If there are sad faces and tired eyes on the International Space Station this week, it's likely not a caffeine crash but the despair of knowing they're going to have to wait another few months for a freshly brewed cappuccino.

The ISSpresso machine -- a joint effort designed by coffee experts at the Italian manufacturer Lavazzo and engineers from Italian company Argotec -- pushes hot water at high pressure through coffee grounds and a long steel tube. The strongly flavored coffee is squeezed out into a pouch that's then sipped through a straw.

The machine, which will bring espresso-based drinks like lattes and cappuccinos to the space station for the first time, was supposed to arrive along with Italian astronaut Samantha Cristoforetti last week.

But new reports suggest Cristoforetti arrived without the espresso maker; its shipment to ISS has apparently been delayed.

David Avino of Argotec said that, subject to launch openings, the company hopes to get ISSpresso aboard the station in time for Cristoforetti's birthday in April.

It's not yet clear what the reasoning for the delay is, but it would be understandable of space and weight was an issue. The rather large contraption weighs 44 pounds.

When it finally does arrive, astronauts may be able to enjoy their expertly brewed espresso in a more traditional fashion -- out of a cup. Earlier this year, a group of researchers at Portland State University presented a paper (called "The Capillary Fluidics of Espresso") on the possibility of sipping the dark-roasted elixir in a low gravity environment.

"Espresso is distinguished by a complex low density colloid of emulsified oils," researcher wrote. "Due to gravity, these oils rise to the surface forming a foam lid called the crema."

"To some, the texture and aromatics of the crema play a critical role in the overall espresso experience. We show how in the low-g environment this may not be possible," the scientists continued. "We also suggest alternate methods for enjoying espresso aboard spacecraft."