Comet HLLV
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]
 Artist's impression of a Comet HLLV being rolled out of the VAB | |
| Function | Crew / Cargo Launch Vehicle |
|---|---|
| Country of origin | United States |
| Size | |
| Height | 124 m (407 ft) |
| Diameter | 11.5 m (38 ft) |
| Stages | 3 |
| Capacity | |
| Payload to LEO | 254,400 kg (560,900 lb) |
| Payload to TLI | 97,600 kg (215,200 lb) or 60,600 kg (133,600 lb) |
| Launch history | |
| Status | Proposed and cancelled |
| Launch sites | Kennedy Space Center |
| Boosters | |
| Length | 155 ft (47 m) |
| Diameter | 21.7 ft (6.6 m) |
| Empty mass | 37,839 kg (83,421 lb) |
| Gross mass | 492,684 kg (1,086,182 lb) |
| Engines | 2 Rocketdyne F-1A |
| Thrust | 6,010 kN (1,350,000 lbf) sea level |
| Fuel | RP-1/LOX |
| First stage | |
| Length | 160.0 ft (48.8 m) |
| Diameter | 33.0 ft (10.1 m) |
| Empty mass | 209,030 kg (460,830 lb) |
| Gross mass | 2,729,770 kg (6,018,110 lb) |
| Engines | 5 Rocketdyne F-1A |
| Thrust | 40,050 kN (9,000,000 lbf) sea level |
| Fuel | RP-1/LOX |
| Second stage | |
| Length | 103 ft (31 m) |
| Diameter | 33.0 ft (10.1 m) |
| Empty mass | 60,767 kg (133,968 lb) |
| Gross mass | 627,729 kg (1,383,906 lb) |
| Engines | 6 Rocketdyne J2-S |
| Thrust | 7,750 kN (1,740,000 lbf) sea level |
| Fuel | LH2/LOX |
| Trans Lunar Injection stage | |
| Length | 55.6 ft (16.9 m) |
| Diameter | 33.0 ft (10.1 m) |
| Empty mass | 21,336 kg (47,038 lb) |
| Gross mass | 134,052 kg (295,534 lb) |
| Engines | 1 Rocketdyne J2-S |
| Thrust | 1,180 kN (270,000 lbf) sea level |
| Fuel | LH2/LOX |
Design
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.
References
- "First Lunar Outpost". www.astronautix.com. Retrieved 2020-01-09.
- "Lunar Base Studies – 1992: First Lunar Outpost (FLO)|National Space Society". Retrieved 2020-02-26.
- Young, Anthony (2019-02-19). The Saturn V F-1 Engine: Powering Apollo into History. Springer. ISBN 978-0-387-09630-8.