Feeds

Sole British 'naut Major Tim embarks on NASA deep space mission

'Splashdown' for Tim Peake, as team heads beyond point of no return

Beginner's guide to SSL certificates

Blighty's one and only astronaut, Tim Peake of the European Space Agency, has just embarked on a bold mission into an environment where few human beings have ever ventured: that of the saturation diver, semi-permanently adapted to life under high pressure and able to survive only deep underwater or inside pressurised containers.

Aquanauts Yui, Metcalf-Lindenburger, Peake and Squyres (L-R) prepare for the NEEMO 16 underwater deep space mission. Credit: NASA/ESA

Test pilot, teacher, test pilot, boffin

As a member of NASA Extreme Environment Mission Operations (NEEMO) expedition 16, Peake has now left the surface off Key Largo in Florida and descended to the Aquarius habitat on the seabed. He and the rest of the NEEMO 16 crew will live and work in and around Aquarius for the next fortnight, using the buoyancy underwater to simulate and practice for operations at an asteroid in deep space beyond the orbit of the Moon.

Aquarius is an ambient-pressure habitat and the surface of the "moon pool" in its entrance/exit chamber is situated at 47 feet below the surface, meaning that the pressure inside is approximately 2.5 times normal. As any diver fule kno, breathing air at this depth a human being must return to the surface within a couple of hours or risk decompression sickness (DCS, "the bends") as nitrogen absorbed into the body fluids fizzes out damagingly.

But Peake and his fellow aquanauts won't bother, simply remaining under pressure as they practice their zero-gravity procedures and returning to the Aquarius between dive sessions. After around a day, their body tissues will be able to absorb no more nitrogen at that pressure - they will be saturated. When their two weeks are up, they will close a pressure door between themselves and the moon pool (to avoid flooding the habitat) and gradually reduce their local pressure over a period of almost 16 hours, releasing the nitrogen from their systems so slowly that the bubbles remain tiny and harmless. Then they'll exit the habitat via an airlock and swim up to meet a boat which will take them back to Florida.

There's some risk involved in such a mission, as the aquanauts won't be able to simply swim up to the surface in the event of a problem with their dive gear or the habitat - they could expect a nasty or even potentially fatal DCS episode if they did that. Technically this is indeed "saturation diving", as NASA proudly says.

However real sat divers would probably sneer at the idea of the aquanauts being like them: commercial saturation divers working offshore typically remain under pressures of 6 bar or more (equivalent to 160+ feet). They have more to contend with than just DCS - at such pressures there are also issues of nitrogen narcosis ("the rapture of the deeps") and, at greater depths still, High Pressure Nervous Syndrome. As a result they must breathe helium/oxygen or exotic helium/hydrogen/oxygen trimixes to stay functional, and their compression and decompression schedules at the beginning and end of a task period last days, not hours.

There's another difference too. Commercial sat-diving operations are ruled by considerations of economics and safety as opposed to the somewhat mysterious imperatives which have placed the one-of-a-kind government funded Aquarius on the sea bed. It's a lot simpler to run and maintain a pressure habitat on the surface where you can get at it easily, so that's how commercial sat divers live during their stint under pressure: inside a small set of linked pressure chambers generally mounted aboard a ship, barge or offshore rig. When it's time to do a job, one of these chambers (the "bell") is detached from the others with divers inside and lowered down to depth by a crane. Once the job is done, the divers get back into the bell again, seal it and are hoisted up to mate on to the main saturation living complex (the "bin", in North Sea parlance).

One thing's for sure: it'll all be rather strange for Tim Peake, who is from one of the mainstream astronaut communities - that of military test pilots. Peake, before being selected by the ESA, was a Major in the British Army Air Corps and an Apache attack-chopper test pilot*. There have been diver astronauts - perhaps the most famous being former US Navy diving officer Heidemarie "Toolbag" Stefanyshyn-Piper, who gained worldwide notice even among her high-profile peers after she dropped a bag of tools into the Earth's atmosphere while spacewalking outside the International Space Station. However serious diving background is rare for an Aquarius "aquanaut": Peake's fellow NEEMO 16 members are also from mainstream 'naut communities. Mission commander Dottie Metcalf-Lindenburger is a NASA "educator astronaut" (a teacher by trade), Japanese 'naut Kimiya Yui is another military test pilot and Steve Squyres - not an astronaut at all, though a regular Aquarius habitué - is a Mars boffin.

Though NEEMO 16 is nominally focused on preparation for a deep-space asteroid mission, it remains unclear just when any such mission will set out - and deeply unclear that any of the NEEMO 16 team will be on it when it does. For the foreseeable future, Peake, Metcalf-Lindenburger and Yui can hope only for a stint on the space station - most probably just one and that if they're lucky, as there are many more astronauts wanting a berth on the orbiting outpost than it can find space for in its remaining likely lifetime.

There's loads more on NEEMO from NASA here, and enthusiastic blog posts from Peake here and here. ®

Bootnote

*This is no doubt a source of much chagrin in the RAF, whose head stated a few years ago that any British astronauts should naturally come from the airforce. Peake seems likely to become the second real British 'naut as and when he flies on a space mission, following Helen Sharman who went into orbit as part of the UK/Russian Project Juno way back in 1991. (Trivia: Peake is the second British Army major named Tim to be chosen as a 'naut - Sharman's understudy in '91 was Major Timothy Mace, also of the AAC.)

Choosing a cloud hosting partner with confidence

More from The Register

next story
Bond villains lament as Wicked Lasers withdraw death ray
Want to arm that shark? Better get in there quick
Antarctic ice THICKER than first feared – penguin-bot boffins
Robo-sub scans freezing waters, rocks warming models
Your PHONE is slowly KILLING YOU
Doctors find new Digitillnesses - 'text neck' and 'telepressure'
SEX BEAST SEALS may be egging each other on to ATTACK PENGUINS
Boffin: 'I think the behaviour is increasing in frequency'
Reuse the Force, Luke: SpaceX's Elon Musk reveals X-WING designs
And a floating carrier for recyclable rockets
The next big thing in medical science: POO TRANSPLANTS
Your brother's gonna die, kid, unless we can give him your, well ...
NASA launches new climate model at SC14
75 days of supercomputing later ...
Renewable energy 'simply WON'T WORK': Top Google engineers
Windmills, solar, tidal - all a 'false hope', say Stanford PhDs
Britain's HUMAN DNA-strewing Moon mission rakes in £200k
3 days, and Kickstarter moves lander 37% nearer takeoff
prev story

Whitepapers

Choosing cloud Backup services
Demystify how you can address your data protection needs in your small- to medium-sized business and select the best online backup service to meet your needs.
Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Designing and building an open ITOA architecture
Learn about a new IT data taxonomy defined by the four data sources of IT visibility: wire, machine, agent, and synthetic data sets.
10 threats to successful enterprise endpoint backup
10 threats to a successful backup including issues with BYOD, slow backups and ineffective security.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?