Explorer 19
Template:Short description Template:DMCA Template:DMCA
Page Module:Infobox/styles.css has no content.Page Template:Infobox spaceflight/styles.css has no content.
| Lua error in package.lua at line 80: module 'Module:InfoboxImage/data' not found. Cutaway diagram of Explorer 19 | |
| Names | AD-A Air Density experiment-A |
|---|---|
| Page Module:Infobox/styles.css has no content. | |
| Mission type | Air density |
| Operator | NASA |
| COSPAR ID | 1963-053A |
| SATCAT no. | 00714 |
| Page Module:Infobox/styles.css has no content. | |
| Spacecraft properties | |
| Spacecraft | Explorer XIX |
| Spacecraft type | Air Density Explorer |
| Bus | AD-A |
| Manufacturer | Langley Research Center |
| Launch mass | Template:Cvt |
| Dimensions | Template:Cvt diameter |
| Power | Solar cells and Rechargeable batteries |
| Page Module:Infobox/styles.css has no content. | |
| Start of mission | |
| Launch date | 19 December 1963, 18:49:25 GMT |
| Rocket | Scout X-4 (S-122R) |
| Launch site | Vandenberg, PALC-D |
| Contractor | Vought |
| Entered service | 19 December 1963 |
| Page Module:Infobox/styles.css has no content. | |
| End of mission | |
| Decay date | 10 May 1981 |
| Page Module:Infobox/styles.css has no content. | |
| Orbital parameters | |
| Reference system | Geocentric orbit |
| Regime | Low Earth orbit |
| Perigee altitude | Template:Cvt |
| Apogee altitude | Template:Cvt |
| Inclination | 78.6° |
| Period | 115.9 minutes |
| Instruments | |
| Satellite Drag Atmospheric Density | |
| Template:Succession links Template:Succession links | |
Script error: No such module "Check for conflicting parameters".
Explorer 19, (Air Density experiment A, or AD-A), was a NASA satellite launched on 19 December 1963, as part of the Explorer program. It was the third of six identical Explorer satellites launched to study air density and composition, and the second to reach orbit.[1] It was identical to Explorer 9.[2]
Spacecraft
Explorer 19 was launched while Explorer 9, the first satellite in the series, was still active, so that densities in two different portions of the atmosphere were sampled simultaneously. The spacecraft consisted of alternating layers of aluminium foil and Mylar polyester film. Uniformly distributed over the aluminum surface were Template:Cvt diameter dots of white paint for thermal control. The sphere was packed in a tube Template:Cvt in diameter and Template:Cvt long and mounted in the nose of the fourth stage of the launch vehicle. Upon separation of the fourth stage, the sphere was inflated by a nitrogen gas bottle, and a separation spring ejected it out into its own orbit. The two hemispheres of aluminum foil were separated with a gap of Mylar at the spacecraft's equator and served as the antenna. A 136.620 MHz, 15 mW beacon was carried for tracking purposes. The spacecraft was successfully orbited, but its apogee was lower than planned. The beacon did not have sufficient power to be received by ground tracking stations, making it necessary to rely solely on the SAO Baker-Nunn camera network for tracking.[3]
Experiments
Nonsystematic Changes of Air Density
This experiment was designed to determine nonsystematic changes of upper atmospheric density by conducting studies of the drag on a Template:Cvt diameter, low-density sphere caused by short-term variations in solar activity. Density values near perigee were deduced from sequential observations of the spacecraft position using optical (Baker-Nunn camera network) and radio/radar tracking techniques.[4]
Systematic Changes of Air Density
The objective of this experiment was to determine atmospheric density as a function of altitude, latitude, and time by measuring atmospheric drag on a low mass-to-area ratio (0.7680 kg per m2) spherical satellite. The orbit was Sun-synchronized so that near-polar densities would always be obtained along noon and midnight meridians.[5]
Launch
Explorer 19 was launched from Launch Area 3 at the Wallops Flight Facility (WFF), atop a Scout X-4 launch vehicle with the serial number S-122R. It was the second spacecraft launched from Wallops Island to achieve orbit.. The launch occurred at 18:49:25 GMT on 19 December 1963, and resulted in Explorer 19 being deployed into an orbit with an apogee of Template:Cvt, a perigee of Template:Cvt, 78.6° of inclination and a period of 115.9 minutes.[6] Upon separation of the fourth stage, the sphere was inflated by a nitrogen gas bottle, and a separation spring ejected it out into its own orbit. The two hemispheres of aluminium foil were separated with a gap of Mylar at the spacecraft's equator and served as the antenna. A 136.620 MHz, 15 mW beacon was carried for tracking purposes, but the beacon failed on the first orbit and the SAO Baker-Nunn camera network had to be relied upon for tracking. Power was supplied by solar cells and rechargeable batteries.[3]
Explorer 19's launch vehicle placed it into a slightly lower than planned orbit.[2]
See also
Lua error in mw.title.lua at line 404: bad argument #2 to 'title.new' (unrecognized namespace name 'Portal').
References
Page Template:Reflist/styles.css has no content.
- ^ Page Module:Citation/CS1/styles.css has no content.Smith, Woody. "Explorer Spacecraft Series". NASA History Division. Retrieved 10 January 2016.
This article incorporates text from this source, which is in the public domain.
- ^ a b Page Module:Citation/CS1/styles.css has no content."AD-A, -B, -C / Explorer S-56, 9, 19, 24, 39". Gunter's Space Page. 8 April 2020. Retrieved 7 November 2021.
- ^ a b Page Module:Citation/CS1/styles.css has no content."Explorer 19 (AD-A) 1963-053A". NASA. 28 October 2021. Retrieved 7 November 2021. This article incorporates text from this source, which is in the public domain.
- ^ Page Module:Citation/CS1/styles.css has no content."Experiment: Nonsystematic Changes of Air Density". NASA. 28 October 2021. Retrieved 7 November 2021. This article incorporates text from this source, which is in the public domain.
- ^ Page Module:Citation/CS1/styles.css has no content."Experiment: Nonsystematic Changes of Air Density". NASA. 28 October 2021. Retrieved 7 November 2021. This article incorporates text from this source, which is in the public domain.
- ^ Page Module:Citation/CS1/styles.css has no content.McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Report. Retrieved 17 June 2010.
External links
- NASA FACTS - EXPLORER XIX. (PDF)
Lua error in package.lua at line 80: module 'Module:Navbox/configuration' not found.
