Dennis Tito’s Mars Mission: Possible but Pointless

Imagine taking two human beings and sealing them in a box for 500 days. The pair must survive on only the boxes of food and water crammed around them. Throughout their confinement they are at risk of being sprayed with a lethal dose of radiation. This is not the cruel and unusual punishment meted out by some fiendish despot, rather this could be Inspiration Mars, mankind’s first adventure into interplanetary space.

Welcome to Mars. How does this HST image of the planet compare to the view from the Dragon’s window. (image credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), J. Bell (Cornell University), and M. Wolff (Space Science Institute, Boulder) )


We could see a mission to Mars with a crew onboard by the end of this decade. Multi-millionaire Dennis Tito, the first space tourist,  is proposing and possibly even planning to send a privately financed manned mission to Mars in January 2018. The  journey would last 501 days. Tito, who paid about $20 million to visit the International Space Station in 2001, has founded a new nonprofit company called the Inspiration Mars Foundation.  The company will hold a press conference on  27 February 2013 to explain how the mission would be accomplished. Rumours say the plan is for a two-person free-return Mars mission that would fly by Mars without going into orbit or landing. The 501 day mission would set off in January 2018 using a modified SpaceX Dragon spacecraft launched by a Falcon Heavy rocket (also from SpaceX). This will be no joy-ride,  the crew’s comfort would be  “limited to survival needs only”.

The  proposed mission is a flyby of Mars with a free return back to Earth, without stopping. This is type of low-energy trajectory which needs only the initial escape from Earth and insertion to solar orbit. It has the advantage that the spacecraft, once launched, will swoop around the Sun, passing within 100 miles of Mars, with no further engine firings needed. This requires a special set of orbital circumstances; if the mission misses the 2018 launch window there will not be another opportunity until 2031.

This is a fantastically bold suggestion, unless there has been a misunderstanding Tito is proposing that in five years time we will have:

  • Cleared the Dragon spacecraft to carry a crew (Dragons have successfully carried cargos to the ISS, but the first Dragon flight with astronauts on board is planned for no earlier than mid-2015).
  • Enhanced the Dragon’s thermal protection system (heatshield) to survive re-entry to Earth’s atmosphere at an interplanetary, rather than orbital velocity. The mission profile includes an aerobraking manouever, followed by re-entry to Earth’s atmosphere at  14.2 km/sec. This would be the fastest ever reentry by any crewed spacecraft.
  • Improved its lifesupport system, currently optimised for a few days in orbit (and which has yet to be demonstrated) to enable a 16 month interplanetary mission. Note that the interplanetary travellers will not have the benefit of regular resupply flights bringing up water, food and spare parts, as crews on the ISS do.
  • Upgraded the Dragon’s radiation shielding to protect the crew from the solar and cosmic radiation absorbed in a 500 day flight beyond the van Allen Belts. Note that it seems impossible to add enough shielding to the Dragon so protect the astronauts from a Coronal Mass ejection. If the Dragon passes through a CME in interplanetary space the crew will die.
  • Cleared the Falcon Heavy rocket (which has yet to fly) to carry passengers.
  • Set up or arranged a suitable tracking and communications network for the mission.

None of these milestones are impossible; SpaceX is one of the rare “New Space” companies to actually deliver on its promises (although it tends to run slightly behind schedule). Still, I believe it will take luck and an astonishing degree of commitment (ie money) to get the all the technology ready in time.

The greatest weakness of this very stripped down interplanetary mission lies in the human factor. This 500 day mission would set a new human spaceflight endurance record (longest flight to date was that of cosmonaut Valeri Vladimirovich Polyakov who spent 438 days on the Mir spacestation). Keeping the crew healthy for so long will be challenging. Muscle tissue and bones waste away rapidly in zero-gravity and space station astronauts must take regular sessions of vigorous exercise to prevent their bodies’ deterioration. How the two occupants of the relatively small Dragon will do this is hard to imagine (especially as the craft will have to be stuffed with the food and water needed to keep the astronauts alive for 500 days).  It is unclear how the two crew will cope with the confinement and isolation; there have been earthbound Mars mission simulations but these have assumed larger crews and more living space and privacy than available on the Dragon.

Is it worth doing? I don’t see the point. Manned planetary flybys were considered by NASA fifty years ago. These would have used large Apollo-derived vehicles and taken place in the 1970s. The crew would have released probes and taken pictures during the encounter Obviously these never happened, and unmanned spacecraft technology has passed them by. We’re expecting the crew to endure nearly a year and half in hellish conditions for what? To snap a few pictures of the night side of Mars through the Dragon’s window as it hurtles past. Please don’t get me wrong, I would love to see meaningful human exploration of the Solar System but a crash-project in the twenty-first century to carry to out a scaled-down version of an obsolete mission with a high chance of ending in disaster seems quixotic and pointless.

UPDATE: the details of the proposed mission are now available, I have amended this post slightly to reflect them more accurately. The official site is at

See inside SpaceX's passenger-carrying Dragon space capsule in this infographic.
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(Article by Colin Johnston, Science Communicator)