Floating Spaceports For Future Rockets

September 14, 2020 by Tom Nardi 36 Comments

While early prototypes for SpaceX’s Starship have been exploding fairly regularly at the company’s Texas test facility, the overall program has been moving forward at a terrific pace. The towering spacecraft, which CEO Elon Musk believes will be the key to building a sustainable human colony on Mars, has gone from CGI rendering to flight hardware in just a few short years. That’s fast even by conventional rocket terms, but then, there’s little about Starship that anyone would dare call conventional.

An early Starship prototype being assembled.

Nearly every component of the deep space vehicle is either a technological leap forward or a deviation from the norm. Its revolutionary full-flow staged combustion engines, the first of their kind to ever fly, are so complex that the rest of the aerospace industry gave up trying to build them decades ago. To support rapid reusability, Starship’s sleek fuselage abandons finicky carbon fiber for much hardier (and heavier) stainless steel; a material that hasn’t been used to build a rocket since the dawn of the Space Age.

Then there’s the sheer size of it: when Starship is mounted atop its matching Super Heavy booster, it will be taller and heavier than both the iconic Saturn V and NASA’s upcoming Space Launch System. At liftoff the booster’s 31 Raptor engines will produce an incredible 16,000,000 pounds of thrust, unleashing a fearsome pressure wave on the ground that would literally be fatal for anyone who got too close.

Which leads to an interesting question: where could you safely launch (and land) such a massive rocket? Even under ideal circumstances you would need to keep people several kilometers away from the pad, but what if the worst should happen? It’s one thing if a single-engine prototype goes up in flames, but should a fully fueled Starship stack explode on the pad, the resulting fireball would have the equivalent energy of several kilotons of TNT.

Thanks to the stream of consciousness that Elon often unloads on Twitter, we might have our answer. While responding to a comment about past efforts to launch orbital rockets from the ocean, he casually mentioned that Starship would likely operate from floating spaceports once it started flying regularly:

While history cautions us against looking too deeply into Elon’s social media comments, the potential advantages to launching Starship from the ocean are a bit too much to dismiss out of hand. Especially since it’s a proven technology: the Zenit rocket he references made more than 30 successful orbital launches from its unique floating pad.

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Falcon 9 Beats Shuttle’s Reflight Record, But Still Has A Long Way To Go

July 27, 2020 by Tom Nardi 77 Comments

Put simply, the goal of any reusable booster is to reduce the cost of getting a payload into space. The comparison is often made to commercial aviation: if you had to throw away the airliner after every flight, nobody could afford the tickets. The fact that the plane can be refueled and flown again and again allows operators to amortize its high upfront cost.

In theory, the same should hold true for orbital rockets. With enough flight experience, you can figure out which parts of the vehicle will need replacement or repair, and how often. Assuming the fuel is cheap enough and the cost of refurbishment doesn’t exceed that of building a new one, eventually the booster will pay for itself. You just need a steady stream of paying customers, which is hardly a challenge given how much we rely on our space infrastructure.

But there’s a catch. For the airliner analogy to really work, whatever inspections and repairs the rocket requires between missions must be done as quickly as possible. The cost savings from reuse aren’t nearly as attractive if you can only fly a few times a year. The key to truly making space accessible isn’t just building a reusable rocket, but attaining rapid reusability.

Which is precisely where SpaceX currently finds themselves. Over the years they’ve mastered landing the Falcon 9’s first stage, and they’ve even proven that the recovered boosters can be safely reused for additional flights. But the refurbishment process is still fairly lengthy. While their latest launch officially broke the record for fastest reflight of a space vehicle that had previously been set by Space Shuttle Atlantis, there’s still a lot of work to be done if SpaceX is ever going to fly their rockets like airplanes.

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Spacing Out: OneWeb Rescue, Starlink Base Stations, And Rocket Tests

July 3, 2020 by Jenny List 23 Comments

Another couple of weeks, and a fresh crop of space news to run through as a quick briefing of the latest in the skies above us.

OneWeb's most recent launch, from Baikonur on the 21st of March 2020. — OneWeb’s most recent launch, from Baikonur on the 21st of March 2020. (OneWeb)

The global positioning orbits are getting pretty crowded, with GPS, Russia’s GLONASS, the EU’s Galileo, Japan’s QZSS, and now with the launch of the final satellite in their constellation, China’s BeiDou. As if five were not enough the chance that they might be joined by a sixth constellation from the United Kingdom resurfaced this week, as the UK government is expressing interest in supporting a rescue package for the troubled satellite broadband provider OneWeb. The idea of an independent GPS competitor from a post-Brexit UK has been bouncing around for a couple of years now, and on the face of it until this opportune chance to purchase an “oven ready” satellite constellation might deliver a route to incorporating a positioning payload into their design. The Guardian has its doubts, lining up a bevvy of scientists to point out the rather obvious fact that a low-earth-orbit satellite broadband platform is a very different prospect to a much-higher-orbiting global positioning platform. Despite the country possessing the expertise through its work on Galileo then it remains to be seen whether a OneWeb purchase would be a stroke of genius or a white elephant. Readers with long memories will know that British government investment in space has had its upsets before.

Happily for Brits, not all space endeavours from their islands end in ignominious retreat. Skyrora have scored another milestone, launching the first ever rocket skywards from the Shetland Islands. The Skylark Nano is a relatively tiny craft at only 2m high, and gathered research data during its flight to an altitude of 6km. We’ve followed their work before, including their testing in May of a Skylark L rocket on the Scottish mainland with a view to achieving launch capability in 2023.

A Starlink phased array end user antenna, spotted in Winsconsin. (darkpenguin22)

SpaceX’s Starlink is never far away from the news, with a fresh set of launches delayed for extra pre-launch tests, and the prospect of signing up to be considered for the space broadband firm’s beta test. Of more interest for Hackaday readers though are a few shots of prototype Starlink ground stations and user terminals that have made it online, on the roof of a Tesla Gigafactory and at a SpaceX facility in Wisconsin. What can be seen are roughly 1.5m radomes for the ground stations and much smaller dinner-plate-sized enclosed arrays for the user terminals. The latter are particularly fascinating as they conceal computer-controlled phased arrays for tracking the constellation as it passes overhead. This is a technology more at home in billion-dollar military radars than consumer devices, so getting it to work on a budget that can put it on a roof anywhere in the world must be a challenge for the Starlink engineers. We can’t wait to see the inevitable eventual teardown when it comes.

Elsewhere, the Virgin Galactic SpaceShip Two completed its second glide test over its Mojave Spaceport home since being grounded in 2019 for extensive refitting, and is now said to be ready for powered tests leading to eventual commercial service giving the extremely well-heeled the chance to float in the zero gravity of suborbital spaceflight. And finally, comes the news that NASA are naming their Washington DC headquarters building for Mary W. Jackson, their first African American female engineer, whose story some of you may be familiar with from the book and film Hidden Figures. The previously unnamed building sits on a section of street named Hidden Figures Way.

Blow Dryers And Metal Shears: Hacks Of Early Falcon 9 Flights

June 13, 2020 by Roger Cheng 10 Comments

Orbiting over our heads right now are two human beings who flew to the International Space Station in a SpaceX Crew Dragon vehicle on top of a Falcon 9. The majority of coverage focused on the years since human spaceflight last launched from Florida, but [Eric Berger] at Ars Technica reminds us it also makes for a grand ten-year celebration of the SpaceX workhorse rocket by sharing some stories from its early days.

Falcon 9 is a huge presence in the global space launch industry today, but ten years ago the future of a young aerospace company was far from certain. The recent uneventful launch is the result of many lessons learned in those ad-hoc days. Some early Falcon 9 flights were successful because the team decided some very unconventional hacks were worth the risk that paid off. A bit of water intrusion? Dry it out with a blow dryer and seal it back up. Small tear in a rocket nozzle? Send in someone to trim a few inches with shears (while the rocket was standing vertical on the launchpad).

Industry veterans appalled at “a cowboy attitude” pounced on every SpaceX failure with “I told you so.” But the disregard for convention is intentional, documented in many places like this old Wired piece from 2012. Existing enshrined aerospace conventions meant the “how” was preserved but the “why” was reduced to “we’ve always done it this way” rarely re-evaluated in light of advancements. Plus the risk-averse industry preferred staying with flight-proven designs, setting up a Catch-22 blocking innovation. SpaceX decided to go a different way, rapidly evolving the Falcon 9 and launching at a high cadence. Learning from all the failures along the way gave them their own set of “why” to back up their “how” growing far beyond blow dryers and metal shears. We’re happy to see the fail-learn-improve cycle at the heart of so many hacker projects have proven effective to send two astronauts to the space station and likely beyond.

[Photo: SpaceX Crew Demo-2 on the launch pad]

Displaying HTML Interfaces And Managing Network Nodes… In Space!

June 8, 2020 by Roger Cheng 44 Comments

The touchscreen interface aboard SpaceX Crew Dragon is just one of its many differences from past space vehicles, but those big screens make an outsized visual impact. Gone are panels filled with indicator needles in gauges, or endless rows of toggle switches. It looked much like web interaction on everyday tablets for good reason: what we see is HTML and JavaScript rendered by the same software core underlying Google’s Chrome browser. This and many other details were covered in a Reddit Ask Me Anything with members of the SpaceX software team.

Various outlets have mentioned Chromium in this context, but without answering the obvious follow-up question: how deep does Chromium go? In this AMA we learn it does not go very deep at all. Chromium is only the UI rendering engine, their fault tolerant flight software interaction is elsewhere. Components such as Chromium are isolated to help keep system behavior predictable, so a frozen tab won’t crash the capsule. Somewhat surprisingly they don’t use a specialized real-time operating system, but instead a lightly customized Linux built with PREEMPT_RT patches for better real-time behavior.

In addition to Falcon rocket and Dragon capsule, this AMA also covered software work for Starlink which offered interesting contrasts in design tradeoffs. Because there are so many satellites (and even more being launched) loss of individual spacecraft is not a mission failure. This gives them elbow room for rapid iteration, treating the constellation more like racks of servers in a datacenter instead of typical satellite operations. Where the Crew Dragon code has been frozen for several months, Starlink code is updated rapidly. Quickly enough that by the time newly launched Starlink satellites reach orbit, their code has usually fallen behind the rest of the constellation.

Finally there are a few scattered answers outside of space bound code. Their ground support displays (visible in Hawthorne mission control room) are built with LabVIEW. They also confirmed that contrary to some claims, the SpaceX ISS docking simulator isn’t actually running the same code as Crew Dragon. Ah well.

Anyone interested in what it takes to write software for space would enjoy reading through these and other details in the AMA. And since it had a convenient side effect of serving as a recruiting event, there are plenty of invitations to apply if anyone has ambitions to join the team. We certainly can’t deny the attraction of helping to write the next chapter in human spaceflight.

[Photo credit: SpaceX]

NASA’s Long-Delayed Return To Human Spaceflight

June 1, 2020 by Tom Nardi 55 Comments

With the launch of the SpaceX Demo-2 mission, the United States has achieved something it hasn’t done in nearly a decade: put a human into low Earth orbit with a domestic booster and vehicle. It was a lapse in capability that stretched on far longer than anyone inside or outside of NASA could have imagined. Through a series of delays and program cancellations, the same agency that put boot prints on the Moon and built the iconic Space Shuttle had been forced to rely on Russia to carry its astronauts into space since 2011.

NASA would still be waiting to launch its own astronauts had they relied on America’s traditional aerospace giants to get the job done. The inaugural flight of the Boeing CST-100 “Starliner” to the International Space Station in December was an embarrassing failure that came perilously close to losing the unmanned capsule. A later investigation found that sloppy software development and inconsistent testing had caused at least two major failures during the mission, which ultimately had to be cut short as the vehicle couldn’t even reach the altitude of the ISS, to say nothing of making a docking attempt. NASA and Boeing have since agreed to attempt another test of the CST-100 sometime before the end of the year, though a delay into 2021 seems almost inevitable due to the global pandemic.

But America’s slow return to human spaceflight can’t be blamed on the CST-100, or even Boeing, for that matter. Since the retirement of the Space Shuttle, NASA has been hindered by politics and indecisiveness. With a constantly evolving mandate from the White House, the agency’s human spaceflight program has struggled to make significant progress towards any one goal.

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Spacing Out: All The Orbital News You’re Missing

May 30, 2020 by Jenny List 19 Comments

We keep finding more great space stories than we can cover, so here’s a speed-run through the broader picture of the moment as it applies to space flight.

The big news this week was the first launch of a manned SpaceX Crew Dragon capsule to the ISS. I was excited because the pass en route to the space station was scheduled to be visible from the UK at dusk, and on Wednesday evening I perched atop a nearby hill staring intently at the horizon. Except it had been cancelled due to bad weather. The next launch window is planned for today and you can watch it live.

Meanwhile, fashion is the other piece of this manned-launch’s appeal. Their sharply-designed spacesuits have attracted a lot of attention, moving on from the bulky functional Michelin Man aesthetic of previous NASA and Roscosmos garments for a positively futuristic look that wouldn’t be out of place in Star Trek. Never mind that the two astronauts are more seasoned space dog than catwalk model, they still look pretty cool to us. Against the backdrop of a political upheaval at the top of NASA, this first crewed orbital mission from American soil since the retirement of the Shuttle has assumed an importance much greater than might be expected from a run-of-the-mill spaceflight.

While we’re on the subject of the ISS, it’s worth noting that we’re approaching twenty years since the first crew took up residence there, and it has been continuously crewed ever since as an off-planet outpost. This is an astounding achievement for all the engineers, scientists, and crews involved, and though space launches perhaps don’t have the magic they had five decades ago it’s still an awe-inspiring sight to see a man-made object big enough to discern its shape pass over in the night sky. We understand that current plans are to retain the station until at least 2030, so it’s a sight that should remain with us for a while longer.

Closer to Earth are a couple of tests for relative newcomers to the skies. When Richard Branson’s Virgin group isn’t trying to boot millionaires off the planet through its Virgin Galactic operation, it’s aiming to cheaply fling small satellites into orbit from a rocket-toting airborne Boeing 747 with its Virgin Orbit subsidiary. Their first test launch sadly didn’t make it to space, once the rocket had flawlessly launched from the airliner it suffered a fault and the mission had to be aborted. Getting into space is hard.

The second test was never intended to make it into space, but is no less noteworthy. The British company Skyrora have performed a successful ground test of their Skylark L rocket, aiming for a first launch next year and for offering low-earth orbit services by 2023. This is significant because it will be the first British launch since the ill-fated Black Arrow launch in 1971, and with their Scottish launch site the first ever from British soil. If you’ve seen Skyrora mentioned here before, it is because they were behind the retrieval of the Black Arrow wreckage from the Aussie outback that we mentioned when we wrote about that programme.

Looking forward to the coming week, especially today’s rescheduled SpaceX launch. This time however, I’ll check the weather conditions before climbing any hills.