NASA's Biggest Rocket: Thrust Would Be Useful Now

Photo: The Nova rocket, at bottom, is shown compared to the Saturn 5 rocket at top. credit: NASA Some of the more exciting plans for the future of space exploration are currently quite literally out of reach.

The United States doesn't have the rocket power to send men to the moon or to Mars. There are some big rockets in the pipeline that will soon restore that power to the United States, but none can match the power of Nova. Nova was NASA's first heavy launch vehicle that never made it to the launch pad - let alone off it.

SpaceX's Falcon Heavy is one big rocket, and currently the only commercial one that will have the ability to send men beyond Earth orbit. And we might see it fly sooner rather than later.

Last month, SpaceX named Intelstat as its first customer for the heavy lifting vehicle. The Falcon Heavy is designed to generate an impressive 3,800,000 million pounds of thrust at launch using 27 (yes, 27!) Merlin engines. That's a lot of power, but not quite as much as the Saturn V.

Between 1966 and 1973, 13 Boeing/Douglas/North American/IBM built Saturn V's launched. Three took payload to Earth orbit, one took a crew, and nine took men to the moon. At launch, the Saturn V generated a literally ground-shaking 7.5 million pounds of thrust.

NASA is on track to break its own record with the SLS, providing, of course, the program isn't cancelled. The first iteration of the SLS, the block I, will produce 10 percent more power than the Saturn V with 8.4 million pounds of thrust while the block II will break that record with 9.2 million pounds.

Like the Saturn V, both versions of the rocket will use an upper stage to propel payload from Earth orbit to destinations beyond.

But none of these rockets come close to matching the power of the Nova rocket. Taller and wider than the Saturn V, Nova was designed to generate 12 million pounds of thrust.

The brainchild of German rocket engineer Wernher von Braun, Nova was designed to get men to the moon quickly and directly. Reason suggested, as did science fiction, that taking a big rocket straight to the moon, landing vertically with retrorockets, and taking off again to return to Earth was the best way to go. At first blush it was. Called direct ascent, the method had fewer moving parts so left fewer opportunities for the mission to fail catastrophically.

Direct ascent was only possible with a mammoth rocket; getting straight to the moon from the launch pad would take a lot of power, not to mention the fuel to land and take off from the moon was heavy.

The negative aspects of direct ascent led many to consider lunar missions that used rendezvous. A small, modular spacecraft would be lighter and much more fuel efficient.

The lunar mission mode debate went on for four years during which time the Nova remained a high priority for research and development. Several configurations were proposed between 1958 and 1962, but the most common was its final form.

Nova's first stage used eight F-1 engines, each of which was designed to produce 1.5 million pounds of thrust. It had two upper stages. The second stage used four liquid-hydrogen M-1 engines to produce 4.8 million pounds and the third stage used one J-2 engine with 200,000 pounds of thrust to send a payload to the moon. By comparison, the Saturn V's S-II second stage used five J-2 engines to generate 1 million pounds of thrust and the S-IVB third stage used one J-2 engine for the 200,000 pounds of thrust to send a payload to the moon.

Though it began as the frontrunner in 1958, Nova began to fall out of favor in the beginning of 1962 as the pressure was mounting to reach the moon by the end of the decade. Further study revealed that direct ascent was on par with rendezvous methods using the smaller Saturn V in terms of necessary power. Where the Saturn V won was cost; it was smaller and cheaper to build.

In April 1962, NASA decided to delay awarding the Nova contract to an outside company. By July, it was becoming clear that developing the Saturn and Nova simultaneously was prohibitively expensive. The agency was leaning more and more towards a rendezvous mode for the lunar mission, which meant if one rocket was going to be built it was the Saturn V.

Nova was put on the back burner, expected to go into production after the Saturn flights to facilitate extended exploration through the solar system. In October, the Saturn V was formally selected as the rocket for Apollo and prioritized over the Nova.

Of course, Nova's chance to send men further from the Earth never came. As the 1960s wore on, the Saturn V began straining the budget; the astronomical cost of building and launching the rocket was a major factor in the reusable shuttle launch system.

It's really too bad. Such a powerful rocket would be a huge boon to the U.S. space program right now.