NASA began its "Human Lunar Return study" in September 1995 to identify ways it could conduct future human spaceflight missions to the Moon. The final Human Lunar Return (HLR) briefing took place on August 7, 1996. The study was seen as laying "the foundation for human space activity over the next three decades." [1]
The study called for a mission lasting 16 days, 10 of which would be spent on the lunar surface. [1] The study baselined a lightweight architecture including an open-cockpit lunar lander weighing 4,565 kilograms (10,064 lb) including fuel. [2] The lunar habitat was designed to have an inflatable hull and was scheduled to be delivered in advance of the crew. [3] To protect against cosmic rays and a possible solar particle event, the hull of the lunar habitat to be at minimum 5 grams per square centimetre (1.1 oz/in2) thick and filled with either water or polyethylene. [1] Components and crew for the mission would have been transported to the International Space Station (ISS) by two Space Shuttle flights. The HLR schedule called for the first mission to depart from the ISS in August 2001. [2] One of the primary goals of the mission was to bring 300 kilograms (660 lb) of payload from the lunar surface back to Earth to be studied. [3]
The projected cost of the mission over the five year development timeline ranged between $2.5 [3] and $4 billion. [2] The mission required two shuttle and three Proton launches to land two astronauts and a small habitat structure at Aristarchus crater. [3]
The Space Shuttle program was the fourth human spaceflight program carried out by the U.S. National Aeronautics and Space Administration (NASA), which accomplished routine transportation for Earth-to-orbit crew and cargo from 1981 to 2011. Its official program name was Space Transportation System (STS), taken from a 1969 plan for a system of reusable spacecraft where it was the only item funded for development, as a proposed nuclear shuttle in the plan was cancelled in 1972. It flew 135 missions and carried 355 astronauts from 16 countries, many on multiple trips.
Human spaceflight programs have been conducted, started, or planned by multiple countries and companies. Until the 21st century, human spaceflight programs were sponsored exclusively by governments, through either the military or civilian space agencies. With the launch of the privately funded SpaceShipOne in 2004, a new category of human spaceflight programs – commercial human spaceflight – arrived. By the end of 2022, three countries and one private company (SpaceX) had successfully launched humans to Earth orbit, and two private companies had launched humans on a suborbital trajectory.
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 H-II Transfer Vehicle (HTV), also called Kounotori, is an expendable, automated cargo spacecraft used to resupply the Kibō Japanese Experiment Module (JEM) and the International Space Station (ISS). The Japan Aerospace Exploration Agency (JAXA) has been working on the design since the early 1990s. The first mission, HTV-1, was originally intended to be launched in 2001. It launched at 17:01 UTC on 10 September 2009 on an H-IIB launch vehicle. The name Kounotori was chosen for the HTV by JAXA because "a white stork carries an image of conveying an important thing, therefore, it precisely expresses the HTV's mission to transport essential materials to the ISS". The HTV is very important for resupplying the ISS because after the retirement of the Space Shuttle it is the only vehicle that can transfer new 41.3 in (105 cm) wide International Standard Payload Racks (ISPRs) and dispose old ISPRs that can fit the 51 in (130 cm) wide tunnels between modules in the US Orbital Segment.
A Multi-Purpose Logistics Module (MPLM) is a large pressurized container that was used on Space Shuttle missions to transfer cargo to and from the International Space Station (ISS). Two MPLMs made a dozen trips in the Shuttle cargo bay and initially berthed to the Unity and later the Harmony module on the ISS. Once attached, supplies were offloaded, and finished experiments and waste were reloaded. The MPLM was then transferred back into the Shuttle’s cargo bay for return to Earth. Three modules were built by Alenia Aeronautica for the Italian Space Agency (ASI). They were named Leonardo, Raffaello, and Donatello.
Expedition 1 was the first long-duration stay on the International Space Station (ISS). The three-person crew stayed aboard the station for 136 days, from November 2000 to March 2001. It was the beginning of an uninterrupted human presence on the station which continues as of 2024. Expedition 2, which also had three crew members, immediately followed Expedition 1.
Uncrewed spaceflights to the International Space Station (ISS) are made primarily to deliver cargo, however several Russian modules have also docked to the outpost following uncrewed launches. Resupply missions typically use the Russian Progress spacecraft, European Automated Transfer Vehicles, Japanese Kounotori vehicles, and the American Dragon and Cygnus spacecraft. The primary docking system for Progress spacecraft is the automated Kurs system, with the manual TORU system as a backup. ATVs also use Kurs, however they are not equipped with TORU. The other spacecraft — the Japanese HTV, the SpaceX Dragon and the Northrop Grumman Cygnus — rendezvous with the station before being grappled using Canadarm2 and berthed at the nadir port of the Harmony or Unity module for one to two months. Progress, Cygnus and ATV can remain docked for up to six months. Under CRS phase 2, Cargo Dragon docks autonomously at IDA-2 or 3 as the case may be. As of December 2022, Progress spacecraft have flown most of the uncrewed missions to the ISS.
The Space Transportation System (STS), also known internally to NASA as the Integrated Program Plan (IPP), was a proposed system of reusable crewed space vehicles envisioned in 1969 to support extended operations beyond the Apollo program. The purpose of the system was two-fold: to reduce the cost of spaceflight by replacing the current method of launching capsules on expendable rockets with reusable spacecraft; and to support ambitious follow-on programs including permanent orbiting space stations around Earth and the Moon, and a human landing mission to Mars.
The Exploration Systems Architecture Study (ESAS) is the official title of a large-scale, system level study released by the National Aeronautics and Space Administration (NASA) in November 2005 of his goal of returning astronauts to the Moon and eventually Mars—known as the Vision for Space Exploration. The Constellation Program was cancelled in 2010 by the Obama Administration and replaced with the Space Launch System, later renamed as the Artemis Program in 2017 under the Trump Administration.
Dragon is a family of spacecraft developed and produced by American private space transportation company SpaceX.
The Ares V was the planned cargo launch component of the cancelled NASA Constellation program, which was to have replaced the Space Shuttle after its retirement in 2011. Ares V was also planned to carry supplies for a human presence on Mars. Ares V and the smaller Ares I were named after Ares, the Greek god of war.
NASA proposed several concept moonbases for achieving a permanent presence of humans on the Moon since the late 1950s. Research and exploration of the Moon have been a large focus of the organization since the Apollo program. NASA's peak budget was in 1964–1965, when it comprised 4% of all federal spending in service of the Apollo Moon landing project. Though lunar landings since the conclusion of the Apollo program in 1972 have ceased, interest in establishing a permanent habitation on the lunar surface or beyond low Earth orbit has remained steady. Recently, renewed interest in lunar landing has led to increased funding and project planning. NASA requested an increase in the 2020 budget of $1.6 billion, in order to make another crewed mission to the Moon under the Artemis program by 2025, followed by a sustained presence on the Moon by 2028. A crew was selected for the planned crewed mission, Artemis II, in April 2023.
Space architecture is the theory and practice of designing and building inhabited environments in outer space. This mission statement for space architecture was developed in 2002 by participants in the 1st Space Architecture Symposium, organized at the World Space Congress in Houston, by the Aerospace Architecture Subcommittee, Design Engineering Technical Committee (DETC), American Institute of Aeronautics and Astronautics (AIAA).
The Shuttle-Derived Heavy Lift Launch Vehicle ("HLV") was an alternate super heavy-lift launch vehicle proposal for the NASA Constellation program. It was first presented to the Augustine Commission on 17 June 2009.
DIRECT was a late-2000s proposed alternative super heavy lift launch vehicle architecture supporting NASA's Vision for Space Exploration that would replace the space agency's planned Ares I and Ares V rockets with a family of Shuttle-Derived Launch Vehicles named "Jupiter". It was intended to be the alternative to the Ares I and Ares V rockets which were under development for the Constellation program, intended to develop the Orion spacecraft for use in Earth orbit, the Moon, and Mars.
The retirement of NASA's Space Shuttle fleet took place from March to July 2011. Discovery was the first of the three active Space Shuttles to be retired, completing its final mission on March 9, 2011; Endeavour did so on June 1. The final shuttle mission was completed with the landing of Atlantis on July 21, 2011, closing the 30-year Space Shuttle program.
The Lunar Gateway, or simply Gateway, is a space station which is planned to be assembled in orbit around the Moon. The Gateway is intended to serve as a communication hub, science laboratory, and habitation module for astronauts as part of the Artemis program. It is a multinational collaborative project: participants include NASA, the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), the Canadian Space Agency (CSA) and the Mohammed Bin Rashid Space Centre (MBRSC). The Gateway is planned to be the first space station beyond low Earth orbit.
The Artemis program is a Moon exploration program led by the United States' National Aeronautics and Space Administration (NASA), formally established in 2017 via Space Policy Directive 1. It is intended to reestablish a human presence on the Moon for the first time since the Apollo 17 mission in 1972. The program's stated long-term goal is to establish a permanent base on the Moon to facilitate human missions to Mars.
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.
First Lunar Outpost was a proposal for a crewed lunar mission that would have launched sometime in the 2010s. It was part of George H. W. Bush's Space Exploration Initiative. The main purpose of the proposal was to offer a much less expensive alternative to NASA's 90-day study from 1989 by a factor of US$30 billion. Although it did not gather much mainstream attention, NASA dedicated much time to assembling a detailed and thorough proposal. However, the entire Space Exploration Initiative was cancelled soon after the proposal's completion, and NASA closed the Office of Space Exploration in March 1993.