Mercury-Atlas 7
Encyclopedia
Backup crew
Crew notes
The original prime crew for Mercury Atlas-7 was to have been Deke SlaytonDeke Slayton
Donald Kent Slayton , better known as Deke Slayton, was an American World War II pilot and later, one of the original NASA Mercury Seven astronauts....
, with Schirra as his back-up. However Slayton was removed from all flight crew availability after the discovery of cardiac arrhythmia during a training run in the g-loading centrifuge
Centrifuge
A centrifuge is a piece of equipment, generally driven by an electric motor , that puts an object in rotation around a fixed axis, applying a force perpendicular to the axis...
. If Slayton had flown MA-7, his spacecraft would have been named Delta 7, as this would have been the fourth manned flight and Delta (Δ) is the fourth letter in the Greek alphabet.
Mission parameters
- MassMassMass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
: 2975 lb (1350 kg) - PerigeePerigeePerigee is the point at which an object makes its closest approach to the Earth.. Often the term is used in a broader sense to define the point in an orbit where the orbiting body is closest to the body it orbits. The opposite is the apogee, the farthest or highest point.The Greek prefix "peri"...
: 154 km - Apogee: 260 km
- InclinationInclinationInclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
: 32.5° - PeriodOrbital periodThe orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...
: 88.3 min
Mission highlights
Mercury spacecraft No. 18 was delivered to Cape CanaveralCape Canaveral Air Force Station
Cape Canaveral Air Force Station is an installation of the United States Air Force Space Command's 45th Space Wing, headquartered at nearby Patrick Air Force Base. Located on Cape Canaveral in the state of Florida, CCAFS is the primary launch head of America's Eastern Range with four launch pads...
, Florida on November 15, 1961. Atlas No. 107-D was rolled out of the Convair factory in San Diego, California on February 25, 1962. It was delivered to Cape Canaveral on March 6, 1962.
The focus of Carpenter's five-hour mission was on science. The full flight plan included the first study of liquids in weightlessness, Earth photography and an unsuccessful attempt to observe a flare fired from the ground. At dawn of the third and final orbit, Carpenter inadvertently bumped his hand against the inside wall of the cabin and solved a mystery from the previous flight
Mercury-Atlas 6
Mercury-Atlas 6 was a human spaceflight mission conducted by NASA, the space agency of the United States. As part of Project Mercury, MA-6 was the successful first attempt by NASA to place an astronaut into orbit. The MA-6 mission was launched February 20, 1962. It made three orbits of the Earth,...
. The resulting bright shower of particles outside the spacecraft - what John Glenn
John Glenn
John Herschel Glenn, Jr. is a former United States Marine Corps pilot, astronaut, and United States senator who was the first American to orbit the Earth and the third American in space. Glenn was a Marine Corps fighter pilot before joining NASA's Mercury program as a member of NASA's original...
had called "fireflies" - turned out to be ice particles shaken loose from the spacecraft's exterior.
Like Glenn, Carpenter circled the Earth three times. Total time weightless 4 h 39 min 32 s. The performance of the Mercury spacecraft and Atlas launch vehicle was excellent in nearly every respect. All primary mission objectives were achieved. The single mission-critical malfunction which occurred involved a failure in the spacecraft pitch horizon scanner, a component of the automatic control system. This anomaly was adequately compensated for by the pilot in subsequent in-flight operations so that the success of the mission was not compromised. A modification of the spacecraft control-system thrust units was effective. Cabin and pressure-suit temperatures were high but not intolerable. Some uncertainties in the data telemetered from the bioinstrumentation prevailed at times during the flight; however, associated information was available which indicated continued well-being of the astronaut.
Equipment was included in the spacecraft which provided valuable scientific information; notably that regarding liquid behavior in a weightless state, identification of the airglow layer observed by Astronaut Glenn, and photography of terrestrial features and meteorological phenomena. An experiment which was to provide atmospheric drag and color visibility data in space through deployment of an inflatable sphere was partially successful. The flight further qualified the Mercury spacecraft systems for manned orbital operations and provided evidence for progressing into missions of extended duration and consequently more demanding systems requirements.
Partly because he had been distracted watching the fireflies and partly because of his busy schedule, and a malfunction of the automatic alignment system, Carpenter overshot his planned reentry mark and splashed down 402 kilometers from target.
Aurora 7 is displayed at the Museum of Science and Industry
Museum of Science and Industry (Chicago)
The Museum of Science and Industry is located in Chicago, Illinois, USA in Jackson Park, in the Hyde Park neighborhood adjacent to Lake Michigan. It is housed in the former Palace of Fine Arts from the 1893 World's Columbian Exposition...
in Chicago
Chicago
Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...
, Illinois
Illinois
Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
.
Mercury-Atlas three-orbit flight events
| T+ Time | Event | Description |
|---|---|---|
| T+00:00:00 | Liftoff | Mercury-Atlas lifts off, onboard clock starts. |
| T+00:00:02 | Roll Program | Mercury-Atlas rotates along its axis 2.5 deg/s from 30° to 0°. |
| T+00:00:16 | Pitch Program | Mercury-Atlas begins a 0.5 deg/s pitch from 90° to 0°. |
| T+00:00:30 | Radio Guidance Lock | General Electric-Burroughs guidance system locks onto radio transponder in Atlas booster to guide the vehicle until orbit insertion. |
| T+00:01:24 | Max Q | Maximum dynamic pressure ~980 lbf/ft² (47 kPa) |
| T+00:02:10 | BECO | Atlas Booster Engine Cutoff. Booster engines drop away. |
| T+00:02:33 | Tower Jettison | Escape Tower Jettison, no longer needed. |
| T+00:02:25 | Atlas Pitchover | After tower separation, vehicle pitches over further. |
| T+00:05:20 | SECO | Atlas Sustainer Engine Cutoff, spacecraft reaches orbit, velocity 17,547 mph (7,844 m/s). |
| T+00:05:24 | Spacecraft Separation | Posigrade rockets fire for 1 second giving 15 ft/s (5 m/s) separation. |
| T+00:05:25 | 5-Second Rate Damping | ASCS damps spacecraft rates for 5 seconds in preparation for turnaround maneuver. |
| T+00:05:25 | Turnaround Maneuver | Spacecraft (ASCS) system rotates spacecraft 180 degrees, to heat shield forward attitude. Nose is pitched down 34 degrees to retro fire position. |
| T+00:05:30 T+04:30:00 |
Orbital Operations | Orbital operations and experiments for 3 orbits. |
| T+04:30:00 | Retro Sequence Start | Retrofire in 30 s; (ASCS) checks for proper retro attitude −34° pitch, 0° yaw, 0° roll. |
| T+04:30:30 | Retrofire | Three retro rockets fire for 10 seconds each. They are started at 5 second intervals, firing overlaps for a total of 20 seconds. Delta V of 550 ft/s (168 m/s) is taken off forward velocity. |
| T+04:31:00 | Retract Periscope | Periscope is automatically retracted in preparation for reentry. |
| T+04:31:50 | Retro Pack Jettison | One minute after retrofire retro pack is jettisoned, leaving heatshield clear. |
| T+04:33:00 | Retro Attitude Maneuver | (ASCS) orients spacecraft in 34° nose down pitch, 0° roll, 0° yaw. |
| T+04:40:30 | 0.05 G Maneuver | (ASCS) detects beginning of reentry and rolls spacecraft at 10 degrees per second to stabilize spacecraft during reentry. |
| T+04:50:20 | Drogue Parachute Deploy | Drogue parachute deployed at 22,000 ft (6.7 km) slowing descent to 365 ft/s (111 m/s) and stabilizing spacecraft. |
| T+04:50:25 | Snorkel Deploy | Fresh air snorkel deploys at 20,000 ft (6 km) ECS switches to emergency oxygen rate to cool cabin. |
| T+04:51:55 | Main Parachute Deploy | Main parachute deploys at 10,000 ft (3 km). Descent rate slows to 30 ft/s (9 m/s). |
| T+04:52:00 | Landing Bag Deploy | Landing Bag Deploys, dropping heat shield down four feet (1.2 m). |
| T+04:52:30 | Fuel Dump | Remaining hydrogen peroxide fuel automatically dumped. |
| T+04:57:10 | Splashdown | Spacecraft lands in water. |
| T+04:57:10 | Rescue Aids Deploy | Rescue aid package deployed. The package includes green dye marker, recovery radio beacon and whip antenna. |