CAPE CANAVERAL, Fla. — A plant growth experiment lost in the 2003 Space Shuttle Columbia accident is being revamped for reflight to the international space station aboard the next Space Exploration Technologies Corp. (SpaceX) Dragon cargo ship.

The experiment, called BioTube, is intended to test if a strong magnetic field can replace gravity in influencing the direction plant roots grow in space.

“Right after the germination, the roots decide which way to grow. So the entire experiment is really interested in about the first 48 hours of how these roots grow when they are subjected to a magnetic field with no gravity,” said Don Platt, president of Melbourne, Fla.-based Micro Aerospace Solutions, which is developing the revamped BioTube.

The experiment is a follow-on to one that flew on STS-107, the last flight of Columbia, which was destroyed during re-entry following a 16-day research mission. All seven astronauts aboard were killed.

“The experiment worked quite well but obviously the payload was lost,” said Platt, who was previously employed by experiment developer Bionetics Corp. in Cape Canaveral, Fla.

Platt’s company is now preparing the backup unit, which did not fly on Columbia, to be launched on SpaceX’s third space station cargo run. NASA’s launch schedule shows the mission is slated for liftoff in November.

“They’ve changed the seeds because of genetic mapping and what they have maps of now, so we’ve redone the experiment totally to fly to the international space station,” Platt said.

BioTube, which is about the size of a microwave oven, originally flew inside a Spacehab module in the shuttle’s cargo bay. It was part of an overall research initiative to understand how gravity sensing systems in plants and small organisms operate.