Mounted in an adapted Boeing 747, the Airborne Laser (ABL) was to be a dream antimissile weapon, acquiring the trajectory of a Scud or other theater-range ballistic missile, pointing a high-power laser beam precisely at a certain area of the fast-moving target, and holding it there until the missile surface heated and ruptured. But the ABL fell eight years behind schedule and went $4 billion over budget before the program was finally axed in 2010. A classic defense boondoggle, the ABL is also a frightening example of how committed military officials, scientists, and defense contractors can persuade Congress to keep a defense program alive against, seemingly, all reason, the author writes. An ABL postmortem should be carried out by truly independent scientists and engineers. Beyond determining just what the ABL project did and didnÕt accomplish, however, the US government needs to address the chronic lack of transparency and accountability in defense science and technology programs exemplified by the ABL fiasco. The White House Office of Science and Technology Policy should be the agency responsible for coordinating efforts to increase scrutiny of such programs, particularly those at the far technical edge of missile defense research.

The jgh Performance O2 Ldar Lurveillance Lensor system (HI-CLASS) is a state-ofthe-art coherent ladar system which will provide precision tracking and high resolution imaging at the Air Force Maui Optical Station (AMOS). System development is occurring in 3 phases representing increasing hardware/software complexity and system capability. The recently-completed Phase I HI-CLASS system employs a compact, pulsed, coherent CO2 oscillator, a heterodyne receiver, and signal recorder coupled to the AMOS O.6m Laser Beam Director (LBD) to demonstrate target (satellite) acquisition and tracking, illumination, return signal detection, signal recording, and off-line processing for range and range rate extraction and range-amplitude imaging. A description of the Phase I satellite ranging and ground-based remote sensing tests verifying the FLD system operating concept will be presented. The cooperative target range and range rate measurements, as well as imaging precursor demonstration, will be discussed. The talk will include a discussion of the 21 km demonstration of remote sensing using natural terrain returns. Results generated on phase I data with the phase II algorithm will also be described. INTRODUCTIONThe HI-CLASS system, encompassing a coherent, high power CO2 transmitter and a receiver-processor coupled to existing beam directors and associated subsystems, will be capable of state-of-the-art target measurements at the United States Air Force Maui Optical Station (AMOS). These measurements will include precision trajectory determination and high resolution range-Doppler image generation. The system, scheduled for completion in late 1996, is being developed in three phases.Phase I involved the initial demonstration of a complete, pulsed, 100 watt class ladar system with an off-line data processing capability. This effort culminated with a series of ladar tests employing sun-lit cooperative (retro-equipped) targets (GEOS-C and LACE) which yielded satellite range and range rate as a function of time. A series of tests with a wide bandwidth waveform (pulse-burst) also provided an initial demonstration of the system imaging resolution.Phase II , a brass-board oscillator and receiver-processor to extract real-time range and range rate data and to record satellite image data for post-mission analysis is now being tested at AMOS. Phase III will incorporate the full-power, kilowatt system (oscillatoramplifier) for real-time trajectory and image data generation. + This paper is an update of SPIE paper 2702-07 presented at the SPIE conference in San Jose in January, 1996. As such, it contains a review of material previously published along with new material generated since the previous publication date. O-8194-2129-4196/$6.QQ SPIE Vol. 2748 / 309 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/24/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx

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A conceptual design study of the laser transmitter was completed during Phase A of the NASA's LAWS instrument development program. The proposed LAWS instrument is a space-based doppler lidar wind profiler consisting of a pulsed, frequency-stable laser as its transmitter, which is the subject of this paper. The telescope, heterodyne detection system and signal processor designs will be reported in another paper.(1) While both solid-state and CO2 lasers were considered as potential candidates for the LAWS instrument, it became clear early on that CO2 lasers had definite advantages over the solid-state at the present time. Although, the solid-state technology is rapidly advancing, it does not yet have the maturity enjoyed by the CO2 technology.(2) Furthermore, the CO2 wavelength is clearly favored from eye safety consideration. Therefore, our design study was performed primarily for a pulsed CO2 laser.

A multi-joule, wavelength agile, CO2 transceiver is being assembled in support of a two phase, airborne chemical sensing demonstration employing both direct (Phase I) and coherent (Phase II) detection methods. The Phase II, coherent detection iransceiver concept design, and performance are described below.