Editing Space Shuttle program (section)

==Successors==
During the three decades of operation, various follow-on and replacements for the STS Space Shuttle were partially developed but not finished.<ref name="ReferenceA">{{cite web|url=http://www.space.com/11363-nasa-space-shuttle-replacement-30-years-anniversaries.html|title=Politics played a big role in why NASA doesn't already have a new spacecraft to replace the retiring space shuttles. Funding and technical challenges put a stop to any attempts to build the ' Space Shuttle 2.'|website=[[Space.com]]|date=April 12, 2011}}</ref>

Examples of possible future space vehicles to supplement or supplant STS:<ref name="ReferenceA"/>
*Advanced Crewed Earth-to-Orbit Vehicle
*[[Shuttle II]], Johnson Space Center concept for a follow-on, with 2 boosters and 2 tanks mounted on its wings.<ref>{{Cite web|url=http://www.astronautix.com/s/shuttleii.html|archive-url=https://web.archive.org/web/20161228021051/http://astronautix.com/s/shuttleii.html|url-status=dead|archive-date=December 28, 2016|title = Shuttle II}}</ref>
*National Aero-Space Plane (NASP)
**[[Rockwell X-30]] (not funded)
*[[VentureStar]], SSTO spacelane concept using an aerospike engine.
**[[Lockheed Martin X-33]] (cancelled 2001)
*[[Ares I]] (ended with Constellation cancellation)
*[[Orbital Space Plane Program]]

One effort in the direction of space transportation was the Reusable Launch Vehicle (RLV) program, initiated in 1994 by NASA.<ref name="spinoff.nasa.gov">{{cite web|url=https://spinoff.nasa.gov/spinoff1996/14.html|archive-url=https://web.archive.org/web/20130224062451/http://spinoff.nasa.gov/spinoff1996/14.html|url-status=dead|archive-date=February 24, 2013|title=Reusable Launch Vehicle}}</ref> This led to work on the X-33 and X-34 vehicles.<ref name="spinoff.nasa.gov"/> NASA spent about US$1&nbsp;billion on developing the X-33 hoping for it be in operation by 2005.<ref name="spinoff.nasa.gov"/> Another program around the turn of the millennium was the [[Space Launch Initiative]], which was a next generation launch initiative.<ref name="nasa.gov">{{cite web|url=https://www.nasa.gov/centers/marshall/pdf/172379main_ngltfacts.pdf|title=NASA's Space Launch Initiative: The Next Generation Launch Technology Program|date=May 2003|access-date=November 20, 2022|publisher=NASA}}</ref>

The Space Launch Initiative program was started in 2001, and in late 2002 it was evolved into two programs, the [[Orbital Space Plane Program]] and the [[Next Generation Launch Technology]] program.<ref name="nasa.gov"/> OSP was oriented towards provided access to the International Space Station.<ref name="nasa.gov"/>

Other vehicles that would have taken over some of the Shuttles responsibilities were the [[HL-20 Personnel Launch System]] or the [[NASA X-38]] of the [[Crew Return Vehicle]] program, which were primarily for getting people down from ISS. The X-38 was cancelled in 2002,<ref>{{cite web|url=http://www.chron.com/news/nation-world/article/X-38-project-s-cancellation-irks-NASA-partners-2064969.php|title=X-38 project's cancellation irks NASA, partners|date=June 9, 2002}}</ref> and the HL-20 was cancelled in 1993.<ref>{{cite web|url=http://www.aerospaceguide.net/hl_20.html|title=HL-20 – Lifting Body Spaceplane for Personnel Launch System|last=x0av6|date=August 4, 2016}}</ref> Several other programs in this existed such as the Station Crew Return Alternative Module (SCRAM) and Assured Crew Return Vehicle (ACRV)<ref>{{cite web|url=http://www.astronautix.com/n/nasaacrv.html|archive-url=https://web.archive.org/web/20161224031240/http://www.astronautix.com/n/nasaacrv.html|url-status=dead|archive-date=December 24, 2016|title=NASA ACRV}}</ref>

According to the 2004 Vision for Space Exploration, the next human NASA program was to be [[Constellation program]] with its [[Ares I]] and [[Ares V]] launch vehicles and the [[Orion spacecraft]]; however, the Constellation program was never fully funded, and in early 2010 the Obama administration asked Congress to instead endorse a plan with heavy reliance on the private sector for delivering cargo and crew to LEO.

The [[Commercial Orbital Transportation Services]] (COTS) program began in 2006 with the purpose of creating commercially operated uncrewed cargo vehicles to service the ISS.<ref>{{cite press release |publisher=NASA |date=August 18, 2006 |title=NASA Selects Crew and Cargo Transportation to Orbit Partners |url=http://www.nasa.gov/home/hqnews/2006/aug/HQ_06295_COTS_phase_1.html |access-date=November 21, 2006}}</ref> The first of these vehicles, [[SpaceX Dragon 1]], became operational in 2012, and the second, [[Orbital Sciences]]'s [[Cygnus (spacecraft)|Cygnus]] did so in 2014.<ref>{{cite web|url=http://www.nasaspaceflight.com/2011/10/iss-partners-welcome-spacex-orbital-busy-2012/|title=ISS partners prepare to welcome SpaceX and Orbital in a busy 2012|last=Bergin|first=Chris|date=October 6, 2011|publisher=NASASpaceFlight.com (Not affiliated with NASA)|access-date=December 13, 2011}}</ref>

The [[Commercial Crew Development]] (CCDev) program was initiated in 2010 with the purpose of creating commercially operated crewed spacecraft capable of delivering at least four crew members to the ISS, staying docked for 180 days and then returning them back to Earth.<ref>{{cite web|url=http://www.spacenews.com/venture_space/100201-biggest-ccdev-award-goes-sierra-nevada.html|archive-url=https://archive.today/20120909235028/http://www.spacenews.com/venture_space/100201-biggest-ccdev-award-goes-sierra-nevada.html|url-status=dead|archive-date=September 9, 2012|title=Biggest CCDev Award Goes to Sierra Nevada|last=Berger|first=Brian|date=February 1, 2011|publisher=Imaginova Corp.|access-date=December 13, 2011}}</ref> These spacecraft, like [[SpaceX]]'s [[Dragon 2]] and [[Boeing CST-100 Starliner]] were expected to become operational around 2020.<ref>{{cite web|url=https://www.nasa.gov/feature/nasa-commercial-crew-program-mission-in-sight-for-2018|title=NASA Commercial Crew Program Mission in Sight for 2018|date=January 4, 2018|publisher=NASA|access-date=April 14, 2018}}</ref> On the [[Crew Dragon Demo-2]] mission, SpaceX's Dragon 2 sent astronauts to the ISS, restoring America's human launch capability. The [[SpaceX Crew-1|first operational SpaceX mission]] launched on November 15, 2020, at 7:27:17&nbsp;p.m. ET, carrying four astronauts to the ISS.

Although the Constellation program was canceled, it has been replaced with a very similar [[Artemis program]]. The [[Orion spacecraft]] has been left virtually unchanged from its previous design. The planned [[Ares V]] rocket has been replaced with the smaller [[Space Launch System]] (SLS), which is planned to launch both Orion and other necessary hardware.<ref>{{cite web|url=http://www.nasa.gov/exploration/systems/sls/sls1.html|title=NASA Announces Design for New Deep Space Exploration System|date=September 14, 2011|publisher=NASA|access-date=April 28, 2012}}</ref> [[Exploration Flight Test-1]] (EFT-1), an uncrewed test flight of the Orion spacecraft, launched on December 5, 2014, on a [[Delta IV Heavy]] rocket.<ref name=schedule>{{cite web|url=http://www.nasaspaceflight.com/2012/02/acronyms-ascent-sls-managers-create-developmental-milestone-roadmap/|title=Acronyms to Ascent – SLS managers create development milestone roadmap|last=Bergin|first=Chris|date=February 23, 2012|publisher=NASA|access-date=April 29, 2012}}</ref>

[[Artemis 1]] is the first flight of the SLS and was launched as a test of the completed Orion and SLS system.<ref>{{cite news|title=SLS launches Artemis 1 mission|first=Jeff |last=Foust|date=November 16, 2022|url=https://spacenews.com/sls-launches-artemis-1-mission/|access-date=November 27, 2022|publisher=[[Space News]]}}</ref> During the mission, an uncrewed Orion capsule spent 10 days in a {{Convert|57000|km|nmi|sp=us|adj=on|abbr=off}} [[distant retrograde orbit]] around the Moon before returning to Earth.<ref name="a1-1">{{cite web|title=Artemis I – Flight Day 10: Orion Enters Distant Retrograde Orbit |first=Sandra |last=Jones|date=November 25, 2022|url=https://blogs.nasa.gov/artemis/2022/11/25/flight-day-10-orion-enters-distant-retrograde-orbit/|publisher=NASA|access-date=November 27, 2022}}</ref> [[Artemis 2]], the first crewed mission of the program, will launch four astronauts in 2024<ref>{{cite web |url=https://www.oversight.gov/sites/default/files/oig-reports/IG-20-018.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.oversight.gov/sites/default/files/oig-reports/IG-20-018.pdf |archive-date=October 9, 2022 |url-status=live |title=Report No. IG-20-018: NASA's Management of the Orion Multi-Purpose Crew Vehicle Program |work=[[OIG]] |publisher=[[NASA]] |date=July 16, 2020 |access-date=December 28, 2020}}</ref> on a [[free-return trajectory|free-return]] flyby of the Moon at a distance of {{Convert|8520|km|nmi|sp=us|abbr=off}}.<ref>{{Cite web|url=http://www.nasa.gov/feature/nasa-s-first-flight-with-crew-important-step-on-long-term-return-to-the-moon-missions-to|title=First Flight With Crew Important Step on Long-Term Return to Moon|last=Hambleton|first=Kathryn|date=August 27, 2018|website=NASA|access-date=November 27, 2022}}</ref><ref>{{Cite web|url=https://www.nasa.gov/feature/nasa-s-first-flight-with-crew-important-step-on-long-term-return-to-the-moon-missions-to|title=NASA's First Flight With Crew Important Step on Long-term Return to the Moon, Missions to Mars|last=Hambleton|first=Kathryn|date=May 23, 2019|website=NASA|access-date=July 10, 2019}}</ref> After Artemis 2, the Power and Propulsion Element of the [[Lunar Gateway]] and three components of an expendable lunar lander are planned to be delivered on multiple launches from commercial [[launch service provider]]s.<ref name="a3-1">{{cite news|url=https://www.space.com/nasa-moon-missions-before-2024.html|title=NASA Has a Full Plate of Lunar Missions Before Astronauts Can Return to Moon|first=Hanneke |last=Weitering |date=May 23, 2019|publisher=Space.com|access-date=November 27, 2022|quote=And before NASA sends astronauts to the moon in 2024, the agency will first have to launch five aspects of the lunar Gateway, all of which will be commercial vehicles that launch separately and join each other in lunar orbit. First, a power and propulsion element will launch in 2022. Then, the crew module will launch (without a crew) in 2023. In 2024, during the months leading up to the crewed landing, NASA will launch the last critical components: a transfer vehicle that will ferry landers from the Gateway to a lower lunar orbit, a descent module that will bring the astronauts to the lunar surface, and an ascent module that will bring them back up to the transfer vehicle, which will then return them to the Gateway.}}</ref> [[Artemis 3]] is planned to launch in 2025 aboard a SLS Block 1 rocket and will use the minimalist Gateway and expendable lander to achieve the first crewed lunar landing of the program. The flight is planned to touch down on the [[lunar south pole]] region, with two astronauts staying there for about one week.<ref name="a3-1" /><ref>{{cite web|url=https://www.theverge.com/2019/5/17/18627839/nasa-administrator-jim-bridenstine-artemis-moon-program-budget-amendment|title=NASA administrator on new Moon plan: 'We're doing this in a way that's never been done before'|last=Grush|first=Loren|date=May 17, 2019|publisher=The Verge|access-date=November 27, 2022|quote=Now, for Artemis 3 that carries our crew to the Gateway, we need to have the crew have access to a lander. So, that means that at Gateway we're going to have the Power and Propulsion Element, which will be launched commercially, the Utilization Module, which will be launched commercially, and then we'll have a lander there.}}</ref><ref>{{cite web|url=https://www.theverge.com/2019/5/17/18627839/nasa-administrator-jim-bridenstine-artemis-moon-program-budget-amendment|title=NASA administrator on new Moon plan: 'We're doing this in a way that's never been done before'|last=Grush|first=Loren|date=May 17, 2019|publisher=The Verge|access-date=November 27, 2022|quote=The direction that we have right now is that the next man and the first woman will be Americans, and that we will land on the south pole of the Moon in 2024.}}</ref><ref name="a3-2">{{Cite web|last=Chang|first=Kenneth|title=For Artemis Mission to Moon, NASA Seeks to Add Billions to Budget| url=https://www.nytimes.com/2019/05/13/science/trump-nasa-moon-mars.html| website=[[The New York Times]]| access-date=May 25, 2019| archive-url=https://web.archive.org/web/20190525034839/https://www.nytimes.com/2019/05/13/science/trump-nasa-moon-mars.html |archive-date=May 25, 2019 |date=May 25, 2019| quote=Under the NASA plan, a mission to land on the moon would take place during the third launch of the Space Launch System. Astronauts, including the first woman to walk on the moon, Mr. Bridenstine said, would first stop at the orbiting lunar outpost. They would then take a lander to the surface near its south pole, where frozen water exists within the craters.| url-status=live|url-access=limited}}</ref><ref>{{cite news|url=https://spacenews.com/nasa-outlines-plans-for-lunar-lander-development-through-commercial-partnerships/|title=NASA outlines plans for lunar lander development through commercial partnerships|date=July 21, 2019}}</ref>

For many Artemis missions, the Space Launch System's two solid rocket boosters' engines and casings and four main engines and the Orion spacecraft's main engine will all be previously flown [[RS-25|Space Shuttle main engines]], [[Space Shuttle Solid Rocket Booster|solid rocket boosters]], and [[Orbital Maneuvering System]] engines. They are refurbished legacy engines from the Space Shuttle program, some of which even date back to the early 1980s. For example, Artemis I had components that flew on 83 of the 135 Space Shuttle missions. From Artemis I to Artemis IV recycled Shuttle main engines will be used before manufacturing new engines. From Artemis I to Artemis III recycled Shuttle solid rocket boosters' engines and steel casings will be used before manufacturing new ones. From Artemis I to Artemis VI the Orion main engine will use six previously flown Space Shuttle OMS engines.<ref>http://www.collectspace.com/news/news-082422a-artemis-i-space-shuttle-hardware.html . Retrieved 15 March 2025.</ref><ref>https://www.nasa.gov/missions/artemis/orion/fired-up-engines-and-motors-put-artemis-mission-in-motion/ . Retrieved 15 March 2025.</ref><ref>https://www.nasa.gov/reference/sls-space-launch-system-solid-rocket-booster/ . Retrieved 15 March 2025.</ref>

=== Gallery ===
<gallery>
File:Twin Linear Aerospike XRS-2200 Engine PLW edit.jpg|Linear aerospike engine for the cancelled X-33
File:COTS2Dragon.2..jpg|The Dragon spacecraft, one of the Space Shuttle's several successors, is seen here on its way to deliver cargo to the ISS
File:Orion Spacecraft ArtemisI DEC2019 PBS.jpg|NASA's Orion Spacecraft for the Artemis 1 mission seen in Plum Brook On December 1, 2019
File:SLS CS1 JAN1 2020-1.jpg|The Core Stage for the Space Launch System rocket for Artemis I
File:Spacelaunchsystem-enginesection-jan2020.jpg|The Space Launch System Core Stage rolling out of the Michoud Facility for shipping to Stennis
File:Boeing's Starliner crew ship approaches the space station (iss067e066735) (cropped).jpg|The Boeing CST-100 Starliner spacecraft in the process of docking to the International Space Station
Crew Dragon at the ISS for Demo Mission 1 (cropped).jpg|The SpaceX Crew Dragon in the process of docking to the International Space Station 
</gallery>