In the early 1960s, America was riding high on its successes in space. NASA had plans to land astronauts on the Moon before the end of the decade using the mighty Saturn V rocket. But some engineers were already looking ahead to even more ambitious goals, such as crewed missions to Mars. One audacious concept was the Convair Nexus, a massive reusable rocket proposed by the aerospace company Convair.
Origins of a Super Rocket
The Nexus was the brainchild of Krafft Ehricke, a German rocket engineer who had worked on the V-2 missile during World War II before immigrating to the United States. In 1962, Ehricke was tasked by NASA’s Future Projects Office to design concepts for a heavy lift launch vehicle that could fly in the 1975-2000 timeframe, building on the capabilities of the Saturn V. What Ehricke proposed went far beyond anything NASA was considering – a fully reusable single-stage-to-orbit (SSTO) rocket of epic proportions.
The Nexus would have stood an incredible 400 feet tall with a diameter of 150 feet, dwarfing the 363-foot Saturn V. In its largest conceived variant, it would have weighed a colossal 48 million pounds when fueled, compared to the Saturn V’s 6.5 million pounds. According to Ehricke’s designs, the Nexus would have been capable of delivering a whopping one million pounds to low Earth orbit – over 8 times the Saturn V’s capacity. Even more impressive, it was intended to fly over and over again, landing vertically on the ocean and being towed back to port by ships after each mission.
Design Innovations of a Space Freighter
The Nexus incorporated multiple innovations in its design. Like NASA’s later Space Shuttle concept, it was a winged vehicle. However, the Nexus had tiny, stubby wings relative to its huge rocket body. These served to provide lift during the initial unpowered descent back to Earth. Four large parachutes would further slow the vehicle down until it gently splashed down in the ocean, whereupon landing rockets would fire to cushion the vertical touchdown. The wide flattened bottom of the Nexus provided stability, giving it characteristics similar to a badminton shuttlecock as it floated down.
The Nexus would be powered by a gargantuan rocket engine array consisting of millions of pounds of thrust, burning liquid hydrogen and liquid oxygen propellants. It would launch vertically and fly a ballistic arc to orbit. In space, payload modules or even complete interplanetary spacecraft could be deployed from its cavernous cargo bay. After releasing its payloads, the Nexus would fire its engines again to begin the journey back, using its wings and parachutes to steer towards a soft ocean landing.
If successful, the Nexus would have revolutionized space access. Ehricke envisioned it enabling routine flights to construct large orbital space stations, return samples from across the solar system, and even conduct manned missions to Mars. It was to be America’s gateway to the stars.
The End of a Dream
Despite its promise, the Nexus never progressed beyond conceptual designs and models. In the end, NASA decided to pursue the partially reusable Space Shuttle as its post-Apollo human spaceflight program. The Shuttle was smaller and less technically daring than the Nexus, even though it never achieved the full reusability or ultra heavy lift capacity that Ehricke had envisioned. Political and budgetary constraints forced NASA to think more incrementally.
The Nexus was probably too futuristic and immense to be practical with 1960’s technology. Many doubted whether its unprecedented scale was even feasible. But the boldness of its vision still inspires. The fully reusable rocket concept would be revived decades later by SpaceX’s Starship. And NASA’s Space Launch System megarocket continues the quest for Saturn V-exceeding heavy lift today.
The Nexus showed the immense possibilities of space and challenged engineers to dream big. Its giant shadow still looms over the landscape of launch vehicles. Like an unfinished cathedral, the ambitious architecture of the Nexus hints at the towering heights human space exploration could one day achieve. America may have chosen the path of incremental steps in the Space Age dawn, but the allure of giant leaps continues to spur engineers ever upwards in pursuing the final frontier.
