electronics – Rocketology: NASA’s Space Launch System

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]

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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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.

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Tag: electronics

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