NASA's Space Technology 5 (ST5) mission is set to launch on a space weather-watching test flight.

Part of NASA’s New Millennium Program to develop and test new technologies for spacecraft, ST5 consists of three probes the size of large cakes that will be deployed in succession (seen in the above artist’s concept) in low-Earth orbit.

The mission, set to launch at 9:02 a.m. EST (1402 GMT) on March 15 atop an Orbital Sciences-built Pegasus booster, will drop from a parent aircraft before rocketing into space. Poor weather at the mission’s Vandenberg Air Force Base staging ground in California prevented a Tuesday launch attempt, mission managers said.

Each of the three ST5 spacecraft weighs 55 pounds (25 kilograms) and is expected to test six technologies – among them a new microthruster, heat-dissipating vehicle “skin” and software for autonomous ground operations – as well as study the effects of radiation and energetic particles from the Sun.

Such particles can set off aurora when they hit Earth’s magnetic field, and can also prove hazardous for satellites, interrupt communications and – in some cases – knock out power grids on Earth.

Researchers said the $130 million, 90-day ST5 mission could help them work toward developing a 100-strong sward of ST5-like microsatellites to form a space weather monitoring and alert system.

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-- Tariq Malik