SOLRAD 8
{{Infobox spaceflight
| name = Solrad 8
| image = File:SOLRAD 8.jpg
| image_caption =
| mission_type = Solar science
| operator = NASA
| Harvard_designation =
| SATCAT = 1738
| mission_duration = {{time interval|November 19, 1965, 22:11:30}} (in orbit)
| COSPAR_ID = 1965-093A
| spacecraft_bus =
| manufacturer = Naval Research Lab
| dry_mass =
| launch_mass = {{convert|56.7|kg|lb}}
| power =
| launch_date = {{start-date|November 19, 1965, 22:11:30|timezone=yes}} UTC {{cite web|url=http://rammb.cira.colostate.edu/dev/hillger/solar-observing.htm |title=Solar-observing satellites |publisher=Rammb.cira.colostate.edu |access-date=2014-05-27}}{{cite web|url=https://planet4589.org/space/log/launchlog.txt|title=Launch Log|publisher=Jonathan's Space Report |date=21 July 2021|access-date=9 November 2021}}
| launch_rocket = Scout X-4
| launch_site = Wallops LA-3
| last_contact = {{end-date|August 1967}}
| decay_date =
| orbit_epoch = 19 November 1965, 04:48:00 UTC
| orbit_reference = Geocentric{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/displayTrajectory.action?id=1965-093A|title=Trajectory: Explorer 30 (Solrad 8) 1965-093A|publisher=NASA|date=28 October 2021|access-date=9 November 2021}} {{PD-notice}}
| orbit_regime = Circular orbit
| orbit_periapsis = {{convert|704|km|mi|sp=us}}
| orbit_apoapsis = {{convert|891|km|mi|sp=us}}
| orbit_inclination = 59.7 degrees
| orbit_semimajor =
| orbit_eccentricity = 0.01302
| orbit_period = 100.8 minutes
| orbit_RAAN =
| orbit_arg_perigee =
| orbit_mean_anomaly =
| orbit_mean_motion =
| orbit_rev_number =
| apsis = gee
| programme = Explorers
| previous_mission = Explorer 29
| next_mission = Explorer 31
| programme2 = SOLRAD
| previous_mission2 = Solrad 7B
| next_mission2 = Solrad 9
}}
The SOLRAD 8,Explorer 30 or SE-A satellite was one of the NASA SOLRAD (Solar Radiation) program that began in 1960 to provide continuous coverage of solar radiation with a set of standard photometers. SOLRAD 8 was a spin-stabilized satellite oriented with its spin axis perpendicular to the sun-satellite line so that the 14 solar X-ray{{Cite FTP |url=ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SATELLITE_ENVIRONMENT/XRAY_BGND/docs/solrad.txt |server=ftp.ngdc.noaa.gov |title=FTP link }} and ultraviolet photometers{{cite web|url=http://www.designation-systems.net/dusrm/app3/solrad.html |title=Solrad |publisher=Designation-systems.net |access-date=2014-05-27}} pointing radially outward from its equatorial belt viewed the sun on each revolution. Data were transmitted in real time by means of an FM / AM the satellite's telemetry system and were recorded by the stations on the Spacecraft Tracking and Data Acquisition Network (STADAN) tracking network.{{cite web |url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1965-093A|title=Display: Explorer 30 (Solrad 8) 1965-093A|publisher=NASA|date=28 October 2021|access-date=9 November 2021}} {{PD-notice}}
Eclipse 1966
The satellite observed the solar eclipse on 20 May 1966.{{cite journal|doi=10.1038/211393a0|title=Solar Eclipse of 20 May 1966, observed by the Solrad 8 Satellite in X-ray and Ultraviolet Bands |journal=Nature|volume=211|issue=5047|page=393|year=1966|last1=Landini|first1=M.|last2=Russo|first2=D.|last3=Tagliaferri|first3=G. L.|bibcode=1966Natur.211..393L|s2cid=4174785}} This observation may have been the first observation of a solar eclipse by an artificial satellite.
Mission
The satellite performed normally, except for the spin system,{{cite web |url=http://spacearchaeology.org/?p=436 |title=SOLRAD 8 |publisher=Space Archaeology |access-date=2014-05-27 |archive-date=2017-12-08 |archive-url=https://web.archive.org/web/20171208003936/http://spacearchaeology.org/?p=436 |url-status=dead }} which failed to maintain 60 rpm (at spin rates below 10 rpm data reduction became difficult). The spin rate gradually decreased to 4 rpm on September 12, 1966.{{cite book|url=https://archive.org/details/bub_gb_3WIrAAAAYAAJ|title=United States Space Science Program: Report to COSPAR.|publisher=National Academies|year=1967|author=National Research Council (U.S.). Space Science Board, COSPAR|page=[https://archive.org/details/bub_gb_3WIrAAAAYAAJ/page/n53 47]}} At that time, ground command succeeded in reactivating spinup to 78 rpm, which exhausted the gas supply. From this point, the spin rate gradually decreased to 10 rpm in August 1967, when data collection was substantially decreased.{{cite web|url=https://history.nasa.gov/SP-4312/ch1.htm |title=NASA:SP-4312 Dreams, Hopes, Realities-Chapter 1:Goddard's First Forty: The Quest to Learn |publisher=History.nasa.gov |date=1957-10-04 |access-date=2014-05-27}}
Experiment
= Solar X-Ray and Ultraviolet Monitor =
This experiment was designed to monitor solar X-ray and ultraviolet emissions with a set of standardized detectors so that the data could be compared directly with that produced by other experiments in the SOLRAD series. Eight ion chambers and two Geiger counters covering the spectral regions from 0.5 A to 60 A and 1080 A to 1350 A were mounted perpendicular to the satellite spin axis. Analog outputs from the detectors were transmitted continuously on six IRIG telemetry channels. The experiment provided good data for all detectors from 27 November 1965 to 24 August 1967, with the following exceptions: (1) the Lyman-alpha detector and the UV detectors were saturated for normal aspect angles, (2) the core memory failed at launch so that the data were collected in real-time telemetry only, and (3) a gradual decrease in spin rate caused the aspect angle to drift away from normal in the second year of operation.{{cite web |url=https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=1965-093A-01|title=Experiment: Solar X-Ray and Ultraviolet Monitor|publisher=NASA|date=28 October 2021|access-date=9 November 2021}} {{PD-notice}}
See also
{{Portal|Spaceflight}}
References
{{Include-NASA}}
{{reflist}}
External links
- http://www.techarchive.org/solrad-satellites/
- [https://web.archive.org/web/20080920041827/http://nssdc.gsfc.nasa.gov/nmc/datasetSearch.do?spacecraft=SOLRAD%20%208 NSSDC Solrad 8 data collections]
{{Explorer program}}
{{Orbital launches in 1965}}
{{Use American English|date=January 2014}}
Category:Spacecraft launched in 1965