Forum Rozmowy (nie)kontrolowane Nauka Napędy Re: Napędy


A tak to sobie dokładnie planowali... sorry za angielszczyznę, ale nie chciało mi się tego wszystkiego tłumaczyć...

A Study of Early Manned Interplanetary Missions Final Summary Report, Report AOK63-0001, General Dynamics Astronautics, January 31, 1963.

General Dynamics (GD) produced this report on contract to NASA's Marshall Space Flight Center as part of the Early Manned Planetary Interplanetary Roundtrip Expeditions (EMPIRE) study effort. The first EMPIRE phase occurred from March 1962 to January 1963. GD was one of three EMPIRE contractors - the others were Lockheed and Ford. Krafft Ehricke, who led this study for GD, helped develop the V-2 missile for Nazi Germany. He came to the U.S. with Wernher Von Braun's rocket team in 1945. In 1953 Ehricke joined GD, where he was instrumental in Atlas missile development. In the late '50s he became involved in Mars expedition studies. Ehricke's team looks at piloted Venus and Mars "capture" (orbiter) missions. The Venus mission falls outside the scope of Romance to Reality. The 450-day Mars mission, set to occur in 1975, includes an optional piloted landing capability. GD's report describes modularized Mars ships traveling in "convoys" made up of at least one crew ship and two automated service ships. According to the report, "[t]he main difference between the two types of convoy vehicles is that the crew vehicle carries a life support system, and the [service vehicle] does not." Their systems "are standardized as much as practical" so the crew ship can cannibalize the service ships for replacement parts. At Earth-orbit departure the typical vehicle is arranged as follows (aft to fore):

The M-1 engine system performs Maneuver-1 of the Mars expedition - escape from Earth orbit - hence its designation. The "booster," as it is known, includes one large or four small nuclear rocket engines, and from 400,000 to 1,400,000 pounds of liquid hydrogen propellant in a cluster of two 60-foot-diameter, two 25-foot-diameter, and two 33-foot-diameter tanks. In all the engine systems the smaller tanks are arranged around the larger tanks to reduce propellant loss in the event of a meteor strike. Loss of one tank means loss of from 5% to 15% of the propellant earmarked for a given maneuver. A damaged crew vehicle tank can be ejected and replaced by an identical tank from one of the service vehicles.

The M-2 engine system slows the ship at Mars so the planet's gravity can capture it into orbit (Maneuver-2). M-2 includes one nuclear rocket engine and 244,000 to 730,000 pounds of hydrogen propellant. Tankage consists of seven 14-foot-diameter tanks around one 20-foot-diameter tank or nine 14-foot-diameter tanks around one 30-foot-diameter tank.

The M-3 engine system launches the spacecraft out of Mars orbit toward Earth (Maneuver-3). M-3 includes one nuclear rocket engine and 138,000 to 275,000 pounds of hydrogen propellant in one 20-foot-tank surrounded by seven 14-foot-diameter tanks or one 30-foot-diameter tank surrounded by nine 14-foot-diameter tanks.

The M-4 engine system slows the ship at expedition's end (Maneuver-4). M-4 includes either one nuclear rocket engine or one chemical rocket engine. If nuclear, M-4 propellant is 11,800 to 21,400 pounds of hydrogen in one 20-foot-diameter tank. If chemical, M-4 propellant is 16,800 to 33,000 pounds of hydrogen/oxygen; the hydrogen is stored in a 14-foot-diameter tank and the oxygen in a 10-foot-diameter tank.

The 10-foot-diameter, 75-foot-long spine module, or "neck," serves two structural functions - it places distance between the crew and the nuclear engines, thereby decreasing crew radiation exposure, and it places distance between the crew and the ship's center-of-gravity (CG). The GD team's preferred method of generating artificial gravity - tumbling the ship end over end around the CG - makes adequate crew/CG separation distance important (see number 1 below). The spine also houses the electrical power system (SNAP-8 nuclear source or solar arrays).

The crew ship includes the Life Support Section (LSS), which houses the eight-person crew. GD proposes two standard LSS configurations - Dry and Wet. Both include a 10-foot diameter central section attached to front end of the spine module. This houses the Command Module, repair shop, radiation shelter, and food storage. Command Module radiation shielding in the Dry configuration consists of boron-filled polyethylene supplemented in the floor by tanks of drinking water. The ship's bridge doubles as the "blockhouse" from which the crew controls the service vehicles. Crewmembers sleep in the radiation shelter to reduce their overall radiation exposure. The Dry LSS includes two-level, 10-foot-diameter Mission ("extension") Modules clustered around the central section. Individual levels can be sealed off if penetrated by meteors or otherwise rendered uninhabitable. Entire Mission Modules may be discarded if the crew must reduce spacecraft mass to return to Earth - for example, if a large amount of propellant is lost and cannot be replaced from the service vehicles. In the Wet configuration, the M-4 hydrogen propellant tank surrounds the Command Module to provide radiation shielding. The central section repair shop protrudes from the front of the M-4 tank to provide attachment points for the four mission modules. Both configurations include two "taxis" docked to ports on the central section - see number 2 below.

On the service ship the Service Module Section (SMS) replaces the LSS. Each service vehicle has a spine in case the crew vehicle propulsion section becomes damaged and must be replaced by the service vehicle propulsion section. The SMS is a hangar for auxiliary vehicles and scientific probes. See number 2 below.

Earth Entry Module (EEM): Both the crew and services ships carry this auxiliary vehicle. See number 2 below.

The M-5 propulsion unit on the ship's nose spins the ship to create artificial gravity, de-spins it to permit maneuvers, and controls attitude. It carries 9500 pounds of propellant. Both the crew and services vehicles carry M-5, though the service vehicles do not spin.

Ehricke's team focuses on the following areas:

Artificial gravity: "It would be rather presumptious [sic] at this early date," the report states, "to make a decision whether gravity will be mandatory for crews during missions of long duration. . .If gravity is provided, the design of much of the equipment aboard is simplified because it can be built by long-adopted engineering practices where gas convection and liquid flow are natural." However, the only known means of producing artificial gravity - rotation - produces undesired effects. A person walking toward the center of a rotating system will tend to veer sideways; often they will become nauseated if they turn their head. The shorter the rotating system's radius and faster its rotation, the more pronounced these effects become. The report states that five rotations per minute is the approximate upper limit. The Ehricke team foresees tumbling the crew vehicle end over end about the ship's CG to create about 25% Earth gravity. As engine systems M-1, M-2, and M-3 are cast off, the crew ship grows progressively shorter. The ship's CG shifts forward - for example, CG before the M-1 maneuver is at the aft end of the M-2 system, 420 feet from the ship's nose; at the start of the M-2 maneuver it is located at the front of the M-2 engine system, 265 feet from the nose. This forces faster rotation to sustain the same gravity level. The report proposes joining the crew vehicle to the aft end of a service vehicle to shift CG away from the crew, permitting an acceptable rotation rate during return to Earth. Spinning the ship also makes sighting on stars difficult, interfering with celestial navigation. Ehricke's team points out that the non-spinning service vehicles can be used to assist navigation.

Auxiliary vehicles & probes: According to Ehricke's team, "[a] large number of vehicles is involved in a manned planetary capture mission." Auxiliary vehicles include the EEM, a conical capsule carried in a housing on the front of the LSS and SMS. The crew reenters Earth's atmosphere in the EEM at expedition's end; it serves also as an emergency abort vehicle during the M-1 maneuver. The service vehicles each carry a spare EEM to provide a pressurized volume for visiting crewmembers and backup to the crew vehicle EEM. The taxi is a "commuter between convoy vehicles. . ." and serves as "a 'tugboat' for conveying fuel tanks or bulky spare material between convoy vehicles." Each taxi weighs 1350 pounds fully fueled. The piloted Mars Excursion Vehicle (MEV) lander, if included, is carried in the SMS. The MEV can support two men for seven days on the martian surface. The SMS also carries most of the expedition's automated probes. These include the Returner Mars sample collector, which resembles the MEV; Mars Lander, based on Surveyor lunar soft-landing technology; Deimos Probe (Deipro) and Phobos Probe (Phopro) Mars moon hard landers based on Ranger lunar hard lander technology; Mars Environmental Satellite (Marens) orbiter; and Floater balloons. There are also two novel automated probes - the Mapper travels to Mars attached to the crew ship and operates as a crew ship instrument in Mars orbit. It only detaches when the crew ship prepares to leave Mars orbit, becoming an independent satellite for beaming images back to Earth. The Convoy Companion (C2) detaches from a service vehicle to perform "sensitive space physical experiments" free from interference en route between planets or at Mars.

Launch vehicles & assembly: Ehricke's team favors replacing or augmenting the Saturn C-5 (as the Saturn V was known at this time) with a "Post Saturn" heavy lift rocket capable of placing 1 million pounds in Earth orbit - four times the C-5's capacity. Two Post Saturn launches could place an entire ship into orbit so only one rendezvous and docking would be required to complete assembly. By contrast, eight C-5 launches are needed to launch one ship's components, followed by seven rendezvous and docking maneuvers to complete assembly. Ehricke's team envisions using tethers, winches, small thrusters, and space taxis to push various spacecraft components into place.

Crew complement: The eight-person crew consists of a 1) mechanical engineer who serves as Commander; 2) electrical engineer who serves as Deputy Commander; 3) engineer-physicist specializing in nuclear equipment; 4) engineer-astronomer and 5) engineer-physicist who share responsibility for communications, navigation, and the meteor radar; 6) physicist-geophysicist and 7) astronomer-geologist who share responsibility for onboard science instruments; and 8) physician-biologist who serves as Flight Surgeon. The crewmembers have rotating 12-hour duty shifts, in part because "a busy schedule is probably the most efficient antidote against psychological and morale problems. . ." The Ehricke team recommends table tennis as a form of in-flight exercise.

Ehricke's team includes a manned Mars capture mission development schedule. Highlights include:

July 1965: Post Saturn launch vehicle receives "Full go-ahead."

May 1968-April 1970: Nuclear rocket engines tested in Nevada.

July 1968: Crew selection (three crews of eight men each, later reduced to Prime and Backup crews).

November 1968: First LSS module tested attached to Earth-orbiting space station.

June 1969: First of four Earth-orbital flight tests of the M-4 engine system.

First quarter 1971: LSS modules declared operational.

November 1972: Manned lunar landing test flight with MEV, Returner, and Lander.

March-April 1973: The prime and backup crews perform an interplanetary launch dress rehearsal in Earth orbit.

August 1973: Post Saturn launch vehicle declared operational.

November 1973-July 1974: The prime and backup crews conduct simulated flight operations aboard the crew vehicle in Earth orbit.

March 1975: Mission departure.

i link do sowieckiego silnika jądrowego -

a tym - - chcieli sowieci na Marsa polecieć... niezłe monstrum.

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