In October, 1998, the first of the NASA New Millennium Spacecraft, DS1, was successfully launched into space. The objectives for this spacecraft are to test advanced technologies that can reduce the cost or risk of future missions. One of these technologies is the Solar Concentrator Array with Refractive Linear Element Technology (SCARLET). Although part of the advanced technology validation study, the array is also the spacecraft power source. Funded by BMDO, the SCARLET™ concentrator solar array is the first spaceflight application of a refractive lens concentrator.As part of the DS1 validation process, the amount of array diagnostics is very extensive. The data obtained includes temperature measurements at numerous locations on the 2-wing solar array. For each individual panel, a 5-cell module in one of the circuit strings is wired so that a complete I-V curve can be obtained. This data is used to verify sun pointing accuracy and array output performance. In addition, the spacecraft power load can be varied from a small fraction of the array capability, up to maximum power. For each of the power loads, array operating voltage can be measured along with the current output from each wing.Preliminary in-space measurements suggest SCARLET performance is within one (1) percent of predictions made from ground data. This paper will discuss the results of the SCARLET in-space validation, including array performance as a function of changing solar distance and array performance compared to pre-launch predictions.