Mars Direct is a proposal for a human mission to Mars which purports to be both cost-effective and possible with current technology. It was originally detailed in a research paper by Martin Marietta engineers Robert Zubrin and David Baker in 1990, and later expanded upon in Zubrin's 1996 book The Case for Mars. It now serves as a staple of Zubrin's speaking engagements and general advocacy as head of the Mars Society, an organization devoted to the colonization of Mars.
The Apollo Lunar Module, originally designated the Lunar Excursion Module (LEM), was the lunar lander spacecraft that was flown between lunar orbit and the Moon's surface during the United States' Apollo program. It was the first crewed spacecraft to operate exclusively in the airless vacuum of space, and remains the only crewed vehicle to land anywhere beyond Earth.
The Constellation program was a crewed spaceflight program developed by NASA, the space agency of the United States, from 2005 to 2009. The major goals of the program were "completion of the International Space Station" and a "return to the Moon no later than 2020" with a crewed flight to the planet Mars as the ultimate goal. The program's logo reflected the three stages of the program: the Earth (ISS), the Moon, and finally Mars—while the Mars goal also found expression in the name given to the program's booster rockets: Ares. The technological aims of the program included the regaining of significant astronaut experience beyond low Earth orbit and the development of technologies necessary to enable sustained human presence on other planetary bodies.
The Apollo Applications Program (AAP) was created as early as 1966 by NASA headquarters to develop science-based human spaceflight missions using hardware developed for the Apollo program. AAP was the ultimate development of a number of official and unofficial Apollo follow-on projects studied at various NASA labs. However, the AAP's ambitious initial plans became an early casualty when the Johnson Administration declined to support it adequately, partly in order to implement its Great Society set of domestic programs while remaining within a $100 billion budget. Thus, Fiscal Year 1967 ultimately allocated $80 million to the AAP, compared to NASA's preliminary estimates of $450 million necessary to fund a full-scale AAP program for that year, with over $1 billion being required for FY 1968. The AAP eventually led to Skylab, which absorbed much of what had been developed under Apollo Applications.
Lunar orbit rendezvous (LOR) is a process for landing humans on the Moon and returning them to Earth. It was utilized for the Apollo program missions in the 1960s and 1970s. In a LOR mission, a main spacecraft and a smaller lunar lander travel to lunar orbit. The lunar lander then independently descends to the surface of the Moon, while the main spacecraft remains in lunar orbit. After completion of the mission there, the lander returns to lunar orbit to rendezvous and re-dock with the main spacecraft, then is discarded after transfer of crew and payload. Only the main spacecraft returns to Earth.
The Altair spacecraft, previously known as the Lunar Surface Access Module or LSAM, was the planned lander spacecraft component of NASA's cancelled Constellation program. Astronauts would have used the spacecraft for landings on the Moon, which was intended to begin around 2019. The Altair spacecraft was planned to be used both for lunar sortie and lunar outpost missions. On February 1, 2010, U.S. President Barack Obama announced a proposal to cancel the Constellation program, to be replaced with a re-scoped program, effective with the U.S. 2011 fiscal year budget.
NASA Design Reference Mission 3.0 was a NASA study for a human space mission to the planet Mars in the 1990s. It was a plan for a human exploration architecture for Mars, and was released in 1998 as an addendum to the early design plans released in 1994. The plan is for a series of multiple launches to send various space transpiration, surface exploration hardware, and human crew to Mars, and to return the crew to Earth in the early 21st century. Various technologies are explored to launch the payloads into space, to send them to Mars, and to reduce overall weight of the mission by various technologies or techniques including nuclear, solar, aerobraking, and in-situ resource use.
The idea of sending humans to Mars has been the subject of aerospace engineering and scientific studies since the late 1940s as part of the broader exploration of Mars. Long-term proposals have included sending settlers and terraforming the planet. Proposals for human missions to Mars have come from agencies such as NASA, CNSA, the European Space Agency, Boeing, and SpaceX. Currently, only robotic landers and rovers have been on Mars. The farthest humans have been beyond Earth is the Moon, under the Apollo program.
Advanced Gemini is a number of proposals that would have extended the Gemini program by the addition of various missions, including crewed low Earth orbit, circumlunar and lunar landing missions. Gemini was the second crewed spaceflight program operated by NASA, and consisted of a two-seat spacecraft capable of maneuvering in orbit, docking with uncrewed spacecraft such as Agena Target Vehicles, and allowing the crew to perform tethered extra-vehicular activities.
Space architecture is the theory and practice of designing and building inhabited environments in outer space. This mission statement for space architecture was developed at the World Space Congress in Houston in 2002 by members of the Technical Aerospace Architecture Subcommittee of the American Institute of Aeronautics and Astronautics (AIAA). The architectural approach to spacecraft design addresses the total built environment. It is mainly based on the field of engineering, but also involves diverse disciplines such as physiology, psychology, and sociology.
Mars orbit rendezvous (MOR) is a space travel concept where two spacecraft meet up and/or dock in Mars orbit.
A Mars flyby is a movement of spacecraft passing in the vicinity of the planet Mars, but not entering orbit or landing on it. Uncrewed space probes have used this method to collect data on Mars, as opposed to orbiting or landing. A spacecraft designed for a flyby is also known as a "flyby bus" or "flyby spacecraft".
The Asteroid Redirect Mission (ARM), also known as the Asteroid Retrieval and Utilization (ARU) mission and the Asteroid Initiative, was a space mission proposed by NASA in 2013; the mission was later cancelled. The Asteroid Retrieval Robotic Mission (ARRM) spacecraft would rendezvous with a large near-Earth asteroid and use robotic arms with anchoring grippers to retrieve a 4-meter boulder from the asteroid.
Austere Human Missions to Mars is a concept for a human mission to Mars by the United States space agency, NASA. Released in 2009, it proposed a modified and even less costly version of Design Reference Architecture (DRA) 5.0, itself a combination of nearly 20 years of Mars planning design work. The mission profile was for a conjunction class with a long surface stay, pre-deployed cargo, aerocapture and propulsive capture, and some in-situ resource production. As of 2015, the concept had not yet been adapted to the Space Launch System that replaced NASA's Constellation program in 2011.
Crewed Mars rovers are Mars rovers for transporting people on the planet Mars, and have been conceptualized as part of human missions to that planet.
A flyby is a spaceflight operation in which a spacecraft passes in proximity to another body, usually a target of its space exploration mission and/or a source of a gravity assist to impel it towards another target. Spacecraft which are specifically designed for this purpose are known as flyby spacecraft, although the term has also been used in regard to asteroid flybys of Earth for example. Important parameters are the time and distance of closest approach.
Mars Base Camp (MBC) is a crewed Mars laboratory orbiter concept under study that was commissioned by NASA from Lockheed Martin in US. It would use both future and proven concepts as well as the Orion MPCV, also built by Lockheed Martin.
The Lockheed Martin Lunar Lander is a series of design concepts by Lockheed Martin for a crewed lunar lander.
The International Lunar Resources Exploration Concept (ILREC) was a proposed mission architecture under President George H. W. Bush's Space Exploration Initiative (SEI) by Kent Joosten, an engineer at Johnson Space Center. The plan would have used the help of international partners, mainly the Soviet Union, to assemble a lunar base and sustainable lunar transportation service.
