Buzz
At present, rockets are the only means of traveling to space or delivering payloads. However, the future might hold some surprising alternatives. There are ongoing plans to develop innovative travel methods, and some of them are truly out of this world.
Inventors have proposed using space elevators, underwater space cannons, catapults, and even balloons to transport people and goods into space. While some of these ideas may seem far-fetched and unlikely to come to fruition, others could potentially become reality within the coming decades. Only time will tell.
10. Space Elevators
A space elevator is exactly what it sounds like—an elevator stretching all the way from Earth to space. This visionary concept was first introduced by Russian scientist Konstantin Tsiolkovsky in 1895.
The system would involve four to six cables connected to a central elevator. Each cable would support an electromagnetic vehicle (essentially an elevator) leading to various platforms in space or the upper atmosphere. The elevator would travel at speeds of thousands of kilometers per hour.
The cables’ upper ends would be anchored to a massive object like a space station or even an asteroid. The cables' lower ends would be linked to a towering 50-kilometer (31 mi) structure on Earth. Most plans suggest building this ground tower along the equator, as areas outside this region are prone to hurricanes and tornadoes.
NASA envisions the space elevator as a future replacement or significant reduction in our reliance on rockets. Although the technology is still in development, both China and the Obayashi Corporation of Japan have set plans to complete their versions by 2045 and 2050, respectively. If realized, it could lower the cost of sending 0.5 kilograms (1 lb) of payload into space from $3,500 to just $25.
9. Skyhook
Picture a massive fishing hook reaching down from space and stopping somewhere high in the sky. That’s essentially what a skyhook is. It’s also referred to as the beanstalk, inspired by the story of 'Jack and the Beanstalk,' or as Jacob’s ladder, referencing a Bible verse where a ladder was lowered from the heavens to Earth.
A skyhook is often described as a more compact version of the space elevator. While both follow the same concept, the skyhook’s cable doesn’t extend all the way to Earth. There’s no ground station involved either.
The payload is first launched by a rocket or another propulsion system and connected to the end of the skyhook’s cable, which then propels the payload into space. It has also been proposed that the skyhook could work in reverse, sending minerals mined from asteroids or other planets back to Earth.
8. Space Gun
A massive space gun could theoretically launch payloads into space. However, it’s not feasible for sending humans, as the immense force would instantly crush a person, reducing their size by half and resulting in death. While we haven't perfected the technology yet, some inventors are still determined to bring it to life.
One such inventor is John Hunter. He introduced the idea of the QuickLauncher, a 1,100-meter (3,600 ft) space gun designed to shoot payloads into orbit. Hunter began developing the QuickLauncher in 1992 and even tested a 130-meter (425 ft) prototype. When finished, the QuickLauncher would be positioned 490 meters (1,600 ft) beneath the sea near the equator.
Only the top of the barrel would be visible, with a rig holding the upper part of the gun above the water’s surface. Hunter proposed that the QuickLauncher could dramatically cut the cost of sending payloads to space to just $113 per kilogram ($250/lb). He estimated that the project could be completed within seven years, provided he secured $500 million in funding.
7. Mass Driver
The mass driver, also known as an electromagnetic catapult, operates similarly to a giant catapult. Imagine it as a sort of train. In 2012, aerospace engineers Dr. George Maise and Dr. James Powell—one of the creators of the maglev train—worked on developing a mass driver they named the StarTram.
The StarTram would rely on magnetic levitation (maglev) technology, the same technology that powers many high-speed trains today. Unlike traditional trains, maglev trains have no wheels; instead, they use magnets to glide over the track. The StarTram would function similarly, operating within a tube.
One end of the tube would be located on the ground, while the other would extend into the upper atmosphere. However, the upper end would remain firmly secured to the ground by steel beams or similar structures. The payload would be magnetically propelled through the tube until it reaches the other end, where it would be launched into space.
The inventors envisioned two mass drivers: one for cargo and another for human transport. They estimated the cargo version would cost around $20 billion to build and could be operational in roughly 10 years. The passenger version would be more expensive, costing about $60 billion and taking approximately 20 years to complete.
According to Powell and Maise, the StarTram could send 1 kilogram (2.2 lbs) of cargo to space for just $50 (in 2012 currency). In similar terms, transporting humans to the International Space Station could cost only $5,000, a far cry from the $20 million it currently takes (based on 2012 prices).
The pair also envisions the StarTram being used for a variety of purposes beyond space travel. These include defending Earth against large asteroids, harnessing solar energy, and enabling the mining of raw materials from asteroids.
6. Launch Loop
The launch loop would be made up of magnetic cables enveloped in a protective material. It has been described as an advanced iteration of the mass driver we previously discussed. Unlike the mass driver, however, both ends of the launch loop would be located on the ground, rather than one end reaching into the atmosphere.
The track's center would rise into the air, much like a roller coaster. The spacecraft, or train, would begin its journey at one end of the track, launching into space from the track's midpoint. While this concept sounds intriguing, it’s unlikely we’ll see it come to life anytime soon due to the astronomical costs involved in building such a structure.
5. Catapults
A space start-up called SpinLaunch is exploring the possibility of using catapults to send payloads into space. These aren’t traditional catapults, but high-speed centrifuges that spin so quickly they launch an attached payload into space at speeds of up to 4,800 kilometers per hour (3,000 mph).
Interestingly, NASA had tested a similar concept, though it used rail tracks instead of centrifuges. The space agency ultimately abandoned the project, finding it less reliable than rockets. However, SpinLaunch remains confident in the technology, with air resistance being the primary obstacle that could prevent the payload from reaching space.
4. Balloons
A company named World View is taking a more traditional approach. Rather than reinventing the wheel to reach space, they’ve chosen helium balloons as their method of transport. These balloons will ascend to the stratosphere, the second layer of Earth’s atmosphere, as we move closer to space.
A single flight will accommodate two pilots and six tourists, with a ticket for the six-hour journey priced at around $75,000. While World View successfully tested a prototype on June 18, 2014, it missed the 2016 deadline for launching its first commercial flight.
One drawback of using a balloon is its slow pace. It will take about two hours to reach space, which is significantly slower than rockets, which take less than four minutes. On the plus side, the balloon offers a spectacular view for tourists, and passengers won’t have to endure the violent takeoffs or intense g-forces that come with rockets.
As another downside, the balloon might end up drifting as far as 480 kilometers (300 mi) from its original launch site due to wind currents. To mitigate this, World View offers return flights for its passengers. The company also ensures safety by implementing measures to prevent the balloon from falling back to Earth or being carried off into space.
3. Space Fountain
Space fountains are viewed as an alternative to space elevators. These systems include both ground and space stations but do away with the need for elevators. The concept was put forward by a six-person team, including Robert L. Forward, who detailed it in his book Indistinguishable from Magic.
The concept behind the space fountain is similar to how a water fountain works. A ball can stay suspended at the top of the water stream in a fountain if the force of the water is consistently maintained. Similarly, the water that falls back into the fountain is recirculated to keep the ball afloat, continuing the cycle.
In a space fountain, the ground station takes the form of a U-shaped chamber, while the space station is essentially an inverted U-shaped chamber. The concept works similarly to the previously mentioned ball; the space station remains afloat in space because the ground station continually fires millions of tiny magnetic pellets at it. The space station, in turn, sends these pellets back to the ground station, maintaining the cycle.
The walls of the ground chamber would be lined with electromagnetic accelerators, propelling any payload into space. However, the space fountain remains an impractical solution due to the astronomical amounts of energy required. For example, a space fountain with a space station 2,000 kilometers (1,240 mi) away from the ground station would consume as much energy as an entire city.
2. Orbital Ring
The orbital ring shares similarities with the space elevator but differs in that it forms a vast ring encircling Earth. Various points along this ring would connect to ground stations on Earth. Elevators within these ground stations would allow people to ascend into space.
The concept of the orbital ring was initially proposed by Nikola Tesla in the 1870s, but it was Paul Birch who is credited with the modern iteration of the idea, which he introduced in 1982. Birch envisioned building the orbital ring in space using materials mined from space itself.
Unfortunately, the idea of creating the orbital ring has struggled to gain traction due to misquotations and misunderstandings of Birch's work. A persistent rumor claims that Birch estimated the cost of building the ring at a staggering $31 trillion. Though an orbital ring around Earth remains a distant dream, there are ideas to instead build one around the Moon or other planets, enabling much easier access to and from these celestial bodies.
1. Airplanes
Charles Bombardier and Juan Garcia Mansilla have proposed the use of specialized airplanes for space exploration. Their concept, known as the Paradoxal, is a supersonic or hypersonic aircraft with a jet engine that transforms into a rocket engine to break free of Earth's atmosphere. Upon returning to Earth, the engine switches back to a jet engine.
The jet engine transforms into a rocket when liquid oxygen is introduced into the exhaust, boosting its speed until it reaches the velocity required to break free from Earth's atmosphere. However, Bombardier and Mansilla aren't primarily focused on space exploration. Their main goal is to design the aircraft for business travel purposes.
This airplane would venture into space to take advantage of the Earth's curvature, drastically reducing flight times. For example, the Paradoxal could complete the 12,200 kilometers (7,600 miles) journey from Los Angeles to Sydney in under three hours, whereas traditional aircraft take about 14 hours to cover the same distance.
Equipped with external cameras, the airplane would allow passengers to view its exterior. As an added bonus, they would experience the sensation of weightlessness for a brief minute before the airplane begins its descent back to Earth.
