Using Marcis Law of Obtaining Anime which states "If you can't download it - buy it" with addition "if you can afford it of course" i have obtained all three Astray manga volumes from amazon.com
Also laid my hands on volumes 1 & 3 of Astray R manga. 1&3 because amazon.com is too lazy to label volumes properly. I will buy volume 2 along with 4 (last one) which will come out in November.

Astray manga provides quite an interesting side story parallel to SEED anime. Mostly it follows exploits of Junk Guid tech named Lowe Gear who happens to find prototype Gundam Astray (Red Frame) mobile suit in the ruins of Heliopolis.
He also meets pilot of Astray Blue Frame Serpet Tail mercenary Gai Murakamo and Gold Frame Astray pilot Rondo.
Worth reading imo.