The Space Launch System (abbreviated as SLS) is an American super heavy-liftexpendable launch vehicle under development by NASA since 2011. It replaces the Ares I and Ares V launch vehicles, which were cancelled along with the rest of the Constellation program.[29][30][31] The SLS is intended to become the primary launch vehicle of NASA's deep space exploration plans throughout the 2020s and further, with planned crewed lunar flights from the Artemis program and a possible human mission to Mars.[32][33][34][35][36] The SLS is being developed in three major phases with increasing capabilities: Block 1, Block 1B, and Block 2.[16] As of 22 December 2019[update], SLS Block 1 launch vehicles are planned to launch the first three Artemis missions.[37] After this point Block 1B will take over until the introduction of Block 2.[38][36][39]
The SLS is planned to launch the Orion spacecraft as part of the Artemis program and use the ground operations and launch facilities at NASA's Kennedy Space Center in Florida. Artemis will use one SLS each year until at least 2030.[40] The rocket will use the Launch Complex 39B at the Kennedy Space Center. The first launch was originally scheduled for 2016,[41] but it has slipped at least eight times, adding more than five years to the original six-year schedule.[note 2] As of September 2021[update], the first launch is scheduled for no earlier than January 2022.[21][42]
The SLS is a Space Shuttle-derived launch vehicle, with the first stage of the rocket being powered by one central core stage and two outboard solid rocket boosters. All SLS Blocks share a common design for the core stage to avoid the need for redesigns to meet varying requirements.[43][44][45][46] The SLS is designed to be able to tolerate up to 23 tanking cycles, 13 are reserved for launch attempts on Artemis 1. The assembled rocket is to be able to remain at the launch pad for at least 180 days and can remain in a stacked configuration for at least 200 days.[47][48]
Stages
Core stage
The SLS core stage rolling out of the Michoud Facility for shipping to Stennis
The core stage is responsible for propelling the upper stage and payload out of the atmopshere and accelerating up to almost orbital velocity with the assistance of the solid rocket boosters. It contains the fuel and oxidizer tanks for the ascent phase, the forward and aft solid rocket booster attach points, avionics, and the Main Propulsion System (MPS). The MPS is responsible for supplying the four RS-25 engines[43] with fuel and oxidizer, gimbaling the engines via hydraulic actuators, and pressurizing the propellant tanks via autogenous pressurization. The core stage provides approximately 25% of the liftoff thrust.[49][50] The stage is 65 m (212 ft) long by 8.4 m (27.6 ft) in diameter and is structurally and visually similar to the Space Shuttle external tank,[30][51] containing the liquid hydrogenfuel and liquid oxygenoxidizer. The first four flights will each use and expend four of the remaining sixteen RS-25D engines that had previously flown on Space Shuttle missions.[52][53]Aerojet Rocketdyne modified these engines with modernized engine controllers, higher throttle limits, as well as insulation for the high temperatures the engine section will experience from the solid rocket boosters.[54] Later flights will switch to an expendable optimized RS-25 variant, lowering per engine costs by over 30%.[55][56]Boeing manufactures the core stage at NASA's Michoud Assembly Facility.[57]
Blocks 1 and 1B of the SLS are planned to use two five-segment solid rocket boosters. These solid rocket boosters use segments that were flown on Shuttle flights as parts of the four-segment Space Shuttle Solid Rocket Boosters, with the addition of a center booster segment, new avionics, lighter insulation, and without a parachute recovery system.[58] The five-segment solid rocket boosters provide approximately 25% more total impulse than the Shuttle Solid Rocket Boosters, but will no longer be recovered after use.[59][60]
The stock of SLS Block 1 to 1B boosters is limited by the number of casings leftover from the Shuttle program, which is enough for eight flights of the SLS.[61] On the 2nd of March 2019, the Booster Obsolescence and Life Extension (BOLE) program were announced. This program will develop new solid rocket boosters, which will be built by Northrop Grumman Innovation Systems for further SLS flights, marking the beginning of Block 2. These boosters will be derived from the composite-casing solid rocket boosters in development for the now-canceled OmegA launch vehicle, and are projected to increase Block 2's payload to 130 metric tons (130 long tons; 140 short tons) to LEO and at least 46 metric tons (45 long tons; 51 short tons) to TLI.[62][63][64]
Upper stages
The Interim Cryogenic Propulsion Stage (ICPS) is planned to fly on Artemis 1. It is a stretched and human-rated Delta IV 5-meter (16 ft) Delta Cryogenic Second Stage (DCSS) powered by a single RL10B-2 engine.[65][66] Block 1 is intended to be capable of lifting 95 t (93 long tons; 105 short tons) to low Earth orbit (LEO) in this configuration, including the weight of the ICPS as part of the payload.[16] Artemis 1 is to be launched into an initial 1,806 by 30 km (1,122 by 19 mi) suborbital trajectory to ensure safe disposal of the core stage.[67] ICPS will then perform an orbital insertion burn at apogee and a subsequent translunar injection burn to send Orion towards the Moon.[68] As of February 2020[update], ICPS (not EUS) is planned for Artemis 1, 2, and 3.[69] ICPS will be human-rated for the crewed Artemis 2 flight.[69]
The Exploration Upper Stage (EUS) is planned to fly on Artemis 4. Similar to the S-IVB, the EUS will complete the SLS ascent phase and then re-ignite to send its payload to destinations beyond LEO.[70] It is expected to be used by Block 1B and Block 2, share the core stage diameter of 8.4 meters, and be powered by four RL10C-3 engines.[71] It will eventually be upgraded to use four RL10C-X engines instead.[72]
During the joint Senate-NASA presentation in September 2011, it was stated that the SLS program had a projected development cost of US$18 billion through 2017, with US$10 billion for the SLS rocket, US$6 billion for the Orion spacecraft, and US$2 billion for upgrades to the launch pad and other facilities at Kennedy Space Center.[75][76] These costs and schedules were considered optimistic in an independent 2011 cost assessment report by Booz Allen Hamilton for NASA.[77] An internal 2011 NASA document estimated the cost of the program through 2025 to total at least $41 billion for four 95 t (93 long tons; 105 short tons) launches (1 uncrewed, 3 crewed),[78][79] with the 130 t (130 long tons; 140 short tons) version ready no earlier than 2030.[80] The Human Exploration Framework Team (HEFT) estimated unit costs for Block 0 at US$1.6 billion and Block 1 at US$1.86 billion in 2010.[81] However, since these estimates were made the Block 0 SLS vehicle was dropped in late 2011, and the design was not completed.[43]
In September 2012, an SLS deputy project manager stated that US$500 million is a reasonable target average cost per flight for the SLS program.[82] In 2013, the Space Review estimated the cost per launch at US$5 billion, depending on the rate of launches.[83][84] NASA announced in 2013 that the European Space Agency (ESA) will build the Orion service module.[85] In August 2014, as the SLS program passed its Key Decision Point C review and entered full development, costs from February 2014 until its planned launch in September 2018 were estimated at US$7.021 billion.[86] Ground systems modifications and construction would require an additional US$1.8 billion over the same time.[87]
In October 2018, NASA's inspector general reported that the Boeing core stage contract had made up 40% of the US$11.9 billion spent on the SLS as of August 2018. By 2021, core stages were expected to have cost US$8.9 billion, twice the initially planned amount.[88] In December 2018, NASA estimated that yearly budgets for the SLS will range from US$2.1 to US$2.3 billion between 2019 and 2023.[89]
In March 2019, the Trump Administration released its Fiscal Year 2020 Budget Request for NASA. This budget did not include any money for the Block 1B and Block 2 variants of SLS. It was therefore uncertain whether these future variants of SLS will be developed, but congressional action restored this funding in the passed budget.[90] Several launches previously planned for the SLS Block 1B are now expected to fly on commercial launcher vehicles such as Falcon Heavy, New Glenn, and Vulcan.[91] However, the request for a budget increase of US$1.6 billion towards SLS, Orion, and crewed landers along with the launch manifest seem to indicate support of the development of Block 1B, debuting Artemis 3. Block 1B will be used mainly for co-manifested crew transfers and logistical needs rather than constructing the Gateway. An uncrewed Block 1B is planned to launch the Lunar Surface Asset in 2028, the first lunar outpost of the Artemis program. Block 2 development will most likely start in the late 2020s after NASA is regularly visiting the lunar surface and shifts focus towards Mars.[92]
Budget
For fiscal years 2011 through 2020, the SLS program had expended funding totaling US$18.648 billion in nominal dollars. This is equivalent to US$20.314 billion in 2020 dollars using the NASA New Start Inflation Indices.[93] For the fiscal year 2021, US$2.257 [inconsistent] billion.[1]
On top of this, the costs to assemble, integrate, prepare and launch the SLS and its payloads are funded separately under Exploration Ground Systems,[95] currently about US$600 million[96] per year. Payloads that launch on SLS, such as the Orion crew capsule, are similarly accounted separately from SLS. Predecessor programs contributed development to SLS, such as the Ares V Cargo Launch Vehicle (funded from 2008 to 2010, a total of US$70 million)[97] and Ares I Crew Launch Vehicle (funded from 2006 to 2010, a total of US$4.8 billion[97][98] in development that included the 5-segment Solid Rocket Boosters that will be used on the SLS[99]).
Programs that are included under the above SLS cost table include the interim Upper Stage for the SLS, the Interim Cryogenic Propulsion Stage (ICPS), which includes a US$412 million contract.[100] Also included is the future Upper Stage for the SLS, the Exploration Upper Stage[inconsistent] (funded at US$85 million in 2016,[101] US$300 million in 2017,[102] US$300 million in 2018,[103] and US$150 million in 2019[104])
Launch costs
Estimates of the per launch costs for the SLS have varied widely, partly due to uncertainty over how much the program will expend during development and testing before the operational launches begin, and partly due to various agencies using differing cost measures (for example, a marginal cost per one additional launch, which ignores the development and annual recurring fixed costs vs. total cost per launch, including recurring costs but excluding development); but also based on differing purposes for which the cost estimates were developed.
There are no official NASA estimates for how much the SLS will cost per launch, nor for the SLS program annual recurring costs once operational. Cost per launch is not a straightforward figure to estimate as it depends heavily on how many launches occur per year.[13] For example, similarly, the Space Shuttle was estimated (in 2012 dollars) to cost US$576 million per launch had it been able to achieve 7 launches per year, while the marginal cost of adding a single additional launch in a given year was estimated to be less than half of that, at just US$252 million of marginal cost. However, at the rate that it flew, the cost, in the end, was US$1.64 billion per Space Shuttle launch, including development.[105]: III−490
NASA associate administrator William H. Gerstenmaier said in 2017 that there would be no official per flight cost estimates of any variety provided by NASA for the SLS.[106] Other bodies, such as the Government Accountability Office (GAO), the NASA Office of Inspector General, the Senate Appropriations Committee, and the White House Office of Management and Budget have put out cost per launch figures, however. Several internal NASA programs and project concept study reports have released proposed budgets that include future SLS launches. For example, a concept study report for a space telescope stated it was advised by NASA HQ in 2019 to budget US$500 million for an SLS launch in 2035.[107] Another study in 2019 also proposing a space telescope assumed a budget for their launch of US$650 million in current-day dollars, or US$925 million for when the launch would occur, also in the "mid-2030s".[108]
Europa Clipper is a NASA scientific mission that was initially required by Congress to launch on the SLS. Oversight bodies both internal and external to NASA disagreed with this requirement. First, NASA's Inspector General office published a report in May 2019[109][110] that stated Europa Clipper would need to give up US$876 million for the "marginal cost" of its SLS launch. Then, an addendum to the letter published in August 2019 increased the estimate and stated that switching to a commercial rocket would save over US$1 billion. (Although these savings may have included a portion of costs related to the delay in launch schedule; a commercial alternative could launch sooner than SLS) A JCL (Joint Cost and Schedule Confidence Level) analysis cited in that letter put the cost savings at US$700 million, with the SLS at US$1.05 billion per launch and the commercial alternative at US$350 million.[111][112] In July 2021, NASA announced that instead of SLS, a SpaceX Falcon Heavy would be used to launch Europa Clipper.[113] The shaking caused by the SLS's solid-fuel boosters would have required expensive changes to the Europa Clipper itself, and the total cost savings was estimated at US$2 billion.[114]
Finally, a letter from the White House Office of Management and Budget (OMB) to the Senate Appropriations Committee in October 2019 revealed that SLS's total cost to the taxpayer was estimated at "over US$2 billion" per launch after development is complete (program development has cost US$20 billion in 2020 dollars).[14] The letter suggested Congress remove this requirement, agreeing the NASA Inspector General, adding that using a commercial launch vehicle for Europa Clipper instead of the SLS would save US$1.5 billion overall. NASA did not deny this US$2 billion cost of launch and an agency spokesperson stated it "is working to bring down the cost of a single SLS launch in a given year as the agency continues negotiations with Boeing on the long-term production contract and efforts to finalize contracts and costs for other elements of the rocket".[13] This OMB figure is dependent on the rate of construction, so building more SLS rockets faster could decrease the per-unit cost.[13] For example, Exploration Ground Systems – whose only role is to support, assemble, integrate, and launch SLS – has separately budgeted fixed costs of US$600 million per year on facilities, spread across however many rockets launch that year.[96] Then NASA Administrator Jim Bridenstine shared informally that he disagrees with the US$2 billion figure since the marginal cost of an SLS launch should decrease after the first few, and is expected to end up around US$800 million to US$900 million, although contract negotiations were only just beginning for those later cores.[115]
Early plans
Planned evolution of the SLS, 2018
The SLS was created by an act of Congress, in which NASA was directed to create a system for launching payloads and crew into space that would replace the capabilities lost with the retirement of the Space Shuttle.[41] The act set out certain goals, such as being able to lift a certain mass into low earth orbit, a target date for the system being operational, and a directive to use "to the extent practicable" existing components, hardware, and workforce from the Space Shuttle and from Ares I.[41]: 12 On 14 September 2011, NASA announced their plan to meet these requirements: the design for the SLS, with the Orion spacecraft as payload.[116][117][118][119]
The SLS has considered several future development routes of potential launch configurations, with the planned evolution of the blocks of the rocket having been modified many times.[99] Many options, all of which just needed to meet the congressionally mandated payload minimums,[99] were considered, including a Block 0 variant with three main engines,[43] a variant with five main engines,[99] a Block 1A variant with upgraded boosters instead of the improved second stage,[43] and a Block 2 with five main engines plus the Earth Departure Stage, with up to three J-2X engines.[46]
In the initial announcement of the design of the SLS, NASA also announced an "Advanced Booster Competition", to select which boosters would be used on Block 2 of the SLS.[116][120][50][121] Several companies proposed boosters for this competition, all of which were indicated as viable[122]: Aerojet and Teledyne Brown proposed three booster engines each with dual combustion chambers,[123]Alliant Techsystems proposed a modified solid rocket booster with lighter casing, more energetic propellant, and four segments instead of five,[124] and Pratt & Whitney Rocketdyne and Dynetics proposed a liquid-fueled booster named Pyrios.[125] However, this competition was planned for a development plan in which Block 1A would be followed by Block 2A, with upgraded boosters. NASA canceled Block 1A and the planned competition in April 2014, in favor of simply remaining with the Ares I's five-segment solid rocket boosters (themselves modified from the Space Shuttle's solid rocket boosters) until at least the late 2020s.[99][126] The overly powerful advanced booster would have resulted in unsuitably high acceleration, and would need modifications to Launch Pad 39B, its flame trench, and Mobile Launcher.[127][99]
On 31 July 2013, the SLS passed the Preliminary Design Review (PDR). The review included not only the rocket and boosters but also ground support and logistical arrangements.[128] On 7 August 2014, the SLS Block 1 passed a milestone known as Key Decision Point C and entered full-scale development, with an estimated launch date of November 2018.[86][129] In 2013, NASA and Boeing analyzed the performance of several EUS engine options. The analysis was based on a second-stage usable propellant load of 105 metric tons, and compared stages with four RL10 engines, two MARC-60 engines, or one J-2X engine.[130] In 2014, NASA also considered using the European Vinci instead of the RL10. The Vinci offers the same specific impulse but with 64% greater thrust, which would allow for the same performance at a lower cost.[131][132]
Blue Origin submitted a proposal to replace the Exploration Upper Stage with a cheaper alternative to be designed and fabricated by the company, but it was rejected by NASA in November 2019 on multiple grounds; these included lower performance compared to the existing EUS design, incompatibility of the proposal with the height of the door of the Vehicle Assembly Building being only 390 feet, and unacceptable acceleration of Orion components such as its solar panels.[133][134]: 8
From 2009 to 2011, three full-duration static fire tests of five-segment solid rocket boosters were conducted under the Constellation Program, including tests at low and high core temperatures, to validate performance at extreme temperatures.[135][136][137] The 5-segment solid rocket booster would be carried over to SLS.[99]Northrop Grumman Innovation Systems has completed full-duration static fire tests of the five-segment solid rocket boosters. Qualification Motor 1 (QM-1) was tested on 10 March 2015.[138] Qualification Motor 2 (QM-2) was successfully tested on 28 June 2016.
Operation
SLS construction history
As of 2020[update], three SLS versions are planned: Block 1, Block 1B, and Block 2. Each will use the same Core Stage with its four main engines, but Block 1B will feature the Exploration Upper Stage (EUS), and Block 2 will combine the EUS with upgraded boosters.[139][74][140] In mid-November 2014, construction of the first Core Stage hardware began using a new welding system in the South Vertical Assembly Building at NASA's Michoud Assembly Facility.[141] Between 2015 and 2017, NASA test fired RS-25 engines in preparation for use on SLS.[55] The ICPS for Artemis 1 was delivered by ULA to NASA about July 2017[142] and was housed at Kennedy Space Centre as of November 2018.[143]
The core stage for the first SLS, built at Michoud Assembly Facility, had all four engines attached in November 2019,[144] and it was declared finished by NASA in December 2019.[145]
Exploration Ground Systems and Jacobs prepare to lift and place the core stage of the SLS rocket
The first core stage left Michoud Assembly Facility for comprehensive testing at Stennis Space Center in January 2020.[146] The static firing test program at Stennis Space Center, known as the Green Run, operated all the core stage systems simultaneously for the first time.[147][148] Test 7 (of 8), the wet dress rehearsal, was carried out in December 2020 and the fire (test 8) took place on 16 January 2021, but shut down earlier than expected,[149] about 67 seconds in total rather than the desired eight minutes. The reason for the early shutdown was later reported to be because of conservative test commit criteria on the thrust vector control system, specific only for ground testing and not for flight. If this scenario occurred during a flight, the rocket would have continued to fly normally. There was no sign of damage to the core stage or the engines, contrary to initial concerns.[150] The second fire test was completed on 18 March 2021, with all 4 engines igniting, throttling down as expected to simulate in-flight conditions, and gimballing profiles. The core stage was shipped to Kennedy Space Center to be mated with the rest of the rocket for Artemis 1. It left Stennis on April 24 and arrived at Kennedy on April 27.[151] It was refurbished there in preparation for stacking.[152] On 12 June 2021, NASA announced the assembly of the first SLS rocket was completed at the Kennedy Space Center. The assembled SLS is planned to be used for the unmanned Artemis 1 mission in 2022.[21]
Originally planned for late 2016, the intended uncrewed first flight of SLS has slipped more than eight times and more than five years.[note 2] NASA plans to announce a specific projected first launch date after Orion is stacked on Artemis 1.[163] NASA limits the amount of time the solid rocket boosters can remain stacked to "about a year" from the time two segments are joined.[164] The first and second segments of the Artemis 1 boosters were joined on 7 January 2021.[165] NASA can choose to extend the time limit based on an engineering review.[166] On 29 September 2021, Northrup Grumman indicated that the limit can be extended to eighteen months for Artemis 1, based on an analysis of the data collected when the boosters were being stacked.[21] As of late 2015, the SLS program was stated to have a 70% confidence level for the first Orion flight that carries crew (the second SLS flight overall) by 2023,[167][168][169] and as of 2020[update], NASA is continuing to project a 2023 launch.[170]
Uncrewed maiden flight of the SLS, first operational flight of the Orion capsule. Carrying cubesats for ten missions in the CubeSat Launch Initiative (CSLI), and three missions in the Cube Quest Challenge.[172][173] The payloads were sent on a trans-lunar injection trajectory.[174][175]
Crewed mission to the Lunar Gateway, rendezvousing with the first Lunar Exploration Transportation Services (LETS) lander for a lunar landing. Delivery and integration of the ESPRIT module to the Gateway.[181]
Criticism
Visual from the March 2020 Inspector General report, showing how NASA used accounting to "mask"[182]: iv a cost increase by moving the boosters (which cost US$889M) from the SLS to another cost center, without updating the SLS budget to match.[182]: 22
The SLS has been criticized based on program cost, lack of commercial involvement, and the non-competitive nature of a vehicle legislated to use Space Shuttle components.
Funding
In 2011, Rep. Tom McClintock and other groups called on the Government Accountability Office (GAO) to investigate possible violations of the Competition in Contracting Act (CICA), arguing that Congressional mandates forcing NASA to use Space Shuttle components for the SLS are de facto non-competitive, single-source requirements assuring contracts to existing Shuttle suppliers.[183][184][185] The Competitive Space Task Force, in September 2011, said that the new government launcher directly violates NASA's charter, the Space Act, and the 1998 Commercial Space Act requirements for NASA to pursue the "fullest possible engagement of commercial providers" and to "seek and encourage, to the maximum extent possible, the fullest commercial use of space".[186][185] Opponents of the heavy launch vehicle have critically used the name "Senate launch system",[65][185][187]a name that was still being used by opponents to criticize the program in 2021, as "the NASA Inspector General said the total cost of the rocket would reach $27 billion through 2025."[188]
Lori Garver, then NASA Deputy Administrator, called for canceling the launch vehicle alongside the Mars 2020 rover.[189]Phil Plait shared his criticism of the SLS in light of ongoing budget tradeoffs between the Commercial Crew Development and SLS budgets, also referring to earlier critiques by Garver.[190] In 2019, the Government Accountability Office found that NASA had awarded Boeing over US$200 million for service with ratings of good to excellent despite cost overruns and delays. As of 2019[update], the maiden launch of the SLS was expected in 2021.[191][192] NASA continued to expect that the first orbital launch would be in 2021 as late as May 2021.[160]
NASA moved out US$889 million of costs relating to SLS boosters, but did not update the SLS budget to match, a March 2020 Inspector General report found. This kept the budget overrun to 15% by FY 2019.[182]: 22 At 30%, NASA would have to notify Congress and stop funding unless Congress reapproves and provides additional funding.[182]: 21–23 The Inspector General report found that were it not for this "masking" of cost, the overrun would be 33% by FY 2019.[182]: iv, 23 The GAO separately stated "NASA's current approach for reporting cost growth misrepresents the cost performance of the program".[193]: 19–20
On 1 May 2020, NASA awarded a contract extension to Aerojet Rocketdyne to manufacture 18 additional RS-25 engines with associated services for US$1.79 billion, bringing the total RS-25 contract value to almost US$3.5 billion.[194][56]Ars Technica, in an article published on the same day, highlighted that over the entire RS-25 contract the price of each engine works out to US$146 million and that the total price for the four expendable engines used in each SLS launch will be more than US$580 million. They critically commented that for the cost of just one engine, six more powerful RD-180 engines could be purchased, or nearly an entire Falcon Heavy launch with two-thirds of the SLS lift capacity.[194][195] Former NASA Administrator Charlie Bolden, who oversaw the initial design and development of the SLS, also shared his criticism of the program in an interview with Politico in September 2020. Bolden said that the "SLS will go away because at some point commercial entities are going to catch up". Bolden further stated, "commercial entities are really going to build a heavy-lift launch vehicle sort of like SLS that they will be able to fly for a much cheaper price than NASA can do SLS".[196]
A NASA study that was not publicly released[203][204] and another from the Georgia Institute of Technology showed this option to be possibly cheaper.[205][206] In 2012, the United Launch Alliance also suggested using existing rockets with on-orbit assembly and propellant depots as needed. The lack of competition in the SLS design was highlighted.[207][208][209][187][210] In the summer of 2019, a former ULA employee claimed that Boeing, NASA's prime contractor for SLS, viewed orbital refueling technology as a threat to the SLS and blocked further investment in it.[211] In 2011, Robert Zubrin, founder of Mars Society and Mars Direct, suggested that a heavy lift vehicle could be developed for US$5 billion on fixed-price requests for proposal.[212]
In 2010, SpaceX's CEO Elon Musk claimed that his company could build a launch vehicle in the 140–150 t (140–150 long tons; 150–170 short tons) payload range for US$2.5 billion, or US$300 million (in 2010 dollars) per launch, not including a potential upper-stage upgrade.[213][214]
^This is for the Block 1 launch vehicle alone and does not include the Orion capsule or service module costs.[13]
^ abNASA has announced at least seven schedule slips: December 2016,[41][29][153] October 2017,[154] November 2018,[155] 2019,[156] June 2020,[157] April 2021,[158] November 2021,[159][160] December 2021,[42] and then to some time between January 2022 and March 2022.[161][162][21]
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^ abcd"Public Law 111–267 111th Congress, 42 USC 18322. SEC. 302 (c) (2) 42 USC 18323. SEC. 303 (a) (2)"(PDF). 11 October 2010. pp. 11–12. Archived(PDF) from the original on 12 November 2020. Retrieved 14 September 2020. 42 USC 18322. SEC. 302 SPACE LAUNCH SYSTEM AS FOLLOW-ON LAUNCH VEHICLE TO THE SPACE SHUTTLE ... (c) MINIMUM CAPABILITY REQUIREMENTS (1) IN GENERAL — The Space Launch System developed pursuant to subsection (b) shall be designed to have, at a minimum, the following: (A) The initial capability of the core elements, without an upper stage, of lifting payloads weighing between 70 tons and 100 tons into low-Earth orbit in preparation for transit for missions beyond low Earth orbit ... (2) FLEXIBILITY ... (Deadline) Developmental work and testing of the core elements and the upper stage should proceed in parallel subject to appro-priations. Priority should be placed on the core elements with the goal for operational capability for the core elements not later than December 31, 2016 ... 42 USC 18323. SEC. 303 MULTI-PURPOSE CREW VEHICLE (a) INITIATION OF DEVELOPMENT (1) IN GENERAL — The Administrator shall continue the development of a multi-purpose crew vehicle to be available as soon as practicable, and no later than for use with the Space Launch System ... (2) GOAL FOR OPERATIONAL CAPABILITY. It shall be the goal to achieve full operational capability for the transportation vehicle developed pursuant to this subsection by not later than December 31, 2016. For purposes of meeting such goal, the Administrator may undertake a test of the transportation vehicle at the ISS before that date.
^Harbaugh, Jennifer (9 December 2019). "NASA, Public Marks Assembly of SLS Stage with Artemis Day". nasa.gov. NASA. Archived from the original on 6 February 2020. Retrieved 10 December 2019. NASA and the Michoud team will shortly send the first fully assembled, 212-foot-tall core stage...27.6-feet-in-diameter tanks and barrels. This article incorporates text from this source, which is in the public domain.
^Batcha, Amelia L.; Williams, Jacob; Dawn, Timothy F.; Gutkowski, Jeffrey P.; Widner, Maxon V.; Smallwood, Sarah L.; Killeen, Brian J.; Williams, Elizabeth C.; Harpold, Robert E. (27 July 2020). "Artemis I Trajectory Design and Optimization"(PDF). NASA Technical Reports Server. NASA. Archived(PDF) from the original on 9 September 2021. Retrieved 8 September 2021. This article incorporates text from this source, which is in the public domain.
^ ab"Space Launch System"(PDF). NASA Facts. NASA. 11 October 2017. FS-2017-09-92-MSFC. Archived(PDF) from the original on 24 December 2018. Retrieved 4 September 2018. This article incorporates text from this source, which is in the public domain.
^"NASA FY 2019 Budget Estimates"(PDF). nasa.gov. p. BUD-2. Archived(PDF) from the original on 24 December 2018. Retrieved 16 December 2018. This article incorporates text from this source, which is in the public domain.
^"NASA FY 2019 Budget Overview"(PDF). Archived(PDF) from the original on 4 December 2019. Retrieved 24 June 2019. Quote: "Supports launch of the Power and Propulsion Element on a commercial launch vehicle as the first component of the LOP–Gateway, (page 14) This article incorporates text from this source, which is in the public domain.
^"NASA, Assessments of Major Projects"(PDF). General Accounting Office. March 2016. p. 63. Archived(PDF) from the original on 13 April 2016. Retrieved 23 June 2016. This article incorporates text from this source, which is in the public domain.
^"FY 2008 Budget Estimates"(PDF). NASA. p. ESMD-14. Archived(PDF) from the original on 3 June 2016. Retrieved 23 June 2016. This article incorporates text from this source, which is in the public domain.
^"Origins Space Telescope Mission Concept Study Report"(PDF). 11 October 2019. p. ES-11. Archived(PDF) from the original on 12 July 2020. Retrieved 14 May 2020. The launch cost (US$500 million for the SLS launch vehicle, as advised by NASA Headquarters) is also included. This article incorporates text from this source, which is in the public domain.
^Town Hall with Administrator Bridenstine and NASA's New HEO Associate Administrator Douglas Loverro (YouTube). NASA. 3 December 2019. Event occurs at 24:58. Retrieved 20 January 2021. "I do not agree with the US$2 billion number, it is far less than that. I would also say that the number comes way down when you buy more than one or two. And so I think at the end we're going to be, you know, in the US$800 million to US$900 million range - I don't know, honestly. We've recently just begun negotiations on what number three through whatever - we don't have to buy any quite frankly, but we intend to. But we're looking at what we could negotiate to get the best price for the American taxpayper, which is my obligation as the head of NASA". This article incorporates text from this source, which is in the public domain.
^Kenneth Chang (14 September 2011). "NASA Unveils New Rocket Design". The New York Times. Archived from the original on 21 February 2017. Retrieved 14 September 2011.
^"Redacted_EUS.pdf". sam.gov. 31 October 2019. Archived(PDF) from the original on 5 October 2021. Retrieved 6 October 2021. ((cite web)): |archive-date= / |archive-url= timestamp mismatch; 6 October 2021 suggested (help)
^Foust, Jeff (21 May 2019). "In 2020, NASA Will Send Living Things to Deep Space for First Time Since Apollo". Space.com. Archived from the original on 6 August 2019. Retrieved 6 August 2019. BioSentinel is one of 13 cubesats flying aboard the Artemis 1 mission, which is currently targeted for mid-2020. [...] The other 12 cubesats flying aboard Artemis 1 are a diverse lot. For example, the Lunar Flashlight and Lunar IceCube missions will hunt for signs of water ice on the moon, and Near-Earth Asteroid Scout will use a solar sail to rendezvous with a space rock.
^Northon, Karen (9 June 2017). "Three DIY CubeSats Score Rides on Exploration Mission-1". National Aeronautics and Space Administration (NASA). Archived from the original on 6 August 2019. Retrieved 6 August 2019. NASA's Space Technology Mission Directorate (STMD) has awarded rides for three small spacecraft on the agency's newest rocket, and $20,000 each in prize money, to the winning teams of citizen solvers competing in the semi-final round of the agency's Cube Quest Challenge.
^Clark, Stephen (22 July 2019). "First moon-bound Orion crew capsule declared complete, major tests remain". SpaceflightNow. Archived from the original on 6 August 2019. Retrieved 6 August 2019. The Artemis 1 mission profile. Credit: NASA [...] The Artemis 1 mission sent the Orion spacecraft into a distant retrograde lunar orbit and back...
^ abcde"NASA'S MANAGEMENT OF SPACE LAUNCH SYSTEM PROGRAMCOSTS AND CONTRACTS"(PDF). NASA - Office of Inspector General - Office of Audits. 10 March 2020. Archived(PDF) from the original on 28 August 2020. Retrieved 14 September 2020. Based on our review of SLS Program cost reporting, we found that the Program exceeded its Agency Baseline Commitment (ABC) by at least 33 percent at the end of FY 2019, a figure that could reach 43 percent or higher if additional delays push the launch date for Artemis I beyond November 2020. This is due to cost increases tied to Artemis I and a December 2017 replan that removed almost $1 billion of costs from the ABC without lowering the baseline, thereby masking the impact of Artemis I's projected 19-month schedule delay from November 2018 to a June 2020 launch date. Since the replan, the SLS Program now projects the Artemis I launch will be delayed to at least spring 2021 or later. Further, we found NASA's ABC cost reporting only tracks Artemis I-related activities and not additional expenditures of almost $6 billion through FY 2020 that are not being reported or tracked through the official congressional cost commitment or the ABC. ... as a result of delaying Artemis I up to 19 months to June 2020, NASA conducted a replan of the SLS Program in 2017 and removed $889 million in Booster and RS-25 Engine-related development costs because SLS Program officials determined those activities were not directly tied to Artemis I. ... In our judgement, the removal of these costs should have reduced the SLS Program's ABC development costs from $7.02 billion to $6.13 billion. ... SLS Program and HEOMD officials disagreed with our assessment and stated the SLS Program's change in cost estimates for the Booster and Engines element offices were not a removal of costs but rather a reallocation of those activities to appropriately account for them as non-Artemis I costs. ... Federal law requires that any time Agency program managers have reasonable knowledge that development costs are likely to exceed the ABC by more than 30 percent, they must notify the NASA Administrator. Once the Administrator determines the SLS Program will exceed the development cost baseline by 30 percent or more, NASA is required to notify Congress and rebaseline program costs and schedule commitments. If the Administrator notifies Congress of the need to rebaseline, NASA is required to stop funding program activities within 18 months unless Congress provides approval and additional appropriations. In our judgement, using NASA's cost estimates from October 2019 and accounting for the removed costs from the replan, the SLS Program was required to rebaseline when the program exceeded its ABC by 33 percent at the end of FY 2019, an increase that could reach 43 percent or higher by the Artemis I launch date. This article incorporates text from this source, which is in the public domain.
^ abc"The Senate Launch System". Competitive Space Task Force. 4 October 2011. Archived from the original on 27 October 2011. Retrieved 20 October 2011.
^"NASA HUMAN SPACE EXPLORATION: Persistent Delays and Cost Growth Reinforce Concerns over Management of Programs"(PDF). GAO. Archived(PDF) from the original on 3 October 2021. Retrieved 15 September 2020. NASA's current approach for reporting cost growth misrepresents the cost performance of the program and thus undermines the usefulness of a baseline as an oversight tool. NASA's space flight program and project management requirements state that the agency baseline commitment for a program is the basis for the agency's commitment to the Office of Management and Budget (OMB) and the Congress based on program requirements, cost, schedule, technical content, and an agreed-to joint cost and schedule confidence level. Removing effort that amounts to more than a tenth of a program's development cost baseline is a change in the commitment to OMB and the Congress and results in a baseline that does not reflect actual effort. ... Further, the baseline is a key tool against which to measure the cost and schedule performance of a program. A program must be rebaselined and reauthorized by the Congress if the Administrator determines that development costs will increase by more than 30 percent. Accounting for shifted costs, our analysis indicates that NASA has reached 29.0 percent development cost growth for the SLS program. ... In addition, as we previously reported in May 2014, NASA does not have a cost and schedule baseline for SLS beyond the first flight. As a result, NASA cannot monitor or track costs shifted beyond EM-1 against a baseline. We recommended that NASA establish cost and schedule baselines that address the life cycle of each SLS increment, as well as for any evolved Orion or ground systems capability. NASA partially concurred with the recommendation, but has not taken any action to date. ... By not adjusting the SLS baseline to account for the reduced scope, NASA will continue to report costs against an inflated baseline, hence underreporting the extent of cost growth. NASA's Associate Administrator and Chief Financial Officer stated that they understood our rationale for removing these costs from the EM-1 baseline and agreed that not doing so could result in underreporting of cost growth. Further, the Associate Administrator told us that the agency will be relooking at the SLS program's schedule, baseline, and calculation of cost growth. This article incorporates text from this source, which is in the public domain.
^Review of U.S. Human Space Flight Plans Committee; Augustine, Austin; Chyba, Kennel; Bejmuk, Crawley; Lyles, Chiao; Greason, Ride (October 2009). "Seeking A Human Spaceflight Program Worthy of A Great Nation"(PDF). NASA. Archived(PDF) from the original on 16 February 2019. Retrieved 15 April 2010. This article incorporates text from this source, which is in the public domain.
This Template lists historical, current, and future space rockets that at least once attempted (but not necessarily succeeded in) an orbital launch or that are planned to attempt such a launch in the future
Symbol † indicates past or current rockets that attempted orbital launches but never succeeded (never did or has yet to perform a successful orbital launch)
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