Could Doctor Who really bump into human space dwellers?
There are a few things we'll need to sort out first
On the International Space Station, nothing is wasted. The station has its own miniature water treatment plant to return urine from both the crew and the lab animals onboard to the drinking supply and air is also cycled through the system in various ways. The ISS has regular cargoship drop-offs and pick-ups to help it deal with other waste, but longer term missions would have to come up with something else. It's likely food will be fertilised with treated human waste and there have even been suggestions that faeces could be used in radiation shielding.
So, you've got food, drink and the toilet arrangements sorted. The next important thing, especially for the pioneers, will be communications with each other and people back on Earth for instructions, updates and mission data.
The most active model we have today is the ISS. This uses three different systems for communications between the crew, between the crew and Mission Control, and between crew and scientists on Earth.
There's a two-way audio and video network of high-bandwidth Ku-band, S-band and UHF frequencies. Ku-band used to transmit video and files such as data from experiments to Mission Control and scientists, S-band carries voice and file transfers, commands and telemetry and UHF is used during spacewalks and for other short-distance communication.
ISS is 370 kilometers from Earth but over longer distances the networks start to get stretched. The Moon is OK because it's a two-second trip for radio waves or light to travel the 363,104 kilometers - 405,696 kilometers distance back to Earth, depending on the position of the Earth and Moon. But Mars (between 54.6 million kilometers and 401 million kilometers) or Jupiter at (between 588 million kilometers and 968 million kilometers) - would be a problem.
Time delays are the major difficulty, leaving video messages as the most likely way to keep in touch.
Former ISS 'naut Chris Hadfield serenading us from space
Virgin Galactic's chief said:
"The challenge is planetary bodies that are further away like Mars or even further to Jupiter. It takes minutes for light to travel depending on where Earth is in its orbit and it becomes more difficult to have a real time conversation when the delay between me sending you a piece of sound and you sending something back could be a half an hour or even an hour or more."
But there are possible technologies that could at least improve the quality of those answerphone messages.
"We're looking at communication in DSI very heavily and we keep coming back to the fact that it may well be laser-type communications," Tumlinson said. "The aiming and focusing and things like that are a little more difficult, but the amount of information you're able to send back and forth is dramatically higher."
Tumlinson isn't the only one who sees a future in free space optical communications. In December, NASA is due to launch its Optical Payload for Lasercomm Science (OPALS) experiment to the space station, with the hope that it can improve its data rates for communications with future spacecraft by a factor of ten to 100. The basic technology of laser communications is to transmit data over light, but it's nowhere near as simple as that. OPALS systems engineer Bogdan Oaida of JPL describes the experiment as akin to "aiming a laser pointer continuously for two minutes at a dot the diameter of a human hair from 30 feet away while you're walking".
If boffins can get laser communication technology working reliably, it could prove invaluable, helping to keep crew and pioneers sane for their long journeys and time spent off-world. That means being able to talk to loved ones and friends back home and being kept motivated and on-mission by those running the show back home.
This hints at a bigger issue - the matter of maintaining the mental health of these pioneers heading out into space. This is often overlooked, according to Tumlinson, as is the importance of changing the psychology of people on Earth now.
"The hardest thing to solve right now, the biggest challenge that's facing all of us, is psychological and for people to understand what's possible out there and why it's absolutely a necessity that we do it," he said.
"We're talking about mining asteroids and God forbid, there are people telling us that we can't because somehow all the resources of space are the universal property of humanity, which I think is a crime against humanity for them to say that, to deny us the possibility of creating a future."