are possible that primarily arise due to on going combustion reactions in the near-field (core radiation) 3 and due to effluentatmosphere collisions in the far-field (plume radiation). [4][5][6][7][8] The most recent ground-based 9 and in-flight 4,10 observations of the UV-visible emissions from the Space Shuttle's thrusters have reported intense 336 nm NH(AfX) and 630 nm O( 1 Df 3 P), and strong 558 nm O( 1 Sf 1 D) features in the plume radiation. Analysis and modeling of these features as a function of ramangle and altitude indicate that the mechanism for O( 1 S)/O( 1 D) production is via collisional excitation of atmospheric O( 3 P) by the exhaust effluents, H 2 O and/or N 2 , and for NH(A) production via the O( 3 P) + CH 2 NH reaction.…”

Section: Introductionmentioning

confidence: 99%

Gas Phase Reaction Kinetics of O Atoms with (CH₃)₂NNH₂, CH₃NHNH₂, and N₂H₄, and Branching Ratios of the OH Product

Vaghjiani

2001

J. Phys. Chem. A

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The gas-phase reaction kinetics of O atoms with the two alkylated diamine rocket fuels, (CH3)2NNH2 and CH3NHNH2, was studied in a discharge flow-tube apparatus under pseudo-first-order conditions in [O atom]. Direct vuv cw-resonance fluorescence monitoring of the [O atom] temporal profiles in a known excess of the [diamine] yielded the following absolute second-order O atom rate coefficient expressions: k 1 = (1.94 ± 0.34) × 10-11e(25±25)/ T and k 2 = (2.29 ± 0.40) × 10-11 e(-145±40)/ T cm3 molecule-1 s-1, respectively, for reactions with (CH3)2NNH2 and CH3NHNH2 in the temperature range 232−644 K and in He pressure of 2.0 Torr. The total yields of OH in the reactions were measured to be (0.12 ± 0.09) and (0.14 ± 0.10) at 298 K and in 2.0 Torr He pressure. Close to ∼ 53% and ∼ 59% of the OH produced was estimated to be vibrationally excited. A pulsed-photolysis reactor was used to extend our measurements on the O atom reaction kinetics with the unsubstituted rocket fuel, N2H4 that we had previously studied in the flow-tube apparatus. At 298 K, both the rate coefficient, k 3 = (0.59 ± 0.12) × 10-11 cm3 molecule-1 s-1 and the total OH yield = (0.35 ± 0.14) did not show any discernible dependence on He or N2 buffer gas pressures of up to 404 Torr. The magnitude of, the weak temperature dependence and the lack of pressure effect in the O + N2H4 reaction rate coefficient suggests that simple direct metathesis of H atom may not be important compared to initial addition of the O atom to the diamine, followed by rapid dissociation of the intermediate into a variety of products.

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“…At the first step in process (9.5) any other plume molecule might be introduced instead of the water. However, there are some references indicating higher probability of the O( 1 S) production in collisions of oxygen with water than with other plume components 35,154 . The metastable oxygen atom produced at the first step of process (9.5) was allowed to move away in any direction with sampled velocity.…”

Section: O H O O S H O Ev O S H O Oh a Oh X Evmentioning

confidence: 99%

“…Further the metastable atom either collided with water, entering into reaction with some probability or decayed through radiation with characteristic time τ = 0.73 sec 155 . It should be noted that quenching rate of the O( 1 S) atoms by water molecules is much bigger in comparison with other major plume species 35,154 . Therefore, quenching of the metastable oxygen may be roughly accounted by proper choice of the elastic and reaction cross-sections.…”

Section: O H O O S H O Ev O S H O Oh a Oh X Evmentioning

confidence: 99%

Studying of Atomic and Molecular Interaction Processes in Rarified Hypervelocity Expanding Flows by Methods of Emissive Spectroscopy

Karabadzhak¹

2004

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O(¹S) 557.7 nm and O(¹D) 630 nm emissions in shuttle thruster plumes

Cited by 9 publications

References 17 publications

The interaction of the atmosphere with the space shuttle thruster plume: The NH(A‐X) 336‐nm emission

The interaction of the atmosphere with the space shuttle thruster plume: The NH(A‐X) 336‐nm emission

Gas Phase Reaction Kinetics of O Atoms with (CH₃)₂NNH₂, CH₃NHNH₂, and N₂H₄, and Branching Ratios of the OH Product

Studying of Atomic and Molecular Interaction Processes in Rarified Hypervelocity Expanding Flows by Methods of Emissive Spectroscopy

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O(1S) 557.7 nm and O(1D) 630 nm emissions in shuttle thruster plumes

Cited by 9 publications

References 17 publications

The interaction of the atmosphere with the space shuttle thruster plume: The NH(A‐X) 336‐nm emission

The interaction of the atmosphere with the space shuttle thruster plume: The NH(A‐X) 336‐nm emission

Gas Phase Reaction Kinetics of O Atoms with (CH3)2NNH2, CH3NHNH2, and N2H4, and Branching Ratios of the OH Product

Studying of Atomic and Molecular Interaction Processes in Rarified Hypervelocity Expanding Flows by Methods of Emissive Spectroscopy

Contact Info

Product

Resources

About

O(¹S) 557.7 nm and O(¹D) 630 nm emissions in shuttle thruster plumes

Gas Phase Reaction Kinetics of O Atoms with (CH₃)₂NNH₂, CH₃NHNH₂, and N₂H₄, and Branching Ratios of the OH Product