NATIONAL AERONAUTICS AND SPACE ADMINISTRATION

Scout X-4 | Explorer 20

SUCCESSAug 25, 1964 at 13:43 UTCScout X-4 →
PADSpace Launch Complex 5
SITEVandenberg SFB, CA, USA →
ORBITLow Earth Orbit
TYPEEarth Science

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.

VEHICLE
Scout X-4
MISSION
Explorer 20
MISSION TYPE
Earth Science
TARGET ORBIT
Low Earth Orbit
COUNTRY
USA
CONFIRMEDPrecision: Minute
LAUNCH LIBRARY 2 PRIMARY
API ID: 2d7c492c-a508-4c2d-ab10-2658e8b1c979
Reported date: Aug 25, 1964 at 13:43 UTC
Last synced: 6 hours ago
This launch date and time are confirmed by the launch provider. Countdown is active.
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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.

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.
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
Last data sync: 6 hours ago
Launch Library 26 hours ago
Launch ID: 2d7c492c-a508-4c2d-ab10-2658e8b1c979
Open-Meteo Weather7 hours ago
Pad weather at 34.61, -120.62