There were all kinds of wild ideas about putting spacecraft into orbit. Everything from firing huge cannons to spinning ships at high speed has been established, studied or in some cases even tested to some extent. And yet the good old flaming rockets continue to dominate all because they actually get the job done.
Missiles, fuel and all their supporting infrastructure remain expensive, so the search for an alternative continues. One bold idea involves using airships to launch payloads into orbit. What if you could just drift off into space?
Lighter than air
The concept sounds convincing from the start. By using hydrogen or helium as a lift gas, airships and balloons are able to reach great heights while burning zero fuel. What if you could just keep floating higher and higher until you reach orbital space?
That’s a huge deal when it comes to reaching orbit. One of the biggest problems of our current space effort is called tsolving the rocket equation. Tthe more cargo you want to launch into space, the more fuel you need. But then that fuel adds more weight, which needs even more fuel to carry its weight into orbit. Not to mention the larger structure and supporting material to contain it all.
Carrying even a few extra pounds of weight into space can require huge amounts of extra fuel. This is why we currently use staged rockets to reach orbit. By reducing large amounts of structural weight at the end of each rocket stage, it is possible to move the remaining rocket farther with less fuel.
If you can get to orbit while using zero fuel it would be a complete game changer. It wouldn’t just be cheaper to launch satellites or other payloads. It would also make missions to the Moon or Mars much easier. These rockets will no longer need to carry the huge amount of fuel needed to escape the Earth’s surface and reach orbit. Instead, they could simply carry the smaller amount of fuel needed to go from Earth orbit to their final destination.
Of course, it’s not that simple. Reaching orbit isn’t just about getting high above Earth. If you just go straight up above the surface of the Earth and then stop, you’ll just fall back down. If you want to orbit, you really have to go sideways, really quick.
Thus, an airship-to-orbit launch system would need to do two things. It would have to pull a payload aloft and then develop it to the speed required for the desired orbit. That’s where it gets tricky. The minimum speed to reach a stable orbit around the Earth is 7.8 kilometers per second (28,000 km/h or 17,500 mph). That way, even if you floated a lot, a lot high, you still need a huge rocket or some kind of very efficient ion engine to push your payload to that speed. And you still need fuel to generate that massive delta-V (change in velocity).
For this reason, airships are not as perfect a way to reach orbit as you might think. They are good to carry around and you can even go very, very high. But if you want to circle the Earth again and again and again, you better take a whole bucket of fuel with you.
Someone is working on it
However, this concept is actively being 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 volunteer DIY space program known as JP Aerospace.
The organization has big dreams of launching airships into space. However, its concept isn’t as simple as just getting into a big balloon and soaring into orbit. Instead, it envisions a three-tier system.
The first stage will include an airship designed to travel from ground level to 140,000 feet. The company offers a V-shaped airfoil design to generate extra lift as it moves through the atmosphere. Propulsion will be via propellers that are specially designed to operate in a near vacuum at these altitudes.
Once at this height, the first stage ship will dock with a permanently floating structure called the Dark Sky Station. It will serve as a docking station where the payload can 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 fantastic thing on paper. The team’s current concept is for a V-shaped craft with a canvas outer shell that contains many individual plastic cells filled with lifting gas. That in itself isn’t that wild, but the proposed size is. It’s projected to measure 1,828 meters on each side of the V – well over a mile – with an internal volume of over 11 million cubic meters. Thin-film solar panels on the surface of the ship are designed to generate 90 MW of power, while a plasma generator on the leading edge is designed to help reduce drag. The latter is critical, as the craft will need to reach hypersonic speeds in the ultrathin atmosphere to get its payload up to orbital speeds. To propel the craft to orbital velocity, the team conducts test firings of its own plasma thruster designs.
The JP Aerospace team is passionate, but currently lacks the funds to execute their plans at full scale. The team currently has low-altitude experimental research vessels that are several hundred feet long. Currently, the Dark Sky Station and Orbital Ascender remain far from dreams.
Realistically, the team has yet to find a shortcut to orbit. Building a working version of the Orbital Ascender would require raising massive amounts of material to the high altitudes where it would need to be constructed. Such a ship would be blown to pieces by a mere breeze in the lower atmosphere. A lighter-than-air aircraft capable of operating at such high altitude and speed may not even be practical with modern materials, even if the atmosphere is vanishingly thin above 140,000 feet. There are huge questions about what materials the team will use and whether theoretical concepts for reducing plasma drag can be made to work on the monumentally huge ship.
Even if the basic design of the vessel could work, there are questions about the practicalities of crewing and maintaining a permanent floating station on an airship at high altitude. Not to mention how the payloads will be transferred from one giant balloon ship to another. These problems could be solved with billions of dollars. Perhaps. JP Aerospace has a budget several orders of magnitude smaller than this.
One might imagine that a simpler idea might be worth trying first. Taking conventional rockets up to 100,000 feet with balloons would be easier and still reduce fuel requirements somewhat. But ultimately, the main challenge of orbit remains. You still have to find a way to get your payload up to a speed of at least 5 miles per second, no matter how high you can get it in the air. This would again require a huge rocket and a suitably huge balloon to lift it!
For now, orbit remains devastatingly elusive, whether you want to travel by rocket, airship, or nuclear-powered paddle steamer. Don’t expect to fly to the moon in an airship anytime soon, even if it sounds like a good idea.
