Artemis Updates

SLS Core Stage Pathfinder at Stennis B-2 Test Stand. Photo: NASA

This edition of Artemis Updates brings updates on the Artemis 1 SLS Core Stage, Orion, and Exploration funding. Construction of the Artemis 1 SLS Core Stage has been completed, 12 Orions were ordered by NASA, and the Senate Commerce, Justice, and Science Appropriations Subcommittee gave NASA’s Exploration programs (SLS and Orion) large funding increases.

Engine Section attached to Artemis 1 SLS Core Stage. Photo: NASA

SLS Core Stage Segments Joined

On September 19, NASA, the sole integrator of the SLS rocket, announced that engineers at NASA’s Michoud Assembly Facility (MAF), after a “breakover” when during 48 hours of continuous and careful maneuvering to protect all the critical systems inside the engine section was flipped on its side, had joined the engine section to the 212 foot tall Artemis 1 Core Stage. This completes the structural assembly of the Artemis 1 SLS Core Stage. The SLS Core Stage is the center of the SLS rocket, serving as the attachment for the two solid rocket boosters, avionics, the Interim Cryogenic Propulsion System (ICPS), which is attached to the Orion Crew and Service modules (CSM), and the RS-25 engines.

The engine section is one of most complicated parts of the five sections of the SLS Core Stage. Mounted inside of the engine section are the four RS-25 engines that will generate 2 million pounds of thrust. The SLS Core Stage engine section also serves as the lower attachment point for the two solid rocket boosters, both of which produce 6.8 million pounds of thrust. Together, the four RS-25 engines and two solid rocket boosters product 8.8 million pounds of thrust, making the Core Stage engine section the focal point for the loads generated during lift-off of the SLS. The engine section also includes systems needed for mounting, controlling and delivering fuel from the stage’s two liquid oxygen and liquid hydrogen (LOX/LH2) tanks to SLS’s four RS-25 engines.

Joining of Artemis 1 SLS Core Stage and engine section. Video: NASA

With the joining of the engine section, Boeing and Aerojet Rocketdyne will begin the installation in the engine section of the four RS-25 engines that are sitting, literally, next door to the Artemis 1 Core Stage, and is expected to be completed by the second week in December.

Artemis 1’s four RS-25 engines at MAF. Photo: NASA

Once the RS-25 engines are installed, the Artemis 1 Core Stage will be rolled-out of MAF, signaling the completion of the construction of the first rocket at MAF since the Apollo era. loaded onto the Pegasus barge, and towed to Stennis Space Center. At Stennis, the Core Stage will be loaded onto the B-2 test stand for the Green Run sometime in the early spring of 2020 that will see the four RS-25 engines ignited and run for the full-duration they will during the Artemis 1 launch. Then the SLS Core Stage will be cleaned-up and shipped to Kennedy Space Center, where it will stacked along with the other parts that make up the SLS rocket in preparation for the Artemis 1 launch sometime in late 2020 or early 2021.

SLS Core Stage Structural Testing Enters Final Quarter

LH2 Structural Test Article in NASA Marshall Space Flight Center West Test Area Test Stand. Photo: NASA

NASA and Boeing also announced on September 19 that the liquid hydrogen test article, which began its structural testing in June, had completed its testing at Marshall Spaceflight Center for the Artemis 1 mission. For the structural test, the liquid hydrogen tank was bolted to a huge 80,000-pound steel ring at the base of the test stand at Marshall Spaceflight Center’s test stand 4693. During the 37 separate test cases that simulated the stresses of launch, dozens of hydraulic cylinders at Test Stand 4693 applied forces to the steel ring that pushed and pulled the giant tank to mimic the same stresses and forces that the SLS Block 1A rocket will endure during liftoff and flight.

The Liquid Oxygen (LOX) structural test article arrives at MSFC for structural test. Photo: NASA

Previous to testing the liquid hydrogen tank test article, Marshall Spaceflight Center had subjected test elements of the Interim Cryogenic Propulsion (ICPS) Unit and the Intertank, which completed its testing in June, to structural testing.

The last structural test article, the liquid oxygen (LOX) tank test article, arrived at Marshall Spaceflight Center on July 19th and will, according to NASA, begin its structural testing shortly. The LOX tank structural test article also contains the forward skirt and intertank. Testing will continue on the SLS Core Stage test elements to validate the design is sound for the SLS Block 1B and missions with more extreme stresses. According to Mike Nichols, the test conductor for the liquid hydrogen tank tests, structural testing takes four months. So the beginning of structural testing of the LOX tank test article marks the milestone of Marshall Spaceflight Center entering the final quarter of the largest test campaign since the Space Shuttle. Unlike the Iron Bowl, everyone at Marshall Spaceflight Center is looking forward to reaching the end zone of structural testing of for the Artemis 1 launch and beginning structural testing for SLS Block 1B.

Artemis 2 Engine Section in production at Michoud. Photo: Boeing

Last Element of Artemis 2 Core Stage Welded

Slipping through the cracks of previous “Artemis Updates” was an August 8 announcement by Boeing that “the last element of Core Stage 2 is being welded ahead of the addition of electrical and propulsion systems. The work is proceeding far more quickly than on the first core stage, thanks to an established production system and lessons learned from building and testing its predecessor. Like Core Stage 1, Core Stage 2 will be incrementally tested throughout the build cycle to ensure functionality and reliability.” Also, Boeing released a picture of the Artemis 2 SLS Core Stage engine section, one of the long-lead items on the SLS rocket, undergoing work. Just as a reminder to our readers, NASA announced on August 15 that the Artemis 3 SLS Core Stage engine section had been ordered.

SLS Core Stage Pathfinder “breakover” at Stennis Space Center’s B-2 Test Stand. Photo: NASA

SLS Pathfinder at Stennis’ B-2 Stand

On August 26, NASA announced that the SLS Core Stage Pathfinder was being lifted at the Stennis Space Center’s B-2 test stand. The SLS Core Stage Pathfinder simulates in total weight, weight distribution, and dimensions the 212 foot SLS Core Stage that will be delivered to Stennis Space Center in late December and in early 2020 start its Green Run test at Stennis’ B-2 test stand.

SLS Pathfinder breakover at Stennis Space Center’s B-2 Test Stand. Video: NASA

The SLS Core Stage Pathfinder was lifted from its horizontal position on the B-2 Test Stand tarmac with the facility boom crane line attached to the forward end and a ground crane line attached to the aft end. As NASA describes it, “[T]he pathfinder then was “broken over” into a vertical position. Once the ground crane line was disconnected, the core stage pathfinder was lifted into place by the stand boom crane. This “fit test” validated auxiliary lift equipment, procedures, and verified that stand modifications and preparations are in place and prepared for delivery and testing of the SLS core stage flight hardware.”

To prepare for the upcoming Green Run test, Stennis modified or upgraded every major area and system of the B-2 test stand. One major modification to the B-2 test stand was to move the structural framework that will house the SLS Core Stage 20 feet from its previous position from testing the Space Shuttle’s main engines. Additional modifications included a high-pressure industrial water system and high-pressure gas facility that support test operations.

Six Years of Non-Stop Work Video: NASA/SSC

The SLS Core Stage Pathfinder is not unique to the SLS Program. Pathfinders were constructed for the Saturn V S-1C and the Space Shuttle. The purpose is to allow fit checks on test stands and transportation, whether aircraft, rail, or water-born, without putting at risk of damage expensive flight hardware.

NASA’s Pegasus Barge arrives at the KSC’s LC 39 turn basin wharf to deliver the 212-foot-long Space Launch System rocket Core Stage Pathfinder. Photo: NASA

SLS Pathfinder at Kennedy Space Center

On September 27, NASA announced that the Pegasus barged had arrived at Kennedy Space Center with its first Artemis payload, the SLS Core Stage Pathfinder.

According to NASA, “[T]he pathfinder will be used by the Exploration Ground Systems Program and their contractor, Jacobs, to practice offloading, moving and stacking maneuvers, using important ground support equipment to train employees and certify all the equipment works properly. The pathfinder will stay at Kennedy for approximately one month before trekking back to NASA’s Michoud Assembly Facility in Louisiana.” will work hard to bring its readers images of the Exploration Ground Systems tests with pathfinder.

Orion spacecraft in lunar orbit. Image: NASA

12 Orions Ordered

On September 23, NASA announced that it had awarded the Orion Production and Operations Contract (OPOC) to Lockheed Martin, setting in motion the Orion spacecraft production line to support as many as 12 Artemis missions. One significant focus of Orion spacecraft production will be on reusability with the goal of a sustained presence on the Moon’s surface.

Artemis 1 Orion CSM. Photo: NASA

NASA is immediately ordering, on a cost-plus-incentive-fee basis, three Orion spacecraft for Artemis missions III through V for $2.7 billion. This order will also lower the cost of Gateway’s development by producing for the Gateway Program some spacecraft components that already designed and qualified for Orion, eliminating the need for the Gateway Program to develop and qualify similar components. In fiscal year 2022, NASA will spend $1.9B on a firm-fixed-price order for three additional Orion capsules for Artemis missions VI through VIII. So much for the beaten-down agreement of Orion and SLS having no future.

According to NASA, the significant price-drop of $800M between the current order for three Orion spacecraft for Artemis III-V and the order for Artemis VI-VIII is due to cost incentives in the initial Orion order that are designed to drive cost performance towards substantially lower prices for subsequent orders through, “…efficiencies that become available in the supply chain over time – efficiencies that optimize production and lower costs.”

The Chairman of the Senate Aviation and Space Subcommittee, Sen. Ted Cruz, applauded the contract, stating, “I am pleased that Administrator Bridenstine has heeded my calls and is taking significant steps to ensure that Johnson continues to grow with the exciting future of manned exploration that lies ahead. More needs to be done, and I look forward to production ramping up in the weeks and months to come and to more opportunities with NASA.”

According to NASA, this contract for Orion spacecraft is an, “indefinite-delivery/indefinite-quantity contract that includes a commitment to order a minimum of six and a maximum of 12 Orion spacecraft, with an ordering period through Sept. 30, 2030. Production and operations of the spacecraft for six to 12 missions will establish a core set of capabilities, stabilize the production process, and demonstrate reusability of spacecraft components”.

What about SLS? In his testimony on September 17, interim Human Exploration and Operations (HEO) Mission Directorate chief Ken Bowersox indicated that NASA and Boeing were talking about SLS production beyond Artemis 3, although no agreements had been reached1.

NASA HLS concept at lunar south pole. Image: NASA

Update on Human Landing System

On September 30, NASA released the final broad agency announcement (BAA) for the Human Landing System (HLS), officially part of NextSTEP-2 Appendix-H.

One of the changes in the Appendix-H BAA for HLS (it is unknown how NASA comes up with such catchy titles for programs) was a change in reporting requirements. Previous feedback from potential contracts had indicated that heavy reporting requirements would only slow-down a program that has very little time to waste before a 2024 landing.

Another change was additional language in the October 2 release of the NextSTEP-2 Appendix-H Broad Agency Announcement, Section Launch Operations2,

“The commercial launch vehicle approach does not prevent or preclude offerors from negotiating with the Space Launch System (SLS) and Exploration Ground Systems prime contractors directly (Aerojet Rocketdyne, Boeing, Northrup Grumman, United Launch Alliance, and Jacobs) to provide an SLS-derived commercial cargo vehicle solution for the Artemis launch mission(s) in which NASA is not the integrator or provider. Any proposal to purchase such a launch solution must not interfere with current government plans for SLS development, production, and operations that are required for the successful execution of the 2024 and subsequent lunar lander missions.”

It’s disingenuous, to put it charitably, for NASA, currently the sole integrator of the SLS rocket, to state that HLS contractors can negotiate with the 5 prime contractors to then themselves integrate the finished pieces into an SLS. And there are several questions as to whether in fact an HLS contractor could act as an integrator (video, 1:08:15) for a cargo SLS.

SLS Crewed and Cargo. Image: NASA

Instead, this language was inserted in an attempt, likely to be unsuccessful, to placate congressional and aerospace industry critics of HLS Program’s mandate that the HLS ascent, descent, and transportation elements be launched on commercial launcher. The chief criticism of commercial launchers for launching HLS hardware is the lower safety rating compared to SLS and the limited lunar payload capacity of no more than 15MT, nearly half of that of an SLS Block 1A and 1/5 of that of an SLS Block 1B.

SLS launching. Image: NASA

Artemis Funding

On September 26, the Senate Commerce, Justice, Science, and Related Agencies Appropriations Subcommittee passed S.2584 its fiscal year 2020 budget for NASA. The news for NASA was very good.

Exploration received a funding boost of $1.2B increase over its 2019 budget for a total of $6.2B. This must come as a shock to critics of NASA’s Orion, SLS, and related programs that make up NASA Exploration budget line since such critics have for a decade predicted that Congress will face sticker-shock and withdraw support for those program.

Here are the 2020 vs 2019 budget numbers (in billions, with a B),

Ground Systems$0.590$0.5928

It is noteworthy that the House Commerce, Justice, Science Appropriations Subcommittee appropriated no funding for Gateway or HLS in H.R.3055. The FY2020 funding numbers from the House and Senate CJS subcommittees are as follows,

ProgramSenate (S.2584)House (H.R. 3055)
Ground Systems$0.590$0.5928

There is one change in Senate CJS Appropriations Subcommittee’s S.2584 that breaks with the past. Previous appropriations bill from the subcommittee, such as S.3072 passed in the 115th Congress, specified neither funding for the Europa Program nor the mandate that it be launched upon an SLS3. That changed with the Senate CJS Subcommittee’s latest bill, S.2584, in which it is specified on page 74,

“Provided further, That the National Aeronautics and Space Administration shall use the Space Launch System as the launch vehicle for the Jupiter Europa Clipper mission.”4

This change is likely, at least in part, a reaction to an interesting, if not odd, August 27 letter from NASA Inspector General Paul Martin to the chairs and ranking members of the full Senate Appropriations Committee and its Commerce, Justice, and Science Subcommittee. In his letter, the NASA IG tried to make the case for removing the congressional mandate that Europa program launches occur on the SLS.

There were two troubling aspects raised in the NASA IG’s letter that made it clear that NASA had fully intended to defy a congressional mandate passed in three fiscal year appropriations over two congresses controlled by different parties.

One was NASA IG Martin’s disclosure that, despite legislative mandates to launch the Europa missions on SLS, NASA had spent years ignoring the congressional mandate that Europa program launches occur on a SLS, “In our May 2019 audit, we noted that although Congress mandated NASA use the SLS for the Clipper mission, up to that point the Agency had not formally selected the launch vehicle.”

Martin additionally disclosed in footnote 14 of his letter that NASA had been working with SpaceX to study launching Europa Clipper on an expendable Falcon Heavy5, despite years of congressional mandates.

In these two disclosures, the NASA IG made the case for greater scrutiny by Congress regarding NASA’s management of the Europa program.

To state the obvious, appropriations acts passed by Congress and signed by the president are thereafter known as public laws and are not considered “lesser” laws but have in fact the same standing as any other law.

Normally, NASA has the latitude to pick and choose what launch vehicle one of its payloads will use. However, since fiscal year 2016 with passage of Public Law 114-1136, appropriations law has mandated–that’s what “shall” in the quotes below means–that the Europa missions, all of the Europa missions, be launched on a SLS. Such language has been anything but ambiguous or allowing of wiggle-room. For example, the appropriations law for fiscal year 2016, PL 114-113 states,

Provided further, That the National Aeronautics and Space Administration shall use the Space Launch System as the launch vehicle for the Jupiter Europa mission, plan for a launch no later than 2022, and include in the fiscal year 2017 budget the 5-year funding profile necessary to achieve these goals.

And such language, although with the dates shifted right due to delays in Europa Clipper, continued into the fiscal year 2019 appropriations law, PL 116-6,

Provided further, That the National Aeronautics and Space Administration shall use the Space Launch System as the launch vehicles for the Jupiter Europa missions, plan for an orbiter launch no later than 2023 and a lander launch no later than 2025, and include in the fiscal year 2020 budget the 5-year funding profile necessary to achieve these goals.

Congress had its reasons for such a mandate. There was the case that as a NASA mission it made sense to launch the agency’s own payload on the agency’s own launcher. Simply put, you eat your own dog food. It didn’t hurt that launching on SLS contributed to the amortization of the development cost of NASA’s own rocket.

Europa Clipper in orbit about Europa. Image: NASA

One very attractive feature of launching deep space missions on a powerful rocket like SLS is the compressed transit time compared to launching on a less performant rocket. A launch on SLS of Europa Clipper has a expected transit time to reach Europa of two years while launching on an expendable Falcon Heavy is 5 years. The three year difference, a 150% increase, in transit time for Europa Clipper launched on a SLS vs a Falcon Heavy to reach Europa is far from insignificant. The NASA IG’s omission of any discussion relative to the additional mission management cost that would be incurred over the additional three years were Europa Clipper launched on another rocket was, along with any discussion of launch risk, noted.

As noted by the NASA IG, NASA did eventually come around to the fact that it couldn’t simply ignore a congressional mandate, “…in August 2019 the Agency decided it was unable to select a commercial launch vehicle and instead established the Agency Baseline Commitment for the Europa Clipper mission based on a 2025 launch date using an SLS.” It eventually fell to NASA Administrator Bridenstine to state what should have been obvious, that NASA will follow the law.

None-the-less, one unsought effect of NASA IG Martin’s letter, given its content, will be greater congressional attention to NASA’s conduct with regard to its plans to launch all Europa missions on a SLS. The additional language mandating the launch of Europa Clipper on SLS in the Senate CJS Appropriations Subcommittee’s latest budget for NASA is one reflection of that greater scrutiny.


  1. House Space And Aeronautics Subcommittee Hearing, September 18, “Developing Core Capabilities For Deep Space Exploration: An Update On Nasa’s SLS, Orion, And Exploration Ground Systems”, Video (1:16:000) ↩︎
  2. Next Space Technologies for Exploration Partnerships-2 (NextSTEP-2), Appendix H: Human Landing System Broad Agency Announcement ↩︎
  3. S.3072 (115), page 73 ↩︎
  4. S.2584, p. 74 ↩︎
  5. NASA IOG Letter, August 17, 2019, footnote 14 ↩︎
  6. PL 114-113, 129 STAT. 2315 ↩︎

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