Thousands of worms thrown into space could be "too old" for research when they arrive at the International Space Station (ISS).
The launch of a SpaceX rocket was delayed after the musty food was found in another research group's kit.
The teams of the universities of Exeter, Nottingham and Lancaster hope that microscopic worms can lead to new treatments for muscular dystrophy.
The worms had to be "just turned into adults" at the time of the launch.
The SpaceX Falcon 9 rocket was to be launched from NASA's Kennedy Space Center in Cape Canaveral, Florida on Tuesday evening, but has now been rescheduled for Wednesday's 6:16 GMT.
The 24-hour delay means that worms will be one day older than expected when they reach the ISS, and research groups may have to rely on "reserve colonies" that need to be prepared for their unexpected journey.
Libby Jackson, of the UK Space Agency, said: "Times will be critical enough for worm research, they are ready to enter the capsule and it was planned that they were turning into adults at launch.
"Now everything went out of the window because everything changed a day.
"This is what happens in space flight, we must always be prepared".
The molecular muscle experiment aims to "understand the causes of neuromuscular decline in space," he added.
A Russian ship of the Soyuz crew left Kazakhstan on Monday with two new astronauts: Anne McClain, an American who studied at the Universities of Bath and Bristol, and the Canadian David Saint-Jacques, who studied at the 39; University of Cambridge.
They were joined by veteran cosmonaut Oleg Kononenko.
According to the University of Exeter, worms share many biological characteristics with humans, including "muscle alterations and ability to use energy".
The dott. Timothy Etheridge said that space flight represents "an accelerated model of the condition of human aging".
"Hoping to understand the molecular causes and countermeasures against this, space flight could provide an opportunity to understand human aging on earth," he added.
- Their scientific name is Caenorhabditis elegans
- The transparent worm, or nematode, is about 1 mm long
- Most are hermaphrodites, although some are males
- They do not have respiratory or circulatory systems, but they share some muscular similarities with humans
- It was the first multicellular organism to sequence the entire genome