The SLS Saga: 2020 Mid-Year Project Update
Alabama’s new license plate in honor of SLS Program (Courtesy of Alabama Department of Revenue)
“You may delay, but time will not.”
***2020’s midyear update on the SLS Program. For additional posts, please visit the SLS Saga microsite here.***
So 2020 has certainly brought with it a list of unexpected surprises…. It goes without saying that I hope everyone is keeping safe and healthy! Let’s continue to flatten the curve together by staying safe and healthy!
With the pandemic causing delays everywhere, the SLS Program is certainly no exception. However, since this rocket was not a stranger to delays even before COVID-19, so far in 2020, the program actually has achieved quite a bit of progress. This is the 2020 mid-year update on the SLS Program.
Alabama’s Tributes to the SLS Program
Alabama is no stranger to the SLS Program. The Marshall Space Flight Center, located in Huntsville, is currently conducting critical certification tests for the rocket. So it comes as no surprise that Alabama has recently redesigned its space license tag in honor of the SLS Program. Sponsored by the US Space and Rocket Center Foundation, the license plate features the SLS rocket with its iconic orange core stage along with the tagline: Dare to Explore. The background also pictorially describes the objectives of the Artemis Program—Moon2Mars–with the Moon in the foreground and Mars in the background. The license plate also features the primary color schemes of the Artemis Program: Red, White and Blue. Relatedly, this is not the only thing that Alabama has done recently to honor the Program: July 17 has been officially declared as Artemis Day in the state of Alabama.
SLS’s Maiden Flight: Late 2021 (at the Earliest)
NASA has pretty much officially confirmed what has been common knowledge for many: SLS’s maiden flight will not occur until late 2021. As discussed earlier this year, on Artemis Day 2019, it became clear that Artemis-1, the first mission of the SLS Program, will not occur in 2020. Then when COVID-19 hit, there was even concern about meeting a 2021 launch date. However, it seems like NASA is pretty confident that with all of the testing progressing smoothly, this is one date that NASA will likely not push back further.
Europa Mission Mandate Gone
Although SLS is falling way behind its own schedule, in NASA’s 2020 budget, Congress still mandated that SLS must be the Europa Clipper mission’s launch vehicle. But looks like the times are finally a-changing! In Congress’s initial draft for NASA’s fiscal year 2021 budget, its opening salvo suggests that the mandate might be movable. Noteworthy, Congress introduced the words “as available” to the Europa Clipper mission. Specifically, the document states “[t]hat [NASA] shall use the Space Launch System, if available, as the launch vehicles for the Jupiter Europa missions, plan for an orbiter launch no later than 2025 and a lander launch no later than 2027. . . .” Given that it is likely that SLS will not be ready for this mission before 2025, there is a strong likelihood that Congress is suggesting that the SLS vehicle mandate might be going by the wayside.
Main Engines Made Out of Gold
It looks like SLS’s main workhorse engines will cost $146 million each. These RS-25 engines, developed by Aerojet Rocketdyne, can each individually produce up to 512,000 pounds of thrust at full throttle. Each core stage of the SLS rocket will have four of these engines; and since the core stage is designed to be completely expendable, this means that each SLS launch will have at least $584 million in sunk engine costs. As a comparison, a single fully expendable launch of Falcon Heavy is only expected to cost $150 million. While the SLS rocket is more powerful and has bigger launch capabilities than that of Falcon Heavy, it’s not that much more; currently, SLS has a launch capacity of 70 metric tons to Low Earth Orbit, while Falcon Heavy comes out at 64 metric tons. Facing criticism, Aerojet has defended the engines’ costs by noting that there is a “fair amount of labor above and beyond just making parts” such as creating new manufacturing methods and techniques as well as producing special test equipment.
Side Boosters on the Move as Well
Speaking of SLS’s engines, its side rocket boosters were recently delivered to Kennedy Space Center. These side boosters will be used for the first mission of the Artemis Program. Linking it to the Space Shuttle era, one of these booster segments actually flew on the last mission of the Space Shuttle Program, STS-135. While the core stage for the SLS rocket is still in the middle of Green Run Tests at the Stennis Space Center in Mississippi, this is the second component of Artemis-1 that has arrived at Kennedy Space Center where it will eventually undergo stacking operations for launch.
Pressing Ahead on Supply Contracts
Speaking of side rocket boosters, in late June, NASA signed a $49.5 million extension with Northrop Grumman for the production of these boosters that will be used for six future missions: Artemis 4-9. Although SLS has yet to launch its first mission, this suggests that NASA is ramping up SLS components production. Along with the contract for the new RS-25 engines that will be produced by Aerojet Rocketdyne, NASA has also started negotiations with Boeing for the next ten core stages of the SLS rocket as well. Why is NASA pressing ahead when the SLS is still yet to be flight-proven? It is because there are political considerations at work here too: SLS is necessary as a job creator. And with these contract announcements, it is unlikely that SLS—and this Saga—will go away any time soon!
Green Run Tests Underway
Speaking of tests, although COVID-19 is slowing down SLS’s certification process, the core stage has already completed three of its eight green run tests. The completed tests include applying launch stress forces, powering up, and checking emergency shut down operations. While the core stage still has several more tests to complete before its big static test moment, these successes indicate that the SLS core stage checklist is proceeding smoothly. Even with COVID-19’s impact on the schedule, the green run tests are still on track to be completed by the end of this year. Once the core stage completes its green run tests, it will be shipped to the Kennedy Space Center, where stacking operations can begin.
Tests and More Tests
And still on the subject of tests, the Stennis Space Center is not the only place where SLS tests are being conducted. At the Marshall Space Flight Center in Huntsville, Alabama, SLS rocket parts have been going through the literal pressure cooker as well. Late last month, NASA and Boeing were able to complete all of these structural tests. These pressurization simulations are designed to stress the rocket components to their limits—hence, they will generally end with the parts exploding or the tanks bursting. For instance, on the last test, the liquid oxygen fuel tank was filled with water and pressurized to its maximum breaking point, whereby it exploded but at the load levels expected.
