security requirements, the task group notes that many of its components and the technologies they embody are similar to those required for an advanced astronomical observatory in space. Thus the ATD hardware may potentially have a role to play as a New Technology Orbital Telescope (NTOT) in fields such as cosmology, astrophysics, and planetary astronomy. Given the dual nature of the mission, the task group henceforth refers to a joint military/astronomy mission exploiting the ATD hardware as the ATD/NTOT. A purely military mission is referred to as the ATD.
With funding from the Strategic Defense Initiative Organization (SDIO), Itek Optical Systems has applied many of the techniques relevant to future space telescopes to create a fully active 4-meter mirror system with a very thin facesheet and lightweight carbon-fiber support structure. It has been proposed that Itek’s optics and other hardware be test flown as part of the ATD program sponsored by the Ballistic Missile Defense Organization (BMDO).
The basic philosophy adopted for the as yet unfunded ATD program is not to design hardware to meet requirements set by specific operational (or scientific) objectives. Rather, the ATD is a design-to-cost program in which the specific tasks to be accomplished are designed around the capabilities of existing or minimally modified hardware. Since these components are key to any potential scientific utility, the bulk of this report is devoted to assessing the ability of this hardware to perform a variety of priority astronomical observations.
As presented to the Task Group on BMDO New Technology Orbital Observatory by representatives of BMDO, Lockheed, and Itek, DOD’s technological goals for the ATD program include the following:1
Complete resolution of the ability to track and point a laser beam at a missile in the boosting phase in a space environment from the correct orbit geometries and ranges for a space-based laser;
Track and gather data on reentry vehicles and decoys at long ranges;
Gather imagery in the visible and near-infrared of space objects at geosynchronous orbits;
Gather Earth background data at high resolution on the water and carbon dioxide bands in the short- and medium-wave infrared as a data base for future system design;
Gather data on the observables of a missile in the boost phase; and
Demonstrate the ability to designate targets on the ground from a space platform for the use of laser-guided weapons in a tactical scenario.
The task group emphasizes that it has neither the charge nor the expertise to assess the utility, realism, or feasibility of these technology goals.
The principal components that must be assembled to undertake such tests are the following:
A sensor package to aim at, to track, and to observe targets;
An image stabilization system to enable tracking of targets;
A spacecraft bus to provide housekeeping functions such as power and communications; and
A launch system to place the whole package into an appropriate orbit.
Perhaps the most important element of the ATD is its telescope. Since 1975, the federal government has invested more than $100 million to fund a series of research and development programs at Itek aimed at the design, production, and testing of large, active-optics technology (see Box 1.1, “Optical Heritage,” for more details). Although the ATD is designed to collimate and direct a high-energy laser beam, the changing world situation now means that it is possible to contemplate nonmilitary applications for the large, lightweight, segmented mirrors developed by these programs.