The Comet HLLV was a proposed super heavy-lift

launch vehicle A launch vehicle is typically a rocket-powered vehicle designed to carry a payload (a crewed spacecraft or satellites) from Earth's surface or lower atmosphere to outer space. The most common form is the ballistic missile-shaped multistage ...

designed for NASA's First Lunar Outpost program, which was in the design phase from 1992 to 1993 under the

Space Exploration Initiative The Space Exploration Initiative was a 1989–1993 space public policy initiative of the George H. W. Bush administration. On July 20, 1989, the 20th anniversary of the Apollo 11 Moon landing, US President George H. W. Bush announced plans for ...

. It was a

Saturn V The Saturn V is a retired American super heavy-lift launch vehicle developed by NASA under the Apollo program for human exploration of the Moon. The rocket was human-rated, had multistage rocket, three stages, and was powered by liquid-propel ...

-derived launch vehicle with modernized engines, stretched fuel tanks, and strap-on boosters. Its main goal was to support the First Lunar Outpost program and future

human mission to Mars The idea of sending humans to Mars has been the subject of aerospace engineering and scientific studies since the late 1940s as part of the broader exploration of Mars. Long-term proposals have included sending settlers and terraforming the p ...

. It was designed to be inexpensive and simple while relying on existing technology to lower development costs.

Design

The Comet would have been capable of putting 254.4 tons into

low Earth orbit A low Earth orbit (LEO) is an geocentric orbit, orbit around Earth with a orbital period, period of 128 minutes or less (making at least 11.25 orbits per day) and an orbital eccentricity, eccentricity less than 0.25. Most of the artificial object ...

and 97.6 tons to

trans-lunar injection A trans-lunar injection (TLI) is a propulsive maneuver, which is used to send a spacecraft to the Moon. Typical lunar transfer trajectories approximate Hohmann transfers, although low-energy transfers have also been used in some cases, as with ...

, roughly twice that of the Saturn V, making it one of the largest rockets ever designed in terms of payload. The vehicle resembled a Saturn V, but with stretched first and second stages, an increased-diameter third stage, and new side boosters. Additionally, the engines were updated to the F-1A and J-2S, and a sixth engine was added to the second stage. Each of the two side boosters had two F-1A engines. Development costs were expected to be modest due to reliance on

Apollo Apollo is one of the Twelve Olympians, Olympian deities in Ancient Greek religion, ancient Greek and Ancient Roman religion, Roman religion and Greek mythology, Greek and Roman mythology. Apollo has been recognized as a god of archery, mu ...

-era technology. A nuclear-powered variant of the third stage, with two 222.5-kN engines, was also considered. It would have reduced the rocket's size, but at a predicted development cost of $2 billion over a chemical-only design. The nuclear option was planned to be developed later to support crewed Mars missions. To this end, NASA's

Lewis Research Center NASA John H. Glenn Research Center at Lewis Field is a NASA center within the cities of Brook Park and Cleveland between Cleveland Hopkins International Airport and the Rocky River Reservation of Cleveland Metroparks, with a subsidiary facil ...

established a Nuclear Systems Office to develop and test a fully functional nuclear engine by 2005.

NLS derived launch vehicle

An alternate version of the launcher based on the then-in-development

National Launch System The National Launch System (or New Launch System) was a study authorized in 1991 by President George H. W. Bush to outline alternatives to the Space Shuttle for access to Earth orbit. Shortly thereafter, NASA asked Lockheed Missiles and Space, ...

was proposed. NASA's

Marshall Spaceflight Center Marshall Space Flight Center (officially the George C. Marshall Space Flight Center; MSFC), located in Redstone Arsenal, Alabama (Huntsville, Alabama, Huntsville postal address), is the Federal government of the United States, U.S. government's ...

looked into the Comet rocket or a possible configuration with four F-1A boosters added to the basic 2-stage NLS vehicle. The main expected advantage was that the vehicle could rely on technology currently flying rather than having to resurrect 20 year old technology and manufacturing equipment.

References

{{Reflist NASA Space launch vehicles of the United States Spaceflight Proposed space launch vehicles