Comet HLLV


Comet HLLV
FLO Comet HLV Verticle.jpg
Artist's impression of a Comet HLLV being rolled out of the VAB
FunctionCrew / Cargo Launch Vehicle
Country of originUnited States
Height124 m (407 ft)
Diameter11.5 m (38 ft)
Payload to LEO
Mass254,400 kg (560,900 lb)
Payload to TLI
Mass60,600–97,600 kg (133,600–215,200 lb)
Launch history
StatusProposed and cancelled
Launch sitesKennedy Space Center
Length155 ft (47 m)
Diameter21.7 ft (6.6 m)
Empty mass37,839 kg (83,421 lb)
Gross mass492,684 kg (1,086,182 lb)
Engines2 Rocketdyne F-1A
Thrust6,010 kN (1,350,000 lbf) sea level
First stage
Length160.0 ft (48.8 m)
Diameter33.0 ft (10.1 m)
Empty mass209,030 kg (460,830 lb)
Gross mass2,729,770 kg (6,018,110 lb)
Engines5 Rocketdyne F-1A
Thrust40,050 kN (9,000,000 lbf) sea level
Second stage
Length103 ft (31 m)
Diameter33.0 ft (10.1 m)
Empty mass60,767 kg (133,968 lb)
Gross mass627,729 kg (1,383,906 lb)
Engines6 Rocketdyne J2-S
Thrust7,750 kN (1,740,000 lbf) sea level
Trans Lunar Injection stage
Length55.6 ft (16.9 m)
Diameter33.0 ft (10.1 m)
Empty mass21,336 kg (47,038 lb)
Gross mass134,052 kg (295,534 lb)
Engines1 Rocketdyne J2-S
Thrust1,180 kN (270,000 lbf) sea level

The Comet HLLV was a proposed super heavy-lift launch vehicle designed for NASA's First Lunar Outpost program, which was in the design phase from 1992-1993 under the Space Exploration Initiative. It was a Saturn V-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 manned Mars missions. It was designed to be inexpensive and simple while relying on existing technology to lower development costs. [1]


The Comet would have been capable of putting 254.4 tons into low Earth orbit and 97.6 tons to trans-lunar injection, roughly twice that of the Saturn V, making it one of the largest rockets ever designed in terms of payload.[2] The vehicle resembled a Saturn V, but with engines updated to the F-1A and J-2S, stretched first and second stages, and new side boosters.[1] Each of the two side boosters had two F-1A engines.[3] Development costs were expected to be modest due to reliance on Apollo-era technology.[1]

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 manned Mars missions.[3] To this end, NASA's Lewis Research Center 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 was proposed. NASA's Marshall Spaceflight Center 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.


  1. ^ a b c "First Lunar Outpost". Retrieved 2020-01-09.
  2. ^ "Lunar Base Studies – 1992: First Lunar Outpost (FLO)|National Space Society". Retrieved 2020-02-26.
  3. ^ a b Young, Anthony (2019-02-19). The Saturn V F-1 Engine: Powering Apollo into History. Springer. ISBN 978-0-387-09630-8.