Think small, indeed.

Joining the three diminutive satellites packed cheek-to-jowl on an experimental rocket set for launch on Wednesday is a fourth, standing just 9 inches (24 centimeters) tall, itself loaded with another six satellites, most the size of a deck of cards.

The student-built Orbiting Picosatellite Automatic Launcher (OPAL) will jettison its tiny charges once it enters its sun-synchronous, 434-mile (700-kilometer) orbit above Earth, spitting each of the one-pound (450-gram) satellites out from spring-loaded tubes.

The miniature spacecraft are known as picosatellites -- a class of satellites generally weighing less than 2.2 pounds (1 kilogram).

"Each one is the size of a cigarette pack," said Clem Tillier, one of the 150 students associated with the Stanford University project.

The OPAL team intends the main hexagonal spacecraft, weighing in at just 51 pounds (23 kilograms), to demonstrate the feasibility of using a mother ship to launch multiple picosatellites into orbit.

The picosatellites, all either four inches (10 centimeters) or eight inches (20 centimeters) in length are:

The Aerospace Picosatellites -- Two micro-electromechanical system (MEMS) satellites built by The Aerospace Corp. of El Segundo, California under contract from the Defense Advanced Research Projects Agency (DARPA). The two satellites will be tethered together and communicate with each other and the ground, using MEMS switches to operate an array of experimental radio frequencies. In the future, clouds of the tiny and cheap satellites could convey tactical and surveillance data drawn from micro-sensors deployed across a battlefield.

StenSat: A transponder-equipped satellite built by a group of amateur radio enthusiasts in Washington, D.C. Ham radio users around the world will be able to receive telemetry from StenSat and "ping" it as it cruises overhead. The satellite will operate as a single channel mode "J" FM voice repeater. The uplink frequency will be 145.84 MHz and the downlink will be 436.625 MHz.

Artemis -- Three satellites built by a group of female engineering students at Santa Clara University in California’s Silicon Valley. One will transmit the URL of the website belonging to the group -- named for the ancient Greek goddess of the moon -- in Morse code. The other two will collect radio energy from lightning; as the two measure the field strength of the lightning strikes, it will give a general idea of the picosatellites’ location.

In the future, swarms of such picosatellites -- fanned out in orbit -- could provide what scientists call "distributed sensing," or the taking of simultaneous and calibrated data over a vast region.

"There are a lot of times you’d like to take information over a broad area -- and you just can’t do that with things attached to one satellite," said Bob Twiggs, a consulting professor in the department of aeronautics and astronautics at Stanford.

Indeed, picosatellites could become the Earth-orbiting equivalent of what NASA terms "network science," where multiple microprobes -- like the two that made up last month’s failed Deep Space 2 mission at Mars -- could be used to pepper a planet with scientific instruments.

The nearly dozen satellites set to fly on Wednesday will be carried aloft aboard the JAWsat Launcher, a never-before-flown rocket cobbled together from a Minuteman 2 motor and the upper stages of a Pegasus XL. The launch window opens at 10:03 p.m. Eastern Standard Time Wednesday, January 26. It will launch from Vandenberg Air Force Base, California.

The U.S. Air Force Orbital Suborbital Program Space Launch Vehicle project aims to make peacetime use of the more than 350 Minuteman missiles, originally designed as intercontinental ballistic missiles (ICBMs), that are now deactivated and in storage as a result of the 1991 Strategic Arms Reduction Treaty.

JAWsat also carries satellites built by students from other universities, including Weber State University, Arizona State University and the United States Air Force Academy.