DOUGLAS

Slide 9 of 100

Notes:

cost

launch weight

This illustration depicts an expendable ROMBUS landing on the Moon. Only two LEO tanker flights would be required for soft-landing a 4,536kg payload on the lunar surface. The empty spacecraft has a mass of 306.233t and the structure + tankage might be transformed into a lunar habitat.

Nine LEO tanker missions would be required to land a 226.8t payload on the lunar surface and return the vehicle to Earth with 22.68t of cargo. With seven tanker flights, the lunar payload capability would be 45.359t plus 4.536t of return payload. After ROMBUS has landed on the Moon, its LH2 tanks (now empty) could be transformed into habitation modules for a moonbase. Each 7-tanker mission would leave two fuel tanks behind while the 9-tanker flights would leave four tanks. ROMBUS would have to carry more LH2 coolant (+5,670kg) to survive the high-velocity atmospheric reentry. But this difference would still be far smaller than the 313t of propellant required to propulsively cancel the 3,048m/s difference between reentry from lunar transfer orbit and reentry from low Earth orbit. The Douglas engineers did not expect the thermodynamics to cause significant problems, although they did note that the point of maximum heating on the ROMBUS plug-nozzle underside is different during lunar return: some additional LH2 might be diverted by suitable valving to cope with this problem. The underside of the vehicle would also have to be beefed up to cope with the additional dynamic pressure during reentry from lunar transfer orbit.

40-flight average ROMBUS lifetime.
Personnel delivered to Moon at 90.7kg/man
Life support requirement of 4,536g/man/day
Maximum lunar tour of duty of 4 months
Lunar refueling base will store liquid oxygen and hydrogen propellants for Mars mission
Cryogenic propellant stored in cylindrical tanks at permanently shadowed location on Moon
Reusable Moon-Mars orbit-Earth vehicle lands 21,772kg on Mars (18,143kg useful payload) and consumes 5,343t of propellants per trip. The fourth, manned, Project Deimos mission then departs from Earth orbit in 1986.

DATE		TYPE VEHICLE	TOTAL EARTH LAUNCHES REQUIRED	LUNAR PAYLOAD DELIVERED(t)	COMMENTS
	08/1975	1-ROMBUS,2 RENDEZVOUS	3	5
08/1975-	12/1975	1-ROMBUS,7 RENDEZVOUS	40	224	25-MAN SURFACE RECON.
01/1976-	12/1976	1-ROMBUS,7 RENDEZVOUS	96	544	TEMPORARY 25-MAN BASE ESTABLISHED
01/1977-	02/1978	1-ROMBUS,7 RENDEZVOUS	112	635	ESTABLISH PERMANENT 25-MAN BASE
03/1978-	11/1978	2-ROMBUS,7 RENDEZVOUS	144	816
12/1978-	08/1979	3-ROMBUS,7 RENDEZVOUS	216	1225
06/1979-	01/1981	(1)-3 STAGE EXP. ROMBUS	20	1742
09/1979-	01/1981	1-ROMBUS,9 RENDEZVOUS	170	3856	PERMANENT 1000 MAN BASE ESTABLISHED
02/1981-	01/1984	1-ROMBUS,9 RENDEZVOUS	360	8165
02/1981-	01/1984	(5)-3 STAGE EXP. ROMBUS	180	15740	ESTABLISH 1000-MAN REFUELING BASE
		TOTAL:	1341	32950

"All-Purpose Moon Vehicle" -- Space World 1964/December/p.16

"Reusable Booster for Logistics and Planetary Exploration" -- Bono,Woodworth & Ursini, IAF XV:th INTERNATIONAL ASTRONAUTICAL CONGRESS PROCEEDINGS 1964/p.547