Preparations involving the Exploration Mission -1 (EM-1) Orion are enjoying a relatively trouble-free processing flow at the Kennedy Space Center (KSC). Milestones are being reached on all of the crew module elements, ahead of an All-Hands review that will take place in both the US and Italy. The only issue reported of late related to bracket attach hole threaded inserts, highlighting the lack of more pressing problems that Orion has struggled with over the years.
Over a decade in the making and several billion dollars later, Orion will finally get to fly on the first Space Launch System (SLS) mission. However, that launch won’t take place until deep into 2020, after NASA recently admitted the “risk-informed” target was the realistic goal for EM-1, despite continued wishes to launch by the end of 2019.
A lot of the stretched timeline and huge costs are not Orion’s fault, with continually changing political and technical goals hindering the early years of the spacecraft that began its life as the Crew Exploration Vehicle (CEV).
With a near-term mission plan and spacecraft design finally set, Orion is starting to see some light at the end of the tunnel.
The EM-1 Orion recently came to life via the “power on” milestones and has been put through its paces ever since, especially between various elements of the spacecraft, known as “assembly and testing operations”.
The Crew Module (CM) and Crew Module Adapter (CMA) recently underwent Initial Power On testing, along with the CMA Power Distribution Tests, and CMA Development Flight Instrumentation (DFI) functional tests.
This work is mainly taking place at KSC’s iconic Operations & Checkout (O&C) Building. with the Orion team also performing the CM heater checkout and Reaction Control System (RCS) thruster channelization.
Communication and recovery systems are also being tested, with S-band checkouts and work on the crew module uprighting system tanks all being conducted without issue.
Also related to recovery, the heat shield thermal load test was completed, which checks the quality of workmanship and materials used on Orion’s Thermal Protection System (TPS).
This work was carried out in a thermal chamber and then lifted onto its assembly fixture, ahead of non-destructive evaluation scans of the Avcoat blocks for pre- and post-test comparison and installation of the remaining development flight instrument sensors.
All testing has gone to plan, although one issue was spotted with an associated element that will ride with Orion and SLS during EM-1.
Known as the Orion Stage Adaptor (OSA), this “ring” will be a key element in the mating between SLS and the Orion stack during the Vehicle Assembly Facility (VAB) flow. It is also designed to host a number of secondary payloads that will launch with EM-1.
During checkouts of the OSA, engineers found concerns related to threaded inserts that “backed out” during cable installation.
When this issue was spotted, engineers then checked all of the OSA secondary payload bracket attach hole inserts with an after-swage gage and found a problem with 75 percent of the inserts. In total, 737 threaded inserts were checked.
While it was noted it required significant force to find an issue with the original inserts, NASA isn’t accustomed to taking chances, and as such a solution was employed, which was to replace the method for how the inserts were swaged, with a pneumatic hammer used in place of a ball peen hammer.
In all, this was a minor issue, but the amount of attention it received can be seen as a good sign that there are few other issues to discuss.
This bodes well for Orion as it heads into a major All-Hands review at the end of the month at the Johnson Space Center (JSC) in Houston.
This review will be followed up by another All-Hands meeting in Italy, which will focus on the European contribution to the EM-1 mission, namely the European Service Module. Orion contractor Thales Alenia Space has a facility in Turin.
The ESM has been cited as the main schedule risk item for Orion.
That first launch, Exploration Mission -1 (EM-1), will be a one-off test flight, sending an uncrewed Orion on a mission around the Moon. The launch will be conducted by a Block 1 SLS.
A large standdown period will then occur prior to the next mission, currently Exploration Mission -2 (EM-2) with the larger Block 1B SLS. As such, NASA is technically working on two rockets via near-parallel paths.
Work on the EM-2 Orion is already deep into production at MAF, with the service module primary structure currently being manufactured at Thales Alena Space in Turin.
(Images: Via NASA and L2 render from L2 artist Nathan Koga – The full gallery of Nathan’s (SpaceX Dragon to MCT, SLS, Commercial Crew and more) L2 images can be *found here*)
(To join L2, click here: https://www.nasaspaceflight.com/l2/)