United States Air ForceThor Delta CSpace Launch Complex 17A, Cape Canaveral SFS, FL, USA
Explorer 21
Launched
October 4, 1964
Image: NASA
Summary
Explorer 21 launched on an United States Air Force Thor Delta C from Space Launch Complex 17A, Cape Canaveral SFS, FL, USA on October 4, 1964. It was United States Air Force's 214th launch, 39th this year and humanity's 363rd orbital launch attempt. It was the 2nd Thor Delta C flight and the 1st this year. The payload was bound for Elliptical Orbit (Elliptical). Its tracked orbit, from October 24, 1964, was 369 × 94,835 km inclined 33.8°. One object from this launch is catalogued.
- Watch
- No webcast on record.
- Vehicle
- Thor Delta C · United States Air Force
- Booster
- No booster details on record.
- Mission
- Astrophysics · Elliptical Orbit (Elliptical)
- Milestone
- 2nd Thor Delta C flight · 1st this yearUnited States Air Force's 214th launch39th this yearhumanity's 363rd orbital launch attempt70th orbital launch attempt this year
Flight preview
Orbit: as tracked
IMP 2 · NORAD 889 · 1964-060 · Space-Track
Show the numbers for orbit elements
- Object
- TBA - TO BE ASSIGNED
- Object ID
- 1964-060A
- Epoch
- 1964-10-24 07:25:13 UTC
- Mean motion
- 0.69236459 rev/day
- Eccentricity
- 0.8751199
- Inclination
- 33.77°
- Ascending node
- 222.3976°
- Arg. of perigee
- 136.0696°
- Mean anomaly
- 340.2995°
- Element set
- 999
- Rev at epoch
- 13
- B*
- 0
Perigee, apogee and period are Kepler figures from the catalogued mean elements, not a propagated state. Published orbit: Elliptical. Ascent drawn from padside's representative profile.
Catalogued objects
1 catalogued: 1 payload; none still in orbit
- IMP 2 · NORAD 889 · re-entered
Data from J. McDowell, planet4589.org
About this launch
Explorer 21 (IMP 2) was a solar-cell and chemical-battery powered spacecraft instrumented for interplanetary and distant magnetospheric studies of energetic particles, cosmic rays, magnetic fields, and plasmas.
Pad
Space Launch Complex 17A, Cape Canaveral SFS, FL, USA
25th launch from Space Launch Complex 17A, 3rd this year · 121st from Cape Canaveral SFS, FL, USA
145 launches from this pad · 1,131 from Cape Canaveral SFS, FL, USA
45 days after the previous launch from this pad
Questions
When did Explorer 21 launch?
Explorer 21 launched on October 4, 1964. The time is known to the hour, not the minute.
Where can I watch Explorer 21?
No webcast is on record for this launch.
What rocket launched Explorer 21?
Thor Delta C, flown by United States Air Force. Thor Delta C spec sheet
Where did Explorer 21 launch from?
Space Launch Complex 17A, Cape Canaveral SFS, FL, USA.
What orbit did Explorer 21 reach?
Its tracked orbit, from October 24, 1964, was 369 × 94,835 km inclined 33.8°.
How many satellites did Explorer 21 launch?
1 payload from this launch is catalogued, no longer in orbit (Data from J. McDowell, planet4589.org).