Transcript Spaceflight, Solar System and Interstellar, Lebo, 8-5-08.ppt

SPACE FLIGHT
SOLAR SYSTEM AND INTERSTELLAR
George Lebo
7 DECEMBER 2015
AST 1002/2037
ROBERT GODDARD, 1926
ROCKET SCIENTISTS AT THE ARMY
BALLISTIC MISSILE AGENCY, 1956
FROM LEFT TO RIGHT, ERNST STUHLINGER, MAJOR
GENERAL HOLGER TOFTOY, HERMANN OBERTH, Dr.
WERNER VON BRAUN, Dr. ROBERT LUSSER
PROPOSED SLS – MAY 2011
Details of Apollo 11 Mission
• The Apollo 11 spacecraft was launched from Cape
Kennedy at 13:32:00 UT on July 16, 1969. After 2 hr and
33 min in Earth orbit, the S-IVB engine was reignited for
acceleration of the spacecraft to the velocity required for
Earth gravity escape.
• Lunar-orbit insertion began at 75:50 ground elapsed time
(GET). The spacecraft was placed in an elliptical orbit
(61 by 169 nautical miles), inclined 1.25 degrees to the
lunar equatorial plane. At 80:12 GET, the service module
propulsion system was reignited, and the orbit was made
nearly circular (66 by 54 nautical miles) above the
surface of the Moon. Each orbit took two hours.
Photographs taken from lunar orbit provided broad views
for the study of regional lunar geology.
Apollo Cont’d (2)
• The lunar module (LM), with Astronauts Armstrong and
Aldrin aboard, was undocked from the command-service
module (CSM) at 100:14 GET, following a thorough
check of all the LM systems. At 101:36 GET, the LM
descent engine was fired for approximately 29 seconds,
and the descent to the lunar surface began. At 102:33
GET, the LM descent engine was started for the last time
and burned until touchdown on the lunar surface. Eagle
landed on the Moon 102 hr, 45 min and 40 sec after
launch.
• Immediately after landing on the Moon, Armstrong and
Aldrin prepared the LM for liftoff as a contingency
measure. Following the meal, a scheduled sleep period
was postponed at the astronauts' request, and the
astronauts began preparations for descent to the lunar
surface.
Apollo 11 Cont’d (3)
• Astronaut Armstrong emerged from the spacecraft first.
While descending, he released the Modularized
Equipment Stowage Assembly (MESA) on which the
surface television camera was stowed, and the camera
recorded humankind's first step on the Moon at
109:24:19 GET (pictured at left). A sample of lunar
surface material was collected and stowed to assure
that, if a contingency required an early end to the
planned surface activities, samples of lunar surface
material would be returned to Earth. Astronaut Aldrin
subsequently descended to the lunar surface.
Armstrong – First Step on the
Moon
Apollo 11 Cont’d (4)
• The astronauts carried out the planned sequence of
activities that included deployment of a Solar Wind
Composition (SWC) experiment, collection of a larger
sample of lunar material, panoramic photographs of the
region near the landing site and the lunar horizon,
closeup photographs of in place lunar surface material,
deployment of a Laser-Ranging Retroreflector (LRRR)
and a Passive Seismic Experiment Package (PSEP),
and collection of two core-tube samples of the lunar
surface.
Apollo 11 Cont’d (5)
Approximately two and a quarter hours after descending
to the surface, the astronauts began preparations to reenter the LM, after which the astronauts slept. The
ascent from the lunar surface began at 124:22 GET, 21
hours and 36 minutes after the lunar landing. In
transearth coast only one of four planned midcourse
corrections was required. The CM entered the
atmosphere of the Earth with a velocity of 36,194 feet
per second (~ mach 33) and landed in the Pacific
Ocean.
URL – APOLLO 11 MISSION
• http://www.nasm.si.edu/exhibitions/attm/fli
ghtpath/a11.steps.html
INTERSTELLAR TRAVEL
• QUESTION: Shouldn’t we expect to conquer interstellar travel problems, given our past successes?
A. Compare air-flight problems of the 19th century to
space travel problems now.
B. Fundamental limitations of interstellar travel
1. Spacecraft size
a. Human habitat
b. Fuel (Remember that we’ll need to undo
all of the acceleration that we create.)
2. Elapsed time of mission
3. High velocity flight