Manned Mission to Mars ...

Manned Mission Possible?


A human mission to visit and land on the planet Mars has long been a subject for science fiction writers and a dream of space exploration advocates. Though various mission proposals have been put forth by multiple space agencies for such a mission, the logistical and financial obstacles are considerable, and many critics contend that such a mission would be a risky waste of resources and money. Regardless, preliminary work for such a mission is being undertaken by NASA and the European Space Agency, with each projecting a possible attempt in the 2030s.



Mars Base Station

NASA artist's conception of a human mission to Mars (1989 painting by Les Bossinas of NASA Lewis Research Center).




In the mid to late 1990s NASA developed several conceptual level human Mars exploration architectures. One of the most notable and often quoted was the NASA Design reference mission 3.0 (DRM 3.0). The study was performed by the NASA Mars Exploration Team at the NASA's Johnson Space Center (JSC) in the 1990s. Personnel representing several NASA field centers formulated a “Reference Mission” addressing human exploration of Mars. The plan describes the first human missions to Mars with concept of operations and technologies to be used as a first cut at an architecture. The architecture for the Mars Reference Mission builds on previous work, principally on the work of the Synthesis Group (1991) and Zubrin’s (1991) concepts for the use of propellants derived from the Martian atmosphere. The primary purpose of the Reference Mission was to stimulate further thought and development of alternative approaches, which can improve effectiveness, reduce risks, and reduce cost. Improvements can be made at several levels; for example, in the architectural, mission, and system levels.

Russian Mission Proposals (current)

A number of Mars mission concepts and proposals have been put forth by Russian scientists. Stated dates were for a launch sometime between 2016 and 2020. The Mars probe would carry a crew of four to five cosmonauts, who would spend close to two years in space.

Another proposal for a joint mission with ESA is based on two spacecraft being sent to Mars, one carrying a six-person crew and the other the expedition's supplies. The mission would take about 440 days to complete with three astronauts visiting the surface of the planet for a period of two months. The entire project would cost $20 billion dollars and Russia would contribute 30 per cent of these funds.^[25]

A ground-based biomedical experiment called Mars-500 simulating manned flight to Mars is planned to start at the end of 2008 in Russia.

In 2005 the Mars Society Germany proposed a European Mars Mission (EMM) that could be launched using an improved version of the Ariane 5 booster. The split mission approach was adopted to allow launch of payloads launched directly by this booster from Earth to Mars. Cargo elements would be transferred on low energy, longer transit time trajectories, with only the crew element being sent on a high-energy, fast-transit trajectory. The launches needed to support a mission were spread across two launch windows to allow the Mars surface infrastructure to be pre-positioned and checked out prior to committing crews to the mission.

In 2005 the Mars Society Germany proposed a European Mars Mission (EMM) that could be launched using an improved version of the Ariane 5 booster. The split mission approach was adopted to allow launch of payloads launched directly by this booster from Earth to Mars. Cargo elements would be transferred on low energy, longer transit time trajectories, with only the crew element being sent on a high-energy, fast-transit trajectory. The launches needed to support a mission were spread across two launch windows to allow the Mars surface infrastructure to be pre-positioned and checked out prior to committing crews to the mission.

The scenario included a Mars in-situ propellant production plant. The plant would also generate fuel for surface transportation, reactants for fuel cells, and backup consumables (water, oxygen, and gases) for the life support system. Mars orbit capture and later entry into the Mars atmosphere would use a biconic aeroshell. The EMM mission used four element types:

• Habitat: The quarters used by the crew for the transit to Mars would be identical to the unmanned surface habitat/ laboratory landed robotically on the first cargo mission. The end-result - identical duplicate habitats on the surface - provided redundancy during the longest phase of the mission. The Mars transit/surface habitat would contain the required consumables for the Mars transit and surface duration of approximately 800 days (approximately half a year for transit and 600 days on the surface).

• MAV (Mars Ascent Vehicle): When the surface mission was completed, the crew would ride the MAV from the Martian surface to Martian orbit for a rendezvous with an orbiting Earth Return Vehicle. The MAV consisted of an ascent propulsion system and the crew ascent capsule, and was delivered to the Mars surface atop a cargo descent stage. The ascent propulsion system was delivered with its propellant tanks empty. The same descent stage would deliver a nuclear power source (or solar cells), a propellant manufacturing plant, and several tanks of hydrogen to be used as feedstock for making the required ascent propellant. The pressurized ascent capsule vehicle could accommodate a crew of three-five, their EVA suits, and the samples gathered during the expedition and from experiments conducted in the surface habitat/laboratory. Once the docking with the ERV was achieved, all crew, equipment, and samples would be transferred to the ERV, and the MAV jettisoned.

• ERV (Earth Return Vehicle): This would return the crew from Mars orbit to Earth. The ERV was composed of the propulsion stage, the Earth-return transit habitat, and Earth Re-entry Capsule (ERC). The ERV would be delivered to Mars orbit with the propulsion stage fully fuelled, and loiter there for nearly 4 years before being used by the crew returning to Earth. The propulsion system for the ERV was sized for the velocity change needed to insert the Earth return habitat and the Earth Re-entry Capsule from a highly elliptical parking orbit at Mars to a fast-transit half-year return trajectory to Earth.

• Soyuz spacecraft: The Soyuz TM, launched from Baikonur or Kourou, would be used to shuttle the crew of three (or two launches for a crew of five) to the Transit Habitation prepositioned in low earth orbit.

Mission Sequence would be as follows:

• Launch 1 sent a fully fuelled ERV directly from earth to an elliptical Mars orbit.

• Launch 2 delivered a vehicle to the Mars surface consisting of the unfueled MAV-1, a propellant production module, a nuclear power plant (or solar cells to be deployed), liquid hydrogen (to be used as a reactant to produce the ascent vehicle propellant), and approximately 20 metric tons of additional payload. The propellant production facility used the hydrogen carbon dioxide from the Mars atmosphere to produce oxygen and methane that were the propellants for the MAV. This production would be completed within a year -- several months before the first crew's scheduled departure from Earth.

• Launch 3 was optional, but preferred. It would carry the same payload as Launch 2. The second MAV would serve as a backup for the first crew team, and if unused, as the MAV for the next crew. The second propellant production module, power plant , and liquid hydrogen supplies would similarly provide redundancy in case of failures of any elements.

• Launch 4 was optional as well, delivering a third lander to the Mars surface, This would be an emergency safe haven, consisting of a surface habitat/laboratory and non-perishable consumables.

• Launch 5 would send the transfer habitat toward Mars. This consisted of a single large module shaped to allow aerocapture in the Martian atmosphere. If the launcher was man-rated, the habitat would be sent directly toward Mars with the crew. If not, the module would be placed in a low earth parking orbit and Soyuz TM spacecraft would be launched to dock with it and transfer the crew before departure for Mars.

An Ariane 5M heavy lift booster derived from existing Ariane 5 elements would be developed to support the European Mars Mission. This would cost 2 billion Euros to develop, and have a cost per launch of Euro 250-300 million - three times that of the basic Ariane 5. The three-stage booster would have a payload of 41 metric tons to Trans-Mars Injection and consist of the following:

• Stage 1: Six EAP2 MPS solid boosters, each with 253 metric tons of solid propellant. Each MPS would produce 552 metric tons thrust at lift-off, increasing to 600 metric tons before burnout. After burnout 128 seconds after liftoff, they would separate from the main stage at an altitude of 55 to 70 kilometers, continue on a trajectory peaking at 80 to 140 kilometers, then deploy parachutes and splashdown into the ocean 150 kilometers from the launch site. The motors would be built up from seven steel-cased segments.

• Stage 2: The EPCL ( Etage de Propulsion Cryogénique Large) main cryogenic core stage (EPCL Etage de Propulsion Cryogénique Large) would be primarily aluminum alloy and contain 633 metric tons of Lox/LH2 cryogenic propellants. Three engines would each deliver 410 metric tons of thrust, and be ignited on the pad in parallel with the solid boosters, and operate for 660 seconds. At shutdown the 10-m-diameter booster would be at an altitude of 130 to 420 kilometers, depending on the mission. The stage would be jettisoned at suborbital velocity, and re-enter into the ocean.

• Stage 3: The ESCB1 extended cryogenic upper stage would complete the injection of the payload toward Mars (including a stay in an intermediate low earth parking orbit if required). The stage would have 67.5 metric tons of Lox/LH2 propellant and be powered by 3 Vinci restartable cryogenic engines with an extendible exit cone and vacuum specific impulse of 455 seconds.

Total cost for a European Mars Mission on a ten-year development schedule was estimated as Euro 10-15 billion (2 billion for launcher development, 2 billion for launch costs, and 6 to 11 billion for overall mission and spacecraft design, development, deployment and operations.)

Crew Size: 5. Design Life: 1200 days. Mass: 120,000 kg (260,000 lb). Electrical System: Solar Panels or Nuclear.

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