It’s Pi Day, and while we know that many of you celebrate privately, those that take a moment to put aside their contemplation of all things circular and join us on this mathematically-significant day will likely know the name [Cristiano Monteiro]. Since 2022 he’s made it a yearly tradition to put together a themed project every March 14th, and he’s just put the finishing touches on the 2026 edition.

Generally, [Cristiano] sends in some interesting hardware device that visualizes the calculation of pi, but this year he surprised us a bit by delivering a software project. His Orbital Pi Simulator allows you to see what would happen to an orbiting spacecraft if it’s navigation system suddenly believed the value of pi was something different.

In broad strokes, we can imagine what would happen. If you plug in something significantly higher than 3.14, the orbit becomes elliptical to the point that the craft can fly off into deep space. Drop the value down, and the orbit will intersect with the Earth — a guaranteed recipe for a bad time.

The Kerbal Space Program players in the audience will no doubt point out that in the absence of drag a spacecraft in a stable orbit would more or less stay on that same trajectory indefinitely and not need to manually adjust its velocity in the first place. Further, they would argue that said spacecraft suddenly firing its thrusters retrograde because a flipped bit in its computer resulted in the value of pi suddenly being 1.2 isn’t very realistic. Those people would be correct, but they would also be no fun at parties.

Fans of math and/or circles will no doubt be interested in the previous devices [Cristiano] has built to mark this date. Last year he put together a robotic hand that counted out pi with its 3D printed fingers, and in 2024 he used the Pepper’s Ghost illusion to great effect. For those wondering, not everything he does is pi-related. The portable GPS time server he sent out way in 2021 was a particularly slick piece of hardware.

There’s little about building spacecraft that anyone would call simple. But there’s at least one element of designing a vehicle that will operate outside the Earth’s atmosphere that’s fairly easier to handle: aerodynamics. That’s because, at the altitude that most satellites operate at, drag can essentially be ignored. Which is why most satellites look like refrigerators with solar panels and high-gain antennas attached jutting out at odd angles.

But for all the advantages that the lack of meaningful drag on a vehicle has, there’s at least one big potential downside. If a spacecraft is orbiting high enough over the Earth that the impact of atmospheric drag is negligible, then the only way that vehicle is coming back down in a reasonable amount of time is if it has the means to reduce its own velocity. Otherwise, it could be stuck in orbit for decades. At a high enough orbit, it could essentially stay up forever.

There was a time when that kind of thing wasn’t a problem. It was just enough to get into space in the first place, and little thought was given to what was going to happen in five or ten years down the road. But today, low Earth orbit is getting crowded. As the cost of launching something into space continues to drop, multiple companies are either planning or actively building their own satellite constellations comprised of thousands of individual spacecraft.

Fortunately, there may be a simple solution to this problem. By putting a satellite into what’s known as a very low Earth orbit (VLEO), a spacecraft will experience enough drag that maintaining its velocity requires constantly firing its thrusters.  Naturally this presents its own technical challenges, but the upside is that such an orbit is essentially self-cleaning — should the craft’s propulsion fail, it would fall out of orbit and burn up in months or even weeks. As an added bonus, operating at a lower altitude has other practical advantages, such as allowing for lower latency communication.

VLEO satellites hold considerable promise, but successfully operating in this unique environment requires certain design considerations. The result are vehicles that look less like the flying refrigerators we’re used to, with a hybrid design that features the sort of aerodynamic considerations more commonly found on aircraft.

ESA’s Pioneering Work

This might sound like science fiction, but such craft have already been developed and successfully operated in VLEO. The best example so far is the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE), launched by the European Space Agency (ESA) back in 2009.

To make its observations, GOCE operated at an altitude of 255 kilometers (158 miles), and dropped as low as just 229 km (142 mi) in the final phases of the mission. For reference the International Space Station flies at around 400 km (250 mi), and the innermost “shell” of SpaceX’s Starlink satellites are currently being moved to 480 km (298 mi).

Given the considerable drag experienced by GOCE at these altitudes, the spacecraft bore little resemblance to a traditional satellite. Rather than putting the solar panels on outstretched “wings”, they were mounted to the surface of the dart-like vehicle. To keep its orientation relative to the Earth’s surface stable, the craft featured stubby tail fins that made it look like a futuristic torpedo.

Even with its streamlined design, maintaining such a low orbit required GOCE to continually fire its high-efficiency ion engine for the duration of its mission, which ended up being four and a half years.

In the case of GOCE, the end of the mission was dictated by how much propellant it carried. Once it had burned through the 40 kg (88 lb) of xenon onboard, the vehicle would begin to rapidly decelerate, and ground controllers estimated it would re-enter the atmosphere in a matter of weeks. Ultimately the engine officially shutdown on October 21st, and by November 9th, it’s orbit had already decayed to 155 km (96 mi). Two days later, the craft burned up in the atmosphere.

JAXA Lowers the Bar

While GOCE may be the most significant VLEO mission so far from a scientific and engineering standpoint, the current record for the spacecraft with the lowest operational orbit is actually held by the Japan Aerospace Exploration Agency (JAXA).

In December 2017 JAXA launched the Super Low Altitude Test Satellite (SLATS) into an initial orbit of 630 km (390 mi), which was steadily lowered in phases over the next several weeks until it reached 167.4 km (104 mi). Like GOCE, SLATS used a continuously operating ion engine to maintain velocity, although at the lowest altitudes, it also used chemical reaction control system (RCS) thrusters to counteract the higher drag.

SLATS was a much smaller vehicle than GOCE, coming in at roughly half the mass. It also carried just 12 kg (26 lb) of xenon propellant, which limited its operational life. It also utilized a far more conventional design than GOCE, although its rectangular shape was somewhat streamlined when compared to a traditional satellite. Its solar arrays were also mounted in parallel to the main body of the craft, giving it an airplane-like appearance.

The combination of lower altitude and higher frontal drag meant that SLATS had an even harder time maintaining velocity than GOCE. Once its propulsion system was finally switched off in October 2019, the craft re-entered the atmosphere and burned up within 24 hours. The mission has since been recognized by Guinness World Records for the lowest altitude maintained by an Earth observation satellite.

A New Breed of Satellite

As impressive as GOCE and SLATS were, their success was based more on careful planning than any particular technological breakthrough. After all, ion propulsion for satellites is not new, nor is the field of aerodynamics. The concepts were simply applied in a novel way.

But there exists the potential for a totally new type of vehicle that operates exclusively in VLEO. Such a craft would be a true hybrid, in the sense that its primarily a spacecraft, but uses an air-breathing electric propulsion (ABEP) system akin to an aircraft’s jet engine. Such a vehicle could, at least in theory, maintain an altitude as low as 90 km (56 mi) indefinitely — so long as its solar panels can produce enough power.

Both the Defense Advanced Research Projects Agency (DARPA) in the United States and the ESA are currently funding several studies of ABEP vehicles, such as Redwire’s SabreSat, which have numerous military and civilian applications. Test flights are still years away, but should VLEO satellites powered by ABEP become common platforms for constellation applications, they may help alleviate orbital congestion before it becomes a serious enough problem to impact our utilization of space.

The list of countries to achieve their own successful orbital space launch is a short one, almost as small as the exclusive club of states that possess nuclear weapons. The Soviet Union was first off the rank in 1957, with the United States close behind in 1958, and a gaggle of other aerospace-adept states followed in the 1960s, 1970s, and 1980s. Italy, Iran, North Korea and South Korea have all joined the list since the dawn of the new millennium.

Absent from the list stands Australia. The proud island nation has never stood out as a player in the field of space exploration, despite offering ground station assistance to many missions from other nations over the years. However, the country has continued to inch its way to the top of the atmosphere, establishing its own space agency in 2018. Since then, development has continued apace, and the country’s first orbital launch appears to be just around the corner.

Space, Down Under

The establishment of the Australian Space Agency (ASA) took place relatively recently. The matter was seen to be long overdue from an OECD member country; by 2008, Australia was the only one left without a national space agency since previous state authorities had been disbanded in 1996. This was despite many facilities across the country contributing to international missions, providing critical radio downlink services and even welcoming JAXA’s Hayabusa2 spacecraft back to Earth.

Eventually, a groundswell grew, pressuring the government to put Australia on the right footing to seize growing opportunities in the space arena. Things came to a head in 2018, when the government established ASA to “support the growth and transformation of Australia’s space industry.”

ASA would serve a somewhat different role compared to organizations like NASA (USA) and ESA (EU). Many space agencies in other nations focus on developing launch vehicles and missions in-house, collaborating with international partners and aerospace companies in turn to do so. However, for ASA, the agency is more focused on supporting and developing the local space industry rather than doing the engineering work of getting to space itself.

Orbital Upstarts

Just because the government isn’t building its own rockets, doesn’t mean that Australia isn’t trying to get to orbit. That goal is the diehard mission of Gilmour Space Technologies. The space startup was founded in 2013, and established its rocketry program in 2015, and has been marching towards orbit ever since. As is often the way, the journey has been challenging, but the payoff of genuine space flight is growing ever closer.

Gilmour Space moved fast, launching its first hybrid rocket back in 2016. The successful suborbital launch proved to be a useful demonstration of the company’s efforts to produce a rocket that used 3D-printed fuel. This early milestone aided the company to secure investment that would support its push to grander launches at greater scale. The company’s next major launch was planned for 2019, but frustration struck—when the larger One Vision rocket suffered a failure just 7 seconds prior to liftoff. Undeterred, the company continued development of a larger rocket, taking on further investment and signing contracts to launch payloads to orbit in the ensuing years.

Gilmour Space has worked hard to develop its hybrid rocket engines in-house. 

With orbital launches and commercial payload deliveries the ultimate goal, it wasn’t enough to just develop a rocket. Working with the Australian government, Gilmour Space established the Bowen Orbital Spaceport in early 2024—a launchpad suitable for the scale of its intended space missions. Located on Queensland’s Gold Coast, it’s just 20 degrees south of the equator—closer than Cape Canaveral, and useful for accessing low- to mid-inclination equatorial orbits. The hope was to gain approval to launch later that year, but thus far, no test flights have taken place. Licensing issues around the launch have meant the company has had to hold back on shooting for orbit.

The rocket with which Gilmour Space intends to get there is called Eris. In Block 1 configuration, it stands 25 meters tall, and is intended to launch payloads up to 300 kg into low-Earth orbits. It’s a three-stage design. It uses four of Gilmour’s Sirius hybrid rocket motors in the first stage, and just one in the second stage. The third stage has a smaller liquid rocket engine of Gilmour’s design, named Phoenix. The rocket was first staged vertically on the launch pad in early 2024, and a later “dress rehearsal” for launch was performed in September, with the rocket fully fueled. However, flight did not take place, as launch permits were still pending from Australia’s Civil Aviation Safety Authority (CASA).

The Eris rocket was first vertically erected on the launchpad in 2024, but progress towards launch has been slow since then. 

After a number of regulatory issues, the company’s first launch of Eris was slated for March 15, 2025. However, that day came and passed, even with CASA approval, as the required approvals were still not available from the Australian Space Agency. Delays have hurt the company’s finances, hampering its ability to raise further funds. As for the rocket itself, hopes for Eris’s performance at this stage remain limited, even if you ask those at Gilmour Space. Earlier this month, founder Adam Gilmour spoke to the Sydney Morning Herald on his expectations for the initial launch. Realistic about the proposition of hitting orbit on the company first attempt, he expects it to take several launches to achieve, with some teething problems to come. “It’s very hard to test an orbital rocket without just flying it,” he told the Herald. “We don’t have high expectations we’ll get to orbit… I’d personally be happy to get off the pad.”

Despite the trepidation, Eris stands as Australia’s closest shot at hitting the bigtime outside the atmosphere. Government approvals and technical hurdles will still need to be overcome, with the Australian Space Agency noting that the company still has licence conditions to meet before a full launch is approved. Still, before the year is out, Australia might join that vaunted list of nations that have leapt beyond the ground to circle the Earth from above. It will be a proud day when that comes to pass.

Ever been at a party and landed in a heated argument about exactly where the International Space Station (ISS) is passing over at that very instant? Me neither, but it’s probably happened to someone. Assuming you were in that situation, and lacked access to your smartphone or any other form of internet connected device, you might like the pocket-sized Screen Tracker from [mars91].

The concept is simple. It’s a keychain-sized item that combines an ESP32, a Neopixel LED, and a small LCD screen on a compact PCB with a couple of buttons. It’s programmed to communicate over the ESP32’s WiFi connection to query a small custom website running on AWS. That website processes orbit data for the ISS and the positions of the planets, so they can be displayed on the LCD screen above a map of the Earth. We’re not sure what font it uses, but it looks pretty cool—like something out of a 90s sci-fi movie.

It’s a great little curio, and these sort of projects can have great educational value to boot. Creating something like this will teach you about basic orbits, as well as how to work with screens and APIs and getting embedded devices online. It may sound trivial when you’ve done it before, but you can learn all kinds of skills pursuing builds like these.

Logically we understand that the other planets in the solar system, as well as humanity’s contributions to the cosmos such as the Hubble Space Telescope and the International Space Station, are zipping around us somewhere — but it can be difficult to conceptualize. Is Jupiter directly above your desk? Is the ISS currently underneath you?

If you’ve ever found yourself wondering such things, you might want to look into making something like Space Monitor. Designed by [Kevin Assen], this little gadget is able to literally point out the locations of objects in space. Currently it’s limited to the ISS and Mars, but adding new objects to track is just a matter of loading in the appropriate orbital data.

In addition to slewing around its 3D printed indicator, the Space Monitor also features a round LCD that displays the object currently being tracked, as well as the weather. Reading through the list of features and capabilities of the ESP32-powered device, we get the impression that [Kevin] is using it as a sort of development platform for various concepts. Features like remote firmware updates and the ability to point smartphones to the device’s configuration page via on-screen QR aren’t necessarily needed on a personal-use device, but its great practice for when you do eventually send one of your creations out into the scary world beyond your workbench.

If you’re interested in something a bit more elaborate, check out this impressive multi-level satellite tracker we covered back in 2018.

Reaching orbit around Earth is an incredibly difficult feat. It’s a common misconception that getting into orbit just involves getting very high above the ground — the real trick is going sideways very, very fast. Thus far, the most viable way we’ve found to do this is with big, complicated multi-stage rockets that shed bits of themselves as they roar out of the atmosphere.

Single-stage-to-orbit (SSTO) launch vehicles represent a revolutionary step in space travel. They promise a simpler, more cost-effective way to reach orbit compared to traditional multi-stage rockets. Today, we’ll explore the incredible potential offered by SSTO vehicles, and why building a practical example is all but impossible with our current technology.

A Balancing Act

The SSTO concept doesn’t describe any one single spacecraft design. Instead, it refers to any spacecraft that’s capable of achieving orbit using a single, unified propulsion system and without jettisoning any part of the vehicle.

Today’s orbital rockets shed stages as they expend fuel. There’s one major reason for this, and it’s referred to as the tyranny of the rocket equation. Fundamentally, a spacecraft needs to reach a certain velocity to attain orbit. Reaching that velocity from zero — i.e. when the rocket is sitting on the launchpad — requires a change in velocity, or delta-V. The rocket equation can be used to figure out how much fuel is required for a certain delta-V, and thus a desired orbit.

The problem is that the mass of fuel required scales exponentially with delta-V. If you want to go faster, you need more fuel. But then you need even more fuel again to carry the weight of that fuel, and so on. Plus, all that fuel needs a tank and structure to hold it, which makes things more difficult again.

Work out the maths of a potential SSTO design, and the required fuel to reach orbit ends up taking up almost all of the launch vehicle’s weight. There’s precious mass left over for the vehicle’s own structure, let alone any useful payload. This all comes down to the “mass fraction” of the rocket. A SSTO powered by even our most efficient chemical rocket engines would require that the vast majority of its mass be dedicated to propellants, with its structure and payload being tiny in comparison. Much of that is due to Earth’s nature. Our planet has a strong gravitational pull, and the minimum orbital velocity is quite high at about 7.4 kilometers per second or so.

Stage Fright

Historically, we’ve cheated the rocket equation through smart engineering. The trick with staged rockets is simple. They shed structure as the fuel burns away. There’s no need to keep hauling empty fuel tanks into orbit. By dropping empty tanks during flight, the remaining fuel on the rocket has to accelerate a smaller mass, and thus less fuel is required to get the final rocket and payload into its intended orbit.

So far, staged rockets have been the only way for humanity to reach orbit. Saturn V had five stages, more modern rockets tend to have two or three. Even the Space Shuttle was a staged design: it shed its two booster rockets when they were empty, and did the same with its external liquid fuel tank.

But while staged launch vehicles can get the job done, it’s a wasteful way to fly. Imagine if every commercial flight required you to throw away three quarters of the airplane. While we’re learning to reuse discarded parts of orbital rockets, it’s still a difficult and costly exercise.

The core benefit of a SSTO launch vehicle would be its efficiency. By eliminating the need to discard stages during ascent, SSTO vehicles would reduce launch costs, streamline operations, and potentially increase the frequency of space missions.

Pushing the Envelope

It’s currently believed that building a SSTO vehicle using conventional chemical rocket technology is marginally possible. You’d need efficient rocket engines burning the right fuel, and a light rocket with almost no payload, but theoretically it could be done.

Ideally, though, you’d want a single-stage launch vehicle that could actually reach orbit with some useful payload. Be that a satellite, human astronauts, or some kind of science package. To date there have been several projects and proposals for SSTO launch vehicles, none of which have succeeded so far.

One notable design was the proposed Skylon spacecraft from British company Reaction Engines Limited. Skylon was intended to operate as a reusable spaceplane fueled by hydrogen. It would take off from a runway, using wings to generate lift to help it to ascend to 85,000 feet. This improves fuel efficiency versus just pointing the launch vehicle straight up and fighting gravity with pure thrust alone. Plus, it would burn oxygen from the atmosphere on its way to that altitude, negating the need to carry heavy supplies of oxygen onboard.

Once at the appropriate altitude, it would switch to internal liquid oxygen tanks for the final acceleration phase up to orbital velocity. The design stretches back decades, to the earlier British HOTOL spaceplane project. Work continues on the proposed SABRE engine (Syngergetic Air-Breathing Rocket Engine) that would theoretically propel Skylon, though no concrete plans to build the spaceplane itself exist.

Lockheed Martin also had the VentureStar spaceplane concept, which used an innovative “aerospike” rocket engine that maintained excellent efficiency across a wide altitude range. The company even built a scaled-down test craft called the X-33 to explore the ideas behind it. However, the program saw its funding slashed in the early 2000s, and development was halted.

McDonnell Douglas also had a crack at the idea in the early 1990s. The DC-X, also known as the Delta Clipper, was a prototype vertical takeoff and landing vehicle. At just 12 meters high and 4.1 meters in diameter, it was a one-third scale prototype for exploring SSTO-related technologies

It would take off vertically like a traditional rocket, and return to Earth nose-first before landing on its tail. The hope was that the combination of single-stage operation and this mission profile would provide extremely quick turnaround times for repeat launches, which was seen as a boon for potential military applications. While its technologies showed some promise, the project was eventually discontinued when a test vehicle caught fire after NASA took over the project.

Ultimately, a viable SSTO launch vehicle that can carry a payload will likely be very different from the rockets we use today. Relying on wings to generate lift could help save fuel, and relying on air in the atmosphere would slash the weight of oxidizer that would have to be carried onboard.

However, it’s not as simple as just penning a spaceplane with an air-breathing engine and calling it done. No air breathing engine that exists can reach orbital velocity, so such a craft would need an additional rocket engine too, adding weight. Plus, it’s worth noting a reusable launch vehicle would also still require plenty of heat shielding to survive reentry. One could potentially build a non-reusable single-stage to orbit vehicle that simply stays in space, of course, but that would negate many of the tantalizing benefits of the whole concept.

Single-stage-to-orbit vehicles hold the promise of transforming how we access space by simplifying the architecture of launch vehicles and potentially reducing costs. While there are formidable technical hurdles to overcome, the ongoing advances in aerospace technology provide hope that SSTO could become a practical reality in the future. As technology marches forward in materials, rocketry, and aerospace engineering in general, the dream of a single-stage path to orbit remains a tantalizing future goal.

Featured Image: Skylon Concept Art, ESA/Reaction Engines Ltd

There have been all kinds of wild ideas to get spacecraft into orbit. Everything from firing huge cannons to spinning craft at rapid speed has been posited, explored, or in some cases, even tested to some degree. And yet, good ol’ flaming rockets continue to dominate all, because they actually get the job done.

Rockets, fuel, and all their supporting infrastructure remain expensive, so the search for an alternative goes on. One daring idea involves using airships to loft payloads into orbit. What if you could simply float up into space?

Lighter Than Air

The concept sounds compelling from the outset. Through the use of hydrogen or helium as a lifting gas, airships and balloons manage to reach great altitudes while burning zero propellant. What if you could just keep floating higher and higher until you reached orbital space?

This is a huge deal when it comes to reaching orbit. One of the biggest problems of our current space efforts is referred to as the tyranny of the rocket equation. The more cargo you want to launch into space, the more fuel you need. But then that fuel adds more weight, which needs yet more fuel to carry its weight into orbit. To say nothing of the greater structure and supporting material to contain it all.

Carrying even a few extra kilograms of weight to space can require huge amounts of additional fuel. This is why we use staged rockets to reach orbit at present. By shedding large amounts of structural weight at the end of each rocket stage, it’s possible to move the remaining rocket farther with less fuel.

If you could get to orbit while using zero fuel, it would be a total gamechanger. It wouldn’t just be cheaper to launch satellites or other cargoes. It would also make missions to the Moon or Mars far easier. Those rockets would no longer have to carry the huge amount of fuel required to escape Earth’s surface and get to orbit. Instead, they could just carry the lower amount of fuel required to go from Earth orbit to their final destination.

Of course, it’s not that simple. Reaching orbit isn’t just about going high above the Earth. If you just go straight up above the Earth’s surface, and then stop, you’ll just fall back down. If you want to orbit, you have to go sideways really, really fast.

Thus, an airship-to-orbit launch system would have to do two things. It would have to haul a payload up high, and then get it up to the speed required for its desired orbit. That’s where it gets hard. The minimum speed to reach a stable orbit around Earth is 7.8 kilometers per second (28,000 km/h or 17,500 mph). Thus, even if you’ve floated up very, very high, you still need a huge rocket or some kind of very efficient ion thruster to push your payload up to that speed. And you still need fuel to generate that massive delta-V (change in velocity).

For this reason, airships aren’t the perfect hack to reaching orbit that you might think. They’re good for floating about, and you can even go very, very high. But if you want to circle the Earth again and again and again, you better bring a bucketload of fuel with you.

Someone’s Working On It

Nevertheless, this concept is being actively worked on, but not by the usual suspects. Don’t look at NASA, JAXA, SpaceX, ESA, or even Roscosmos. Instead, it’s the work of the DIY volunteer space program known as JP Aerospace.

The organization has grand dreams of launching airships into space. Its concept isn’t as simple as just getting into a big balloon and floating up into orbit, though. Instead, it envisions a three-stage system.

The first stage would involve an airship designed to travel from ground level up to 140,000 feet. The company proposes a V-shaped design with an airfoil profile to generate additional lift as it moves through the atmosphere. Propulsion would be via propellers that are specifically designed to operate in the near-vacuum at those altitudes.

Once at that height, the first stage craft would dock with a permanently floating structure called Dark Sky Station. It would serve as a docking station where cargo could be transferred from the first stage craft to the Orbital Ascender, which is the craft designed to carry the payload into orbit.

The Orbital Ascender itself sounds like a fantastical thing on paper. The team’s current concept is for a V-shaped craft with a fabric outer shell which contains many individual plastic cells full of lifting gas. That in itself isn’t so wild, but the proposed size is. It’s slated to measure 1,828 meters on each side of the V — well over a mile long — with an internal volume of over 11 million cubic meters. Thin film solar panels on the craft’s surface are intended to generate 90 MW of power, while a plasma generator on the leading edge is intended to help cut drag. The latter is critical, as the craft will need to reach hypersonic speeds in the ultra-thin atmosphere to get its payload up to orbital speeds. To propel the craft up to orbital velocity, the team has been running test firings on its own designs for plasma thrusters.

The team at JP Aerospace is passionate, but currently lacks the means to execute their plans at full scale. Right now, the team has some experimental low-altitude research craft that are a few hundred feet long. Presently, Dark Sky Station and the Orbital Ascender remain far off dreams.

Realistically, the team hasn’t found a shortcut to orbit just yet. Building a working version of the Orbital Ascender would require lofting huge amounts of material to high altitude where it would have to be constructed. Such a craft would be torn to shreds by a simple breeze in the lower atmosphere. A lighter-than-air craft that could operate at such high altitudes and speeds might not even be practical with modern materials, even if the atmosphere is vanishingly thin above 140,000 feet.  There are huge questions around what materials the team would use, and whether the theoretical concepts for plasma drag reduction could be made to work on the monumentally huge craft.

Even if the craft’s basic design could work, there are questions around the practicalities of crewing and maintaining a permanent floating airship station at high altitude. Let alone how payloads would be transferred from one giant balloon craft to another. These issues might be solvable with billions of dollars. Maybe. JP Aerospace is having a go on a budget several orders of magnitude more shoestring than that.

One might imagine a simpler idea could be worth trying first. Lofting conventional rockets to 100,000 feet with balloons would be easier and still cut fuel requirements to some degree. But ultimately, the key challenge of orbit remains. You still need to find a way to get your payload up to a speed of at least 8 kilometers per second, regardless of how high you can get it in the air. That would still require a huge rocket, and a suitably huge balloon to lift it!

For now, orbit remains devastatingly hard to reach, whether you want to go by rocket, airship, or nuclear-powered paddle steamer. Don’t expect to float to the Moon by airship anytime soon, even if it sounds like a good idea.