AMOS 2005 TECHNICAL CONFERENCE

Transcription

1 PREDICTINS F BSERVATINS F SUTTLE ENGINE FIRINGS AMS 2005 TECNICAL CNFERENCE 5-9 September, 2005 Maui, awaii M. Braunstein, L. Bernstein Spectral Sciences, Inc., Burlington, MA M. Venner AFRL, Edwards AFB, CA R. Dressler AFRL, anscom AFB, MA.

2 Report Documentation Page Form Approved MB No Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington eadquarters Services, Directorate for Information perations and Reports, 1215 Jefferson Davis ighway, Suite 1204, Arlington VA Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid MB control number. 1. REPRT DATE 22 AUG REPRT TYPE 3. DATES CVERED - 4. TITLE AND SUBTITLE Predictions of AMS bservations of Space Shuttle Engine Firings 5a. CNTRACT NUMBER F C b. GRANT NUMBER 5c. PRGRAM ELEMENT NUMBER 6. AUTR(S) Matthew Braunstein; Larry Bernstein; Rainer Dressler; Marty Venner 5d. PRJECT NUMBER BMSB 5e. TASK NUMBER R2FT 5f. WRK UNIT NUMBER 7. PERFRMING RGANIZATIN NAME(S) AND ADDRESS(ES) Air Force Research Laboratory (AFMC),AFRL/PRSA,10 E. Saturn Blvd.,Edwards AFB,CA, PERFRMING RGANIZATIN REPRT NUMBER 9. SPNSRING/MNITRING AGENCY NAME(S) AND ADDRESS(ES) 10. SPNSR/MNITR S ACRNYM(S) 12. DISTRIBUTIN/AVAILABILITY STATEMENT Approved for public release; distribution unlimited 13. SUPPLEMENTARY NTES 14. ABSTRACT N/A 15. SUBJECT TERMS 11. SPNSR/MNITR S REPRT NUMBER(S) 16. SECURITY CLASSIFICATIN F: 17. LIMITATIN F ABSTRACT a. REPRT unclassified b. ABSTRACT unclassified c. TIS PAGE unclassified 18. NUMBER F PAGES 18 19a. NAME F RESPNSIBLE PERSN Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18

3 utline Introduction Chemical Mechanisms Source and Apparent Signals Instrumentation Conclusions and Future Work.

4 Acknowledgements M.B. and L. S. acknowledge support through a Small Business Innovative Research (SBIR) award from the Missile Defense Agency (MDA) Contract No. F C-0015, M. Venner, AFRL contract manager, and support from the DoD through contract F C-0006.

5 Shuttle engine firing observation scenario. Engine exhaust, consisting mostly of 2, interacts with -atom in the atmosphere to produce internally excited species, (v) and 2. The radiative decay of these excited species is attenuated by the atmosphere and observed from AMS in the 2-5 μm region. zenith angle atmospheric wind (-atom) atmospheric attenuation wake radiating exhaust + atm. species 2 perp (v) exhaust flux ( 2 ) ram AMS bservation Scenario

6 Chemical Mechanisms Signal is due to two major chemical mechanisms ( 3 P) + 2 (X, 1 A 1 ) (X, 2 Π) + (X, 2 Π), Δ = kcal mol -1, (1) ( 3 P) + 2 (X, 1 A 1, (ν 1 ν 2 ν 3,JK)) ( 3 P) + 2 (X, 1 A 1 (ν 1 ν 2 ν 3,J K )). (2) Single collision models for total signal I space Δλ * σ σ tot N 2 T Δλ = (Photon efficiency) * ( 2 engine flux) * (atmospheric transmittance) = # photons per second * σ σ tot = 1 σ tot species v= 1 vσ species v

7 Energy level diagram for + 2 collisions ( 2 Π) ( 2 Σ + ) Transition States Product States 120 (10.9) 100 (9.9) 80(8.9) + 2 ( 2 S) ( 2 A ) 60(7.7) ( 1 D) 2 ( 1 A 1 ) 40(6.3) ( 3 P) 2 ( 1 A 1 ) ( 3 Σ 3 Π) 1 3 A 2 3 A 1 3 A 2 3 A 1 3 A 2 3 A 1 3 A ( 2 Π) ( 2 Π) ( 3 Δ 3 Σ +- ) 20(4.4) ν 1ν2 ν ( 1 Σ g+ ) 2 ( 3 Σ g- ) kcal/mol (km/s) 0

8 Cross sections for the reaction, + 2 (v) + (v), as a function of collision velocity + 2 (v) + (v) Gas kinetic v=0 v=1 v=2 v=3 v=4

9 Cross sections for the reaction, as a function of collision velocity Gas kinetic v*=1 v*=2 v*=3 v*=4

10 Photon production efficiency per collision and total source signal in photons s -1 as a function of velocity for PRCS engine firings. The 2 contribution has been split into μm and μm contributions. The (v) contribution is here called 2.8 μm. The 2.8 μm and μm curves contribute to the 2-5 μm pass-band. wake perp. ram μm μm 2.8 μm 1.4e25 1.4e24 1.4e23 1.4e22 1.4e21 1.4e20 photons sec -1 Distribution A: Approved for Distribution public release; A: distribution Approved unlimited. for public release; distribution unlimited

11 Normalized spectral radiance from (v) (black curve) and 2 (blue curve) at 8 km s -1 Source and Apparent Signals relative collision velocity. microns km s -1 2 The (v) and 2 curves have been separately normalized to 1.0 and the 2 curve displaced for clarity. The atmospheric transmittance for a 60 degree zenith look angle from AMS is shown in red. Spectral resolution is 5 cm -1. (v) Transmittance 0.0

12 Source and apparent (atmospherically attenuated) (v) + 2 relative spectral radiance at 8 km s -1 relative collision velocity microns microns (a) source (v) + 2 (b) apparent (v) km s -1 8 km s -1

13 Normalized spectral radiance from (v) (black curve) and 2 (blue curve) at 11 km s -1 relative collision velocity. microns km s -1 2 The (v) and 2 curves have been separately normalized to 1.0 and the 2 curve displaced for clarity. The atmospheric transmittance for a 60 degree zenith look angle from AMS is shown in red. Spectral resolution is 5 cm -1. (v) Transmittance 0.0 Distribution A: Approved for public Distribution release; A: distribution Approved for unlimited. public release; distribution unlimited

14 Source and apparent (atmospherically attenuated) (v) + 2 relative spectral radiance at 11 km s -1 relative collision velocity microns microns (a) source (b) apparent (v) + 2 (v) km s km s -1

15 Space Shuttle Plume Measurement Analysis Utilize Total Signal Calculation to Estimate a Signal-to-Noise for Two Available Spectrometers 3.76e04 W (11 km/s Case) Assume Both Integrable onto AMS Telescope (Most Likely B37) 5 km Diameter Plume at 390 km Altitude and 60 Degree View From Zenith Expect Plume Radiance to Fill the FV (B37 is nly 3 mrad Total) Calculate Average Radiance by Dividing by 4π Steradians and Estimated Plume Area

16 ABB (Bomem) FTIR Spectrometer Spec s Two Simultaneous Non-Imaging Detectors 1-6 μm InSb, 1.37e-09 RMS NESR at 1 cm -1 Resolution 2-15 μm MCT, 1.4e-08 NESR at 1 cm -1 Currently Use LN2 for Detector Cooling 5, 28, 75 mrad Telescopes Available as Attachments LN2 Cooled Cold Source Weight 45 kg Nominal Scan Rate and Spectral Resolution Specifications: Resolution (cm -1 ) Frame Rate (scans/sec) Maximum Acq Time (sec)

17 ABB FTIR InSb Detector S/N Calculations 10 0 Spectral Resolution (cm -1 ) Signal-to-Noise Measurement Time (sec)

18 Broadband Array Spectrograph System (BASS) Aerospace Corporation Sensor (Dave Lynch) Wavelength Dispersive System 2 Prisms 116 Total Detectors μm Waveband Approximately 0.1 μm Resolution (Much Lower Than Desired) Noise Equivalent Power: 4.0e-14 W/Sqrt(z) (1 Sec Integration ) Frame Rate: z Estimate S/N = 1448 ver the μm Region Calculation Not Reviewed by Aerospace Corp. Personnel

19 Conclusions and Future Work Total Signal (Watts) = (Efficiency in photons per 2 ) (# 2 from engine s -1 ) (3.33e3 cm -1 / photon) (1.9863e-23 Joules / cm -1 ) (atmospheric attenuation factor) 8 km s e4 Watts 11 km s e4 Watts Results compare well with previous observations at 11 km s -1 (v) is the major contributor More source signal (and a little more attenuation) at higher velocities Need high angle of attack firing to see signal ABB FTIR spectrometer not sensitive enough with present configuration BASS sensor appears to have required sensitivity but at the expense of low spectral resolution Future Work Better cross sections Analyze spatial distribution of radiation Additional instrument analysis required