Even for those of us who follow space news closely, there’s a lot to keep track of these days. Private companies are competing to develop new human-rated spacecraft and assembling satellite mega-constellations, while NASA is working towards a return the Moon and the first flight of the SLS. Between new announcements, updates to existing missions, and literal rocket launches, things are happening on a nearly daily basis. It’s fair to say we haven’t seen this level of activity since the Space Race of the 1960s.
With so much going on, it’s no surprise that not many people have heard of the XS-1 Phantom Express. A project by the United States Defense Advanced Research Projects Agency (DARPA), the XS-1 was designed to be a reusable launch system that could put small payloads into orbit on short notice. Once its mission was complete, the vehicle was to return to the launch site and be ready for re-flight in as a little as 24 hours.
Alternately referred to as the “DARPA Experimental Spaceplane”, the vehicle was envisioned as being roughly the size of a business jet and capable of carrying a payload of up to 2,300 kilograms (5,000 pounds). It would take off vertically under rocket power and then glide back to Earth at the end of the mission to make a conventional runway landing. At $5 million per flight, its operating costs would be comparable with even the most aggressively priced commercial launch providers; but with the added bonus of not having to involve a third party in military and reconnaissance missions which would almost certainly be classified in nature.
Or at least, that was the idea. Flight tests were originally scheduled to begin this year, but earlier this year prime contractor Boeing abruptly dropped out of the program. Despite six years in development and over $140 million in funding awarded by DARPA, it’s now all but certain that the XS-1 Phantom Express will never get off the ground. Which is a shame, as even in a market full of innovative launch vehicles, this unique spacecraft offered some compelling advantages.
No, it’s not the kind of honeycomb you’re probably thinking of. We’re talking about the lightweight panels commonly used in aerospace applications. Apparently they’re rather prone to dents and other damage during handling, so Boeing teamed up with students from the California State University to come up with a way to automate the time-consuming repair process.
The resulting machine, which you can see in action after the break, is a phenomenal piece of engineering. But more than that, it’s an impressive use of off-the-shelf components. The only thing more fascinating than seeing this robotic machine perform its artful repairs is counting how many of its core components you’ve got laying around the shop.
Built from aluminum extrusion, powered by an Arduino Due, and spinning a Dewalt cut-off tool that looks like it was just picked it up from Home Depot, you could easily source most of the hardware yourself. Assuming you needed to automatically repair aerospace-grade honeycomb panels, anyway.
At the heart of this project is a rotating “turret” that holds all the tools required for the repair. After the turret is homed and the condition of all the cutting tools is verified, a hole is drilled into the top of the damaged cell. A small tool is then carefully angled into the hole (a little trick that is mechanical poetry in motion) to deburr the hole, and a vacuum is used to suck out any of the filings created by the previous operations. Finally a nozzle is moved into position and the void is filled with expanding foam.
Boeing says it takes up to four hours for a human to perform this same repair. Frankly, that seems a little crazy to us. But then again if we were the ones tasked with repairing a structural panel for a communications satellite or aircraft worth hundreds of millions of dollars, we’d probably take our time too. The video is obviously sped up so it’s hard to say exactly how long this automated process takes, but it doesn’t seem like it could be much more than a few minutes from start to finish.
Well, this is it. The end of the decade. In a few days the 2010s will be behind us, and a lot of very smug people will start making jokes on social media about how we’re back in the “Roaring 20s” again. Only this time around there’s a lot more plastic, and drastically less bathtub gin. It’s still unclear as to how much jazz will be involved.
Around this time we always say the same thing, but once again it bears repeating: it’s been a fantastic year for Hackaday. Of course, we had our usual honor of featuring literally thousands of incredible creations from the hacking and making community. But beyond that, we also bore witness to some fascinating tech trends, moments that could legitimately be called historic, and a fair number of blunders which won’t soon be forgotten. In fact, this year we’ve covered a wider breadth of topics than ever before, and judging by the record setting numbers we’ve seen in response, it seems you’ve been just as excited to read it as we were to write it.
To close out the year, let’s take a look at a few of the most popular and interesting stories of 2019. It’s been a wild ride, and we can’t wait to do it all over again in 2020.
After a decade in development, the Boeing CST-100 “Starliner” lifted off from pad SLC-41 at the Cape Canaveral Air Force Station a little before dawn this morning on its first ever flight. Officially referred to as the Boeing Orbital Flight Test (Boe-OFT), this uncrewed mission was intended to verify the spacecraft’s ability to navigate in orbit and safely return to Earth. It was also planned to be a rehearsal of the autonomous rendezvous and docking procedures that will ultimately be used to deliver astronauts to the International Space Station; a capability NASA has lacked since the 2011 retirement of the Space Shuttle.
Unfortunately, some of those goals are now unobtainable. Due to a failure that occurred just 30 minutes into the flight, the CST-100 is now unable to reach the ISS. While the craft remains fully functional and in a stable orbit, Boeing and NASA have agreed that under the circumstances the planned eight day mission should be cut short. While there’s still some hope that the CST-100 will have the opportunity to demonstrate its orbital maneuverability during the now truncated flight, the primary focus has switched to the deorbit and landing procedures which have tentatively been moved up to the morning of December 22nd.
While official statements from all involved parties have remained predictably positive, the situation is a crushing blow to both Boeing and NASA. Just days after announcing that production of their troubled 737 MAX airliner would be suspended, the last thing that Boeing needed right now was another high-profile failure. For NASA, it’s yet another in a long line of setbacks that have made some question if private industry is really up to the task of ferrying humans to space. This isn’t the first time a CST-100 has faltered during a test, and back in August, a SpaceX Crew Dragon was obliterated while its advanced launch escape system was being evaluated.
We likely won’t have all the answers until the Starliner touches down at the White Sands Missile Range and Boeing engineers can get aboard, but ground controllers have already started piecing together an idea of what happened during those first critical moments of the flight. The big question now is, will NASA require Boeing to perform a second Orbital Flight Test before certifying the CST-100 to carry a human crew?
Let’s take a look at what happened during this morning’s launch.
It’s fair to say that 2019 has not been a good year for the aircraft manufacturer Boeing, as its new 737 MAX aircraft has been revealed to contain a software fault that could cause the aircraft to enter a dive and crash. Now stories are circulating of another issue with the 737, some of the so-called “Pickle forks” in the earlier 737NG aircraft have been found to develop cracks.
It’s a concerning story and there are myriad theories surrounding its origin but it should also have a reassuring angle: the painstaking system of maintenance checks that underpins the aviation industry has worked as intended. This problem has been identified before any catastrophic failures have occurred. It’s not the story Boeing needs at the moment, but they and the regulators will no doubt be working hard to produce a new design and ensure that it is fitted to aircraft.
The Role of the Pickle Fork
For those of us who do not work in aviation though it presents a question: what on earth is a pickle fork? The coverage of the story tells us it’s something to do with attaching the wing to the fuselage, but without a handy 737 to open up and take a look at we’re none the wiser.
Fortunately there’s a comprehensive description of one along with a review of wing attachment technologies from Boeing themselves, and it can be found in one of their patents. US9399508B2 is concerned with an active suspension system for wing-fuselage mounts and is a fascinating read in itself, but the part we are concerned with is a description of existing wing fixtures on page 12 of the patent PDF.
The pickle fork is an assembly so named because of its resemblance to the kitchen utensil, which attaches firmly to each side of the fuselage and has two prongs that extend below it where they are attached to the wing spar.
For the curious engineer with no aviation experience the question is further answered by the patent’s figure 2, which provides a handy cross-section. The other wing attachment they discuss involves the use of pins, leading to the point of the patented invention. Conventional wing fixings transmit the forces from the wing to the fuselage as a rigid unit, requiring the fuselage to be substantial enough to handle those forces and presenting a problem for designers of larger aircraft. The active suspension system is designed to mitigate this, and we’d be fascinated to hear from any readers in the comments who might be able to tell us more.
We think it’s empowering that a science-minded general public can look more deeply at a component singled out in a news report by digging into the explanation in the Boeing patent. We don’t envy the Boeing engineers in their task as they work to produce a replacement, and we hope to hear of their solution as it appears.
Throughout the history of America’s human spaceflight program, there’s been an alternating pattern in regards to abort systems. From Alan Shepard’s first flight in 1961 on, every Mercury capsule was equipped with a Launch Escape System (LES) tower that could pull the spacecraft away from a malfunctioning rocket. But by the first operational flight of the Gemini program in 1965, the LES tower had been deleted in favor of ejection seats. Just three years later, the LES tower returned for the first manned flight of the Apollo program.
With the Space Shuttle, things got more complicated. There was no safe way to separate the Orbiter from the rest of the stack, so when Columbia made its first test flight in 1981, NASA returned again to ejection seats, this time pulled from an SR-71 Blackbird. But once flight tests were complete, the ejector seats were removed; leaving Columbia and all subsequent Orbiters without any form of LES. At the time, NASA believed the Space Shuttle was so reliable that there was no need for an emergency escape system.
In the post-Shuttle era, NASA has made it clear that maintaining abort capability from liftoff to orbital insertion is a critical requirement. Their own Orion spacecraft has this ability, and they demand the same from commercial partners such as SpaceX and Boeing. But while all three vehicles are absolutely bristling with high-tech wizardry, their abort systems are not far removed from what we were using in the 1960’s.
Let’s take a look at the Launch Escape Systems for America’s next three capsules, and see where historical experience helped guide the design of these state-of-the-art spacecraft.
When the first 737 MAX entered service in May of 2017, it was considered a major milestone for Boeing. For nearly a decade, the aerospace giant had been working on a more fuel efficient iteration of the classic 737 that first took to the skies in 1967. Powered by cutting-edge CFM International LEAP engines, and sporting modern aerodynamic improvements such as unique split wingtips, Boeing built the new 737 to have an operating cost that was competitive with the latest designs from Airbus. With over 5,000 orders placed between the different 737 MAX variants, the aircraft was an instant success.
But now, in response to a pair of accidents which claimed 346 lives, the entire Boeing 737 MAX global fleet is grounded. While the investigations into these tragedies are still ongoing, the preliminary findings are too similar to ignore. In both cases, it appears the aircraft put itself into a dive despite the efforts of the crew to maintain altitude. While the Federal Aviation Administration initially hesitated to suspend operations of the Boeing 737 MAX, they eventually agreed with government regulatory bodies all over the world to call for a temporary ban on operating the planes until the cause of these accidents can be identified and resolved.
Boeing continues to have full confidence in the safety of the 737 MAX. However, after consultation with the U.S. Federal Aviation Administration (FAA), the U.S. National Transportation Safety Board (NTSB), and aviation authorities and its customers around the world, Boeing has determined — out of an abundance of caution and in order to reassure the flying public of the aircraft’s safety — to recommend to the FAA the temporary suspension of operations of the entire global fleet of 371 737 MAX aircraft.
Until both accident investigations are completed, nobody can say with complete certainty what caused the loss of the aircraft and their passengers. But with the available information about what changes were made during the 737 redesign, along with Boeing’s own recommendations to operators, industry insiders have started to point towards a fault in the plane’s new Maneuvering Characteristics Augmentation System (MCAS) as a likely culprit in both accidents.
Despite the billions of dollars spent developing these incredibly complex aircraft, and the exceptionally stringent standards their operation is held to, there’s now a strong indication that the Boeing 737 MAX could be plagued with two common issues that we’ve likely all experienced in the past: a software glitch and poor documentation.