The Path to the Pad

2016 is well underway. Another year over, another year begun.

For the SLS program, it means we’re even further past the halfway point toward launch readiness. It’s been only four years since the program officially began in September 2011, and we’re working toward being ready in less than three years for our first launch.

Artist’s concept of SLS stacking at Kennedy Space Center
The day this is a photograph instead of an artist’s concept will be a good day.

The bulk of the first four years was focused on completing the design. To be sure, there was smoke and fire and bending metal as we tested boosters and engines and began building the barrels for the core stage of the rocket. Building on the foundation of the Space Shuttle Program allowed us to move quickly into testing of the engines and boosters, and the design work on the core stage progressed rapidly enough to allow us to begin early manufacturing, and all of that was preparation for what would come when we completed the critical design review of the plans.

An RS-25 engine being raised into the test stand
RS-25 Engine 2059 is currently in the stand for testing at Stennis Space Center. A few years ago, it powered Atlantis’ longest mission, and a few years from now, it will loft SLS’ first crew into space.

With the design work all but done, the push toward the pad is well underway, and there’s a lot of work that entails.

For the rocket to roll out to the pad for launch, each element of the vehicle has to arrive at the Vehicle Assembly Building at Kennedy Space Center to be stacked together with the Orion crew vehicle. And each part has its own road to get there.

For the upper stage portion of the vehicle, which will push Orion out of Earth orbit and into deep space, to be ready to fly, test articles will be built of the adapters that connect the upper stage to the rest of the rocket and to Orion, along with a test article of the upper stage itself. These three test articles will be placed in a stand together, and subjected to stresses and strains to make sure they’re ready for launch. Based on the results of that test, the actual flight articles of the upper stage and adapters will be completed and transported from Marshall Space Flight Center in Huntsville, Ala., to Kennedy Space Center.

For the solid rocket boosters to be ready to fly, qualification motor tests will take place at Orbital ATK in Utah. The results of those tests will pave the way for processing, fueling and completion of the flight boosters, using hardware already at Kennedy Space Center. The boosters will be the first piece of SLS to be stacked in the VAB at Kennedy.

For the 200-foot-tall core stage, which its large fuel tanks and RS-25 engines to be ready to fly, the engines and the stage itself must each undergo individual preparation, and then be integrated together. Tests will be conducted at Stennis Space Center in Mississippi of individual engines, to make sure the RS-25 is ready for the environment it will encounter during launch. Test articles will be built of the large pieces that make up the core stage, and will be transported from Michoud Assembly Facility outside New Orleans to Marshall, where they’ll be placed in large test stands – which have to be built for this purpose – to undergo structural testing. Using the results of those tests, the actual first flight core stage will be completed. Engines will be transported from Stennis to Michoud to be integrated into the core stage, which will then be transported back to Stennis for the largest rocket test firing since the Apollo era. Once it has been tested, the stage will then be shipped down to Kennedy for stacking.

And that’s just the big pieces. In the meantime, work must be done on things like making sure the software that controls the rocket is ready to go.

A new SLS test stand being built at Marshall Space Flight Center
At Marshall Space Flight Center, work is taking place now on the stands that will be used for the test versions of core stage components.

We’ve already made a good start on this “building” phase of the program. In March of last year, we conducted the first qualification test of the solid rocket boosters, and we’re currently preparing for the next, which will take place later this year. At the same time, we’ve started working on the flight hardware for the boosters for SLS’s first launch.

We’ve completed the first series of individual engine tests, using an unflown development engine, and are about to start the second early this year, using an engine that has flown on shuttle missions and will fly again on the second flight of SLS.

We’re almost finished with the upper-stage element test articles, and will use them to conduct structural tests over the course of this year. At the same time, work has already begun on the actual upper stage that will be used to push Orion beyond the moon on SLS’s first flight.

We’re well underway building the pieces that will be used to finish the core stage test articles and the stands on which they’ll be tested. Very soon, we’ll be welding together test articles of the rocket’s liquid hydrogen and liquid oxygen tanks, as well as other core stage components. Those, in turn, will be followed by the flight articles for the first core stage.

It’s an exciting time, and making it more exciting is the fact that this work is taking place in the modern era of digital media, giving you an unprecedented look at the process. As we continue to grow closer, one step at a time, to launch, you’ll be able to follow us every step of the way.


Next Time: May The Forces Be With You

Join in the conversation: Visit our Facebook page to comment on the post about this blog. We’d love to hear your feedback!

Orion, At Your Service (Module)

What do NASA’s Orion spacecraft and nuclear-powered airplanes have in common? Here’s a hint: It’s something they also both have in common with actor Samuel L. Jackson.

The answer, of course, is that they’ve all been to NASA’s Plum Brook Station in Sandusky, Ohio.

The Orion service module test article with a model of SLS
The piece of hardware on the left fits roughly were the NASA logo is on the rocket to the right.

Plum Brook, a branch of NASA’s Glenn Research Center, was originally created to allow the agency to conduct nuclear research, first related to airplanes and then to nuclear rockets. Today, it’s a unique facility that allows testing that replicates extreme conditions encountered in spaceflight – from vacuum and thermal environments found in orbit to launch-like acoustic levels that would turn a human body into a puddle.

On an average day, the Space Power Facility at Plum Brook is engaged in tasks like using a a vacuum chamber made of aluminum equivalent to about one billion soda cans to test large payload fairings for SpaceX rockets. And on special occasions it’s used for more unique purposes, like serving as a set for Marvel’s The Avengers (in case you’ve ever wondered why there was a NASA banner hanging behind Jackson’s Nick Fury in the opening scene).

I had the opportunity to visit Plum Brook last month for the arrival from Europe of a test article of the Orion crew vehicle’s service module.* Orion, of course, is the aforementioned deep-space spacecraft, which will be launched on SLS to enable human missions beyond the moon and eventually to Mars. Orion is designed to meet the robust demands of human space exploration, from providing life support to keep up to six astronauts healthy and safe to withstanding the high temperatures generated by a high-speed entry into Earth’s atmosphere.

In order to do that, Orion has requirements that dwarf those of a mission to low Earth orbit. Even after it separates from SLS, Orion will need more than twice as much propellant as a spacecraft on an orbital mission. It will have to have four times the ability to scrub carbon dioxide from the atmosphere, and will have to carry five times as much oxygen and drinking water.

Infographic of Orion capabilities
Just some of the ways Orion is designed uniquely for a unique purpose.

Which is where the service module comes in. It’s a combination of a propulsion system and a storage unit for all those helpful things like air and water that keep astronauts alive while traveling hundreds of thousands of miles from home. Orion’s service module is provided by the European Space Agency, in a partnership agreement that has its roots in NASA’s cooperation with ESA on the International Space Station. The service module builds on the success of the European Automated Transfer Vehicle, which has carried cargo to the space station since 2008.

Work is well underway on the service module for the first flight of SLS and Orion on Exploration Mission 1, but, in the meantime, the recently arrived test article will be put through a variety of stresses and loads to make sure the design is ready to fly. Being at the event marking the arrival of the test article was a glimpse into the future of international space exploration – an overlapping of different accents and different languages, united in a common message of working together to do things we’ve never before done.

The Red Planet is waiting. And people from around our planet are already working together to get there.

Speakers in the acoustic testing chamber at Plum Brook
The acoustic test chamber at Plum Brook will subject the test article to 163 decibels of sound.

*If you’d like to join Orion and Samuel L. Jackson in having a Plum Brook connection, your chance is coming. Plum Brook Station and Glenn Research Center, in Cleveland, will hold open houses in 2016, on June 11-12 and May 21-22, respectively, in connection with Glenn’s 75th anniversary.

Join in the conversation: Visit our Facebook page to comment on the post about this blog. We’d love to hear your feedback!