An Australian aerospace firm said Thursday it has delayed a historic first attempt to launch a locally developed rocket into orbit, with a jar of Vegemite as its payload.

Gilmour Space Technologies said a ground system glitch forced it to postpone the first test launch of its three-stage Eris rocket by a day until Friday.

“The issue was with an external power system we use during system checks,” communications chief Michelle Gilmour told AFP.

“We’ve identified the fix but ran out of time to implement it and fuel the rocket within today’s launch window.”

The rocket has a multi-day launch window to fly from a spaceport near the east coast township of Bowen, about 1,000 kilometres (600 miles) up from the Queensland capital Brisbane.

If successful, it would be the first Australian-made rocket to make an orbital launch from Australian soil.

The 23-meter (75-foot) vehicle is designed to launch small satellites into low-Earth orbit but on the first launch it will carry a jar of Vegemite — a popular Australian toast topping.

Chief executive Adam Gilmour said the firm is not expecting things to go smoothly on the first test.

If it orbits Earth “I would probably have a heart attack, actually, because I’ll be so surprised, but deliriously happy,” Gilmour told AFP this week.