Editorial: “Don’t let knee-jerk secrecy slow down space flight“
WANTED: middle-aged, married couple for 501-day round trip to Mars. Must be mechanically gifted, physically and emotionally robust, and willing to decorate the walls with own faeces.
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This will be the profile of the very first Martian astronauts, if first space tourist and multimillionaire Dennis Tito succeeds with his audacious plans. Last week, the that Tito heads announced its intention to launch a capsule on 5 January 2018. Minimising relationship complications, it will take a middle-aged married crew of two to about 160 kilometres above Mars. The Red Planet’s gravity will slingshot the spacecraft back to Earth without burning any more fuel. With no stop-off on Mars, it may not sound like much fun, but the aim is to inspire a new generation of explorers.
It’s a tall order. The 2018 deadline is fixed to make the trip fuel-efficient: the next launch window when Mars and Earth align isn’t until 2031. That means the race is on to develop four critical systems involving totally new technologies by 2015, says chief technology officer Taber MacCallum (see graphic). Three years is the minimum time to ready the systems for take-off.
Even if Inspiration Mars never leaves Earth, the tight deadline and ambitious goals should deliver advances valuable to future deep space missions. “Having those constraints forces you to think through issues you wouldn’t otherwise get to,” MacCallum says. “It’s like a haiku: you can’t write that poem without the constraints.” The team is also seeking non-engineering solutions, including genome-based healthcare for the astronauts (see “The right stuff – genome wise“).
Heavy lifting
First on MacCallum’s list is a launch vehicle. The Inspiration team’s is the , which SpaceX of Hawthorne, California, is designing to carry 14,000 kilograms to the vicinity of Mars. Inspiration estimates the capsule, including crew and supplies, will weigh about 10,000 kilograms. Though Inspiration has no official relationship with SpaceX, a spokesperson says the company “will always consider providing a full spectrum of launch services to interested customers”.
Falcon Heavy has yet to fly – its first demonstration flight is scheduled for later this year. Assuming no hurdles, it might just be ready in time. Otherwise, Inspiration has a problem: the other option is ±·´ˇł§´ˇâ€™s and its first flight isn’t until 2017.
Assuming launch is possible, next up is a crew life-support system. , where MacCallum now works, is contracted to build a prototype by the end of 2013. Like the system on the International Space Station, Inspiration’s will convert exhaled carbon dioxide into oxygen, recycle water from urine and faeces, filter the cabin air and maintain its temperature and pressure. Inspiration’s life support will be smaller and the crew will run it themselves. That should make it simpler, quicker and cheaper to build, and less likely to break. “The ISS automated as much as possible in order to keep crew time available for them to do research,” MacCallum says. His crew will have more free time.
Protective poo
The third challenge MacCallum outlined is protecting the crew from cosmic rays, charged particles that can damage DNA. A magnetosphere protects earthlings, and even ISS astronauts, but there is no natural shield on the long Mars voyage.
As well as a water tank around the aluminium hull of the spacecraft, one bizarre solution suggested by Inspiration is to line the spacecraft’s walls with dehydrated faeces, urine and food. Water, and the hydrocarbons in excrement and food, are good candidates for radiation shielding as they are rich in nuclei, the protective part of the atom. As excrement will be dehydrated by the cabin’s water recycling system, MacCallum says it can double-up as a shield if bagged up in plastic and fixed to the walls. “It’s a little queasy-sounding, but there’s no place for that material to go,” he says.
±·´ˇł§´ˇâ€™s project uses a similar concept, but Inspiration must make it work for real. When NASA tested urine-to-water processing bags in 2011, they were less efficient in orbit.
Even with shielding, Inspiration’s chief medical officer Jonathan Clark concludes that the crew will be exposed to enough radiation from cosmic rays in just one trip to increase their risk of cancer by 3 per cent, the limit NASA sets over an astronaut’s entire career. Solar flares could blast the astronauts with larger doses of radiation, or damage an on-board computer, prompting an in-flight emergency. The Inspiration team says astronauts would know to hunker down in part of their habitat, and turn the craft so that its upper rocket stage is pointed towards the sun.
Record re-entry
Even then, the most dangerous part of the mission still lies ahead, thanks to number four on the to-do list. The spacecraft will be travelling so fast when it returns to Earth, as a result of its slingshot around Mars, that the plan is to spend 10 days in orbit to lose speed. After that, it will still be travelling at a record 14 kilometres per second when it hits Earth’s atmosphere.
“That’s a higher velocity than anything man-made has ever had during re-entry,” says former NASA chief technologist , now at the Georgia Institute of Technology in Atlanta. The next-fastest was the Stardust mission, which collected samples from the tail of a comet and returned at 12.5 kilometres per second. “Fourteen kilometres a second sounds like just a little bit more, but the heating is actually significantly more,” Braun says. NASA has agreed that its engineers will help design the re-entry path and the heat shields that will protect Inspiration’s astronauts.
If all four of MacCallum’s systems are in place by 2015, Inspiration just might make it, Braun says. He points out that ±·´ˇł§´ˇâ€™s Spirit and Opportunity rovers set off for Mars just three years after gaining approval. “If this was a robotic mission, it would be a slam dunk. The issue is we’re talking about humans in space. But I wouldn’t bet against them.”
Tito will bankroll the first two years of mission development, no matter what it costs. Whatever happens, that will go a long way. Meanwhile, Inspiration has had one effect already, says MacCallum: “It’s now cool to be middle-aged and married.”
A slightly different version of this article appeared in print under the headline “On a wing and a prayer”
The right stuff – genome wise
Uppermost in the minds of the Inspiration Mars team over the next five years will be spacecraft engineering, but genetics may play an important role in the success of the mission too.
Personalised medicine is still a niche area on Earth but it could be particularly useful in space, where the normal doctor-patient model of medicine breaks down. So says Graham Scott, a biomedical researcher at the Center for Space Medicine at Baylor College of Medicine, who is collaborating with the Inspiration team.
If astronauts get sick or need an operation en route to Mars, there is no doctor to visit. Unlike patients on Earth though, their genetic make-up will be studied before they get sick. The idea is to predict which medicines the crew are most likely to need – and pack them – as well as to ensure the crew only take treatments that are likely to work. “We can now, in some cases, use genomic tests to figure out what drugs would be effective for an individual, or what might be harmful,” says Scott.
The capsule could even be personalised to suit genomes. For example, sleep differences between individuals were . Scott is now teaming up with the scientists behind the discovery to work out whether the capsule could be adapted to suit certain differences. “If you found someone was going to have a tougher time falling asleep or responding to sudden shifts, you would use that information to design countermeasures,” Scott says.
Combining the extreme environment of space with genetics could also provide insights that are useful on Earth, suggests Jonathan Rothberg of genome sequencing company . “You could think about genes to do with bone density, an area that we know is affected by gravity, and we know must have effects in genome,” he says. Hal Hodson
