Mission logo for Kodiak Star. Photo: NASA

Next week's planned blastoff of a Lockheed Martin Athena rocket from Alaska has been postponed by two days because America's grounded commercial air fleet has made travel to the launch site impossible.

Liftoff is now slated for the evening of Wednesday, September 19, during a window of 5 to 7 p.m. Alaska Time, which is 9 to 11 p.m. EDT and 0100-0300 GMT on the 20th.

The Athena 1 rocket will carry a quartet of small satellite payloads for NASA and the Air Force in the first space launch from the Alaska Aerospace Development Corporation spaceport on Kodiak Island, Alaska.

The terrorist attacks on the World Trade Center towers and Pentagon using hijacked commercial airliners on Tuesday forced the government to ground all passenger jets. Until air travel resumes, launch personnel won't be able to reach the remote site on Kodiak Island, which is located about 250 miles south of Anchorage.

Dubbed Kodiak Star, this launch aims to deliver the NASA-sponsored, student-built Starshine 3 satellite in space. Covered with 1,500 aluminum mirrors, the highly reflective sphere will be seen flying overhead with the naked eye, allowing schoolchildren around the world to track the satellite.

The three Department of Defense Space Test Program payloads are PICOSat, PCSat and Sapphire.

PICOSat, built by Surrey Satellite Technology in the U.K., features four onboard experiments including tests of a flexible polymer battery, using GPS to study the ionospheric impacts to communications and navigation signals and vibration control for satellite sensors.

The Prototype Communications Satellite, or PCSat, is the first in a planned series of small spacecraft designed, built and tested by midshipmen at the U.S. Naval Academy. The craft will be used to relay position data from amateur radio operators to ground stations.

Sapphire, built by Stanford University, carries a couple of experiments and a voice synthesizer microchip designed to convert text messages into a human voice for transmission over amateur radio frequencies.