Dennis Tito's bombshell announcement that he wants to fly two passengers to Mars--with the mission taking off in less than five years, on January 5, 2018--provoked a lot of intense reactions. Many people were astonished. Many were inspired. Many were deeply skeptical. I was on Fox News yesterday talking with Shepard Smith (the clip is here), who dismissed the idea as "hogwash"; many NASA insiders are more quietly expressing similar levels of skepticism about Tito's plans.
Artist's conception of the Inspiration Mars mission, including an inflatable crew module, passing Mars in August, 2018. (Credit: Inspiration Mars Foundation) So let's break it down and look at the four key questions about the proposed Inspiration Mars mission.Question #1: Is it a publicity stunt? Of course it is. Tito has basically said as much, and the evidence is right there on Inspiration Mars's stated goals: "It will encourage and embolden all Americans to believe again, in doing the hard things that make our nation great, while inspiring the next generation of explorers to pursue their destiny through STEM education and exploration." (STEM is science, technology, engineering, and mathematics, for those of you who are not up on educators' jargon.) There is no way for Tito to spread the excitement of space exploration without publicity, and there is no way for him to raise the necessary funds either. But by the same token, the whole Apollo program was basically a publicity stunt. Publicity can be a wonderful thing when it is directed toward worthy goals. Question #2: Can he do it? This one is a lot tougher. Tito and his brain trust put together an impressively thorough, 18-page "feasibility analysis," posted in PDF form on the Inspiration Mars web site. The January 5, 2018 launch date was carefully selected because at that time Earth and Mars will be oriented in a way that allows a spacecraft to follow a "free return" trajectory. In essence that means that gravity does almost all of the work, minimizing the size of the rocket needed for launch. Inspiration Mars would first fall inward toward the sun to pick up speed, then arc outward to intersect with the orbit of Mars, fly within 100 miles of the surface of the Red Planet, then use Martian gravity to send the spacecraft hurtling back home. The only additional rocket power expended during flight would be small course corrections.
Proposed flight plan for Inspiration Mars. The looping trajectory uses gravitational assists from the sun and Mars greatly reduce the amount of rocket fuel needed. But there is no landing--just a flyby. (Credit: Inspiration Mars Foundation) Note that Tito is not proposing to land on Mars. Many commentators have snickered at the prospect of going all the way to Mars without landing, but getting down to the surface and back is a drastically more complicated task that takes far more fuel. Tito sees this as a proof-of-concept mission that will help develop the technology needed to get to Mars and inspire the engineers (and the funders) who could eventually make a manned landing possible. The mission would be analogous to Apollo 8, not Apollo 11. But the first one definitely paved the way for the second. All of that does nothing to disguise the fact that the rocket, capsule, and life-support technologies that Tito would need do not exist, at least not quite yet. The Inspiration Mars team proposes using a modified Dragon space capsule and Falcon Heavy rocket. Both of these are built by Elon Musk's SpaceX corporation, which so far has an impressive track record. But the Dragon is not yet approved for carrying a crew to the International Space Station, much less to Mars, and the Falcon Heavy has not made its debut launch. In the feasibility analysis plan, the Inspiration Mars team bases its information about the Falcon Heavy on things they read on the SpaceX web site, which doesn't exactly inspire confidence. The life-suppport techniques would be based on ones developed aboard the International Space Station, which provides a good baseline for the kinds of health problems that would arise during the 501-day Inspiration Mars voyage. But radiation levels in deep space are far higher than they are in low-Earth orbit, where our planet's magnetic field blocks out most of the charged particles. Tito's proposed mission date would send his crew out during a time when solar activity (and the associated radiation) is relatively low, but there is no precedent for the kind of exposure the Inspiration Mars crew would experience. The feasibility plan says that "Further study needs to be done to find creative solutions for radiation protection, including the amount of radiation and the level of risk of a high radiation event deemed to be acceptable." Or as Jonathan Clark of Baylor College of Medicine, one of Tito's advisors, told the Washington Post: "a lot of this stuff is kind of McGyvered." Question #3: Can he do it for $1 billion? To ordinary people a billion dollars sounds like a lot, but in the space world is it chump change. In 1989 President George H.W. Bush proposed a manned mission to Mars, but the concept sank when the media got wind of the estimated $500 billion price tag. Nevertheless, Tito's goal is not quite as crazy as it initially sounds. SpaceX developed the crew-carrying version of the Dragon space capsule on a $440 million contract. SpaceX further promises that its Falcon Heavy flights will cost just $128 million a launch. It might be possible--just maybe--to put together rocket, capsule, and supplies and not bust the budget.
SpaceX's upcoming Falcon Heavy is designed to carry 53 tons to low-Earth orbit, making it the most powerful rocket since the Saturn V. Dennis Tito is counting on it, or something like it, to take humans to Mars. (Credit: SpaceX) That still leaves a lot of other work, including a new kind of heat shield to handle the extreme reentry velocity of Inspiration Mars; the life support systems; the radiation protection systems; and a proposed inflatable crew compartment, which would utilize a new design and largely untested technology. And again, the above analysis is describing technologies that should be ready by 2018 but are not actually operational right now. In a sense, Tito is hoping to will the technology into existence with the prospect of the money and publicity that Inspiration Mars could provide. Question #4: Will the crew make it back OK? This is a high-risk mission with a very real possibility of catastrophic failure. Tito hasn't really addressed that possibility. Even if Inspiration Mars unfolds flawlessly, the radiation doses alone could have serious health implications. For this reason, Tito suggests sending an older couple, past reproductive age. That way they don't have to worry about the radiation effect on their offspring. Although Tito does not say so, that also leaves fewer years for them to experience the effects of irradiation. But he probably won't have any trouble finding volunteers. Taber MacCallum and Jayne Poynter of Paragon Space Development--two of Tito's advisors--have already offered themselves up. Tito might be able to find volunteers even if this were a suicide mission. The nonprofit Mars One organization is currently signing people up for a one-way trip to colonize Mars, and claims that they are getting volunteers. Compared to their plans, Tito's Inspiration Mars looks positively sane.