June 20, 2010: The U.S. Air Force is moving rapidly in developing and testing smaller reconnaissance and communications satellites. These birds weigh a ton or less (down to 100 kg/220 pounds). The smallest ones have limited usefulness and endurance. But when you get to half a ton or more, you have a very useful bird. It is believed these smaller satellites will be needed to replace wartime losses.

Usually, the U.S. has four KH-11s and four Lacrosse radar satellites in orbit, plus several smaller, and more secret birds. Often, these satellites last longer than their design life of eight years (some have gone on for 10-15 years). Eventually they all wear out. The KH-11 and Lacrosse satellites weigh 14-16 tons. In a future war, existing recon and communication satellites will be attacked. Replacements will be needed, fast. The air force isn't releasing many details of this program, as that would simply make it easier for a potential foe to take down the replacements. But stockpiling small replacement satellites, and having rockets ready to get them in orbit, is now considered an imperative.

 The quickest way to launch replacements is to use solid fuel ICBMs or SLBMs (Sea Launched, from a sub, Ballistic Missiles). Most of these missiles cannot lift more than a ton, which is one reason American little birds top out at that weight. Both the air force and navy have worked out what would be required to quickly convert ICBMs and SLBMs to satellite launcher use. The navy has even proposed that one or two silos on each SSBN (ballistic missile carrying sub) be dedicated to emergency replacement satellite delivery.

It's different in Russia, where many recently retired Cold War era ICBMs use liquid fuel, and can carry more weight. These are being offered to carry commercial satellites. Retired RS-18 (SS-19) ICBMs were converted (by adding a third stage) to satellite launchers. Such missiles can lift 1.8 tons into orbit. Current technology enables small satellites (as small as 200 pounds or less) to do useful work. The heavier (217 ton) RS-20 ICBMs have a max satellite payload of nearly three tons. Russia could also use these older ICBMs to quickly launch mini-satellites, although they are not working on this at the moment.