Space station supply launch: What does Scott Kelly miss most?

The third attempt to launch a supply shuttle to the ISS was canceled Saturday due to weather, but Scott Kelly and the other astronauts living on board the ISS are still finding ways to feel at home in space.

Living on a spacecraft may sound glamorous to the rest of the Earth-bound human race, but the astronauts live on what is essentially a orbiting prison – with no outdoor privileges – for months at a time. 

The third attempted launch by Orbital was postponed due to bad weather Saturday, so NASA will have to try again on Sunday to send supplies to the ISS, Marcia Dunn reported for the Associated Press. The delay, former astronaut Mark Kelly warned, means his brother Scott Kelly will have to wait another day to read the "Mousetronaut" books he is sending up as part of an astronaut-in-space reading program for children.

Kelly expressed lighthearted disappointment via Twitter. 

"Star Wars" may not be the only piece of Earth life astronauts miss during a mission to the International Space Station. Kelly sometimes misses home, especially being able to walk outside on the grass and feel a breeze, he told the Associated Press.

"Something people don't recognize is that being on the space station is probably a lot like being in some kind of confinement — like isolation," he told the AP by video. "Not having the ability to leave is ... an all-present feeling."

What do they do in their down time?

Well, there are only so many photos one can take of the blue marble Earth – not that America's astronauts aren't doing their duty in that department by sending celestial photos earthward via Twitter on a regular basis.  

Astronauts started accessing the Internet on board the ISS in January 2010.  They can now surf the web in much the same way they did from Earth, although they have said the connection is slow. Kelly told CNBC the Internet was not much better than dial-up access because the space station constantly moves relative to providers on the ground.

"I use it for a bunch of things," he said. "Certainly e-mail, social media type stuff with Twitter, Instagram, that kind of stuff. I actually do some banking."

On Thanksgiving, Kelly and Kjell Lindgren spent a little time kicking back and watching football, they reported in a video-based holiday greeting to America. Unfortunately, NASA did not provide any footage of the game-watching, so Earthlings can only imagine how the astronauts loafed at their ease or floated to their feet during tense plays in a very low-gravity living room. 

They may indulge on Thanksgiving, but astronauts are required to exercise for two hours each day, as staying in shape is a matter of practical necessity on the space station. NASA astronaut Sunita Williams ran the Boston Marathon remotely in 2007, and Britain's ISS astronaut hopes to run the London marathon via an ISS treadmill on April 24, the BBC reported.

Astronauts have busy jobs, but work-life balance is still a goal. Some spend time with hobbies such as reading, photography, drawing, short-wave "ham" radio, and musical instruments, and they keep in touch with friends and family by e-mail, according to NASA. They also ask mission control to send up movies, and they have a projector for that purpose.

They used the on-board projector to watch The Martian" from space in September, as seen in a tweet.

But wait, does Kelly's tweet mean that he'll miss the opening of "Star Wars: The Force Awakens" on Earth? Or does it mean NASA has an early-release copy and once the supply ship arrives, Kelly's getting a 10-day jump on the rest of humanity?