Space-based laser completes tests

A team developing the Space-Based Laser Integrated Flight Experiment (SBL-IFX) have gathered new data from a recent integrated ground test of the Alpha high-energy laser.

A team developing the Space-Based Laser Integrated Flight Experiment (SBL-IFX) have gathered new data from a recent integrated ground test of the Alpha high-energy laser, its beam director telescope and the associated beam alignment and correction system. The information will guide the team on how best to monitor and maintain the pointing of the SBL-IFX beam director on orbit.

The beam director is the part of the US Air Force and Ballistic Missile Defence Organisation’s (BMDO) proposed experimental missile defence system that will project the high-energy laser beam across space to knock out distant boosting missile targets.

Team SBL-IFX, a joint venture comprising Lockheed Martin TRW and Boeing, conducted the six-second test on December 8, 2000. It was performed as part of the team’s current $240 million SBL-IFX development contract with the US Air Force.

This latest test involved generating a megawatt-class laser beam with the TRW-built Alpha, then feeding it through the Lockheed Martin-built beam control system and a 4-meter diameter beam director telescope, both of which are housed in a special vacuum chamber that simulates the space environment.

The primary goal of the test was to determine if the telescope’s metrology systems could maintain the pointing and proper alignment of its primary and secondary optics during a high-energy lasing event.

Lockheed Martin operates the telescope and beam alignment and correction system used during the test. They were integrated with the Alpha laser in the early 1990s as part of the Alpha LAMP (Large Advanced Mirror Program) Integration program, one of several previous SBL technology demonstration programs.

A secondary goal of the test was to determine if laser characteristics such as power, beam uniformity and frequency spectrum would be adversely affected by the interaction of the laser beam with the optical systems used to correct, point and focus the beam on its target. Initial evaluation of the test data indicates that no such adverse interactions occurred.

‘A critical part of a successful on-orbit IFX demonstration is being able to know precisely where the beam director will direct the laser beam,’ said Art Woods, Lockheed Martin’s SBL program manager. ‘We proved with this test that the metrology systems designed to measure the alignment of the beam director telescope and the relationship between the beam director’s primary and secondary mirrors can operate effectively in the presence of the high-power laser beam.’

Without these metrology systems, he added, the IFX laser beam could become distorted, which would degrade its strength or cause it to miss its target altogether,

Plans call for the SBL-IFX, a satellite carrying a high-energy laser, to be launched in 2012, with an on-orbit demonstration of its defensive capabilities against a live, boosting target planned for 2013.