NASA’s Giant SLS Rocket Rolled Back For Repairs

April 27, 2022 by Tom Nardi 33 Comments

There’s little debate that the most exciting move in a rocket’s repertoire is when it launches itself skywards on a column of flame. But failing that, it’s still pretty interesting to see how these massive vehicles get juggled around down here on terra firma before getting fired off into the black. Which is great for anyone interested in NASA’s towering Space Launch System (SLS), as it’s been doing an awful lot of milling about on the ground for a vehicle designed to return humanity to the Moon.

Most recently, the SLS completed a trek from the iconic Vehicle Assembly Building (VAB) to launch pad 39B and back again aboard the same “crawler” that moved the Space Shuttle and Saturn V before it. While the nearly 60-year-old tracked vehicle has received some updates to carry the 98 meter (322 ft) tall booster, clearly the space agency subscribes to the “if it ain’t broke, don’t fix it” school of thought.

The SLS itself however is definitely in need of some work. The rocket was brought out to the pad for the first time on March 18th, where it was to conduct what’s known as a “wet dress rehearsal” — a test of the pre-flight operations, propellant loading, and countdown that includes everything except engine ignition. Unfortunately, the test was plagued with technical issues, and after three attempts, it was decided to bring the rocket back into the VAB to make the necessary repairs to both it and the ground support equipment.

One issue involves a valve in the Interim Cryogenic Propulsion Stage (ICPS), a propulsion module that’s being used on the early SLS flights to provide the trans-lunar injection (TLI) burn that will send the Orion spacecraft on a course towards the Moon. As the name implies, the ICPS is destined to be replaced with the larger Exploration Upper Stage on later missions. There’s also a leak on the launch tower itself that will need to be addressed. After the identified problems are repaired and some adjustments are made, the SLS will once again be rolled out to the pad to reattempt the launch rehearsal.

Now in development for over a decade, the Space Launch System has been plagued with technical issues and delays. At the same time, commercial launch providers like SpaceX have moved the state of the art forward considerably, leading many to wonder if the mind-bogglingly expensive rocket will be able to compete with in-development vehicles such as Starship and New Glenn. The fact that missions which were previously assigned to the SLS have started to get shifted over to commercial rockets would seem to indicate that even NASA is losing confidence in their flagship program.

DIY SLS 3D Printer Getting Ready To Print

March 25, 2022 by Dave Rowntree 12 Comments

Ten years ago the concept of having on our desks an affordable 3D printer knocking out high quality reproducible prints, with sub-mm accuracy, in a wide range of colours and material properties would be the would be just a dream. But now, it is reality. The machines that are now so ubiquitous for us hackers, are largely operating with the FDM principle of shooting molten plastic out of a moving nozzle, but they’re not the only game in town. A technique that has also being around for donkeys’ years is SLS or Selective Laser Sintering, but machines of this type are big, heavy and expensive. However, getting one of those in your own ‘shop now is looking a little less like a dream and more of a reality, with the SLS4All project by [Tomas Starek] over on hackaday.io.

[Tomas] has been busy over the past year, working on the design of his machine and is now almost done with the building and testing of the hardware side. SLS printing works by using a roller to transfer a layer of powdered material over the print surface, and then steering a medium-power laser beam over the surface in order to heat and bond the powder grains into a solid mass. Then, the bed is lowered a little, and the process repeats. Heating of the bed, powder and surrounding air is critical, as is moisture control, plus keeping that laser beam shape consistent over the full bed area is a bit tricky as well. These are all hurdles [Tomas] has to overcome, but the test machine is completed and is in a good place to start this process control optimisation fun. Continue reading “DIY SLS 3D Printer Getting Ready To Print” →

Europa Decision Delivers Crushing Blow To NASA’s Space Launch System (SLS)

February 12, 2021 by Tom Nardi 110 Comments

These days, NASA deciding to launch one of their future missions on a commercial rocket is hardly a surprise. After all, the agency is now willing to fly their astronauts on boosters and spacecraft built and operated by SpaceX. Increased competition has made getting to space cheaper and easier than ever before, so it’s only logical that NASA would reap the benefits of a market they helped create.

So the recent announcement that NASA’s Europa Clipper mission will officially fly on a commercial launch vehicle might seem like more of the same. But this isn’t just any mission. It’s a flagship interplanetary probe designed to study and map Jupiter’s moon Europa in unprecedented detail, and will serve as a pathfinder for a future mission that will actually touch down on the moon’s frigid surface. Due to the extreme distance from Earth and the intense radiation of the Jovian system, it’s considered one of the most ambitious missions NASA has ever attempted.

With no margin for error and a total cost of more than $4 billion, the fact that NASA trusts a commercially operated booster to carry this exceptionally valuable payload is significant in itself. But perhaps even more importantly, up until now, Europa Clipper was mandated by Congress to fly on NASA’s Space Launch System (SLS). This was at least partly due to the incredible power of the SLS, which would have put the Clipper on the fastest route towards Jupiter. But more pragmatically, it was also seen as a way to ensure that work on the Shuttle-derived super heavy-lift rocket would continue at a swift enough pace to be ready for the mission’s 2024 launch window.

But with that deadline fast approaching, and engineers feeling the pressure to put the final touches on the spacecraft before it gets mated to the launch vehicle, NASA appealed to Congress for the flexibility to fly Europa Clipper on a commercial rocket. The agency’s official line is that they can’t spare an SLS launch for the Europa mission while simultaneously supporting the Artemis Moon program, but by allowing the Clipper to fly on another rocket in the 2021 Consolidated Appropriations Act, Congress effectively removed one of the only justifications that still existed for the troubled Space Launch System.

Continue reading “Europa Decision Delivers Crushing Blow To NASA’s Space Launch System (SLS)” →

Hackaday Links: January 31, 2021

January 31, 2021 by Dan Maloney 12 Comments

There are an awful lot of machines on the market these days that fall under the broad category of “cheap Chinese laser cutters”. You know the type — the K40s, the no-name benchtop CO2 cutters, the bigger floor-mount units. If you’ve recently purchased one of these machines from one of the usual vendors, or even if you’re just thinking about doing so, you’ll likely have some questions. In which case, this “Chinese Laser Cutters 101” online class might be right up your alley. We got wind of this though its organizer, Jonathan Schwartz of American Laser Cutter in Los Angeles, who says he’s been installing, repairing, and using laser cutters for a decade now. The free class will be on February 8 at 5:00 PM PST, and while it’s open to all, it does require registration.

We got an interesting tip the other day that had to do with Benford’s Law. We’d never heard of this one, so we assumed was a “joke law” like Murphy’s Law or Betteridge’s Rule of Headlines. But it turns out that Benford’s Law describes the distribution of leading digits in large sets of numbers. Specifically, it says that the leading digit in any given number is more likely to be one of the smaller numbers. Measurements show that rather than each of the nine base 10 digits showing up about 11% of the time, a 1 will appear in the leading digit 30% of the time, while a 9 will appear about 5% of the time. It’s an interesting phenomenon, and the tip we got pointed to an article that attempted to apply Benford’s Law to image files. This technique was used in a TV show to prove an image had been tampered with, but as it turns out, Hollywood doesn’t always get technical material right. Shocking, we know, but the technique was still interesting and the code developed to Benford-ize image files might be useful in other ways.

Everyone knew it was coming, and for a long time in advance, but it still seems that the once-and-for-all, we’re not kidding this time, it’s for realsies shutdown of Adobe Flash has had some real world consequences. To wit, a railroad system in the northern Chinese city of Dalian ground to a halt earlier this month thanks to Flash going away. No, they weren’t using Flash to control the railroad, but rather it was buried deep inside software used to schedule and route trains. It threw the system into chaos for a while, but never fear — they got back up and running by installing a pirated version of Flash. Here’s hoping that they’re working on a more permanent solution to the problem.

First it was toilet paper and hand sanitizer, now it’s…STM32 chips? Maybe, if the chatter on Twitter and other channels is to be believed. Seems like people are having a hard time sourcing the microcontroller lately. It’s all anecdotal so far, of course, but the prevailing theory is that COVID-19 and worker strikes have lead to a pinch in production. Plus, you know, the whole 2020 thing. We’re wondering if our readers have noticed anything on this — if so, let us know in the comments below.

And finally, just because it’s cool, here’s a video of what rockets would look like if they were transparent. Well, obviously, they’d look like twisted heaps of burning wreckage on the ground is they were really made with clear plastic panels and fuel tanks, but you get the idea. The video launches a virtual fleet — a Saturn V, a Space Shuttle, a Falcon Heavy, and the hypothetical SLS rocket — and flies them in tight formation while we get to watch their consumables be consumed. If the burn rates are accurate, it’s surprising how little fuel and oxidizer the Shuttle used compared to the Saturn. We were also surprised how long the SLS holds onto its escape tower, and were pleased by the Falcon Heavy payload reveal.

Failed Test Could Further Delay NASA’s Troubled SLS Rocket

January 25, 2021 by Tom Nardi 74 Comments

The January 16th “Green Run” test of NASA’s Space Launch System (SLS) was intended to be the final milestone before the super heavy-lift booster would be moved to Cape Canaveral ahead of its inaugural Artemis I mission in November 2021. The full duration static fire test was designed to simulate a typical launch, with the rocket’s main engines burning for approximately eight minutes at maximum power. But despite a thunderous start start, the vehicle’s onboard systems triggered an automatic abort after just 67 seconds; making it the latest in a long line of disappointments surrounding the controversial booster.

When it was proposed in 2011, the SLS seemed so simple. Rather than spending the time and money required to develop a completely new rocket, the super heavy-lift booster would be based on lightly modified versions of Space Shuttle components. All engineers had to do was attach four of the Orbiter’s RS-25 engines to the bottom of an enlarged External Tank and strap on a pair of similarly elongated Solid Rocket Boosters. In place of the complex winged Orbiter, crew and cargo would ride atop the rocket using an upper stage and capsule not unlike what was used in the Apollo program.

The SLS core stage is rolled out for testing.

There’s very little that could be called “easy” when it comes to spaceflight, but the SLS was certainly designed to take the path of least resistance. By using flight-proven components assembled in existing production facilities, NASA estimated that the first SLS could be ready for a test flight in 2016.

If everything went according to schedule, the agency expected it would be ready to send astronauts beyond low Earth orbit by the early 2020s. Just in time to meet the aspirational goals laid out by President Obama in a 2010 speech at Kennedy Space Center, including the crewed exploitation of a nearby asteroid by 2025 and a potential mission to Mars in the 2030s.

But of course, none of that ever happened. By the time SLS was expected to make its first flight in 2016, with nearly $10 billion already spent on the program, only a few structural test articles had actually been assembled. Each year NASA pushed back the date for the booster’s first shakedown flight, as the project sailed past deadlines in 2017, 2018, 2019, and 2020. After the recent engine test ended before engineers were able to collect the data necessary to ensure the vehicle could safely perform a full-duration burn, outgoing NASA Administrator Jim Bridenstine said it was too early to tell if the booster would still fly this year.

What went wrong? As commercial entities like SpaceX and Blue Origin move in leaps and bounds, NASA seems stuck in the past. How did such a comparatively simple project get so far behind schedule and over budget?

Continue reading “Failed Test Could Further Delay NASA’s Troubled SLS Rocket” →

Getting Closer To Metal 3D Printing

January 21, 2021 by Al Williams 31 Comments

Most of our 3D printers lay down molten plastic or use photosensitive resin. But professional printers often use metal powder, laying out a pattern and then sintering it with a laser. [Metal Matters] is trying to homebrew a similar system (video, embedded below). And while not entirely successful, the handful of detailed progress videos are interesting to watch. We particularly enjoyed the latest installment (the second video, below) which showed solutions to some of the problems.

Because of the complexity of the system, there are small tidbits of interest even if you don’t want to build a metal printer. For example, in the most recent video, a CCD camera gives up its sensor to detect the laser’s focus.

Continue reading “Getting Closer To Metal 3D Printing” →

3D Printing Damascus-like Steel

July 1, 2020 by Lewin Day 16 Comments

Recreating Damascus steel remains a holy grail of materials science. The exact process and alloys used are long ago lost to time. At best, modern steelworking methods are able to produce a rough visual simulacra of sorts that many still consider to be pretty cool looking. Taking a more serious bent at materials science than your average knifemaker, a group of scientists at the Max Planck institute have been working to create a material with similar properties through 3D printing.

The technology used is based on the laser sintering of metal powders. In this case, the powder consists of a mixture of iron, nickel and titanium. The team found that by varying the exact settings of the laser sintering process on a layer-by-layer basis, they could create different microstructures throughout a single part. This allows the creation of parts that are ductile, while remaining hard enough to be sharpened – a property which is useful in edged weapons like swords.

While the process is nothing like that used by smiths in Damascus working with Wootz steel, the general idea of a metal material with varying properties throughout remains the same. For those eager to get into old-school metalwork, consider our articles on blacksmithing. For those interested in materials research, head to a good university. Or, better yet – do both!

[Thanks to Itay for the tip, via New Atlas]