The Mars One project envisages using the SpaceX Falcon Heavy rocket to lift the components of the transit vehicle into earth orbit where it will be assembled. The crew capsule under consideration is a variant of the existing SpaceX Dragon capsule, the Dragon version 2. The capsule will land on Mars using retro rockets to control the speed of descent and achieve a soft landing. The plan appears to require 8 unmanned flights to be sent before the first manned flight. The first flight (launching in 2020) will land a rover. This will be followed later by a trailer (to transport capsules to the required position) and six capsules, two of which will carry life support systems, two will be for crew habitat, and two will carry other stores. The timing for the trailer launch is unclear, but would presumably be shortly before the 6 cargo capsules in 2022.
The existing Dragon capsule was designed for seven astronauts but at present has only been used for unmanned supply missions to the ISS. It is not yet rated for manned flight, although critical steps in this process are expected to be achieved in the near future, and a return manned flight (to Earth) may be achieved in the next 2-3 years (2016/2017). The Dragon version 2, unveiled by SpaceX in May 2014, would have the ability to return to Earth under power using retro rockets rather than parachutes (as used on the current Dragon capsule and previous US designs) which allows for a soft landing on land. There is little information available on the likely pace of deployment of the version 2 capsule.
SpaceX are reported not to have any agreement in place with the Mars One project.
The Mars One roadmap requires a suitable capsule to be available for a flight in 2022. Given that time is required for flight planning and the likely modifications needed for the specific flight requirements for the Mars One mission, a proven capsule design, including demonstrated soft landing capability for Mars, would have to be available in perhaps 2020, just 6 years from now. It seems unlikely, given that a Dragon version 2 has not yet flown.
The Mars One website does not give any description of how the rover and the trailer will be landed, for example whether a modified capsule will be used, or a delivery system similar to that used for the Curiosity rover.
The latest (and largest) Mars rover, Curiosity, landed in August 2012 and is still operational after 2 and a half years. It landed within 2.4 km of its intended landing point. It has a mass of 900 kg and can travel at up to 900 m/hr. The actual achievable average speed is understood to be around 36 m/hr since the rover has to stop frequently to assess the surface around it before setting off again. If the Mars One rover had similar performance it could travel 450 km in the 17 months or so before the cargo missions are launched. The actual distance would be far less, since it would have to stop to take and analyze soil samples and to survey the area. In the first two years Curiosity travelled just 40 km (an average of 2.3 m/hr) and its wheels suffered damaged.
The rover will be tasked exploring the surface to collect data to determine the most suitable location for the settlement, including taking soil water measurements. The search radius which the rover might be able to cover is not indicated. The chosen settlement site will have to take into account the nature of the surface across which the capsules are to be transported (probably flat, with no significant boulders, gullies or other obstacles). The trailer and the six capsules containing the other equipment and supplies will be landed to a position guided by a signal from the rover.
Exactly how the trailer will transport the capsules is not explained by the Mars One project. To assemble the habitat the trailer will have to pick up a capsule, transport it over the Mars surface to the required position and offload it in the correct orientation. The accuracy with which the capsules could be landed is not known, but the landing envelope (the area within which the capsule might land, allowing for uncertainties and navigation errors) would have to lie well away from the proposed settlement (or the rover/trailer positions). The Mars One website states that the capsules may land up to 10 km from the habitat location. That may not sound very far but it’s significant, especially when viewed against the distances travelled by Curiosity.
Needless to say this has never been done before on the surface of another planet, yet Mars One are going to design and test a trailer of the size, power and endurance to do this by remote control whilst meeting any payload limits imposed by the as yet undefined delivery system. And ready for launching by 2022. There is no information on the design of the rover or trailer, nor, as already noted, on the delivery system for either. There is no information to suggest that the design of this hardware has been initiated.
Apart from searching for a suitable site, the rover design has to be flexible enough perform a range of other tasks including connecting the habitat units, deploying the PV solar panels, and servicing the life support water extraction unit by obtaining and feeding regolith into it, and removing the processed material.
According to NASA the small size of modern electronics makes susceptibility to damage by radiation a big issue. It is not seen as a problem for the ISS but is of concern for travel to Mars or even the moon. This underlines the need to thoroughly test and prove all equipment in the environment where it will be used.
Curiosity Rover - Selfie August 2015 [credit : NASA]
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