From the first link I'm taking the liberty to quote some of the conclusions that might help to understand the whole document.

The conclusions are:
Air Force activities which occurred over a period of many years have been consolidated and are now represented to have occurred in two or three days in July 1947.

"Aliens" observed in the New Mexico desert were actually anthropomorphic test dummies that were carried aloft by U.S. Air Force high altitude balloons for scientific research.

The "unusual" military activities in the New Mexico desert were high altitude research balloon launch and recovery operations. Reports of military units that always seemed to arrive shortly after the crash of a flying saucer to retrieve the saucer and "crew," were actually accurate descriptions of Air Force personnel engaged in anthropomorphic dummy recovery operations.

Claims of "alien bodies" at the Roswell Army Air Field hospital were most likely a combination of two separate incidents:

) a 1956 KC-97 aircraft accident in which 11 Air Force members lost their lives; and,
) a 1959 manned balloon mishap in which two Air Force pilots were injured.
This report is based on thoroughly documented research supported by official records, technical reports, film footage, photographs, and interviews with individuals who were involved in these events.