Project Constellation - AbsoluteAstronomy.com

Constellation Program is a human spaceflight

Human spaceflight

Human spaceflight is spaceflight with humans on the spacecraft. When a spacecraft is manned, it can be piloted directly, as opposed to machine or robotic space probes and remotely-controlled satellites....

program within NASA

NASA

The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...

, the space agency of the United States. The stated goals of the program were to gain significant experience in operating away from Earth's environment, develop technologies needed for opening the space

Space

Space is the boundless, three-dimensional extent in which objects and events occur and have relative position and direction. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum...

frontier, and conduct fundamental science.

Constellation began in response to the goals laid out in the Vision for Space Exploration

Vision for Space Exploration

The Vision for Space Exploration is the United States space policy which was announced on January 14, 2004 by President George W. Bush. It is seen as a response to the Space Shuttle Columbia disaster, the state of human spaceflight at NASA, and a way to regain public enthusiasm for space...

under NASA Administrator Sean O'Keefe

Sean O'Keefe

Sean O'Keefe is the CEO of EADS North America, a subsidiary of the European aerospace firm EADS, a former Administrator of NASA, and former chancellor of Louisiana State University . O'Keefe is also a former member of the board of directors of DuPont...

. It had already begun development, under several proposals After Sean O'Keefe's retirement, his replacement Michael D. Griffin

Michael D. Griffin

Michael Douglas Griffin is an American physicist and aerospace engineer. From April 13, 2005 to January 20, 2009 he served as Administrator of NASA, the space agency of the United States...

ordered a complete review, termed the Exploration Systems Architecture Study

Exploration Systems Architecture Study

The Exploration Systems Architecture Study is the official title of a large-scale, system level study released by the National Aeronautics and Space Administration in November 2005 in response to American president George W...

, which reshaped how NASA would pursue the goals laid out in the Vision for Space Exploration. With the NASA Authorization Act of 2005

NASA Authorization Act of 2005

The NASA Authorization Act of 2005 is an act of the United States Congress. It was signed by the then President George W. Bush and became Public Law 109-155 on December 30, 2005....

formalizing the findings of the Exploration Systems Architecture Study, work began on this revised Constellation Program to send astronaut

Astronaut

An astronaut or cosmonaut is a person trained by a human spaceflight program to command, pilot, or serve as a crew member of a spacecraft....

s first to the International Space Station

International Space Station

The International Space Station is a habitable, artificial satellite in low Earth orbit. The ISS follows the Salyut, Almaz, Cosmos, Skylab, and Mir space stations, as the 11th space station launched, not including the Genesis I and II prototypes...

, then to the Moon

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

, and afterward to Mars

Mars

Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

and other destinations beyond.

On February 1, 2010, President Barack Obama

Barack Obama

Barack Hussein Obama II is the 44th and current President of the United States. He is the first African American to hold the office. Obama previously served as a United States Senator from Illinois, from January 2005 until he resigned following his victory in the 2008 presidential election.Born in...

announced a proposal to cancel the program, effective with the U.S. 2011 fiscal year budget

2010 United States federal budget

The United States Federal Budget for Fiscal Year 2010, titled A New Era of Responsibility: Renewing America's Promise, is a spending request by President Barack Obama to fund government operations for October 2009–September 2010...

, but later announced changes to the proposal in a major space policy speech

Barack Obama space policy speech at Kennedy Space Center

The space policy of the Barack Obama administration was announced by U.S. President Barack Obama on April 15, 2010, at a major space policy speech at Kennedy Space Center. He committed to increasing NASA funding by $6 billion over five years and completing the design of a new heavy-lift launch...

at Kennedy Space Center on April 15, 2010. Obama signed the NASA Authorization Act of 2010

NASA Authorization Act of 2010

The NASA Authorization Act of 2010 is a U.S. law which authorizes NASA appropriations for fiscal years 2011–2013 with the same top-line budget values as requested by President of the United States Barack Obama...

on October 11 which brought the program to an end, but Constellation contracts remain in place until Congress acts to overturn the previous mandate. The program has been replaced by the U.S. National Space Policy of the Barack Obama administration. NASA announced that it had selected the design of the Space Launch System

Space Launch System

The Space Launch System, or SLS, is a Space Shuttle-derived heavy launch vehicle being designed by NASA, following the cancellation of the Constellation Program, to replace the retired Space Shuttle. The NASA Authorization Act of 2010 envisions the transformation of the Ares I and Ares V vehicle...

in September 2011.

Spacecraft

Constellation included the development of spacecraft

Spacecraft

A spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....

and booster vehicles

Launch vehicle

In spaceflight, a launch vehicle or carrier rocket is a rocket used to carry a payload from the Earth's surface into outer space. A launch system includes the launch vehicle, the launch pad and other infrastructure....

to replace the Space Shuttle

Space Shuttle

The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...

. NASA had already begun designing two boosters, the Ares I and Ares V. Ares I would have had the sole function of launching mission crews into orbit, while Ares V would have been used to launch other hardware for use on missions requiring a heavier lift capacity than the Ares I booster. In addition to these two boosters, NASA designed a set of other spacecraft for use during Constellation. These included the Orion

Orion (spacecraft)

Orion is a spacecraft designed by Lockheed Martin for NASA, the space agency of the United States. Orion development began in 2005 as part of the Constellation program, where Orion would fulfill the function of a Crew Exploration Vehicle....

crew capsule, the Earth Departure Stage

Earth Departure Stage

The Ares V Earth Departure Stage was a rocket stage which NASA planned to design at its Marshall Space Flight Center in Huntsville, Alabama as part of Project Constellation...

and the Altair lunar lander.

Orion

Orion (spacecraft)

was originally designed as the crew compartment for the Constellation program and Earth orbit missions. Lockheed Martin

Lockheed Martin

Lockheed Martin is an American global aerospace, defense, security, and advanced technology company with worldwide interests. It was formed by the merger of Lockheed Corporation with Martin Marietta in March 1995. It is headquartered in Bethesda, Maryland, in the Washington Metropolitan Area....

was selected as the prime contractor to build Orion on August 31, 2006, and Boeing

Boeing

The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...

was selected to build the primary heat shield for the Orion crew exploration vehicle on September 15, 2006. NASA planned to develop different Orion capsules tailored for specific missions. The Block I Orion was to be used for International Space Station

International Space Station

crew rotation and resupply and other Earth orbit missions, while the Block II and III variants were designed for deep-space exploration.

Orion consists of three main parts: a Crew Module (CM) similar to the Apollo Command Module but capable of holding four to six crew members; a cylindrical Service Module (SM) containing the primary propulsion systems and consumable supplies; and the Launch Abort System (LAS) which provides capability for the astronauts and Crew Module to escape from the launch vehicle should problems arise during launch ascent. The Orion Crew Module is designed to be reusable for up to ten flights, allowing NASA to construct a fleet of Orion crew modules.

Altair

Altair (formerly known as the Lunar Surface Access Module, LSAM) would have been the main transport vehicle for lunar-bound astronauts. The Altair design was much larger than the Apollo Lunar Module

Apollo Lunar Module

The Apollo Lunar Module was the lander portion of the Apollo spacecraft built for the US Apollo program by Grumman to carry a crew of two from lunar orbit to the surface and back...

(LM), with almost five times the volume, occupying a total of 1120 ft3 compared with the Apollo lander's 235 ft3. It was to stand 32 feet (9.8 m) tall and span 49 feet (14.9 m) wide from landing gear tip to tip.

Like its Apollo LM predecessor, Altair consisted of two parts: an ascent stage which houses the four-person crew; and a descent stage which has the landing legs, the majority of the crew's consumables (oxygen and water), and scientific equipment. Unlike the Apollo LM, Altair would have touched down in the lunar polar regions favored by NASA for future lunar base construction. Altair, like the LM, is not reusable; the ascent stage would be discarded after use.

The Altair descent stage was to be powered by four RL-10

RL-10

The RL10 was USA's first liquid hydrogen fueled rocket engine. An updated version is used in several current launch vehicles. Six RL10 engines were used in the S-IV second stage of the Saturn I rocket. One or two RL10 engines are used in the Centaur upper stages of Atlas and Titan rockets...

rocket engines that are used for the Centaur upper stage

Centaur (rocket stage)

Centaur is a rocket stage designed for use as the upper stage of space launch vehicles. Centaur boosts its satellite payload to geosynchronous orbit or, in the case of an interplanetary space probe, to or near to escape velocity...

used on the Atlas V rocket. Unlike the current RL-10 engines in use, the newer RL-10s would be able to throttle down to as low as 10% rated thrust (the current specifications allow for 20%), thus allowing the use of Altair for both the lunar orbit insertion (LOI) and landing stages of the lunar mission. The ascent stage was to be powered by a single engine, likely a hypergolic engine similar or identical to the main engine of the Orion CSM, using the descent stage as a launchpad and as a platform for future base construction. There was a small possibility that the original plan of using LOX/CH4 – fueled engines on board the Block II (lunar) Orion CSM and Altair ascent stage could come to pass.

Earth Departure Stage

The Earth Departure Stage (EDS) was the main propulsion system that would have sent the Ares V Orion/Altair upper stage from low Earth orbit to the Moon. It was to have been the second liquid stage of the Ares V rocket. The Orion spacecraft would have launched separately on Ares I, and rendezvous and dock with the Ares V EDS/Altair combination, which would have then been configured for the journey to the Moon (known as Earth orbit rendezvous

Earth orbit rendezvous

Earth orbit rendezvous is a type of space rendezvous and a spaceflight methodology most notable for enabling round trip human missions to the moon...

Legacies of Apollo and Space Shuttle

NASA would have used the vehicles of the Constellation Program to replace the Space Shuttle

Space Shuttle

. But unlike the X-33 and other programs meant to replace the Shuttle, Constellation reused concepts already learned from the Apollo and Space Shuttle program

Space Shuttle program

NASA's Space Shuttle program, officially called Space Transportation System , was the United States government's manned launch vehicle program from 1981 to 2011...

s.

For instance, the shape of the Orion command ship closely resembled the aerodynamic shape of the Apollo Command/Service Module

Apollo Command/Service Module

The Command/Service Module was one of two spacecraft, along with the Lunar Module, used for the United States Apollo program which landed astronauts on the Moon. It was built for NASA by North American Aviation...

. However, in other respects – such as with the cockpit displays and heatshield – Orion employs new technology. The design of the launch vehicle taking Orion into orbit, the Ares I, was closely based on Apollo designs. It was based on a J-2X engine, a redesigned version of the J-2 engine used in the Saturn family of boosters.

In working on the J-2X, NASA engineers visited museums, searched for Apollo-era documentation and consulted with engineers who worked on the Apollo program. "The mechanics of landing on the moon and getting off the moon to a large extent have been solved," said Constellation program manager Jeff Hanley. "That is the legacy that Apollo gave us."

Like Apollo, Constellation would have flown a lunar orbit rendezvous

Lunar orbit rendezvous

Lunar orbit rendezvous is a key concept for human landing on the Moon and returning to Earth.In a LOR mission a main spacecraft and a smaller lunar module travel together into lunar orbit. The lunar module then independently descends to the lunar surface. After completion of the mission there, a...

mission profile, but unlike Apollo, Constellation would have also employed an Earth orbit rendezvous

Earth orbit rendezvous

Earth orbit rendezvous is a type of space rendezvous and a spaceflight methodology most notable for enabling round trip human missions to the moon...

. The lander, known as Altair, would have been launched separately on the Ares V

Ares V

The Ares V was the planned cargo launch component of the 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...

rocket, a rocket based on both Space Shuttle and Apollo technologies. Orion would have been launched separately and would have linked up with Altair in low earth orbit. Also unlike Apollo, Orion would have remained unmanned in lunar orbit while the entire crew landed on the lunar surface (specifically at the lunar polar regions, unlike the equatorial regions explored by Apollo). At the end of the mission, the Altair spacecraft would have launched into lunar orbit to link up with the Orion spacecraft in lunar orbit rendezvous.

Ares boosters

Unlike the Saturn V

Saturn V

The Saturn V was an American human-rated expendable rocket used by NASA's Apollo and Skylab programs from 1967 until 1973. A multistage liquid-fueled launch vehicle, NASA launched 13 Saturn Vs from the Kennedy Space Center, Florida with no loss of crew or payload...

and Space Shuttle

Space Shuttle

, where the crew and cargo were launched together on the same rocket, NASA planned to use two separate launch vehicles for the Constellation Program – the Ares I for crew and the Ares V for cargo. This would have allowed the two launch vehicles to be optimized for their respective missions, especially for a much heavier cargo load per mission. The Constellation Program thus combined the Lunar Orbit Rendezvous

Lunar orbit rendezvous

method which was used by Apollo with the Earth Orbit Rendezvous

Earth orbit rendezvous

Earth orbit rendezvous is a type of space rendezvous and a spaceflight methodology most notable for enabling round trip human missions to the moon...

method.

Ares I

The Orion spacecraft would have been launched into a low Earth orbit

Low Earth orbit

A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...

using the Ares I rocket (the "Stick"), developed by Alliant Techsystems

Alliant Techsystems

Alliant Techsystems Inc., most commonly known by its ticker symbol, ', is one of the largest aerospace and defense companies in the United States with more than 18,000 employees in 22 states, Puerto Rico and internationally, and 2010 revenues in excess of an estimated...

, Rocketdyne

Rocketdyne

Rocketdyne was a Rocket engine design and production company headquartered in Canoga Park, California, United States. The company was related to North American Aviation for most of its history. NAA merged with Rockwell International, which was then bought by Boeing in December, 1996...

, and Boeing

Boeing

. Formerly referred to as the Crew Launch Vehicle (CLV), the Ares I consisted of a single Solid Rocket Booster

Space Shuttle Solid Rocket Booster

The Space Shuttle Solid Rocket Boosters were the pair of large solid rockets used by the United States' NASA Space Shuttle during the first two minutes of powered flight. Together they provided about 83% of liftoff thrust for the Space Shuttle. They were located on either side of the rusty or...

(SRB) derived from the boosters used in the Space Shuttle

Space Shuttle

system, connected at its upper end by an interstage support assembly to a new liquid-fueled second stage powered by an uprated Apollo-era J-2X rocket engine. NASA selected the Ares designs for their anticipated overall safety, reliability and cost-efficiency.
NASA began developing the Ares I low Earth orbit launch vehicle (analogous to Apollo's Saturn IB), returning to a development philosophy used for the original Saturn I, test-launching one stage at a time, which George Mueller

George Mueller (NASA)

George Mueller was Associate Administrator of the NASA Office of Manned Space Flight from September 1963 until December 1969...

abandoned in favor of "all-up" testing for the Saturn V. As of May 2010, the program got as far as launching the first Ares I-X first-stage flight on October 28, 2009 and testing the Orion launch abort system.

Ares V

Ares V would have had a maximum payload capacity of about 188 metric tons (414,000 lb) to low earth orbit

Low Earth orbit

A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...

(LEO), compared to the Space Shuttle

Space Shuttle

's capacity of 24.4 metric tons, and the Saturn V's 118 metric tons. The Ares V would have carried about 71 metric tons (157,000 lb) to the Moon

Moon

.

The Ares V design incorporated six RS-68 engines with assistance from a pair of 5.5-segment SRBs. Five Space Shuttle Main Engine

Space Shuttle main engine

The RS-25, otherwise known as the Space Shuttle Main Engine , is a reusable liquid-fuel rocket engine built by Pratt & Whitney Rocketdyne for the Space Shuttle, running on liquid hydrogen and oxygen. Each Space Shuttle was propelled by three SSMEs mated to one powerhead...

s (SSME) were originally planned for the Ares V, but the RS-68 engines are more powerful and less complex and therefore less expensive than the SSMEs. The Ares V would have flown for the first eight minutes of powered flight, then the Earth Departure Stage would have placed itself and the Altair spacecraft into low Earth orbit while awaiting the arrival of the Orion.

History

A number of alternatives to Constellation have been suggested in response to critiques of the program. Debates persist regarding whether the present program should continue, be discontinued, or rectified in some way.

President Bush

On January 14, 2004 President George W. Bush

George W. Bush

George Walker Bush is an American politician who served as the 43rd President of the United States, from 2001 to 2009. Before that, he was the 46th Governor of Texas, having served from 1995 to 2000....

requested NASA develop a proposal for continuing manned space exploration after the completion of the International Space Station

International Space Station

and the planned retirement of the Space Shuttle

Space Shuttle

program in 2010. This proposal was to be a way to "establish an extended human presence on the Moon" to "vastly reduce the costs of further space exploration." Inclusive to this would be the "harvesting and processing of lunar soil

Lunar soil

Lunar soil is the fine fraction of the regolith found on the surface of the Moon. Its properties can differ significantly from those of terrestrial soil...

into rocket fuel or breathable air." According to Bush, experience gained could help "develop and test new approaches and technologies and systems" to begin a "sustainable course of long-term exploration."

When President Bush established his new space exploration policy to return humans to the moon, NASA estimated the policy would cost $230 billion (in 2004 dollars) through 2025. This figure includes the Commercial Crew and Cargo program, which is separate from the Constellation program. NASA has estimated that the Constellation program would cost over $97 billion (in 2008 dollars) through 2020, half of which would be for Ares I and Orion. However, unsolved technical and design challenges made it impossible for NASA to provide a credible estimate. To provide some perspective, in 1972 NASA estimated the life-cycle costs (development, procurement, and twelve years of operation) of the Space Shuttle program at $16.1 billion (in 1972 dollars). The actual life-cycle costs for twelve years of operation came to $25 billion (in 1972 dollars), a 55% over-run.

President Obama

President Barack Obama

Barack Obama

's stance is that Constellation is "over budget, behind schedule, and lacking in innovation."

In 2009, concerned by price increases on the program, U.S. President Barack Obama

Barack Obama

ordered a review of the project which indicated that both returning to the Moon and manned flights to Mars were out of NASA's current budget. The Augustine panel proposed various options that included two primary destination points (the Moon, and Deep Space), three different types of Super Heavy Launch vehicles, and utilizing Commercially based crew to LEO transport systems, as well as a robust research and development program that would include work on propellant depot

Propellant depot

An orbital propellant depot is a cache of propellant that is placed on an orbit about the Earth or another body to allow spacecraft to be fuelled in space. Launching a spacecraft separately from some of its propellant enables missions with more massive payloads...

s.

After reviewing the report, following congressional testimony, the Obama administration decided to exclude Constellation from the 2011 United States federal budget

2011 United States federal budget

The 2011 United States federal budget is the United States federal budget to fund government operations for the fiscal year 2011, which is October 2010–September 2011. The budget is the subject of a spending request by President Barack Obama...

. On February 1, 2010, the President's proposed budget was released, which included no funding for the project.

President Obama's response to critics is that the lifetime for the International Space Station

International Space Station

would be extended by an additional five years and an additional billion would be paid to private companies for shuttling astronauts to and from it after the Space Shuttle program ends while NASA develops new technology for future space exploration missions. According to Obama, his vision embodies a "bold new approach to human space flight that embraces commercial industry, forges international partnerships, and invests in the building blocks of a more capable approach to space exploration."

President Obama hosted a Space Conference on April 15, 2010, in Florida. This came at a time when the Obama administration was taking a considerable amount of criticism for leaving the Constellation Program out of the 2011 budget. At the conference Obama and top officials as well as leaders in space discussed the future of U.S. efforts in human space flight and unveiled a plan for NASA that follows the Augustine Panel's "Flexible Path to Mars" option, modifying Obama's prior proposal in two important respects:

He proposed continuing development of the Orion capsule, but initially using it as an escape capsule for the ISS so that the ISS crew could be increased to seven, with the technology subsequently forming the basis for future deep space exploration vehicles (cancellation of Orion would have cost a comparable amount to keeping it).
He set the year 2015 as the year to choose the architecture for a heavy-lift vehicle and to commence construction.

Neil Armstrong support for Constellation

Neil Armstrong

Neil Alden Armstrong is an American former astronaut, test pilot, aerospace engineer, university professor, United States Naval Aviator, and the first person to set foot upon the Moon....

, commander of Apollo 11

Apollo 11

In early 1969, Bill Anders accepted a job with the National Space Council effective in August 1969 and announced his retirement as an astronaut. At that point Ken Mattingly was moved from the support crew into parallel training with Anders as backup Command Module Pilot in case Apollo 11 was...

and the first man on the Moon, has expressed strong support for the Constellation program, unlike his former Apollo crewmate Buzz Aldrin

Buzz Aldrin

Buzz Aldrin is an American mechanical engineer, retired United States Air Force pilot and astronaut who was the Lunar Module pilot on Apollo 11, the first manned lunar landing in history...

, who has expressed strong support for the Obama administration's new plan.

Testifying before the United States Congress

United States Congress

The United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....

in 2010, Neil Armstrong opposed an administrative scrap of Constellation, stating "substantial turmoil" has arisen "by the President's proposal ... because a few planners with little or no space operation experience attempted an end run on the normal planning process." Armstrong argued that "a return to the Moon would be a most productive path to expanding the human presence in the Solar System

Solar System

The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...

."

Armstrong testified, "The lunar vicinity is an exceptional location to learn about traveling to difficult distant places.... The long communication delays to destinations beyond the Moon may mandate new techniques and procedures for spacecraft operations ... in the case of severe emergencies."

Armstrong clarified this point with an example: "For Mission Control on Earth to play an important and timely role in flight operations," with Moon travelers "communication delays with Earth are less than two seconds." By contrast, "Mission Control cannot provide a Mars

Mars

crew their normal helpful advice if ... the time delay of radar, communications and telemetry back to Earth is 19 minutes.... Flight experience at lunar distance can provide valuable insights into practical solutions for handling such challenges."

Armstrong stated that he finds the arguments of opponents to Constellation's return to the Moon "mystifying." "Afterall, they say, we have already been there." But, he continued, "there is much to be learned on Luna

Moon

– learning to survive in the lunar environment, investigating many science opportunities, determining the practicality of extracting Helium 3 from the lunar regolith

Lunar soil

Lunar soil is the fine fraction of the regolith found on the surface of the Moon. Its properties can differ significantly from those of terrestrial soil...

, prospecting for Palladium group

Platinum group

The platinum group metals is a term used sometimes to collectively refer to six metallic elements clustered together in the periodic table.These elements are all transition metals, lying in the d-block .The six...

metals, meeting challenges not yet identified." To date the Moon "leaves more than 14 million square miles yet to be explored" (or about 36 million square kilometres).

In response to a request for what he believes U.S. spaceflight priorities ought to be, Armstrong responded:

Maintain U.S. leadership in space
Guarantee U.S. access to space
Continue to explore the solar system

Armstrong cited Constellation as among those federal programs that "motivate the citizenry ... inspiring them."

Justification

The National Space Society

National Space Society

The National Space Society is an international nonprofit 501, educational, and scientific organization specializing in space advocacy...

(NSS) regards a return to the Moon as a high space program priority, to begin development of the knowledge and identification of the industries unique to the Moon. "Such industries can provide economic leverage and support for NASA activities, saving the government millions."p. 13. The NSS believes that the Moon may be a repository of the history and possible future of our planet, and that the six Apollo

Project Apollo

The Apollo program was the spaceflight effort carried out by the United States' National Aeronautics and Space Administration , that landed the first humans on Earth's Moon. Conceived during the Presidency of Dwight D. Eisenhower, Apollo began in earnest after President John F...

landings only scratched the surface.

According to NASA, the answer to the question, "Why should we return to the Moon?," would be to:

extend human colonization
Colonization of the Moon
The colonization of the Moon is the proposed establishment of permanent human communities on the Moon. Advocates of space exploration have seen settlement of the Moon as a logical step in the expansion of humanity beyond the Earth. Recent indication that water might be present in noteworthy...

,
further pursue scientific activities intrinsic to the Moon,
test new technologies, systems, flight operations and techniques to serve future space exploration
Space exploration
Space exploration is the use of space technology to explore outer space. Physical exploration of space is conducted both by human spaceflights and by robotic spacecraft....

missions,
provide a challenging, shared and peaceful activity to unite nations in pursuit of common objectives,
expand the economic sphere while conducting research activities that benefit our home planet,
engage the public and students to help develop the high-technology workforce that will be required to address the challenges of tomorrow.

In the words of former NASA Administrator, Michael D. Griffin

Michael D. Griffin

Michael Douglas Griffin is an American physicist and aerospace engineer. From April 13, 2005 to January 20, 2009 he served as Administrator of NASA, the space agency of the United States...

, "The goal isn't just scientific exploration.... It's also about extending the range of human habitat out from Earth into the solar system

Solar System

as we go forward in time.... In the long run a single-planet species will not survive.... If we humans want to survive for hundreds of thousands or millions of years, we must ultimately populate other planets ... colonize the solar system and one day go beyond."

Congressional critics

Senator Richard Shelby

Richard Shelby

Richard Craig Shelby is the senior U.S. Senator from Alabama. First elected to the Senate in 1986, he is the ranking member of the United States Senate Committee on Banking, Housing, and Urban Affairs and was its chairman from 2003 to 2007....

has stated "It is unfortunate that this administration is choosing to abandon our nation's only chance at remaining the leader in human space flight. It is ironic that Constellation, a program born out of the recommendations of the Columbia Accident Investigation Board

Columbia Accident Investigation Board

The Columbia Accident Investigation Board was convened by NASA to investigate the destruction of the Space Shuttle Columbia during STS-107 upon atmospheric re-entry on February 1, 2003. In addition to determining the cause of the accident, the panel also recommended changes that should be made...

, would be eliminated in lieu of rockets repeatedly deemed unsafe for astronauts by NASA's own Aerospace Safety Advisory Panel." Shelby argues further, "If this budget is enacted, NASA will no longer be an agency of innovation and hard science; it will be the agency of pipe dreams and fairy tales."

"As I see it, the commission didn't find anything wrong with the current program, didn't find anything safer, more reliable, cheaper or faster," former NASA Administrator Michael D. Griffin

Michael D. Griffin

Michael Douglas Griffin is an American physicist and aerospace engineer. From April 13, 2005 to January 20, 2009 he served as Administrator of NASA, the space agency of the United States...

has testified to Congress. "The roots are healthy. So why throw away four years and $8 billion pulling the flowers? Let's apply some plant nutrient and watch them grow.... Exactly why does the policy which we established in law – twice – need to be changed?" According to Griffin, NASA spending has declined approximately 20% since 1993.

Further hearings regarding the program's proposed cancellation continue within the United States Congress

United States Congress

. Particularly, the United States House Science Subcommittee on Space and Aeronautics

United States House Science Subcommittee on Space and Aeronautics

The Science Subcommittee on Space and Aeronautics is one of five subcommittees of the United States House Committee on Science and Technology.- Jurisdiction :...

and the United States Senate Commerce Subcommittee on Science and Space must now review and offer individual recommendations...

Hearings held to date regarding the Constellation's proposed cancellation within the House Subcommittee

United States House Science Subcommittee on Space and Aeronautics

The Science Subcommittee on Space and Aeronautics is one of five subcommittees of the United States House Committee on Science and Technology.- Jurisdiction :...

include NASA Aerospace Safety Advisory Panel Chairperson and retired US Navy Vice Admiral Joseph W. Dyer concluding that the proposed cancellation, without alternative "demonstrated capability or proven superiority is unwise and probably not cost-effective." Regarding any risk associated with Ares I

Ares I

Ares I was the crew launch vehicle that was being developed by NASA as part of the Constellation Program. The name "Ares" refers to the Greek deity Ares, who is identified with the Roman god Mars...

, Admiral Dyer notes, "If the goal is to minimize the gap between the Shuttle and the follow-on, the Ares I offers the safest, quickest opportunity and probably the most cost-effective one. If the nation is willing to accept a wider gap, more risk, and a higher cost, then other opportunities avail themselves." Ranking member of the United States House Committee on Science and Technology, Representative Ralph Hall

Ralph Hall

Ralph Moody Hall is a United States Representative from . First elected in 1980, Hall is the chairman of the Science Committee and a senior member of the Energy and Commerce Committee...

continues, it is "naïve to assume that a do-over will somehow deliver a safer, cheaper system faster than the current path we’re on."

Alternatives

Proposed manned Commercial Crew Development

Commercial Crew Development

Commercial Crew Development is a multiphase space technology development program, funded by the U.S. government, and administered by NASA. The program is intended to stimulate development of privately operated crew vehicles to low Earth orbit. It is run by the Commercial Crew and Cargo Program...

Vehicle alternatives to Ares I for servicing the Space Station are the Boeing/Bigelow Aerospace unofficially-named "Orion-Lite" capsule launched on a future-man-rated Delta IV Heavy, the manned version of the SpaceX Dragon spacecraft, and Sierra Nevada Dreamchaser. None of these spacecraft are designed to leave low earth orbit as required for lunar missions and the majority of the Constellation program, they are purely alternative methods for space station access.

Delta IV Heavy

The Delta IV is a rocket family, designed to launch payloads into orbit for the US Air Force Evolved Expendable Launch Vehicle (EELV) program as well as for commercial satellite launches. The most powerful variant of the family, Delta IV Heavy, is capable of delivering 25 tonnes of payload to LEO, matching the capability of the Ares I.

The Aerospace Corporation was asked by NASA three times, in 2005, 2008 and 2009, to assess technical feasibility and cost of human-rating

Human-rating certification

Human-rated or man-rated are terms used to describe the certification of a spacecraft, launch vehicleor airplaneas worthy of transporting humans. NASA and the U.S. GAO now uses "Human-rating" when describing requirements for these systems...

an EELV. Two latter assessments addressed the possibility of replacing the Ares I with Delta IV Heavy. The reports indicate that the Delta IV Heavy meets ISS and lunar target performance requirements. Unlike other modifications of Delta IV, the Heavy variant does not use solid rocket boosters.

The first launch of a Delta IV rocket occurred in 2002. The first launch of the Heavy variant was performed in 2004.

Falcon 9/Dragon

The Falcon 9

Falcon 9

Falcon 9 is a rocket-powered spaceflight launch system designed and manufactured by SpaceX. Both stages of its two-stage-to-orbit vehicle use liquid oxygen and rocket-grade kerosene propellants...

launch vehicle along with the manned version of the Dragon capsule, developed by SpaceX

SpaceX

Space Exploration Technologies Corporation, or more popularly and informally known as SpaceX, is an American space transport company that operates out of Hawthorne, California...

, have been contemplated as a possible commercial alternative. NASA has already awarded SpaceX a contract to deliver unmanned cargo to the ISS

ISS

The ISS is the International Space Station.ISS may also refer to:* I See Stars, an American electronic rock band* ISS A/S, a Danish service company* Idea Star Singer, a Malayalam music reality show by Asianet TV...

under the Commercial Orbital Transportation Services

Commercial Orbital Transportation Services

Commercial Orbital Transportation Services is a NASA program to coordinate the delivery of crew and cargo to the International Space Station by private companies. The program was announced on January 18, 2006...

(COTS) program.

CST-100

CST-100 is a planned manned vehicle, developed by Boeing and Bigelow Aerospace, that would deliver astronauts to ISS as well as Bigelow Space Station. It could be launched on an Atlas V, Delta IV, or Falcon 9 rocket.

Dreamchaser

The Dream Chaser is a planned manned suborbital and orbital spacecraft being developed by SpaceDev, a wholly owned subsidiary of Sierra Nevada Corporation. It is a spaceplane based on previous NASA & Soviet spaceplane work.

Missions

Like that of the Apollo Program, Constellation program will involve its main vehicle, the Orion spacecraft, flying missions in low earth orbit

Low Earth orbit

A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...

(LEO) with an emphasis of servicing the International Space Station, and in conjunction with the Altair and Earth Departure Stage

Earth Departure Stage

The Ares V Earth Departure Stage was a rocket stage which NASA planned to design at its Marshall Space Flight Center in Huntsville, Alabama as part of Project Constellation...

, on flights to the polar regions of the Moon. , there are no well-defined plans for a manned flight to Mars

Mars

, as flights to the Red Planet will most likely not occur before 2030, but a mission to a Near-Earth asteroid is in the initial planning phase.

International Space Station and low-Earth orbit flights

After being brought together at the Kennedy Space Center

Kennedy Space Center

The John F. Kennedy Space Center is the NASA installation that has been the launch site for every United States human space flight since 1968. Although such flights are currently on hiatus, KSC continues to manage and operate unmanned rocket launch facilities for America's civilian space program...

from various parts of the country (Utah and Louisiana for the Ares I booster, and various Lockheed Martin

Lockheed Martin

facilities in the southern U.S. for the Orion) and completion of major testing, including spacecraft integrity testing in a vacuum chamber, the components of the Orion/Ares I stack would be assembled in the Vehicle Assembly Building

Vehicle Assembly Building

The Vehicle Assembly Building, or VAB, at NASA's Kennedy Space Center was used to assemble and house American manned launch vehicles from 1968-2011. It is the fourth largest building in the world by volume...

in a manner similar to the stacking and assembly of both the Shuttle and the Saturn IB

Saturn IB

The Saturn IB was an American launch vehicle commissioned by the National Aeronautics and Space Administration for use in the Apollo program...

and Saturn V rockets.

Once assembly is completed and a launch date set, the Crawler-Transporter

Crawler-Transporter

The crawler-transporters are a pair of tracked vehicles used to transport spacecraft from NASA's Vehicle Assembly Building along the Crawlerway to Launch Complex 39. They were originally used to transport the Saturn IB and Saturn V rockets during the Apollo, Skylab and Apollo–Soyuz programs....

will pick up and transport the completed Orion-Ares I stack, along with the launch support tower and the Mobile Launcher Platform

Mobile Launcher Platform

The Mobile Launcher Platform or MLP is one of three two-story structures used by NASA to support the Space Shuttle stack during its transportation from the Vehicle Assembly Building to Launch Pad 39-A at the Kennedy Space Center as well as serve as the vehicle's launch platform...

, out to Launch Pad 39B, which is currently undergoing conversion from use in Shuttle missions to be used for Ares I operations. Once the Crawler-Transporter reaches the pad, the Ares I and its platform is left in place and the Crawler-Transporter is taken to a safe, yet reasonable distance in order to facilitate pickup of the platform for an equipment rollback to the VAB.

After final checks, the ground crew will fill up the second stage with liquid hydrogen (LH₂) and liquid oxygen (LOX), with the crew, suited up in new all-purpose spacesuits

Constellation Space Suit

The Constellation Space Suit was a planned full pressure suit system that would have served as an intra-vehicular activity and Extra-vehicular activity garment for the proposed Project Constellation flights, which were planned to begin after the Space Shuttle retired...

, entering the spacecraft only three hours before liftoff. Once locked in, and after all systems are cleared by controllers at both the Cape and Mission Control in Houston, the Ares I is then launched, clearing the launch tower and (after a roll program and pitch over), heads out on the proper trajectory.

At T+120 seconds into the flight the solid-fueled first stage is jettisoned for recovery, and the onboard J-2X engine is ignited. 30 seconds later both the launch abort system and the fairings covering the Orion crew and service modules would also be jettisoned. At T+330 seconds after liftoff, the J-2X engine cuts off, and the Orion spacecraft would enter an initial entry orbit, which, 45 minutes later, is circularized by a second burn of the onboard J-2X engine, after which the Orion spacecraft separates (allowing the second stage to burn up in the atmosphere) and extends a pair of paddle-shaped solar panels.

After a two-day chase, the Orion spacecraft would meet with the International Space Station

International Space Station

. After getting the go ahead from Houston, Orion would dock with the ISS. The six-man crew, the largest number that can fly on an Orion spacecraft, would then enter the station in order to perform numerous tasks and activities for the duration of their flight, usually lasting six months, but can be shortened to four or lengthened to eight, depending upon NASA's goals for that particular ISS Expedition. Once completed, the crew then reenters the Orion, which has been kept attached to the station as an emergency "lifeboat," seal off the hatches between it and the ISS, and then undock from the station.

Once the Orion reaches a safe distance from the ISS, the spacecraft will turn around so the main engine faces forward and fire its onboard Aerojet

Aerojet

Aerojet is an American rocket and missile propulsion manufacturer based primarily in Rancho Cordova, California with divisions in Redmond, Washington, Orange, Gainesville and Camden, Arkansas. Aerojet is owned by GenCorp. They are the only US propulsion company that provides both solid rocket...

AJ-10

The AJ-10 or AJ10 is a hypergolic rocket engine. It has been used to propel the upper stages of several carrier rockets, including the Delta II and Titan III. It will also be used as the main engine of the Orion Crew Exploration Vehicle for NASA's Project Constellation.It was first used in the Able...

engine. After the de-orbit burn has been completed, the service module is then jettisoned, allowing it to burn up in the atmosphere while the crew module re-enters in the same manner as all NASA spacecraft prior to the Shuttle, using the ablative heat shield to both deflect heat from the spacecraft and to slow it down from a speed of 28,000 km/h (17,500 mph or Mach 5) to 480 km/h (300 mph or Mach 0.5). After reentry is completed, the forward assembly is jettisoned, and two drogue parachutes will be released, followed at 20000 feet (6,096 m) by three main parachutes and airbags filled with nitrogen (N₂), which does not combust when exposed to heat, allowing the spacecraft to splashdown. The Orion CM is then returned to Kennedy Space Center for refurbishment for a later flight. Unlike the Apollo CM, which was used only for one flight, an Orion CM can be used up to ten times under normal operating conditions.

Lunar sortie/outpost flights

Unlike the Apollo flights, where both the Apollo Command/Service Module

Apollo Command/Service Module

and the Apollo Lunar Module

Apollo Lunar Module

The Apollo Lunar Module was the lander portion of the Apollo spacecraft built for the US Apollo program by Grumman to carry a crew of two from lunar orbit to the surface and back...

were launched together on the Saturn V rocket, the manned Orion craft would be launched separately from the unmanned EDS and lunar lander. The Ares V/EDS/Altair stack would be assembled at the Vehicle Assembly Building

Vehicle Assembly Building

and then transported to Pad A of Kennedy Space Center Launch Complex 39. Approximately a day later, the Ares I/Orion stack would be transported to the adjacent Pad 39B. The Ares V/EDS/Altair vehicle would be launched first, into a 360 kilometres (223.7 mi) high circular orbit. Approximately 90 minutes later, the Ares I/Orion would launch with the crew into a nearly identical orbit.

The Orion would then rendezvous

Space rendezvous

A space rendezvous is an orbital maneuver during which two spacecraft, one of which is often a space station, arrive at the same orbit and approach to a very close distance . Rendezvous requires a precise match of the orbital velocities of the two spacecraft, allowing them to remain at a constant...

and dock with the Altair/EDS combination already in low-Earth orbit. After the necessary preparations for lunar flight, the EDS would fire for 390 seconds to make the translunar injection (TLI) maneuver, accelerating the spacecraft to 40200 kilometres per hour (24,979.1 mph). Unlike Apollo, the Constellation TLI burn would be done in an "eyeballs-out" fashion (with the astronauts facing the EDS and thus being pulled from their seats by the acceleration). After the TLI burn, the EDS would be jettisoned and sent either into an orbit around the Sun or to crash into the lunar surface.

During the three-day trans-lunar coast, the four-man crew monitor the Orion's systems, inspect their Altair spacecraft and its support equipment, and correct their flight path as necessary to allow the Altair to land at a near-polar landing site suitable for a future lunar base. Approaching the lunar far side, the Orion/Altair combination orients the Altair's engines forward and make the lunar orbit insertion (LOI) burn.

Once in lunar orbit, the crew refines the trajectory and configures the Orion CSM for unmanned flight, allowing all four crew members to transfer to the Altair and land on the Moon, while the Orion waits for its return. Upon receiving clearance from Mission Control, the Altair undocks from the Orion and performs an inspection maneuver, allowing ground controllers to inspect the spacecraft via live TV mounted on Orion for any visible problems that would prevent landing (on Apollo this was done by the Command Module Pilot). After receiving approval from ground controllers, the two craft separate to a safe distance and the Altair's descent engines fire again for powered descent to a pre-determined landing spot previously scouted out by unmanned spacecraft.

Upon landing, the crew dons their extravehicular activity (EVA) spacesuits and commence the first of five to seven lunar EVAs, collecting samples and deploying experiments. After completing their Lunar Sortie operations, the crew enters the Altair and fires the ascent stage engine to lift off from the surface, using the descent stage as a launchpad (and as a platform for future base construction). Upon entering orbit, the Altair rendezvous and docks with the waiting Orion spacecraft, and the crew then transfers, along with samples collected on the moon, back to the Orion. After jettisoning the Altair and sending it to crash into the lunar far side, the crew performs the Trans Earth Injection

Trans Earth Injection

Trans-Earth injection is a term describing the propulsion maneuver used to set a spacecraft on a trajectory which will intersect the Earth....

(TEI) burn for the return trip to Earth.

After a two-and-a-half day coast, the crew jettisons the Service Module (allowing it to burn up in the atmosphere) and the CM reenters the Earth's atmosphere using a special reentry trajectory designed to slow the vehicle from its speed of 40200 kilometres per hour (24,979.1 mph) to 480 kilometres per hour (298.3 mph) and allow a Pacific Ocean splashdown. The Crew Module is then flown back to KSC for refurbishment, while lunar samples are routed to the Johnson Space Center's (JSC) Lunar Receiving Laboratory

Lunar Receiving Laboratory

The Lunar Receiving Laboratory was a facility at NASA's Lyndon B. Johnson Space Center that was constructed to quarantine astronauts and material brought back from the Moon during the Apollo program to mitigate the risk of back-contamination...

for analysis.

Orion asteroid mission

The Orion Asteroid Mission is a proposed NASA mission to a near-Earth asteroid

Near-Earth object

A near-Earth object is a Solar System object whose orbit brings it into close proximity with the Earth. All NEOs have a perihelion distance less than 1.3 AU. They include a few thousand near-Earth asteroids , near-Earth comets, a number of solar-orbiting spacecraft, and meteoroids large enough to...

(NEA) which would use the standard Orion spacecraft, and a landing module based on Altair. Such a mission could assess the potential value of water, iron, nickel, platinum and other resources on the asteroid; test possible ways to extract them; and possibly examine or develop techniques which could be used to protect the Earth from asteroid impacts. This would be the first manned mission beyond both the Earth and the Moon, and would represent a step toward a manned mission to Mars

Manned mission to Mars

A manned mission to Mars has been the subject of science fiction, engineering, and scientific proposals throughout the 20th century and into the 21st century...

, envisioned for after 2030.

The mission would start in a similar fashion to a Constellation lunar landing mission, with an Ares V launching the landing module into Low Earth orbit

Low Earth orbit

A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...

, followed by the launch of an Orion spacecraft, with a two or three person crew (as opposed to a four person crew for lunar missions) on an Ares I rocket. Once the Orion spacecraft docks with the landing module and the Earth Departure Stage

Earth Departure Stage

The Ares V Earth Departure Stage was a rocket stage which NASA planned to design at its Marshall Space Flight Center in Huntsville, Alabama as part of Project Constellation...

(EDS), the EDS would then fire again and propel the Orion spacecraft to a nearby near-Earth asteroid where the crew would then land and explore its surface.

Once their task is completed, the Orion spacecraft will then depart from the asteroid and, upon reaching the vicinity of Earth, would jettison both the service module

Service module

A service module is a spacecraft compartment containing a variety of support systems used for spacecraft operations. Usually located in the uninhabited area of the spacecraft, the service module is jettisoned upon the completion of the mission, and usually burns up during atmospheric reentry...

and the landing module in a manner similar to that of Apollo 13 (i.e. separating the service module before the landing module) before entering the atmosphere for a Pacific Ocean splashdown.

Orion Mars mission

The Orion Mars mission plan for NASA's Constellation program is a manned mission with the intent to land humans on Mars

Mars

in the 2030s. Originally the ultimate goal of NASA's Apollo Applications Program

Apollo Applications program

The Apollo Applications Program was established by NASA headquarters in 1968 to develop science-based manned space missions using surplus material from the Apollo program...

(AAP) in the 1960s, the Orion Mars Mission would utilize the hardware, primarily the Orion spacecraft (or a variation based on the Orion), and the Ares V cargo-launch vehicle, along with methods of carrying out the mission, which would be developed on board the International Space Station and the planned Lunar Outpost

Lunar outpost (NASA)

A lunar outpost was an element of the George W. Bush era Vision for Space Exploration, which has been replaced with President Barack Obama's space policy. The outpost would have been an inhabited facility on the surface of the Moon. At the time it was proposed, NASA was to construct the outpost...

which is to be set up on the surface of the Moon

Moon

after 2020.

Although no specific mission has yet been defined, it will most likely follow the Mars Direct

Mars Direct

Mars Direct is a proposal for a manned mission to Mars. Proponents of the scheme have claimed it to be both cost-effective and that it can be conducted with current technology. It was originally detailed in a research paper by NASA engineers Robert Zubrin and David Baker in 1990, and later expanded...

concept developed by Robert Zubrin

Robert Zubrin

Robert Zubrin is an American aerospace engineer and author, best known for his advocacy of the manned exploration of Mars. He was the driving force behind Mars Direct—a proposal intended to produce significant reductions in the cost and complexity of such a mission...

. Zubrin's concept utilizes an "Earth Return Vehicle", which would be sent out to Mars on a low-consumption trajectory which would arrive at Mars during the planet's conjunction period, when the planet is behind the Sun as seen from Earth. Once the Earth Return Vehicle lands it is planned to use an onboard Sabatier reactor in order to create liquid oxygen and methane fuel for the return trip; a second spacecraft, carrying the crew, would follow after. Arriving at Mars, the crew will land near the Earth Return Vehicle and will explore the planet for a period of nearly one Earth year. At the same time the astronaut crew explores the planet, another Earth Return Vehicle is sent to Mars, allowing NASA an "insurance policy" in the event the first Earth Return Vehicle is unable to perform its task.

Once the crew finishes its surface exploration of the planet, they will then enter the first Earth Return Vehicle and then lift off from the planet's surface. After docking with an orbiting return rocket, the crew then fires the rocket and returns to Earth, making a high-speed reentry

Atmospheric reentry

Atmospheric entry is the movement of human-made or natural objects as they enter the atmosphere of a celestial body from outer space—in the case of Earth from an altitude above the Kármán Line,...

in order to land approximately four months after leaving Mars.

Originally envisioned, along with the Apollo Lunar Base, the Voyager Mars Program, and the Manned Venus Flyby

Manned Venus Flyby

A manned Venus flyby was considered by NASA in the mid 1960s as part of the Apollo Applications Program, using hardware derived from the Apollo program...

, the AAP "Man-on-Mars" program was canceled, along with the rest of the AAP program, and replaced by the Skylab

Skylab

Skylab was a space station launched and operated by NASA, the space agency of the United States. Skylab orbited the Earth from 1973 to 1979, and included a workshop, a solar observatory, and other systems. It was launched unmanned by a modified Saturn V rocket, with a mass of...

"dry workshop" space station and the Space Shuttle. The Orion Mars Mission, if eventually launched, would occur in the 2030s. Had the AAP Mars mission not been canceled, the first manned landing on Mars was scheduled to have occurred around 1985.

External links

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

Spacecraft

Orion

Altair

Earth Departure Stage

Legacies of Apollo and Space Shuttle

Ares boosters

Ares I

Ares V

History

President Bush

President Obama

Neil Armstrong support for Constellation

Justification

Congressional critics

Alternatives

Delta IV Heavy

Falcon 9/Dragon

CST-100

Dreamchaser

Missions

International Space Station and low-Earth orbit flights

Lunar sortie/outpost flights

Orion asteroid mission

Orion Mars mission

See also

External links