Volume 4, Number 2 May/June 1996
Expanding the use of space depends in large measure upon reduced costs and greater safety. Toward economic ends, the "ship and shoot" concept is important to accomplish. One main "ship and shoot" inhibitor has been the need to shut down operations while pyrotechnics are being installed into launch vehicles. This procedure is necessary so that electrical systems, such as those that control the ordnance system are not accidentally fired. Clearly, using optical circuits and lasers to operate the ordnance function can potentially accomplish this objective because they do not have the induced current safety problems as electrical circuits. In addition, optical circuits and lines could offer other safety and operational advantages such as weight reduction.
This technology has been pursued by industry researchers for nearly two decades. Rod lasers were demonstrated on one tactical missile program, but the cost of fleet operational use was proven to be too high, thereby eliminating consideration for further use. Until relatively recently, laser powered laser diodes did not have the power output needed to accomplish ordnance initiation. Yet it was becoming evident that this important technology was not being given serious consideration for flight applications. So, NASA's Office of Space Access and Technology (OSAT) initiated a three-phase program, headed by Norman R. Schulze at NASA Headquarters, to demonstrate the practicality of solid state laser diode ordnance (LIO) in a program having the widest variety of applications.
The first planned test demonstration was to use LIO aboard a commercial launch vehicle (one having no contractual relationship to NASA from either a launch vehicle or payload perspective) to demonstrate the technology's feasibility, but be implemented so that failure would not be mission critical. An agreement with Ensign Bickford Company (EBCo), performed under Steve McComb and Craig Boucher accomplished this objective. While this program was planned to be first, it actually occurred later due to launch vehicle and payload circumstances. In April 1995, two LIO experiments were successfully launched; one igniting two tail fin rockets onboard the Orbital Science Corporation's Pegasus launch vehicle and another which fired an initiator into a pressure container to compare in-flight data with ground data.
The second step was to demonstrate the LIO technology for manned operations and provide flight data on whether accidental ignition could result by exposure of the fiber optic line to various sources of light in a space environment. In January 1996, an experiment named SELODE (Space Exposure Laser Ordnance Diode Experiment) was launched on the OSAT Free Flyer aboard the Space Shuttle. Various hardware such as initiators, detonators, fiber optic lines, lasers, and firing circuits were flown in a variety of configurations to expose the ordnance fibers directly to sunlight as well as with a ten power magnification of solar light, to over stress the exposure. The work was performed by Johnson Space Center's Barry Wittchen and so far the results have been fully successful, although complete analysis will take approximately six months after landing.
The third phase, LOSRD (Laser Ordnance Sounding Rocket Demonstration), demonstrated that an all solid state laser initiated ordnance system in an operational application without requiring FR silence could be safely used, under the most severe operational environment. This project provided the most hazardous application of LIO: use of ground circuits and procedures to ignite the first stage motor, use of flight systems (see figure above) to ignite the second stage motor and a planned termination of the second-stage motor thrust under the most severe light dynamics. A maximum acceleration of over 24 g's was reached. This fast track program took only seven months from proposal receipt to flight and was actually the first of the three projects flown. Managed by Norman Schulze at NASA Headquarters and Bonnie Maxfield at the NASA Wallops Flight Facility, the LOSRD was launched aboard a Nike-Orion Sounding Rocket from the Wallops Flight Facility on March 15, 1995, and was 100 percent successful.
The three-phase LIO program was implemented with less than $600,000 by using several management innovations, such as a cooperative agreement with industry-the first used for this type of activity. This program also used hardware already developed for the Navy. In addition, a wide range of experience existed from a government-industry team that addressed the needs of both users. Information was rapidly made available to industry with user participation in the launch in the case of the sounding rocket and its first application program. Conferences were held at the NASA Goddard Space Flight Center in April 1995 and another wrap-up session at Vandenberg Air Force Base in December 1995. A third conference is being planned at Lockheed-Martin, currently scheduled for October 1996.
For more information concerning the fall 1996 workshop and various aspects of the technology, contact Lance Wood at Lockheed Martin Co. Phone: 303/971-1218 or John Merson, Sandia National Laboratory Phone: 505/844-2756. For technical information on the laser ordnance hardware, contact Craig Boucher at EBCo. Phone: 203/843-2870. Norman Schulze has since retired from NASA Headquarters and can be reached at Phone: 703/818-2328. Please mention that you read about it in Innovation.
