CubeSat – Rocketology: NASA’s Space Launch System

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.

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 engines – none 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=https://www.youtube.com/watch?v=njb9Z2jX2fA[/embedyt]

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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.

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.

https://www.youtube.com/watch?v=http://youtu.be/zJXQQv9UZNg[/embedyt]
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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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One Giant Rocket, Batteries Not Included

This week, guest blogger Jared Austin, a fellow writer on the SLS Strategic Communications team, is back for a look at an example of the innovative technology work taking place in the SLS program. — David

Would you like a cellphone, tablet, or laptop that is lighter and more powerful and will recharge for use in a matter of seconds? If your answer is “Yes!” then the Space Launch System Program is working to make your life a little bit better. (If your answer is “no,” are you sure you’re in the right place?)

Rockets and smartphones may not seem like they have much in common, but one thing they do share is a need for reliable power for electronic systems. And that’s where ultracapacitors come in.

Ultracapacitors are small devices, as small as roughly the size of a business card, which means more room and less weight than a traditional battery. On top of that, ultracapacitors charge rapidly.

Close-up of an ultracapacitor power storage unit

NASA’s new Space Launch System will be NASA’s exploration ride for decades to come, and that presents a unique challenge. While the first version of the rocket will be ready to fly in three years, NASA will continue to evolve it into more powerful configurations through the 2020s, meaning that NASA engineers are working today to make sure the final version of the rocket will still be state-of-the-art when it flies. To accomplish that, engineers are already engaged in the long-lead work of maturing new technologies for spaceflight.

For instance, every NASA system – from small “CubeSats” to rovers, satellites, and even rockets – has an electrical system that requires power. The most common power source is a battery. Despite their widespread use, rechargeable batteries come with a number of drawbacks. They are slow to charge up (hours) and are necessarily bulky in order to meet power requirements. Batteries heat up during use (feel the bottom of your laptop after an hour’s use), and that overheating can wear on the device its powering. On top of that, batteries contain harmful chemicals that are bad for the environment, and suffer from early wear-out, especially in the harsh environments of space where many NASA systems operate.

Meet avionics failure analyst Terry Rolin, who kept seeing battery failures that were creating problems for NASA systems.

“I have learned that failures present opportunities for individuals to learn new ways of doing things, build character, and teach new pathways for problem solving,” Terry said.

Rolin at his workstation — The work that Rolin and is team are doing has the potential to benefit not only SLS but also electronics devices.

In 2012, he learned about ultracapacitors and was sure he had found the future.

The ultracapacitors can be significantly smaller than batteries, allowing more room for payloads, which is especially important to CubeSats where every centimeter matters. Ultracapacitors do not heat up during use, which is good for the system it’s powering. Also, due to their solid-state design (batteries contain a liquid core), the harsh environments of space – radiation, extreme temperatures, and pressures – do not affect them the same way they do batteries.

While ultracapacitors pose substantial promise for spaceflight applications, there was one major issue that had to be resolved before they could be rocket-ready. To build the compact ultracapacitors in a way that would maximize their capacity to store energy, they need to be as thin as possible; an ultracapacitor’s ability to store electrical charges actually decreases as it grows in size. Terry and his team won an innovation fund in the summer of 2012 to develop ultracapacitors that could power NASA systems using 3-D printing techniques and nanotechnology in order to manufacture the smaller ultracapacitors.

For SLS, despite the enormous size of the rocket, there are numerous small avionics computer boxes requiring power systems that fit in a tight space. Ultracapacitors are being evaluated for use down the road, either as the primary power system, or in a hybrid combination with batteries taking advantage of the best of both power sources.

“I was seeing increases in the ability of the capacitors to store energy by several orders of magnitude, and getting charging times of seconds rather than hours,” Terry said. “It was very exciting.”

But Terry’s team had difficulty reproducing their efforts. They found micro- and nano-fractures in their ultracapacitors, so they reached out to industry and academia for help.

It turned out that the nanoparticles in the commercial electrode ink they were using during the 3-D printing process the devices required a temperature so high that it damaged the ultracapacitors. So, Terry’s team developed a new ink that would sinter, or “print,” at lower temperatures, but still work for commercial manufacturing processes. Because of this work, down the road, commercial companies could release a nanoparticle ink that lets anyone with a 3-D printer to create their own ultracapacitors to power their electronics.

While their full potential is still being researched by Terry and his team in the space systems department at NASA’s Marshall Space Flight Center, ultracapacitors show promise to not only make NASA systems smaller, lighter, more durable, easily rechargeable, and more environmentally friendly, but to potentially bring those same benefits to electronic devices in your home or pocket.

Ultracapacitors are only one of the many technologies the SLS program has been developing, both internally with NASA engineers and in partnership with industry and academia. NASA has a long history of “spin-offs” that have taken space system research to make lives on Earth better, from Hubble software that helps with cancer detection to filtration systems that help provide clean drinking water in remote areas.

A rocket for missions to Mars that makes life better on Earth? That truly is the best of both worlds.

Next Time: Hey, Want A Ride?

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