JAN. 16, 2021–NASA is currently targeting this fall for the launch of Artemis I, the uncrewed first test flight of the agency’s Space Launch System rocket and the Orion Spacecraft together. With less than a year of time remaining until the launch, NASA has already begun launch preparation operations.
Last summer, Northrop Grumman delivered the ten Artemis I solid rocket booster segments from their facility in Promontory, UT, to Kennedy Space Center in Florida. At Kennedy, the segments were taken to the Rotation, Processing, and Surge Facility (RPSF). At the RPSF, eight out of the ten segments were put in storage, and the remaining two segments, which were to be the aft segments of the two boosters, underwent some assembly. Soon after the booster segments arrived, the inter-stage adapter for Artemis I, known as the Launch Vehicle Stage Adapter, or LVSA for short, also arrived, coming from NASA’s Marshall Space Flight Center via the “Pegasus” barge. The LVSA connects the SLS core stage with the upper stage for the Block 1 variant, known as the Interim Cryogenic Propulsion Stage, or ICPS. The ICPS is a Delta IV derived upper stage.
Booster stacking on SLS’s mobile launcher platform (ML-1) began in November where the two aft segments were positioned onto the platform of the tower. Stacking was then put on hold, due to schedule uncertainties regarding the completion date of the core stage’s “Green Run” tests, and in turn the delivery of the stage to KSC. Late last year, NASA attempted a wet dress rehearsal of the final test, a full-duration static fire, on Dec. 7, however, this attempt was scrubbed. A second attempt was also scrubbed before any fuel entered the stage, and then on Dec. 20, the wet dress rehearsal test was completed. While stopped earlier than expected, the test still gave NASA the data they needed to be confident in proceeding with the final static fire test.
After the wet dress rehearsal, NASA announced earlier this month that the static fire test could occur “as early as Jan. 17,” however the test was moved up, a rare occurrence in aerospace, by a day to Jan. 16, or today, as well as announcing at what time the test would happen and where it would be streamed (here). With the schedule regarding Artemis I’s core stage becoming more clear, NASA decided to commit to launching Artemis I this year by stacking the third segment on top of the already-stacked aft segments of SLS’s boosters. This starts an invisible clock for the launch of the mission – as the boosters can only ever be stacked for 12 months without requiring disassembly and recertification. However, to create more schedule margin, NASA is looking into ways to expand that timeframe.
In a pre-test briefing to the media, NASA officials answered several questions regarding the static fire and what would happen next. SLS program manager, John Honeycutt, said that the core stage was on track to be delivered to KSC for integration by February. For comparison, NASA expects to deliver the Artemis II core stage directly from the Michoud Assembly Facility to KSC by June 2022, ahead of its own 2023 mission. However, an important factor to note with the static fire test is that if a delay were to occur post-fueling, it would be a minimum of seven days, due to resource replenishment at NASA’s Stennis test facility. Stennis is not equipped for regular tests of super-heavy vehicles like SLS, and requires a week to replenish enough oxygen and hydrogen to proceed with another test. However, if a delay was to happen mid-fueling, or before, this timeline would be considerably shorter.
On Jan. 14, NASA held a media day at KSC, where members of the media were invited into the Vehicle Assembly Building to view the current Artemis I stack, as well as the turnover of Artemis I’s Orion spacecraft to Exploration Ground Systems at the Neil Armstrong Operations and Checkouts Building. In a press release, NASA said this milestone marked an “increasing confidence in the approaching 2021 launch date when the spacecraft will lift off atop the Space Launch System from Launch Pad 39B at Kennedy.” The Orion short stack, which includes the crew and service module, was position on top of a transport platform, after which it will make a three-hour journey from the O&C building to the Multi-Payload Processing Facility, where the spacecraft will be fueled and receive its NASA and ESA branding, including the famous “worm” logo. Once the work at the MPPF is done, Orion will be placed back on the transporter where it will be taken to the Launch Abort System Facility, and then mated to its launch escape system as well as the ogive fairing panels that surround it during launch. Finally, after this, it will be taken to the VAB, and integrated with the Space Launch System rocket by June this year. “The handover of Orion is a big milestone for the Artemis program – it represents the culmination of years of hard work by both the Orion and the Exploration Ground Systems teams,” said Mike Bolger, EGS manager.
Recently, NASA has also just finished stacking the fourth segment of the two SLS boosters for Artemis I. On the media day on Jan. 14, media were able to view not only the stacked segments on ML-1 but also both center booster segments (the fourth and fifth), both emblazoned with the iconic NASA “worm”. When the core stage arrives at KSC in February, the twin side boosters will already be fully stacked, allowing for the integration of the core stage. The LVSA is already at the VAB, and will be added to the stack once the core is already in place. Then, the ICPS second stage will be integrated, however, before Orion integration, Exploration Ground Systems will place a mass simulator on top of the vehicle instead, in order to conduct a modal test of the vehicle before stacking. Finally, in June, Orion will be integrated to the full Block 1 Space Launch System rocket, resulting in the complete Artemis I stack, still scheduled to launch in fall of this year. The time between final stacking and launch is necessary for final tests and pre-flight reviews in order to increase confidence even more in the already thoroughly-tested SLS stack.
Today, the Artemis I core stage is planning to conduct its static fire. The stream will begin at 4:20 p.m. EST on NASA TV and the agency’s various social media accounts, with a post-test briefing about 2 hours afterwards. If the test is a success, NASA will be one step closer to launching into a new era of space exploration, with commercial partners in hand, launching the next man and first woman to the Moon – to stay.