NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
Scout X-4 | Explorer 20
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Aug 25, 1964 at 13:43 UTC
▸ Flight profile›
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MISSION OVERVIEW
Explorer 20 (IE A, Ionospheric Explorer A, TOPSI, Top Side Explorer or S 48) was designed to measure electron distribution, ion density and temperature, and to estimate cosmic noise levels between 2 and 7 MHz.
LAUNCH DETAILS
VEHICLE
Scout X-4MISSION
Explorer 20
MISSION TYPE
Earth Science
TARGET ORBIT
Low Earth Orbit
LAUNCH PAD
Space Launch Complex 5LAUNCH SITE
Vandenberg SFB, CA, USACOUNTRY
USA
LAUNCH TIME VERIFICATION
CONFIRMEDPrecision: Minute
LAUNCH LIBRARY 2 PRIMARY
API ID: 2d7c492c-a508-4c2d-ab10-2658e8b1c979
Reported date: Aug 25, 1964 at 13:43 UTC
Last synced: 4 minutes ago
This launch date and time are confirmed by the launch provider. Countdown is active.
LAUNCH MAP
PAD WEATHER
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VEHICLE — Scout X-4 →
MANUFACTURER
Vought
VARIANT
4
FLIGHTS
12
SUCCESSES
11
SUCCESS RATE
91.7%
The Scout family of rockets were were American launch vehicles designed to place small satellites into orbit around the Earth. The Scout multistage rocket was the first orbital launch vehicle to be entirely composed of solid fuel stages.
FREQUENTLY ASKED QUESTIONS
When is the Scout X-4 | Explorer 20 launch?
The Scout X-4 | Explorer 20 is scheduled for Tuesday, August 25, 1964 at 1:43 PM UTC. This is the NET (No Earlier Than) time and may be subject to change. Current status: SUCCESS.
What rocket is being used for Explorer 20?
The Scout X-4 | Explorer 20 mission uses the Scout X-4 rocket, manufactured by Vought. The Scout X-4 has flown 12 times with a 91.7% success rate.
Where is the Scout X-4 | Explorer 20 launching from?
The launch takes place from Space Launch Complex 5 at Vandenberg SFB, CA, USA.
What orbit is Explorer 20 going to?
The Explorer 20 mission is targeting Low Earth Orbit.
Who is launching Explorer 20?
The Scout X-4 | Explorer 20 is operated by National Aeronautics and Space Administration.
Can I watch the Scout X-4 | Explorer 20 launch live?
Yes. Visit the launch detail page on Space Launch Live for embedded YouTube webcasts, replay videos, and links to live coverage from SpaceX, NASA, NASASpaceflight, and other channels.
LAUNCH TIMELINE
Mar 28, 2026 20:13 UTC
Launch added to tracker
Imported from Launch Library 2 API
Mar 28, 2026 20:13 UTC
Launch date set: Aug 25, 1964 at 13:43 UTC
NET (No Earlier Than) confirmed by National Aeronautics and Space Administration
Mar 28, 2026 20:13 UTC
Launch completed successfully
Updated via Launch Library 2
LIVE DATA SOURCES
Last data sync: 4 minutes ago
●Launch Library 24 minutes ago
Launch ID: 2d7c492c-a508-4c2d-ab10-2658e8b1c979
●Open-Meteo Weather1 day ago
Pad weather at 34.61, -120.62
BROWSE BY
Mission Profile
Explorer 20 was a Scout X-4 mission operated by National Aeronautics and Space Administration that lifted off from Space Launch Complex 5, Vandenberg SFB, CA, USA on August 25, 1964. The flight carried its payload on a earth science mission to Low Earth Orbit. The launch was a success.