Lunokhod 2/Luna 21:

The positions of the second soviet rover and its lander

A. M. Abdrakhimov, A. T. Basilevsky

 Laboratory for comparative planetology, Vernadsky Institute, Russian Academy of Science

March 21, 2010

Figure 1. Lunokhod-2

On January 16, 1973, the spacecraft Luna 21 landed the Lunokhod 2 rover in the eastern side of Mare Serenitatis, inside mare-filled 50 km crater Le Monnier. The main purpose of the mission was the study of the transitional zone between mare and highland and the Fossa Recta graben located on the mare surface in the SE part of the Le Monnier floor.

Figure 2. Photo mosaic Lunokhod 2 route site (NASA AS15-M-0392, AS15-M-0394, AS15-P-9294). Figure 3.Scheme geomorphologic map of Lunokhod 2 working site [Florensky et al., 1976]: 1-3 – Late, Middle and Early Copernican craters; 4 - joint fissure Fossa Recta; 5-7 –Late, Middle and Early Eratosthenian craters; 8 - joint fissure Fossa Incospicua; 9 - Le Monnier lava-flooded crater floor; 10 – Late Imbrian craters; 11 –Le Monnier crater rim; 12 –tectonic reaps; 13 – large crater edges; 14 – hill slopes; 15 - ridges; 16 – geomorphologic boundaries; 17 - Lunokhod 2 route.

Lunokhod 2 worked for 4 months (5 lunations) and covered 37 kilometers. 86 detailed TV panoramas were obtained during this mission.

The vehicle was equipped with panoramic camera and navigation cameras, XRF spectrometer (RIFMA) and other instruments.

Figure 4. Lunation 1. Session 2. Panorama 05. The bottom of Le Monnier Crater is covered by regolith, which is formed on mare basalts.

On the first lunation Lunokhod 2 moved to south on the floor of Le Monnier crater covered with mare regolith.

Figure 5. Lunation 2. Session 14. Panorama 34. "Highland" site near the rim of Le Monnier Crater, Oncoming (Vstrechnye) Hills.

On the second lunation Lunokhod 2 reached the southern edge of Le Monnier Crater and entered into highland area.

Figure 6. Lunation 3. Session 4. Panorama 11. "Mare" site between Oncoming Hills and Fossa Incospicus. "Mare" landscape.

On the third lunation Lunokhod 2 turned to the east and returned into mare area.

Figure 6. Lunation 4. Session 11. Panorama 9.The site near Fossa Recta (Pryamaya)

On the forth lunation the vehicle reached the Fossa Recta graben and investigated both sides of this tectonic structure during the two last lunar days.

Figure 8. The identification of the final position of Lunokhod 2 (big white arrow). Credit: NASA / GSFC / ASU / Sergei Gerasimenko.

The final position of Lunokhod 2 on LROC images was independently found by LROC Team (see Mark Robinson's report) and Sergey Gerasimenko (Kharkov National University, Ukraine) and Vadim Kaidash (Kharkov National University, Ukraine). (fig. 8).

Figure 8. Fragment of LROC NAC M109039075LC image [NASA/GSFC/Arizona State University] with Lunokhod 2 seen in it as a bright spot with prominent shadow of its cap with solar batteries on it. Approximate coordinates: 25.84009 N, 30.90191 E.

The new approximate coordinates of Lunokhod 2 are 25.84009 N, 30.90191 E.

On March 19, 2010 Jeff Plescia (JPL, LROC Team) reported about the revealing of Luna 21 position and the Lunokhod 2 traces at the beginning of the work (see more details).

Figure 9. Fragment of LROC NAC M122007650LE image [NASA/GSFC/Arizona State University] with Luna 21 lander. Some dark bands close to the lander are tracks of Lunokhod 2. Approximate coordinates: 26.9232 N, 30.4449 E.

The new approximate coordinates of Luna 21 are 26.9232 N, 30.4449 E (Fig. 9).

The coordinates will be corrected more precisely soon.

March 21, 2010

A. M. Abdrakhimov, A. T. Basilevsky

Vernadsky Institute, Russia, 119991, Kosygina 19, alexander_basilevsky @ brown.edu.