Notes on the design and flight profile of the Luna 15-24 series

 Sven Grahn

Flight timelines of various missions

 

 
 Summary of flight timelines for E-8 series
Flight Translunar flight time Time in lunar orbit Time to surface Time on surface Trans-earth flight time Total flight time Age at landing Lunar landing coordinates
Returners                
Luna 15 4.29 4.25 8.64 - - - 7.06 57E 16N
Luna 16 4.38 3.28 7.66 1.10 2.90 11.67 19.3 56.3 E 0.68S
Luna 18 4.38 4.38 8.76 - - - 21.3 56.5E 3.57N
Luna 20 4.38 3.27 7.65 1.15 2.84 11.65 6.7 56.6 E 3.4 N
Luna 23 4.30 4.33 8.63 - - - 21.7 58E 18N
Luna 24 4.34 4.31 8.65 0.99 3.52 13.12 22.3 62.2E 12.8 N
                 
              Age at launch  
Orbiters                
Luna 19 4.58 - - - - - 8.82 -
Luna 22 4.31 - - - - - 7.47 -
              Age at landing  
Rovers                
Luna 17 4.38 2.17 6.55 - - - 17.9 35.0W 28.3N
Luna 21 4.38 3.27 7.65 - - - 11.24 30.5E 25.9N

 
 

Flight profiles for Luna 16, 20 and 24 - landed and returned

The three return flights from the moon were Luna 16, 20, and 24. The table below summarizes the flight profiles of these missions.
Direct transfer from Moon-Earth, the Luna 16,20,24 flights
- no lunar orbit
- vertical ascent
- zero out moon's orbital velocity using the parabolic excess velocity
- i.e. only eastern lunar longitudes feasible
- with more easternly location the less parabolic excess velocity is needed and the longer is the Moon-Earth transfer time.
 
 
 
Luna 16
Luna 20
Luna 24
Event Time (UT) Interval Time (UT) Interval Time (UT) Interval
Launch 12 Sept 1970 
1326 UT		   14 Feb 1972 
0328 UT		   9 Aug 1976 
1504 UT		  
    105.1 h   105.0 h   104.1 h
Lunar 
Orbit 
Insertion		 16 Sept 1970 
2234 UT		   18 Feb 1972 
1230 UT		   13 Aug 1976 
2311 UT		  
    78.7 h   78.4 h   103.4 h
Moon 
Landing		 20 Sept 1970 
0518 UT		   21 Feb 1972 
1919 UT		   18 Aug 1976 
0636 UT		  
    26.3 h   27.65 h   22.85 h
Lunar 
Launch		 21 Sept 1970 
0743 UT		   22 Feb 1972 
2258 UT		   19 Aug 1976 
0525 UT		  
    69.7 h   68.2 h   84.5 h
Earth 
Landing		 24 Sept 1970 
0526 UT		   25 Feb 1972 
1912 UT		   22 Aug 1976 
1755 UT		  

Flight profiles for Luna 15, 18 and 23 - landed but did not return

The three return flights from the moon were Luna 16, 20, and 24. The table below summarizes the flight profiles of these missions.
 
 
 
Luna 15
Luna 18
Luna 23
Event Time (UT) Interval Time (UT) Interval Time (UT) Interval
Launch 13 July 1969 
0255 UT		   2 Sept 1971 
1341 UT		   28 Oct 1974 
1430 UT		  
    103.1 h   105.1 h   103.3 h
Lunar 
Orbit 
Insertion		 17 July 1969 
1000 UT		   6 Sept 1971 
2248 UT		   1 Nov 1974 
2150 UT		  
    101.9 h   105.0 h   103.8 h
Moon 
Landing		 21 July 1969 
1551 UT		   11 Sept 1971 
0748 UT		   6 Nov 1974 
0537 UT		  

Flight profiles for Luna 17 and 21 - rovers

The three return flights from the moon were Luna 16, 20, and 24. The table below summarizes the flight profiles of these missions.
 
 
 
Luna 17
Luna 21
Event Time (UT) Interval Time (UT) Interval
Launch 10 Nov 1970 
1444 UT		    8 Jan 1973 
0655 UT		  
    105.0 h   105.1 h
Lunar 
Orbit 
Insertion		 14 Nov 1970 
2345 UT		    12 Jan 1973 
1605 UT		  
    52.0 h   78.5 h
Moon 
Landing		 17 Nov 1970 
0347 UT		   15 Jan 1973 
2235 UT		  

 

Flight profiles for Luna 19 and 22 - orbiters

The three return flights from the moon were Luna 16, 20, and 24. The table below summarizes the flight profiles of these missions.
 
 
 
Luna 19
Luna 22
Event Time (UT) Interval Time (UT) Interval
Launch 28 Sept 1971 
1000 UT		    29 May 1974 
0857 UT		  
    110 h    103.4 h
Lunar 
Orbit 
Insertion		 3 Oct 1971 
0000 UT?		    1 June 1974 
1620 UT		  
    12 mo   16 mo
End of  
Mission		 3 Oct 1972   Nov 1975  

 

Landing sites on the Moon and Earth

It can also be instructive to look at the landing sites on the moon and earth for the various returner missions:
 
 
 
Moon
Earth
  Lat. (N) Long. (E) Lat. (N) Long. (E)
Luna 16 -0.68 56.30 47.4 68.6
Luna 18 3.57 56.50 - - 
Luna 20 3.57 56.50 48 67.56
Luna 23  18 58 - -
Luna 24 12.75 62.20 61.01 75.90

 


Back to Space History Notes