Washington, Nov 24 (IANS): When astronauts in the Orion spacecraft travel beyond the moon to explore deep space destinations, they may have a number of food bars to select from in a variety of flavours like orange, cranberry or barbeque nut for breakfast.

To help reduce the amount of supplies Orion will carry for its crew, scientists are developing a variety of food bars that astronauts can eat for breakfast during the spaceflight, NASA said.

Orion has limited room to accommodate the supplies and food astronauts will need during their mission.

But designing a food bar to a specific nutritional balance for astronauts while also increasing caloric density and passing the taste test is no small task.

"There's no commercially-available bar right now that meets our needs, so we've had to go design something that will work for the crew, while trying to achieve a multi-year shelf-life," said Takiyah Sirmons, a food scientist with the Advanced Food Technology team at NASA's Johnson Space Center in Houston.

Because flights to deep space will not rely on resupply spacecraft to deliver what astronauts need and dispose of trash, the Orion crew will have to take everything they need with them and bring it all back home.

Given the distances Orion will travel, teams also must limit Orion's mass, since a heavier spacecraft requires more fuel and energy to propel it to its ultimate destination.

Food scientists determined that developing a single calorically dense breakfast substitution can help meet mass reduction requirements.

"When you have 700 to 900 calories of something, it's going to have some mass regardless of what shape it's in, so we've taken a look at how to get some mass savings by reducing how we're packaging and stowing what the crew would eat for breakfast for early Orion flights with crew," said Jessica Vos, deputy health and medical technical authority for Orion.

"When you think about multi-week missions in Orion, having just one package for breakfast items for crew will help us limit the space we need to store them," Vos said.

For lunch and dinner, Orion astronauts will be able to select from similar items space station crew members eat and have a food warmer to help them prepare their meals.

The food bars, which are being developed in coordination with NASA's Human Research Programme have been tested by crew members inside HERA, the agency's three-story habitat at Johnson Space Center designed to serve as an analog for the isolation and remote conditions in exploration scenarios.

Orion's first mission with crew will launch as early as 2021 atop the powerful Space Launch System rocket currently in development, NASA said.

The flight will help set the stage for future missions in the proving ground around and beyond the moon, where NASA will refine the technologies and operations needed to send astronauts to Mars.