Hi everybody - it's your occasional science contributor Ray again. This time I'm tuning in with something a little different than the usual movie science discussion, but it's undeniably badass, so I hope you'll permit the tangent.
Many of you probably saw the news of an announcement of a private mission to Mars last week. It hit the mainstream media with the usual sensationalism and lack of detail, making it look like either a crackpot stunt or the end of the era of publicly funded space missions. The truth, as it turns out, is far more nuanced and interesting, and in the days since there's been a healthy discussion on the space blogs. This week I had the good fortune to attend a conference talk presenting a feasibility study by the folks who originated the plan. So, I thought I'd check in with an update to our lively and engaged BAD community to get your thoughts on the matter.
So, here's what we know: the plan comes from the non-profit Inspiration Mars Foundation, a new group founded by millionaire Dennis Tito. The space cadets among you may recognize that name: he's the world's first space tourist, who bought a ride to the International Space Station from the Russian space agency back in 2001. The mission is set to launch on January 5, 2018 to take advantage of a rare orbital alignment that will allow the round trip to be completed in only 501 days, and it will only involve a Mars flyby. Because they'll be relying on the planet to redirect the vehicle back to Earth (a so-called free return trajectory), the two crew members won't land on, or even orbit, the red planet. At their closest approach, they'll be within about 100 km of Mars' night side for about 10 hours. All told, Mars will be clearly visible to the crew for around 24 hours.
The plan as it stands now is it use an upgraded version of SpaceX's Dragon capsule, which has yet to fly with a crew but has made three successful unmanned supply runs to the ISS in the last year. The craft will only sustain its two crew members at a minimum metabolic rate to make scant supplies last for the entirety of the mission. Even with the addition of a proposed inflatable module, there will be little room for the crew to move about, and there will be no provision for extra-vehicular activity (EVA) suits, meaning that the crew will be sealed in their craft for the duration of the trip. And since their trajectory relies on an assist from Mars to turn the craft back to Earth, once they leave Earth's orbit, there's no turning back.
The approach is tantalizing because it uses elements that largely already exist or will exist in advance of the 2018 launch date. Dragon is slated to fly with a crew starting in 2015, so there should be at least a handful of missions worth of flight heritage by 2018. The integration schedule will be ridiculously tight - for example, Dragon will have to be modified so that major subsystems can be serviced from inside the craft, since there will be no EVA capability for the crew. But it's not hard to imagine that the right group of motivated scientists, engineers and technicians, with a little of that Apollo derring-do, might actually be able to make the launch window.
So, it does seem attemptable. But, is it achievable? That's where things get far more interesting.
Inspiration Mars intends to select a married, middle-aged couple as the crew. In the media, much has been made of a married couple having to spend 501 days together cooped up in a small capsule, but I think that's really missing the point. This mission is so on the bleeding edge of what's possible that the real dangers to the crew far eclipse the kibitzing of a loving, committed couple. For example, the radiation danger is significant. You'll see that Inspiration Mars makes a big deal of the fact that the mission takes place during a solar minimum, which is a period of reduced solar activity. And this will indeed reduce the danger to the crew of radiation coming from the sun (e.g., solar flares). But it turns out there are two types of radiation that can impact crew health. Solar radiation is the first, but galactic cosmic radiation (GCR) is the second. GCR comes into the solar system from intergalactic space, and guess what tends to reduce the incursion of GCR? It’s the pressure from the solar wind. So a solar minimum actually means an increased risk of GCR. And while solar events can be forecast, and the crew can be warned to take a defensive posture, GCR is far more insidious. Crew will constantly be bombarded by GCR with very little warning or possibility to mitigate the danger (at least, using technology that’ll be ready in time for the flight).
In fact, the radiation risk is why Inspiration Mars is selecting a middle aged couple as crew. Since they have a reduced life span (compared to a crew in its 30s), the degenerative effects of the radiation exposure will be comparatively reduced. That being said, there are many among us, myself included, who would gladly trade a few years on this blue marble for a chance to see the red one with our own eyes. But the more significant health threats to the crew are far more banal. Something as simple as a toothache, if left untreated, can prove fatal. And in the extremely tight confines of Dragon, after accounting for 501 days of provisions for two people, it's very unlikely that the crew will have access to all the medical implements they'd need to treat the variety of things that could kill them, even if they had the training to do so.
And here's a far more macabre problem: say that, God forbid, one crew member does succumb to a fatal illness. Because there is no room for EVA suits in the craft, that means that it can't be depressurized to jettison anything*, including the deceased crew member. The medical and psychological implications of this on the surviving spouse are sobering.
So, the risks in this kind of mission are extremely high. Even given twice the time to prepare that the current launch schedule imposes, there would still be plenty of risk left unmitigated. But the fact that it's being seriously attempted is to me the most fascinating thing. Simply put, government space agencies could never put astronaut lives in such jeopardy - we've seen the consequences of mistakes arising from far less risky missions gone wrong. But when it's private citizens, using private craft with private funding, any level of risk is theoretically tolerable, if you find the right crew. And make no mistake - they will have no problem finding an abundance of qualified crew candidates.
It certainly seems like we're on the verge of a new era in human space exploration, provided that the Inspiration Mars folks can make their launch date. Is what they're trying attemptable? I'd say so, with a bit of luck on their side. Is it achievable? At this point, I'm really not certain, but I'm sure pulling for them. What are the consequences of their success on future manned exploration endeavors? Their failure? Historically, tragedy in manned spaceflight has led to slower progress. Would that be the same when it's a non-governmental group behind the mission? And would success prompt a renewed interest in both governmental and non-governmental space exploration?
Time will only tell, but I, for one, am watching with extreme interest and support. And how about you? Please let me know your thoughts in the comments below!
*In fact, the provision for crew fecal waste is to simply store it and have it double as radiation shielding.