| . |  |
 |
|
Space History for August 2
If you are not already a subscriber, you are welcome to enter your email address here to sign up to receive the Space History newsletter on a daily basis. Under no circumstances will we release your legitimate email address entered here to outside persons or organizations, and it will only be used for mailing the specific information you have requested.
| Enter your email address here: |
Unsubscribe instructions are included in every newsletter issue in case you decide you no longer wish to receive it.
Note: We record the IP address from which subscriptions are entered to help prevent SPAM abuses.
Race To Space
Someone will win the prize...
... but at what cost?
Visit RaceToSpaceProject.com
to find out more!
1799
Died, Jacques Etienne Montgolfier, built the first practical hot air balloon in 1783 with his brother Joseph Michel
The Montgolfier brothers, Joseph Michel Montgolfier (26 August 1740 - 26 June 1810) and Jacques Etienne Montgolfier (6 January 1745 - 2 August 1799), built the first practical hot-air balloon (1783).
https://en.wikipedia.org/wiki/Montgolfier_brothers
1819
The first parachute jump in the USA was made by M. Charles Guille, jumping from a balloon over New York City. (Note the date in the Web page doesn't match the picture of the newspaper.)
http://www.rarenewspapers.com/view/219406
1835
Born, Elisha Gray, American inventor, invented the telephone about the same time as Alexander Graham Bell, considered the father of the modern music synthesizer, received over 70 patents for inventions
https://en.wikipedia.org/wiki/Elisha_Gray
1904
M. Wolf discovered asteroid #539 Pamina.
1922
Died, Alexander Graham Bell, Scottish inventor. In addition to his work in telecommunications, he also was responsible for important advances in aviation and hydrofoil technology.
https://en.wikipedia.org/wiki/Alexander_Graham_Bell
1926
K. Reinmuth discovered asteroid #1064 Aethusa.
1934
Born, Valeri Fyodorovich Bykovsky (at Pavlowski Possad, Moscow Oblast, Russian SFSR), Colonel Soviet AF, Soviet cosmonaut (Vostok 5, Soyuz 22, Soyuz 31/Salyut 6/Soyuz 29; over 20d 17.75h total time in spaceflight) (deceased)
Cosmonaut Valeri Bykovsky, photo by Frank Leuband
Source: Wikipedia
http://www.spacefacts.de/bios/cosmonauts/english/bykovsky_valeri.htm
1949
Born, Farkas Bertalan (at Gyulahaza, Hungary), Brig. General Hungarian AF, USSR cosmonaut (Soyuz 36/Salyut 6 EP-5/Soyuz 35; 7d 20.75h in spaceflight), first Hungarian to fly in space
Cosmonaut Farkas Bertalan, photo by Modis Agnes Vadszederke
Source: Wikipedia
http://www.spacefacts.de/bios/international/english/farkas_bertalan.htm
1949
K. Reinmuth discovered asteroids #1682 Karel, #1820 Lohmann, #2465, #2591, #3020 and #3183.
1962 17:56:00 GMT
NASA and the USAF launched X-15A MH-96 fixed gain test mission # 65 in which Joe Walker attained a maximum speed of 3438 mph (5533 kph, Mach 5.07) and reached a maximum altitude of 144,500 ft (44.044 km, 27.367 mi).
https://en.wikipedia.org/wiki/List_of_X-15_flights
1971 17:11:22 GMT
The NASA Apollo 15 LEM ascent stage lifted off from the Moon after 66 hours, 55 minutes on the Lunar surface, the first time a launch from the Moon was televised.
Apollo 15 was the fourth mission in which humans walked on the Lunar surface and returned to Earth: On 30 July 1971, Apollo 15 Commander David R. Scott and LM pilot James B. Irwin landed in the Hadley Rille/Apennines region of the Moon in the Lunar Module (LM) while the Command and Service Module (CSM), with CM pilot Alfred M. Worden, continued in Lunar orbit. During their stay on the Moon, the astronauts set up scientific experiments, took photographs, and collected Lunar samples. The LM took off from the Moon on 2 August, and the astronauts returned to Earth on 7 August.
Apollo 15 was launched on 26 July 1971 on Saturn V SA-510 from Pad 39A at the Kennedy Space Center, Florida. The spacecraft was inserted into Earth orbit 11 minutes 44 seconds after liftoff, at 13:45:44 UT, and translunar injection took place at 16:30:03 UT. The CSM separated from the S-IVB stage at 16:56:24 UT, and docked with the LM at 17:07:49 UT, televised using an onboard color camera.
The S-IVB stage was released and sent into a Lunar impact trajectory, impact occurring on 29 July at 20:58:42.9 UT at 1.51 S, 11.81 W with a velocity of 2.58 km/s (5760 mph) at a 62 degree angle from the horizontal, 188 km (117 mi) northeast of the Apollo 14 landing site and 355 km (221 mi) northeast of the Apollo 12 site. The impact was detected by both the Apollo 12 and Apollo 14 seismometers, left on the moon in November 1969 and February 1971.
A short was discovered in the service propulsion system, and contingency procedures were developed for using the engine. A mid-course correction was performed on 27 July at 18:14:22 UT and another on 29 July at 15:05:15. During the translunar cruise, it was discovered that the LM range/range-rate exterior glass cover had broken and a small water leak had developed in the CM requiring repair and clean up, in part to avoid breathing in the glass shards. The Scientific Instrument Module (SIM) door was jettisoned at 15:40 UT on 29 July, and Lunar orbit insertion took place at 20:05:47 UT. The descent orbit maneuver was executed at 00:13:49 UT on 30 July.
Scott and Irwin entered the LM and the LM-CSM undocking maneuver was initiated at 17:48 UT, but undocking did not take place. Worden found a loose umbilical plug and reconnected it, allowing the LM to separate from the CSM at 18:13:30 UT. The LM fired its descent engine at 22:04:09 UT and landed at 22:16:29 UT on 30 July 1971 in the Mare Imbrium region at the foot of the Apennine mountain range at 26.1 N, 3.6 E, 600 meters 2000 ft) north-northwest of the proposed target. The CSM remained in a slightly elliptical orbit from which Worden performed scientific experiments.
About two hours after landing, following cabin depressurization, Scott performed a 33 minute 7 second standup EVA in the upper hatch of the LM, during which he described and photographed the landing site.
The first crew EVA on the Lunar surface began at 13:04 UT 31 July. The crew collected and stowed a contingency sample, unpacked the ALSEP and other experiments, and prepared the Lunar Roving Vehicle (LRV) for operations. Some problems were encountered in the deployment and checkout of the LRV, used for the first time, but they were quickly resolved. The first EVA traverse was to the Apennine mountain front, after which the ALSEP was deployed and activated, and one probe of a Heat Flow experiment was emplaced. A second probe was not emplaced until EVA-2 because of drilling difficulties. The first EVA lasted 6 hours 32 minutes 42 seconds.
The second EVA began at 11:49 UT 1 August. The astronauts made a maintenance check on the LRV, then began the second planned traverse of the mission. On completion of the traverse, Scott and Irwin completed the placement of heat flow experiment probes, collected a core sample, and deployed the American flag. They then stowed the sample container and the film in the LM, completing a second EVA of 7 hours 12 minutes 14 seconds.
The third EVA began at 8:52 UT 2 August, included another traverse, and ended 4 hours 49 minutes 50 seconds later. After the final EVA, Scott performed a televised demonstration of a hammer and feather falling at the same rate in the Lunar vacuum.
The total Apollo 15 Lunar surface EVA time was 18 hours 34 minutes 46 seconds. During the three moonwalks, Scott and Irwin covered 27.9 km (17.3 mi), collected 76.8 kg (170 pounds) of rock and soil samples, took photographs, and set up the ALSEP and performed other scientific experiments. This was the first mission to employ the LRV, used to explore regions within 5 km (3 mi) of the LM landing site.
While the Lunar Module was on the Moon, Worden completed 34 Lunar orbits in the CSM, operating SIM experiments and cameras to obtain data concerning the Lunar surface and environment. The SIM equipment included a panoramic camera, gamma ray spectrometer, mapping camera, laser altimeter, and a mass spectrometer. X-ray spectrometer data indicated a richer abundance of aluminum in the highlands, especially on the far side, but greater concentrations of magnesium in the maria.
The LM ascent stage lifted off from the Moon at 17:11:22 UT on 2 August, televised for the first time, after 66 hours, 55 minutes on the Lunar surface. After the LM docked with the CSM at 19:09:47 UT, the Lunar samples, film, and other equipment were transferred from the LM to the CSM. The LM was jettisoned at 01:04:14 UT on 3 August, after a one orbit delay to ensure LM and CSM hatches were completely sealed. The LM impacted the Moon on 3 August 03:03:37.0 UT at 26.36 N, 0.25 E, 93 km west of the Apollo 15 ALSEP site, with an estimated impact velocity of 1.7 km/s (3800 mph) at an angle of ~3.2 degrees from horizontal. Its impact was recorded by the Apollo 12, Apollo 14, and Apollo 15 seismometers, left on the Moon during each of those missions.
Experiments were performed from orbit over the next day. After Apollo 15 executed an orbit-shaping maneuver, the scientific subsatellite was spring-launched from the SM SIM bay at 20:13:19 UT on 4 August into a 102.0 x 141.3 km (63.4 x 87.8 mi) Lunar orbit. The satellite measured interplanetary and Earth magnetic fields near the Moon, and carried charged-particle sensors and equipment to detect variations in Lunar gravity caused by mascons (mass concentrations).
Transearth injection began on the next orbit with a 2 minute, 21 second main engine burn at 21:22:45 UT. On 5 August, Worden carried out the first deep space EVA when he exited the CM and made three trips to the SIM bay at the rear of the SM to retrieve film cannisters and check the equipment. Total EVA time was 38 minutes, 12 seconds.
The CM separated from the SM at 20:18:00 UT on 7 August. During descent, one of the three main parachutes failed to open fully, resulting in a descent velocity of 35 km/hr (21.8 mph), 4.5 km/hr (2.8 mph) faster than planned, causing a hard but safe landing. Apollo 15 splashed down in the Pacific Ocean on 7 August 1971 at 20:45:53 UT (4:45:53 PM EDT) after a mission elapsed time of 295 hours, 11 minutes, 53 seconds (12 days 7 hours 12 minutes). The splashdown point was 26 deg 7 min N, 158 deg, 8 min W, 330 miles (530 km) north of Honolulu, Hawaii and 9.8 km (6.1 mi) from the recovery ship USS Okinawa. The astronauts were carried to the ship by helicopter, and the CM was retrieved and placed on board.
Performance of the spacecraft, the first of the Apollo J-series missions (long duration stays on the Moon with a greater focus on science than on previous flights), was excellent for most aspects of the mission. The primary mission goals of exploration of the Hadley-Appenine region, deployment of the ALSEP and other scientific experiments, collection of Lunar samples, surface photography, and photography and other scientific experiments from orbit, and engineering evaluation of new Apollo equipment, particularly the rover, were achieved. Scott, 39, was an Air Force Colonel on his third spaceflight (he'd flown previously on Gemini 8 and Apollo 9), Worden, 39, was an Air Force Major on his first spaceflight, and Irwin, 41, was an Air Force Lt. Colonel also on his first spaceflight.
The Apollo 15 command module "Endeavor" is on display at the USAF Museum at Wright-Patterson Air Force Base, Dayton, Ohio.
See also the pages for the Apollo 15 Lunar Module /ALSEP and the Apollo 15 SIVB
The Apollo program included a large number of uncrewed test missions and 12 crewed missions: three Earth orbiting missions (Apollo 7, 9 and Apollo-Soyuz), two Lunar orbiting missions (Apollo 8 and 10), a Lunar swingby (Apollo 13), and six Moon landing missions (Apollo 11, 12, 14, 15, 16, and 17). Two astronauts from each of the six missions walked on the Moon (Neil Armstrong, Edwin Aldrin, Charles Conrad, Alan Bean, Alan Shepard, Edgar Mitchell, David Scott, James Irwin, John Young, Charles Duke, Gene Cernan, and Harrison Schmitt), the only humans to date (2014) to have set foot on another solar system body.
https://www.youtube.com/watch?v=A3x40HerKQo
https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1971-063A
1976
Work began on modification of 747 N9668 to carry NASA's space shuttle on its back in a $30 million contract. After completion of the conversion, the aircraft would be rolled out as N905NA.
https://web.archive.org/web/20150611160003/http://www.tailsthroughtime.com/2011/01/747-shuttle-carrier-aircraft-sca.html
1982
Died, Nikolay Alekseyevich Pilyugin, Russian Chief Designer of Nll-885 and NII AP (1948-1982), specialized in missile and spaceship guidance
https://en.wikipedia.org/wiki/Nikolay_Pilyugin
1984 20:30:00 GMT
Japan launched Himawari 3 from Tanegashima, positioned in geosynchronous orbit at 140 deg E 1984-1989; 120 deg E 1989-1995, to improve meteorological observation and develop meteorological satellite technology, and study alpha particles and electrons.
https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1984-080A
1984 21:37:00 GMT
USSR launched Gorizont 10 from Baikonur for provision of telephone and telegraph radio communications and television broadcasting, which was positioned in geosynchronous orbit at 80 deg E 1984-1989, 170 deg W 1989-1990.
https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1984-078A
1985 07:15:00 GMT
During the 5h 0m Salyut 7 EO-4-1 EVA, cosmonauts Dzhanibekov and Savinykh installed a solar array.
https://en.wikipedia.org/wiki/Salyut_7#Spacewalks
1985 11:44:00 GMT
USSR launched Cosmos 1671 from the Plesetsk Cosmodrome aboard a Soyuz 11 rocket, a Soviet military cartographic photo-surveillance satellite.
https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1985-065A
1990 05:39:00 GMT
The US Air Force launched Navstar 2-08 (USA 63), a GPS Block 2 satellite component of the Global Positioning System, which was placed in Plane E Slot 2.
https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1990-068A
1991 11:01:59 EDT (GMT -4:00:00)
NASA launched STS 43 (Atlantis 9, 42nd Shuttle Mission) to carry TDRS-E to orbit, and to fly the SSBUV and SHARE-II experiments.
The launch of STS 43 was originally set for 23 July 1991, but was moved to 24 July to allow time to replace a faulty integrated electronics assembly that controls orbiter/external tank separation. The mission was postponed again about five hours before liftoff on 24 July due to a faulty main engine controller on engine number three. The controller was replaced and retested, and the launch reset for 1 August. The liftoff set for 11:01 AM EDT was delayed due to a cabin pressure vent valve reading, and postponed at 12:28 PM EDT due to unacceptable return-to-launch site weather conditions. The launch was then reset for 2 August, when STS 43 was finally launched.
The STS 43 primary payload, Tracking and Data Relay Satellite-5 (TDRS-5), attached to an Inertial Upper Stage (IUS), was deployed about six hours into flight, and the IUS propelled the satellite into geosynchronous orbit; TDRS-5 became the fourth member of the orbiting TDRS cluster. The secondary payloads were: the Space Station Heat Pipe Advanced Radiator Element II (SHARE II); the Shuttle Solar Backscatter Ultra-Violet (SSBUV) instrument; the Tank Pressure Control Equipment (TPCE); and Optical Communications Through Windows (OCTW). Other experiments included the Auroral Photography Experiment (APE-B); Protein Crystal Growth III (PCG III); Bioserve/Instrumentation Technology Associates Materials Dispersion Apparatus (BIMDA); Investigations into Polymer Membrane Processing (IPMP); Space Acceleration Measurement System (SAMS); Solid Surface Combustion Experiment (SSCE); Ultraviolet Plume Instrument (UVPI); and the Air Force Maui Optical Site (AMOS) experiment.
STS 43 ended on 11 August 1991 when Atlantis landed on revolution 142 on Runway 15, Kennedy Space Center, Florida, the first landing scheduled at KSC since STS 61-C in January 1986 (which was diverted to Edwards). Rollout distance: 9,890 feet. Rollout time: 59 seconds. Launch weight: 259,374 pounds. Landing weight: 196,088 pounds. Orbit altitude: 174 nautical miles. Orbit inclination: 28.45 degrees. Mission duration: eight days, 21 hours, 21 minutes, 25 seconds. Miles Traveled: 3.7 million.
The flight crew for STS 43 was: John E. Blaha, Commander; Michael A. Baker, Pilot; Shannon W. Lucid, Mission Specialist 1; James C. Adamson, Mission Specialist 2; G. David Low, Mission Specialist 3.
NASA STS-43 crew photo
Source: Wikipedia
https://www.nasa.gov/mission_pages/shuttle/shuttlemissions/archives/sts-43.html
1995 23:59:11 GMT
Russia launched Interbol 1 from Plesetsk for energetic particle and fields research, which released the Czech Magion 4 subsatellite on 3 August 1995 for solar wind studies in conjunction with Interbol 1.
The Interball Project was a multi-national effort that consisted of four spacecraft: two main Prognoz series spacecraft made in Russia, each with a small subsatellite made in Czechoslovakia. The main objective was to study the physical mechanisms responsible for transmission of solar wind energy to the magnetosphere, its storage there, and subsequent dissipation in the tail and auroral regions of the magnetosphere, ionosphere, and atmosphere during magnetospheric substorms. A ground-based support group was to provide coordinated and simultaneous ground-based data of many types, including observations from auroral and polar cap regions. Interball was an IACG-related mission. Key physical parameters were to be generated, and and made available for exchange with other projects. Campaigns for intercomparison with the Wind and Geotail spacecraft were expected.
One pair of spacecraft, Tail Probe and its subsatellite S2-X (X for the first letter of the Russian word for "Tail"), was to be launched into the magnetospheric tail. The second pair, Auroral Probe and S2-A (A for ``Auroral''), was to have an orbit that crossed the auroral oval to observe the acceleration of auroral particles and the flow of electric currents that connect the magnetospheric tail with the conducting ionosphere. To study the equilibrium tail structure, during about half of each year the Tail Probe pair was to cross the main parts of the magnetotail every four days. The Auroral Probe pair would support the Tail Probe pair with auroral region measurements.
Each main spacecraft had more than twenty scientific instruments. The spacecraft was cylindrical, with its spin axis toward the Sun (within 10 degrees), and with a spin period of ~120 s. The electric and magnetic field sensors were on booms connected to the ends of the solar panels. The subsatellites were small, each with about ten scientific instruments. Their spin axis was to be directed within 10 degrees of the Sun, with a spin period of ~120 s, as with the main spacecraft. The subsatellites also carried gas-jet thrusters for limited orbital control. Separation distances were to range from hundreds of kilometers to several tens of thousands of kilometers for the Tail Probe pair, and from hundreds of meters to hundreds of kilometers for the Auroral Probe pair. The Tail Probe had two telemetry systems, at up to 32 Kbps in real-time, with a memory mode capacity of 30 Mb in the RTK telemetry system and 120 Mb in the SSNI system. The Auroral Probe had similar capability plus the additional real-time-only STO system, capable of 40 Kbps. Each subsatellite had only the STO real-time telemetry system. For S2-X the rate could be varied from 2-40 kbps. The Tail Probe had an adapting alert mode while in the memory mode, allowing time resolutions that were the same as in the real-time mode. The aim was to have the highest time resolution available at the thin borders of magnetospheric regions or the sharp borders of some features. In the alert mode, triggered by an on-board computer monitoring plasma and field parameters, the bit rate was increased for plasma, field, and wave measurements. The duration of these alert periods was about 10 minutes, and there could be 5-6 of them during one orbit.
https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1995-039A
1996
Died, Aleksandr Emmanuelovich Nudelman, Russian Chief Designer of OKB8-16 (1965-1987), pre-eminent designer of aircraft guns in the Soviet Union, adapted his aircraft designs for space guns for Kozlov's Soyuz VI and Chelomei's Almaz spacecraft
https://en.wikipedia.org/wiki/Alexander_Nudelman
1998 16:24:00 GMT
A Pegasus XL/HAPS, air-launched by the L-1011 carrier originating from Wallops Island, Virginia, lofted eight Orbcomm communications satellites (Orbcomm FM-13 - FM-20) into space, placed in Plane B Ascending nodes at approximately 60 degrees.
https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1998-046A
2005
NASA's MESSENGER spacecraft first flew by Earth at an altitude of 2347 km (1458 mi) on its way to Mercury.
The Mercury Surface, Space Environment, Geochemistry and Ranging (MESSENGER) mission was designed to study the characteristics and environment of Mercury from orbit. Specifically, the scientific objectives of the mission were to characterize the chemical composition of Mercury's surface, the geologic history, the nature of the magnetic field, the size and state of the core, the volatile inventory at the poles, and the nature of Mercury's exosphere and magnetosphere over a nominal orbital mission of one Earth year.
MESSENGER launched into a parking orbit on 3 August 2004 on a Delta 7925H (a Delta II Heavy launch vehicle with nine strap-on solid-rocket boosters). The Delta booster second stage's second burn raised the orbit, then the PAM-D solid motor burned to put the probe on an escape trajectory into a 0.92 x 1.08 AU x 6.4 deg heliocentric orbit. The spacecraft was injected into solar orbit 57 minutes after launch. The solar panels were then deployed and the spacecraft began sending data on its status.
One year after launch, on 2 August 2005, MESSENGER flew by Earth at an altitude of 2347 km. On 12 December 2005 at 11:30 UT, MESSENGER fired its large thruster for 524 seconds, changing the spacecraft velocity by 316 m/s and putting it on course for its 24 October 2006 Venus flyby at an altitude of 2990 km. The second Venus flyby took place on 5 June 2007 at 23:08 UT (7:08 p.m. EDT) at an altitude of approximately 337 km. The first of three Mercury flybys, all at roughly 200 km altitude, occurred on 14 January 2008 at 19:04 :39 UT, and the second on 6 October 2008 at 08:40:22 UT. The third took place on 29 September 2009 at 21:54:58 UT at a distance of 228 km. There were also five deep space manuevers. Data collected during the Mercury flybys was used to help plan the scientific campaign during the orbital phase.
Mercury orbit insertion took place with a 15 minute burn starting at 00:45 UT on 18 March 2011 (8:45 p.m. 17 March EDT) requiring a delta-V of 0.862 km/s from the Aerojet 660N engine. Science observations began on April 4 at 20:40 UT (4:40 p.m. EDT). The nominal orbit had a periapsis of 200 km at 60 degrees N latitude, an apoapsis of 15,193 km, a period of 12 hours and an inclination of 80 degrees. The periapsis slowly rose due to solar perturbations to over 400 km at the end of 88 days (one Mercury year) at which point it was readjusted to a 200 km, 12 hour orbit via a two burn sequence.
Data was collected from orbit for one Earth year, the end of the primary mission was in March 2012. Extensions to the mission allowed the spacecraft to operate for an additional 3 years until the propellant necessary to maintain its orbit was exhausted. The MESSENGER spacecraft impacted the surface of Mercury as planned on 30 April 2015 at 19:26 UT (3:26 p.m. EDT).
Global stereo image coverage at 250 m/pixel resolution was completed. The mission has also yielded global composition maps, a 3-D model of Mercury's magnetosphere, topographic profiles of the northern hemisphere, gravity field, altitude profiles of elemental species, and a characterization of the volatiles in permanently shadowed craters at the poles.
The MESSENGER spacecraft was a squat box (1.27 m x 1.42 m x 1.85 m) with a semi-cylindrical thermal shade (roughly 2.5 meters tall and 2 meters wide) for protection from the Sun and two solar panel wings extending radially about 6 meters from tip to tip. A 3.6 meter magnetometer boom also extended from the craft. The total mass of the spacecraft was 1093 kg, 607.8 kg of which was propellant and helium. The structure was primarily graphite-cyanate-ester (GrCE) composite and consisted of two vertical panels which supported two large fuel tanks, and two vertical panels which supported the oxidizer tank and plumbing panel. The four vertical panels made up the center column and were bolted at their aft ends to an aluminum adapter. A single top deck panel mounted the LVA (large velocity adjust) thruster, small thrusters, helium and auxiliary fuel tanks, star trackers and battery.
Main propulsion was via the 645-N, 317-s bipropellant LVA thruster, four 22-N monopropellant thrusters providing spacecraft steering during main thruster burns, and ten 4-N monopropellant thrusters used for attitude control. There was also a reaction-wheel attitude control system. Knowledge for attitude control was provided by star tracking cameras, an inertial measurement unit, and six solar sensors. Power was provided by the solar panels, which extended beyond the sunshade and were rotatable to balance panel temperature and power generation, and provided a nominal 450 W in Mercury orbit. The panels were 70% optical solar reflectors and 30% GaAs/Ge cells. The power was stored in a common-pressure-vessel nickel-hydrogen battery, with 11 vessels and 2 cells per vessel.
Communications were in the X-band, with downlink through two fixed phased-array antenna clusters, and uplink and downlink through medium- and low-gain antennas on the forward and aft sides of the spacecraft. Passive thermal control, primarily a fixed opaque ceramic cloth sunshade, was utilized to maintain operating temperatures near the Sun. Radiators were built into the structure and the orbit was optimized to minimize infrared and visible light heating of the spacecraft from the surface of Mercury. Multilayer insulation, low conductivity couplings, and heaters were also used to maintain temperatures within operating limits.
Five science instruments were mounted externally on the bottom deck of the main body: the Mercury Dual Imaging System (MDIS), Gamma-Ray and Neutron Spectrometer (GRNS), X-ray Spectrometer (XRS), Mercury Laser Altimeter (MLA), and Atmospheric and Surface Composition Spectrometer (MASCS). The Energetic Particle and Plasma Spectrometer (EPPS) was mounted on the side and top deck and the magnetometer (MAG) was at the end of the 3.6 m boom. Radio Science (RS) experiments used the existing communications system.
The highly successful orbital mission came to an end after more than four years in orbit around Mercury, as the spacecraft ran out of propellant and the force of solar gravity caused it to impact the surface of Mercury at 3:26 p.m. EDT on 30 April 2015.
More information about the spacecraft and its research results can be found on the MESSENGER Web site at John Hopkins University's Applied Physics Laboratory.
https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2004-030A
We are going to run out of oil!
Visit SpacePowerNow.org
to help fix the problem.
SpacePowerNow.org - For Human Survival
Please help support our efforts by shopping from our sponsors.
This newsletter and its contents are Copyright © 2006-2024 by The L5 Development Group. All rights reserved. - Publication, in part or in whole, requires previous written permission. - Academic or personal-use citations must refer to http://L5Development.com as their source. Thank you for your cooperation.