View source for Astronomy:Explorer 24

{{Infobox spaceflight
| name                  = Explorer 24
| image                 = Explorer 24.jpg
| image_alt             = 180px
| image_caption         = Explorer 24.

| mission_type          = [[Earth:Earth science|Earth science]]
| operator              = [[Organization:NASA|NASA]]
| COSPAR_ID             = 1964-076A<ref name="nssdc">{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1964-076A|title=S 55C|work=NSSDC Master Catalog|publisher=NASA Goddard Space Flight Center|accessdate=10 June 2018}} {{PD-notice}}</ref>
| SATCAT                = 931
| mission_duration      = 1,426 days<ref>{{cite web|title=1964-076A - Explorer 24|url=https://www.lib.cas.cz/space.40/1964/076A.HTM|work=Space 40 |publisher=Lubor Lejček, Antonín Vítek|language=Czech|accessdate=10 June 2018}}</ref>

| spacecraft_bus        = ADE bus
| manufacturer          = [[Organization:Langley Research Center|Langley Research Center]]
| dry_mass              = 
| launch_mass           = {{convert|8.6|kg|lb|abbr=on}}
| power                 = 

| launch_date           = {{start-date|21 November 1964, 17:09:39}}&nbsp;UTC<ref name="jonathan">{{cite web|url=http://www.planet4589.org/space/log/launchlog.txt/|publisher=Jonathan's Space Page|title=Launch Log|accessdate=June 10, 2018}}</ref><ref>{{cite web|url=http://www.unoosa.org/documents/pdf/inf088E.pdf/|title=Letter dated 5 February 1965 from the Permanent Representative of the United States of America addressed to the Secretary-General|work=COMMITTEE ON THE PEACEFUL USES OF OUTER SPACE|publisher=UNOOSA|date=November 30, 1964|accessdate=10 June 2018|archive-url=https://web.archive.org/web/20180505205224/http://www.unoosa.org/documents/pdf/inf088E.pdf|archive-date=5 May 2018|url-status=dead}}</ref>
| launch_rocket         = [[Engineering:Scout (rocket family)|Scout X-4]]<ref name="astronautix">{{cite web|title=Explorer|url=http://www.astronautix.com/e/explorer.html/|encyclopedia=Encyclopedia Astronautica|publisher=Mark Wade|accessdate=10 June 2018}}</ref> 
| launch_site           = {{wipe|Vandenberg Air Force Base}} SLC-5<ref name="astronautix"/>

| last_contact          = 
| decay_date            = {{end-date|18 October 1968}}<ref name="nssdc"/>

| orbit_epoch           = 21 November 1964<ref name="nssdc"/>
| orbit_reference       = [[Astronomy:Geocentric orbit|Geocentric]]
| orbit_regime          = [[Astronomy:Low Earth orbit|Low Earth]]
| orbit_periapsis       = {{convert|525|km|abbr=on}}<ref name="nssdc"/>
| orbit_apoapsis        = {{convert|2,498|km|abbr=on}}<ref name="nssdc"/>
| orbit_inclination     = 81.4°<ref name="nssdc"/>
| orbit_semimajor       = 
| orbit_eccentricity    = 0.12496<ref name="nssdc"/>
| orbit_period          = 116.3&nbsp;minutes<ref name="nssdc"/>
| orbit_RAAN            = 
| orbit_arg_periapsis   = 
| orbit_mean_anomaly    = 
| orbit_mean_motion     = 
| orbit_rev_number      = 
| apsis                 = gee

| instruments           = Nonsystematic Changes of Air Density<br/>Systematic Changes of Air Density

| programme             = ''Explorers''
| previous_mission      = [[Astronomy:Explorer 23|Explorer 23]]
| next_mission          = [[Astronomy:Explorer 25|Explorer 25]]
}}
'''Explorer 24''' (also called '''AD-B''' and '''S-56C''') was a U.S. satellite designed for [[Earth:Upper atmosphere|atmospheric studies]]. Explorer 24 was launched on 21 November 1964 from {{wipe|Vandenberg Air Force Base}}, Lompoc, California, with a Scout rocket. Explorer 24 was launched along with its successor satellite, [[Astronomy:Explorer 25|Explorer 25]].

==Mission==
Explorer 24 was placed in orbit together with [[Astronomy:Explorer 25|Explorer 25]] from a single launch vehicle. Explorer 24 was identical in configuration to the previously launched balloon satellites [[Astronomy:Explorer 9|Explorer 9]] and [[Astronomy:Explorer 19|19]]. The spacecraft was 3.6 m in diameter, was built of alternating layers of [[Chemistry:Aluminum|aluminum]] foil and plastic film, and was covered uniformly with 5.1-cm white dots for thermal control. 

It was designed to yield atmospheric density near perigee as a function of space and time from sequential observations of the sphere's position in orbit. To facilitate ground tracking, the satellite carried a 136 [[Megahertz|MHz]] tracking beacon. 

The satellite reentered the earth's atmosphere on October 18, 1968.<ref name="nssdc"/>

==Results==
Explorer 24 helped determine the variation in density between the day and night of the [[Astronomy:Earth|Earth]] and gave rise to studies on the zone winds in the [[Earth:Exosphere|exosphere]], at an altitude of between {{convert|450|km|mi}} and {{convert|620|km|mi}}.<ref>{{cite journal|title=The Shape and Location of the Diurnal Bulge in the Upper Atmosphere|journal=SAO Special Report (207)|publisher= Jacchia, L. G. & Slowey, J.|date=1966|bibcode=1966SAOSR.207.....J|last1=Jacchia|first1=L. G.|last2=Slowey|first2=J.|volume=207}}</ref><ref name"PSS">{{cite journal|title=Exospheric zonal winds between 540 and 620 km from the orbit of Explorer 24|journal=Planetary and Space Science 24: 529–539|publisher=Blum, P. W.; Schuchardt, K. G. H.|date=June 24, 1976|bibcode=1976P&SS...24..529B|last1=Blum|first1=P. W.|last2=Schuchardt|first2=K. G. H.|volume=24|issue=6|pages=529|doi=10.1016/0032-0633(76)90131-8}}</ref>

==References==
{{reflist|2}}

{{Explorers program}}


[[Category:Explorers program (NASA)]]

{{Sourceattribution|Explorer 24|1}}