The processing teams within NASA’s Exploration Ground Systems (EGS) Program are focusing their plans for how they’ll put together the first integrated Orion and Space Launch System (SLS) vehicle to launch Exploration Mission-1 (EM-1). After the spacecraft and launch vehicle components have individually completed all of their first-time and acceptance testing, they will be transported to the Kennedy Space Center (KSC) and turned over to EGS to be assembled, checked out together, and launched.

Each of the components have their own paths through ground processing at KSC before they all converge in the Vehicle Assembly Building at Launch Complex 39.

EGS provided an overview of some of the preparations for stacking, how the pieces fit together, and all extra testing they’ll do before they get to the countdown for their first launch.

Two teams: Spacecraft and Offline Operations, Integrated Operations

Orion and SLS hardware components are still largely in assembly and testing by their contractors at different locations across the United States. There are two teams within Exploration Ground Systems (EGS) based at the Kennedy Space Center (KSC) in Florida that will be processing the flight hardware to launch EM-1 once it turned over to them from the contractors.

The Spacecraft and Offline Operations team processes Orion and SLS upper stage hardware, while the Integrated Operations team processes the SLS Solid Rocket Booster (SRB) and Core Stage hardware and assembles the whole vehicle on the Mobile Launcher (ML) in the Vehicle Assembly Building (VAB), starting with the SRB segments.

After the boosters are stacked and Core Stage mated to them, the Spacecraft and Offline Operations team will turn their processed hardware over to Integrated Operations in the VAB to complete stacking.

“We’re responsible for the Orion vehicle post-turnover from Lockheed Martin to the government and we’re also responsible for the ICPS (Interim Cryogenic Propulsion Stage), which is the upper/second stage of the SLS vehicle for the servicing prior to it being stacked on the SLS and we’re also responsible for the Orion Stage Adapter (OSA) which has about thirteen cubesat satellites,” Lili Villarreal, Flow Manager for NASA EGS Spacecraft and Offline Operations, said.

“We’re responsible for processing, installing those, charging their batteries and getting them ready.”

“Our team basically hands over in pieces,” she explained. “First, we’ll hand over the ICPS fully serviced in the VAB. Then we’ll hand [over] the Orion Stage Adapter which will get stacked on top of the ICPS and then after we’ll do the Orion vehicle.”

“All the work we’re calling ‘Spacecraft and Offline’ is actually working in parallel,” David Diaz, Flow Manager for NASA EGS Integrated Operations, said. “We start off what we call ‘integrated ops’ in the RPSF (Rotation Processing and Surge Facility). Very similar to Shuttle, we start stacking and this whole time we’re starting stacking operations, Lili is off processing on her end getting the spacecraft ready.”

“And then of course we’ll work with the Core Stage once it comes in and then we’ll do some integrated testing with just that stack and then we roll in the LVSA (Launch Vehicle Stage Adapter), and then ICPS, as she just alluded to,” he continued. “So we’ve essentially stacked the vehicle at that point and then when she’s done with her Orion, she’ll bring that to us pretty much already checked out and then we will go ahead and stack it and then we start our integrated testing at that point.”

The EGS teams are monitoring the current work by the contractors as they prepare for receiving the hardware for launch operations. “We do have the capability to go to their sites and do some training with them, because it’s ultimately the best for us to train with them and the hardware before we see the hardware,” Villareal explained.

“Wherever we feel that certain operations that they’re doing in their facilities are going to complement our eventual ground processing, we’ll go and just basically shadow them and learn from them.”

“We work with the flight hardware providers both civil servant and contractor side on the development of the requirements that they give to us to go process and check out the vehicle,” Jeffrey Angermeier, EGS Flow Director for NASA, added.

“We’ve been working with the other programs for years in the development and understanding of those requirements,” he explained. “Those are things that we receive from the other programs and we basically put together work authorizing documents that implement those requirements and that’s how we get the vehicle done.”

“So two opportunities — we work upstream with them on requirements development and we get upstream with them to get as many opportunities as we can to go see the vehicle and observe some of their operations to give a little bit of OJT (On the Job Training) so to speak on what to expect when that hardware gets here,” he added.

Current hardware status

So far, only two of the major hardware elements for EM-1 have been turned over to EGS. The ICPS was turned over to EGS by United Launch Alliance (ULA) late last year and the Orion Stage Adapter that will carry thirteen cubesats on EM-1 and sits between the ICPS and the Orion stack on top was turned over earlier this year.

Both elements are currently being stored at KSC until their turn for stacking. “Right now the ICPS is currently in storage at the Space Station Processing Facility (SSPF),” Villarreal said. “The Space Station Program was really nice enough to let us bring the ICPS over to the SSPF for ‘dwell.'”

A third piece, the LVSA, is close to completion at the Marshall Space Flight Center in Huntsville, Alabama, but may stay there in the interim. “For the LVSA, the plan is that comes directly into us, to integrated ops and that will be stored in High Bay 4,” Diaz explained. “We have some training opportunities from the internal access kits and there’s some checkouts that we’ll do in there.”

“We’re still negotiating a date for that, but then we go ahead and stage in High Bay 4 and we’ll keep it maintained and checked out and so forth until we actually need it for stacking.”

EGS is working backwards from a launch date to plan when the bulk of the processing work would start and when they need certain elements. “What we generally do is we establish what’s considered like ‘no later than’ need dates and so for our flow, when we look at when we need to get everything done to get the vehicle ready to go fly, we essentially start with the launch date and work our way back based on the assumed time we think it takes to do the activities to get the vehicle ready,” Angermeier explained.

SRB hardware for EM-1 is almost ready, but transportation and handover will start closer to the EM-1 launch target date, which is currently forecast for the middle of 2020. The critical paths in the schedule are the Orion European Service Module (ESM) and the SLS Core Stage, and progress in assembly and testing of those first-time builds will continue to influence overall schedule and interim target dates.

Stacking starts with boosters

Integration of the full vehicle will begin with processing and stacking of SRB hardware. As with other parts of SLS, the boosters are derived from Space Shuttle designs and retain much of the reusable, Shuttle-heritage motor casing and forward and aft assembly hardware.

Processing and stacking of the boosters is also similar to Shuttle, with the five-segment motors being the first elements stacked on the launch platform. Start of work will center around the arrival of the ten segments from their Northrop Grumman Innovation Systems (NGIS) production facility north of Salt Lake City, Utah.

The booster assembly hardware on the top and bottom of the SRBs is being processed by NGIS at KSC facilities, and the Integrated Operations team is planning on those being handed over from NGIS a few weeks before the motor segments arrive by rail. “We work with the flight programs to determine the appropriate time to receive it,” Angermeier said.

“Basically about two weeks before we start that work we’ll receive the aft skirts and then the segments arrive basically the first day of our processing flow over there on rail car,” he continued.

“If there is a need, program to program, where they want to get the segments down here a little bit earlier or give us the aft skirts earlier then we’ll work with them to find the appropriate time to take those over. So that’s what we do with the aft skirts.”

“For the forward assemblies, essentially the first day that we start stacking boosters in the VAB is the day we tell them we’d like to have our forward assemblies delivered to us and same thing, if they want to turn them over a little bit earlier we’re not going to fight that,” Angermeier said. “We’d take them a couple of weeks early if that’s something that they desire.”

As noted, the booster hardware will first be prepared for stacking in the RPSF. The loaded motor segments will be offloaded from their rail car transportation canisters and the assemblies will be moved from the Booster Fabrication Facility.

“We start our segment offloads into the RPSF,” Diaz said, starting with the aft segments. “We do offload those first, because we know that that assembly is going to take a little bit longer, so during that time-frame as we work on that, we’ll be offloading our center segments. We’ll do our grain inspections and our clevis inspections and we’ll get those onto our stands and then we’ll roll those over into the Surge facility.”

Talking about the aft segments, Diaz said “What we’ll do is our right-hand first, we’ll get that set up, get it onto the stand, and then we’ll go ahead and move over to our left-hand.”

“Essentially when we start offloading our segments you’ve got the aft skirts already staged in the build up stand and you offload the aft motor, mate it to the skirt, you install the nozzle extension and then you go through the rest of the buildup, which is the Core Stage attach ring, instrumentation, linear-shaped charge, that type of stuff, and that’s about a month of work for each one of those afts.”

One at a time the aft segments will be placed on a transporter and moved the short distance from the RPSF to High Bay 4 of the VAB, for final preparations to go on the Mobile Launcher. “We’ll take it off, move it over to the slap stand, prep the surfaces, and then we bring it up and over to High Bay 3,” Diaz explained.

It’s still very preliminary, but the plan is to alternate work building up the left and right boosters. “We really haven’t figured that one out yet, but we’re definitely looking to go left, right, so we’ll stagger them and the idea is as we start moving up and we pass our leak checks we can start doing the closeouts on one side as we start stacking on the other side,” Diaz noted.

“That’s kind of how we’re going to go all the way until we get to the top.”

Orion and ICPS servicing prior to stacking

The first ESM, Flight Model-1, is currently expected to arrive at KSC at the start of November, kicking off a little more than one year’s worth of integration and testing of the Orion spacecraft. The stack of the ESM, Crew Module (CM), and Crew Module Adapter (CMA) will be mated and checked out by Lockheed Martin at the Operations and Checkout (O&C) Building at KSC and then go through a series of tests at the Plum Brook Station at the Glenn Research Center in Ohio before final installs back in Florida.

The Orion vehicle will then be handed over to EGS and the Spacecraft and Offline Operations team for launch processing. “Our handover point with the Orion vehicle is actually at the O&C,” Villarreal said. “We’re responsible for going to quote ‘pick up’ the Orion vehicle.”

“We’ll use our payload transporter to go pick up the vehicle and then we’ll bring it to the MPPF (Multi-Payload Processing Facility) for servicing. At the MPPF we have a servicing stand that we developed particularly to position Orion and connect to the vehicle from a power, commanding, and servicing panel perspective.”

“We’ll hook up all of our GSE (Ground Support Equipment), and the first thing that we do when the vehicle gets there is power up the vehicle and do some post-transportation checkouts before we move into our servicing operation,” she continued.

“We have to service some nitrogen tanks and then some helium tanks and then after that we’ll do ammonia servicing for the vehicle’s active thermal control system. And then we’ll go into the [propellant] loading operations for both the CM (Crew Module) and the SM (Service Module).”

The Spacecraft and Offline Ops team will also service the ICPS in the MPPF before it can be stacked on top of the LVSA. The ICPS is a modified United Launch Alliance (ULA) Delta 4 upper stage, and its attitude control system thrusters use hydrazine.

Orion has more commodities that need to be serviced and in larger quantities, and it will go through the MPPF first. “We’re going to have to wait until we get Orion out of the MPPF to avoid like a traffic jam kind of thing, but when the Orion vehicle is in the LASF (Launch Abort System Facility), that’s when we bring the ICPS over to the MPPF and we’ll go ahead and do the hydrazine load on that prior to going to the VAB and that’s really the only work we’ll do in the MPPF with respect to the ICPS.

While the ICPS will more or less be ready to stack once it leaves the MPPF, after fueling Orion still has to be integrated with its Launch Abort System (LAS) before it will be transported to the VAB.