We’ve Got (Rocket) Chemistry, Part 1

Written by Beverly Perry

What do water and aluminum have in common?

If you guessed that water and aluminum make SLS fly, give yourself a gold star!

Chemistry is at the heart of making rockets fly. Rocket propulsion follows Newton’s Third Law, which states that for every action there is an equal and opposite reaction. To get a rocket off the launch pad, create a chemical reaction that shoots gas and particles out one end of the rocket and the rocket will go the other way.

What kind of chemical reaction gets hot gases shooting out of the business end of a rocket with enough velocity to unshackle it from Earth’s gravity? Combustion.

Whether it’s your personal vehicle or a behemoth launch vehicle like SLS, the basics are the same. Combustion (burning something) releases energy, which makes things go. Start with fuel (something to burn) and an oxidizer (something to make it burn) and now you’ve got propellant. Give it a spark and energy is released, along with some byproducts.

For SLS to fly, combustion takes place in two primary areas: the main engines (four Aerojet Rocketdyne RS-25s) and the twin solid rocket boosters (built by Orbital ATK) that provide more than 75 percent of thrust at liftoff. Combustion powers both propulsion systems, but the fuels and oxidizers are different.

RS-25 engine during testing
Steam clouds, the product of the SLS main engines’ hydrogen-oxygen reaction, pour from an RS-25 engine during testing at NASA’s Stennis Space Center.

The RS-25 main engines are called “liquid engines” because the fuel is liquid hydrogen (LH2). Liquid oxygen (LOX) serves as the oxidizer. The boosters, on the other hand, use aluminum as fuel with ammonium perchlorate as the oxidizer, mixed with a binder that creates one homogenous solid propellant.

Making water makes SLS fly

Hydrogen doodleHydrogen, the fuel for the main engines, is the lightest element and normally exists as a gas. Gases – especially lightweight hydrogen – are low-density, which means a little of it takes up a lot of space. To have enough to power a large combustion reaction would require an incredibly large tank to hold it – the opposite of what’s needed for an aerodynamically designed launch vehicle.

To get around this problem, turn the hydrogen gas into a liquid, which is denser than a gas. This means cooling the hydrogen to a temperature of ‑423 degrees Fahrenheit (‑253 degrees Celsius). Seriously cold.

Oxgen doodleAlthough it’s denser than hydrogen, oxygen also needs to be compressed into a liquid to fit in a smaller, lighter tank. To transform oxygen into its liquid state, it is cooled to a temperature of ‑297 degrees Fahrenheit (‑183 degrees Celsius). While that’s balmy compared to LH2, both propellant ingredients need special handling at these temperatures. What’s more, the cryogenic LH2 and LOX evaporate quickly at ambient pressure and temperature, meaning the rocket can’t be loaded with propellant until a few hours before launch.

Once in the tanks and with the launch countdown nearing zero, the LH2 and LOX are pumped into the combustion chamber of each engine. When the propellant is ignited, the hydrogen reacts explosively with oxygen to form: water! Elementary!

2H2 + O2 = 2H2O + Energy

This “green” reaction releases massive amounts of energy along with superheated water (steam). The hydrogen-oxygen reaction generates tremendous heat, causing the water vapor to expand and exit the engine nozzles at speeds of 10,000 miles per hour! All that fast-moving steam creates the thrust that propels the rocket from Earth.

It’s all about impulse

But it’s not just the environmentally friendly water reaction that makes cryogenic LH2 a fantastic rocket fuel. It’s all about impulse – specific impulse. This measure of the efficiency of rocket fuel describes the amount of thrust per amount of fuel burned. The higher the specific impulse, the more “push off the pad” you get per each pound of fuel.

The LH2-LOX propellant has the highest specific impulse of any commonly used rocket fuel, and the incredibly efficient RS-25 engine gets great gas mileage out of an already efficient fuel.

But even though LH2 has the highest specific impulse, because of its low density, carrying enough LH2 to fuel the reaction needed to leave Earth’s surface would require a tank too big, too heavy and with too much insulation protecting the cryogenic propellant to be practical.

To get around that, designers gave SLS a boost.


Next time: How the solid rocket boosters use aluminum – the same stuff you use to cover your leftovers – to provide enough thrust to get SLS off the ground.

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Five “Secrets” of Engine 2059

Earlier this month, another successful test firing of a Space Launch System (SLS) RS-25 engine was conducted at Stennis Space Center in Mississippi. Engine testing is a vital part of making sure SLS is ready for its first flight. How do the engines handle the higher thrust level they’ll need to produce for an SLS launch? Is the new engine controller computer ready for the task of a dynamic SLS launch? What happens when if you increase the pressure of the propellant flowing into the engine? SLS will produce more thrust at launch than any rocket NASA’s ever flown, and the power and stresses involved put a lot of demands on the engines. Testing gives us confidence that the upgrades we’re making to the engines have prepared them to meet those demands.

If you read about the test – and you are following us on Twitter, right? – you probably heard that the engine being used in this test was the first “flight” engine, both in the sense that it is an engine that has flown before, and is an engine that is already scheduled for flight on SLS. You may not have known that within the SLS program, each of the RS-25 engines for our first four flights is a distinct individual, with its own designation and history. Here are five other things you may not have known about the engine NASA and RS-25 prime contractor Aerojet Rocketdyne tested this month, engine 2059.

Engine 2059 during testing at Stennis Space Center on March 10
Engine 2059 roars to life during testing at Stennis Space Center.

1. Engine 2059 Is a “Hubble Hugger” – In 2009, the space shuttle made its final servicing mission to the Hubble Space Telescope, STS-125. Spaceflight fans excited by the mission called themselves “Hubble Huggers,” including STS-125 crew member John Grunsfeld, today the head of NASA’s Science Mission Directorate. Along with two other engines, 2059 powered space shuttle Atlantis into orbit for the successful Hubble servicing mission. In addition to its Hubble flight, engine 2059 also made four visits to the International Space Station, including the STS-130 mission that delivered the cupola from which station crew members can observe Earth below them.

Launch of Atlantis on STS-125
The engine farthest to the left in this picture of the launch of the last Hubble servicing mission? That’s 2059. (Click for a larger version.)

2. The Last Shall Be First, and the Second-to-Last Shall Be Second-To-First – The first flight of SLS will include an engine that flew on STS-135, the final flight of the space shuttle, in 2011. So if the first flight of SLS includes an engine that flew on the last flight of shuttle, it only makes sense that on the second flight of SLS, there will be an engine that flew on the second-to-last flight of shuttle, right? Engine 2059 last flew on STS-134, the penultimate shuttle flight, in May 2011, and will next fly on SLS Exploration Mission-2.

View of the test stand during the test of engine 2059 at Stennis Space Center on March 10.
The test of engine 2059 at Stennis Space Center on March 10.

3. Engine 2059 Is Reaching for New Heights – As an engine that flew on a Hubble servicing mission, engine 2059 has already been higher than the average flight of an RS-25. Hubble orbits Earth at an altitude of about 350 miles, more than 100 miles higher than the average orbit of the International Space Station. But on its next flight, 2059 will fly almost three times higher than that – the EM-2 core stage and engines will reach a peak altitude of almost 1,000 miles!

Infographic about engine testing
Click to see larger version.

4. Sometimes the Engine Tests the Test Stand – The test of engine 2059 gave the SLS program valuable information about the engine, but it also provided unique information about the test stand. Because 2059 is a flown engine, we have data about its past testing performance. Prior to the first SLS RS-25 engine test series last year, the A1 test stand at Stennis had gone through modifications. Comparing the data from 2059’s previous testing with the test this month provides calibration data for the test stand.

NASA Social attendees with engine 2059 in the background
Attendees of a NASA Social visiting Stennis Space Center being photobombed by engine 2059.

5. You – Yes, You – Can Meet Awesome SLS Hardware Like Engine 2059 – In 2014, participants in a NASA Social at Stennis Space Center and Michoud Assembly Facility, outside of New Orleans, got to tour the engine facility at Stennis, and had the opportunity to have their picture made with one of the enginesnone other than 2059. NASA Social participants have seen other SLS hardware, toured the booster fabrication facility at Kennedy Space Center in Florida, and watched an RS-25 engine test at Stennis and a solid rocket booster test at Orbital ATK in Utah. Watch for your next opportunity to be part of a NASA Social here.

Watch the test here:
https://www.youtube.com/watch?v=njb9Z2jX2fA[/embedyt]

If you do not see the video above, please make sure the URL at the top of the page reads http, not https.


Next Time: We’ve Got Chemistry!

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Making a Lot of Fire in Two “Easy” Steps

On one end of the technology spectrum, you have rocket science, mastering the laws of physics to allow human beings to break the chains of gravity and sail through the void of space.

On the other end, you have the earliest humans, first learning to use the world around them in innovative ways to do things they previously couldn’t.

What do these two extremes have in common? Making fire. Just like the secret to learning to cook food was mastering the creation of flames, creating fire is also the secret to leaving the planet.

We just use a much bigger fire.

Close-up of aft end of SLS during launch
Solid rocket motors and liquid-fuel engines will work together to propel the first SLS into space.

If you’ve watched the first video in our No Small Steps series you’ve learned why going to Mars is a very big challenge, and why meeting that challenge requires a very big rocket. In the second installment we talked about how NASA’s Space Launch System (SLS) builds on the foundation of the Saturn V and the space shuttle, and then uses that foundation to create a rocket that will accomplish things neither of them could.

Now, the third No Small Steps video takes a step further by looking at the basics of the monumental energy that makes the rocket go up. If you’ve been following this Rocketology blog and the No Small Steps videos, you’re aware that the initial configuration of SLS uses two different means of powering itself during launch – solid rocket boosters and liquid-fuel engines.

But why? What’s the difference between the two, and what role does each play during launch? Well, we’re glad you asked, because those are exactly the questions we answer in our latest video.

With more SLS engine and booster tests coming in the next few months, this video is a great way to get “fired up” about our next steps toward launch.

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#YearInSpace: Mars, Miles, Months, Mass and Momentum

During his yearlong mission aboard the International Space Station, Scott Kelly traveled over 143 million miles in orbit around Earth.

On average, Mars is 140 million miles away from our planet.

Coincidence? Well, basically.

Scott Kelly with plant-growth experiment
NASA astronaut Scott Kelly took this selfie with the second crop of red romaine lettuce in August 2015. Research into things like replenishable food sources will help prepare the way for Mars. (And the red lettuce even kind of matches the Red Planet!)

There’s nothing average about a trip to Mars; so of course you don’t travel an “average distance” to get there. Launches for robotic missions – the satellites and rovers studying Mars today – are timed around when Earth and Mars are about a third of that distance, which happens every 26 months.

While the shortest distance between two points is a straight line, straight lines are hard to do in interplanetary travel. Instead, Mars missions use momentum from Earth to arc outward from one planet to the other. The Opportunity rover launched when Earth and Mars were the closest they’d been in 60,000 years, and the rover still had to travel 283 million miles to reach the Red Planet.

On the International Space Station, Scott Kelly was traveling at more than 17,000 miles per hour, an ideal speed for orbital research that keeps the station steadily circling Earth every 90 minutes. To break free of orbit and go farther to deep space, spacecraft have to travel at higher speeds. Opportunity, for example, traveled at an average of 60,000 miles per hour on the way to Mars, covering twice the distance Kelly traveled on the station in just over half the time.

Graphic showing Opportunity’s trajectory from Earth to Mars
Although Earth and Mars were relatively close together when Opportunity launched, the rover’s trip out was twice the average distance between the two planets.

The fastest any human being has ever traveled was the crew of Apollo 10, who hit a top speed of almost 25,000 miles per hour returning to Earth in 1969. For astronauts to reach Mars, we need to be able to propel them not only faster than the space station travels, but faster than we’ve ever gone before.

But the real lesson of Kelly’s year in space isn’t the miles, it’s the months. The human body changes in the absence of the effects of gravity. The time Kelly spent in space will reveal a wealth of new data about these changes, ranging from things like how fluid shifts in microgravity affected his vision to the behavioral health impacts of his long duration in the void of space. This information reveals more about what will happen to astronauts traveling to Mars and back, but it also gives us insight into how to equip them for that trip, which will be approximately 30 months in duration round-trip. What sort of equipment will they need to keep them healthy? What accommodations will they require to stay mentally acute? What sort of vehicle do we need to build and equip to send them on their journey?

Months and millions of miles. Momentum and mass. These are some of the most basic challenges of Mars. We will need to build a good ship for our explorers. And we will need the means to lift it from Earth and send it on its way fast enough to reach Mars.

An engine section weld confidence article for the SLS Core Stage is taken off the Vertical Assembly Center at NASA's Michoud Assembly Facility in New Orleans
An engine section weld confidence article for the SLS Core Stage is taken off the Vertical Assembly Center at NASA’s Michoud Assembly Facility in New Orleans.

While Scott Kelly has been living in space helping us to learn more about the challenges, we’ve been working on the rocket that will be a foundational part of addressing them. Scott Kelly left Earth last year half a month after the Space Launch System (SLS) Program conducted a first qualification test of one of its solid rocket boosters. Since then, we have conducted tests of the core stage engines. We’ve started welding together fuel tanks for the core stage. We’ve begun assembling the upper stage for the first flight. We’ve been building new test stands, and upgraded a barge to transport rocket hardware. The Orion program has completed the pressure vessel for a spacecraft that will travel around the moon and back. Kennedy Space Center has been upgrading the facilities that will launch SLS and Orion in less than three years.

And that’s just a part of the work that NASA’s done while Kelly was aboard the space station. Our robotic vanguard at Mars discovered evidence of flowing liquid water, and we’ve been testing new technologies to prepare us for the journey.

Down here and up there, it’s been a busy year, and one that has, in so many ways, brought us a year closer to Mars. The #YearInSpace months and millions of miles may be done, but many more Mars milestones are yet to come!


Next Time: Next Small Steps Episode 3

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Think You’re Stressed? Try Being A Rocket

You know how big the SLS vehicle will be. We described the tremendous power and thrust of just one of the RS-25 engines after last year’s test firings. You may have witnessed live as we fired one of the massive five-segment solid rocket boosters last March. Through all that, perhaps you can imagine how incredible it will be at launch when all four engines and both boosters ignite together to lift this 322 feet tall, 5.75 million pound rocket up through the atmosphere and toward deep space. Imagine the thunderous vibration in your chest even as you stand several miles away.

Artist’s concept of an SLS launch
Note: Actually watching an SLS launch from this close is strongly not advised (or permitted). Orion hardware is being tested to withstand sound levels that would turn a person to liquid.

We’ve talked about how it will feel to be there when the rocket launches. Now, let’s talk about how it would feel to BE the rocket, launching.

Envision the power generated at launch as the engines and boosters throttle up to 8.8 million pounds of thrust. The heat is incredible! The vehicle starts to shake. The engine nozzles, as big and solid as they seem, will warp under the pressure of heat when the engines ignite seconds ahead of the boosters. While still on the pad, the boosters are bearing the weight of the entire vehicle even as they fire up for launch – the weight of almost 13 Statues of Liberty resting on an area smaller than an average living room.

Then, you – the rocket – are released to fly, and up you go. More than 5 million pounds of the weight of the rocket pushing down are now counteracted by more than 8 million pounds of thrust pushing from the opposite direction. Remember those 13 Statues of Liberty? Now the bottom of the rocket is feeling the pressure of 29 of them instead!

And now things are heating up on the front end of the rocket as well. Approaching Mach 1, shock waves move over the entire vehicle. Friction from just moving through the air causes the nose of the vehicle to heat. The shock waves coming off the booster nose cones strike the core stage intertank and can raise the temperature to 700 degrees. The foam insulation not only keeps the cryogenic tanks cold, it keeps the heat of ascent from getting into the intertank structure between the hydrogen and oxygen tanks.

Computer model of a shock wave at the front of the SLS vehicle at the time of booster separation during launch.
Computer model of a shock wave at the front of the SLS vehicle at the time of booster separation during launch.

Are you feeling it yet? That’s a lot to handle. These impacts from weight (mass), pressure, temperature and vibration are called “loads.” It’s a key part of the “rocket science” involved in the development of the SLS vehicle.

A load is a pressure acting on an area. Sounds simple, right? There are all kinds of loads acting on SLS, some even before it leaves the launch pad. Tension and compression (pulling and pushing), torque (twisting), thermal (hot and cold), acoustic (vibration), to name a few. There are static (stationary) loads acting on the big pieces of the rocket due to gravity and their own weight. There are loads that have to be considered when hardware is tipped, tilted, rolled, and lifted at the factory. There are “sea loads” that act on the hardware when they ride on the barge up and down the rivers to various test sites and eventually across the Gulf of Mexico and up the Florida coast to Kennedy Space Center for launch. Engineers have to consider every single load, understanding how they will affect the structural integrity of the rocket and how they will couple and act together.

The Pegasus barge that will transport SLS
You’ve probably never thought of “riding on a boat” as rocket science, but SLS has to be designed to handle sea loads as well as space loads.

When SLS is stacked on the mobile launcher at KSC, there are loads acting through the four struts securing the core stage to the boosters and down into the booster aft skirts that have to carry the entire weight of the launch vehicle on the mobile launcher. Then there are roll-out loads when the mobile launcher and crawler take SLS more than 4 miles from the Vehicle Assembly Building to the launch pad. There are many more loads as the vehicle is readied for launch.

How do engineers know the rocket’s ready to handle the loads it has to face to send astronauts into deep space? Step One is good design – developing a rocket robust enough to withstand the strains of launch. However this is difficult as the vehicle needs to be as lightweight as possible. Step Two is digital modeling – before you start building, you run many, many simulations in the computer to a level of detail that would make any Kerbal Space Program fan jealous. Step Three is to do the real thing, but smaller – wind-tunnel models and even scale-model rockets with working propulsion systems provide real-life data. And then comes Step Four – build real hardware, and stress it out. Test articles for the core stage and upper stage elements of the vehicle will be placed in test stands beginning this year and subjected to loads that will mimic the launch experience. Engines and boosters are test-fired to make sure they’re ready to go.

Still want to be the rocket? Stay tuned for more on loads as we do everything possible to shake, rattle, and yes, even roll, the pieces of the rocket, ensuring it’s ready to launch in 2018.


Next Time: No Small Steps Episode 3

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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

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Help Wanted: Be An Astronaut

Actors playing astronauts walk through smoke
These are actors from a video about the first launch of Orion. The actual roles of “Orion crew members” are yet to be cast.

Many moons ago, an Orion program executive asked on a Twitter chat what advice he would have for the first crew that will fly on the spacecraft the team is building.

The answer could have gone in any number of directions, from how the steering’s going to handle to what to pack for the trip. But what he said was this:

“Hang on! You’re about to make history!”

For me, that response was a good reminder – it’s one thing to remember the historic significance of the first crewed flight of Orion and SLS as a huge stepping stone in human exploration of the solar system, but it’s another thing altogether to appreciate that step as an incredibly unique experience for the individuals involved. When the crew returns to Earth at the end of the mission, they will share stories of what it was like to have the personal experience of looking past the moon and seeing our home planet in the distance beyond.

Others will follow them, and come back with their own incredible stories – living long periods farther from Earth than anyone ever has, voyaging deep into the expanses of space, being the first to interact with raw relics of the formation of our solar system floating in the void. And as those pioneers carry us farther in our journey to Mars, others will remain closer to home, performing revolutionary scientific research aboard the International Space Station.

Not long after that Twitter chat, I was privileged to sit in on a briefing about SLS to a unique audience: NASA’s 2013 class of astronaut candidates. It was interesting to watch them as the presenter talked about the rocket we’re building. At the end of the presentation, they were shown a video – an animation of a crewed launch of SLS and Orion. The video included a scene of a crew walking out to board the vehicle, and, to be honest, I was a little envious watching the future astronauts realize it would be them who would be doing that in real life, seeing them get excited about the possibilities and opportunities that lay before them.

But that moment was also a healthy reminder – we’re building this rocket to carry these people, and others like them. SLS and Orion will open the solar system for exploration by humankind, but will do so by carrying not faceless representatives of our species, but by safely transporting real individuals through the unmatched fires of launch and the unrelenting void of space and the unforgiving heat of entry. It is our job to give them a good ship for the journey.

Spacesuit engineers demonstrate how four crew members would be arranged for launch inside the Orion spacecraft, using a mockup of the vehicle at Johnson Space Center.
Spacesuit engineers demonstrate how four crew members would be arranged for launch inside the Orion spacecraft, using a mockup of the vehicle at Johnson Space Center.

And that focus permeates everything we do. When NASA founded the SLS program, one of our key tenets was safety. Before we built, the vehicle was modeled on computers and in small scale. We test the engines and boosters again and again and again. Flight hardware is preceded by test articles that are subjected to incredible stresses to see how they will withstand the dynamic pressures of launch. Where possible, redundancy is included to add an additional level of safety. Contingencies are identified and preparations are made. Spaceflight is an endeavor that will never be without risk. We carry the responsibility of equipping pioneers to face that risk as safely as possible.

Today, NASA is looking for the next group of men and women that will carry forward our work in space, both aboard our outpost science laboratory in Earth orbit and on the proving ground missions that will prepare for missions to Mars, flying on a new fleet of American spacecraft including not only SLS and Orion but also Commercial Crew vehicles.

If you want to apply to be an astronaut, among the credentials you’ll need are a bachelor’s degree in engineering, biological, physical or computer science or mathematics and at least three years of related professional experience, or at least 1,000 hours of pilot-in-command time in jet aircraft. Visit USAJobs.gov and search for the keyword astronaut to apply online.

And for those who are selected, we’re working hard to build you a great ship. Hang on, you’re about to make history!

Next Time: An Orion Overview

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A Model Employee

This week, I’d like to introduce guest blogger Jared Austin, a fellow writer on the SLS Strategic Communications team, for a peek into a part of the SLS team that is rarely seen, but creates some of our most-seen tools. — David

Parts of SLS models during assembly
Ever wonder what the sides of the new SLS booster design look like? Now you know!

Few people know Barry Howell and what he’s done for the space program for decades. Neither astronaut nor engineer, through his work as a master model maker Barry has helped NASA visualize spacecraft before they existed.

For more than 40 years, Barry’s “office” has been a space model workshop filled with the past, present and futures of NASA. Barry has created models of many of NASA’s greatest endeavors – from the mighty Saturn 1B and Saturn V, to the iconic Space Shuttle, to early concepts of the International Space Station, to the Hubble Space Telescope, and many other vehicles. Those models aren’t the mass produced, off-the-shelf toys that little Timmy or Sarah receives for their eighth birthdays. Barry’s models are works of both artistic and technical mastery that are painstakingly crafted to scale in a variety of sizes from models that will fit on your desk to a giant that is over 12 feet tall.

Barry Howell with a freshly updated 1-to-50 scale model of SLS
Barry Howell with a freshly updated 1-to-50 scale model of SLS.

You don’t last forty years at a job unless you’re extremely passionate about what you do. Barry’s craft is a rare calling – there are only a small handful of modellers at Marshall Space Flight Center, and only a few NASA centers have model shops. Model makers who get a job like this tend to keep it for a long time, so turnover is low and opportunities are infrequent. Barry came to the job from a background in machining, which he started working while in high school. But when there is an opening in the model shop, there really is only one job qualification – be the best at what you do. There’s no particular education or experience requirement, unmatched skill is the determining factor.

Over the course of his career, Barry’s work has helped solve the agency’s most challenging problems, letting engineers visualize the hardware they are designing and building, and to prove concepts such as the shade on Skylab. After Skylab’s launch, NASA had only 10 days to design and build a sunshade for the space station. Barry helped build a model to demonstrate that the umbrella-like shade that Marshall engineers were designing would properly shield Skylab from the sun’s heat. And his work is rather unique within NASA.

Now Barry is taking his decades of experience in modeling all types of NASA systems and using it to produce models of America’s next great rocket, the Space Launch System.

A row of Saturn-era models in the model shop archive
In decades past, Barry created his models directly from vehicle engineering blueprints.

During his tenure in the model shop, Barry has seen changes in technology and process, along with classic methods that have stood the test of time. In the old days of Saturn and early Shuttle, each and every model would be carefully machined according to actual blueprints that allowed Barry to ensure they were precise representations of the real rockets. Working with aluminum or plexiglass blocks, Barry would carefully drill into blocks with a mill or strip away pieces with a lathe, using nothing more than his focused eye, steady hands, and well-honed judgment to carve the individual parts of the rocket from those blocks.

Today, for SLS, model production is a combination of old and new techniques. There’s no longer a need to individually handcraft each model that’s produced; resin casting allows for mass production of models, allowing the model shop to churn out the models at a faster rate and lower cost. But in order to produce the mold for that casting, the old ways are still best. To this day, Barry produces his initial master for each model line with the meticulous same mill and lathe machining process that he used during Saturn.

Close-up of parts for SLS models
In order to capture the fine detail of an official Marshall model, Barry machines the prototype for each model series the shop produces.

Recently, though, even more modern techniques have entered the model shop in the form of 3D printing, creating small astronaut figures, handheld models of the rocket, or small versions of the SLS engines. It’s a new area that the modelers have just begun to explore and holds many possibilities for improving the way they make SLS models going forward.

“I truly love every part of the model-making process, as well as the variety of different models that I’ve gotten the chance to make at NASA,” Barry said. “And the young guys I get to work with, they come up with a lot of great ideas on how to make things even better.

Barry has also been very gracious in passing on his knowledge to others. Modelers who create their own models at home will often request Barry’s inputs to help them make custom-made parts that look more realistic.

Now, as Barry rides off into the sunset of retirement in a couple of months, he’ll be leaving behind a legacy of models showing NASA’s greatest technological achievements. Barry has helped tell the exploration story and by capturing NASA history in 3D for decades.

Close-up of parts for SLS models
In addition to providing a way to share the vehicles NASA is building, Barry’s models have allowed engineers to visualize concepts that have been proposed.

Next Time: A Model Worker

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Next Giant Leap, No Small Steps

Our focus today at the Space Launch System (SLS) program is on building a new rocket – the most powerful in the world. On its first test flight, Exploration Mission-1, SLS will carry atop it an uncrewed Orion spacecraft, which will someday carry astronauts on a journey to deep space.

A similar scene was unfolding at NASA 48 years ago. On Nov. 9, 1967, the Saturn V rocket launched for the first time, carrying an Apollo spacecraft.

Less than two years later, a Saturn V rocket and Apollo spacecraft sent three astronauts sailing through the void between two worlds, culminating in two members of the crew becoming the first to set foot on another celestial body. The words spoken as the first boot dug into the powdery gray lunar regolith took their place among the most famous ever said.

“That’s one small step for [a] man; one giant leap for mankind.”*

Launch of Apollo 4
The launch of Apollo 4 was the first from NASA’s Kennedy Space Center in Florida.

With SLS, Orion, and a revitalized space launch complex, we are developing capabilities for our next pioneering endeavor – a journey to Mars.

We continue to make progress toward that journey. Testing has begun on the boosters and engines for the Space Launch System rocket. The One-Year Crew is currently aboard the International Space Station, learning more about living in space for long durations. Our robotic explorers on Mars discovered flowing water and the history of the Martian atmosphere. The Orion vehicle made its first spaceflight, traveling 15 times higher than the orbit of the space station before successfully returning to Earth. These accomplishments, and many more over the last year, bring us closer to the “next giant leap” to Mars, but are all important in their own right. The journey to Mars is hard and the “small steps” along the way aren’t really that small.

And that’s the general idea behind a set of new videos we’re launching today – “No Small Steps.” The challenge of going to Mars is monumental, and it’s going to take a monumental rocket to make it possible. In an entertaining and informative format, “No Small Steps” gets into the “how” of making that happen – taking rocket science and making it relatable to answer questions like how you power a rocket designed for Mars, how you build a rocket the same size as the Saturn V but make it more powerful, how SLS combines the best of NASA’s greatest launch vehicles and makes it even better. We’ll release the next two installments about a month apart, so stay tuned.

Because when it comes to our journey to Mars and beyond, there are no small steps.

https://www.youtube.com/watch?v=TOYXa9jx-TI[/embedyt]


Next Time: A Model Employee

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*My take on the “for man”/”for a man” discussion: Neil was pretty awesome either way.

Mars: Gateway to the Solar System

Graphic of rocket flying with Mars background

The demands of going to Mars are immense.

Meeting that challenge will require delivering our best, and then continuing to do better.

Designed to enable human exploration of deep space, NASA’s Space Launch System will be, from its first launch, the most powerful rocket in the world today. The first SLS to depart Earth will carry about triple the payload of the space shuttle, provide more thrust at launch than the Saturn V, and send Orion further into space than Apollo ever ventured.

But even that power is only a fraction of what is needed for human landings on Mars. To continue the Journey to Mars, we will have to take the most powerful rocket in the world and make it even more powerful.

Engineers prepare a 3-D printed turbopump for a test at NASA’s Marshall Space Flight Center in Huntsville, Alabama
NASA is doing research today on technologies like composite materials and 3-D printing that will be used to make future versions of the rocket more powerful.

Engineers at Marshall’s Space Flight Center, where the program is based, and other engineers across the country, are already in the planning phases for the first major upgrade, which will come in the form of a more powerful upper stage. This will create a version of the rocket that will serve as the workhorse for “Proving Ground” missions that will test out new systems and capabilities in the vicinity of the moon before we heard toward Mars. With the new upper stage, SLS will be able to carry additional payloads to lunar space with Orion, allowing astronauts to make longer stays in deep space.

Then, in order to enable the leap to Mars, SLS will receive new, advanced booster rockets that will make it even more powerful. The SLS Program is already working with industry partners to demonstrate new technologies that will make sure the new boosters are state-of-the-art when they begin flying.

Mars is sometimes discussed as a “horizon goal” in human space exploration. While Mars is a focus of our efforts, it is neither the first step of the journey nor the last. Just as we will develop our capabilities in the Proving Ground near the moon before heading toward Mars, once we have reached the Red Planet, our voyage into deep space will continue.

Space Launch System not only represents a foundation for our first steps on the Red Planet, the robust capability necessary to accomplish that goal will also give us the ability to carry out many other ambitious space missions.

Jupiter hangs in the sky above the surface of a moon
Far beyond Mars, SLS could speed space probes far faster than ever before to the outer solar system.

With the ability to launch far more mass than any rocket currently flying or in development, SLS could be used to help pave the way to Mars with large-scale robotic precursor missions, such as potentially a sample return, that would demonstrate systems needed for human landings.

SLS’s unrivaled ability to speed robotic spacecraft through our solar system offers the potential to revolutionize our scientific expeditions to distant worlds. Reducing the time it takes to reach the outer planets could make it possible to conduct in-depth studies of icy moons that are promising destinations in the search for life.

With payload fairings that make it possible to launch five times more volume than any existing rocket, SLS could be used to launch gigantic space telescopes, which will allow us to peer farther into space, and with greater detail, than ever before, revealing new secrets of our universe.

In addition to the Orion crew vehicle and other large payloads, SLS will be able to carry small, low-cost secondary payload experiments, some not much larger than a lunchbox, providing new opportunities to for research beyond the moon and through the solar system. This will make it possible for groups that otherwise might not be able to afford a dedicated rocket launch to fly innovative ideas that can help pave the way for exploration.

The first launch of the initial configuration of SLS will be just a first step toward these and other opportunities; each upgrade will give us progressively greater ability to explore.

Mars – and the solar system – are waiting.

For more about how NASA is preparing for the Journey to Mars, check out our page, The Real Martians.

https://www.youtube.com/watch?v=dOOHJrqIJqY[/embedyt]

 

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David Hitt works in the strategic communications office of NASA’s Space Launch System Program. He began working in NASA Education at Marshall Space Flight Center in 2002, and is the author of two books on spaceflight history.