Soaring Over Mighty Mt. Hadley

East-to-west view of the Apollo 15 landing site
An oblique view, looking east-to-west over the Apennine Mountains towards Hadley Rille (upper left) (LROC NAC M1123519889, north is to the right). A long shadow is cast by mighty Mt. Hadley (center right). Nestled between the Apennines and Hadley Rille lies Hadley Base, the landing site of Apollo 15. For scale, the v-shaped trough of Hadley Rille is roughly 1 km wide [NASA/GSFC/Arizona State University].

Apollo mission planners selected an adventurous landing site for Apollo 15 located on a relatively small patch of lava plains (mare). This site is nestled between the towering Apennine mountains to the east, attaining heights of 3-5 km (~10,000-16,000 ft), and the 200-m deep v-shaped valley (~650 ft) of Hadley Rille to the west.

Hadley Base and Mountain Ranges
Notable features of the Apennine Mountain Range include Mons Hadley, Mons Hadley Delta and the Swann Range (oblique NAC M1123519889); north is to the right [NASA/GSFC/Arizona State University].

The experience gained from the successful landings of the preceding Apollo missions afforded mission controllers confidence that a landing descending through a mountain range was possible, though it required a steeper descent angle (25° rather than 14°).  A captioned video of the descent of Apollo 15 conveys the excitement of astronauts David Scott and James Irwin as they set down near Hadley Rille. The Hadley Rille landing site also presented an opportunity to test the capabilities of the new lunar roving vehicle (LRV).

Elevation map of the Apollo 15 region
LROC WAC GLD100 elevation overlain on a hillshade model of the Hadley-Apennine region (purple and blue are lower elevations, reds and yellows higher elevations). The peaks of the Apennine Mountains rise more than 5 km over the mare plains in the Imbrium basin [NASA/GSFC/Arizona State University].

The Apennine Mountain Range formed during the Imbrium basin-forming event, and it was hoped these mountains contained materials from very early in the Moon's history (which they did!). As astronauts Irwin and Scott descended over the Apennines, they reported a floating sensation that resulted from glimpsing mountain peaks passing by the windows of the Lunar Module (LM). The descent was a complete success, and the LM set down near the planned site! Although, the astronauts were a little surprised to land with one foot-pad in a small crater, placing the vehicle on a slant.

Falcon lander on a tilt
Falcon lander tilting toward the Apennine Mountains; AS15-86-11600 [NASA/Apollo Lunar Surface Journal].

Three EVAs (or traverses) were planned for Apollo 15 using the LRV, two of which allowed sampling part of the Apennine Mountain Range to the south and southeast and required long (multi-kilometer) traverses. Stay tuned for more about the Apollo 15 exploration of the Hadley-Apennine region later this week! Astronauts Scott and Irwin were accomplished field geologists; listen as Commander Scott recently reflected on his Apollo 15 experience, including the importance of field-geology training.

Explore the full NAC oblique below by panning and zooming. The tiny arrow marks the location of the LM.


Related Posts:

Hadley-Apennine: the Apollo 15 Landing Site

Retracing the Steps of Apollo 15: Constellation Region of Interest

The Mighty Apennine Mountain Range

LROC’s First Look at the Apollo Landing Sites

The Apollo 15 Lunar Laser Ranging Retroreflector - A Fundamental Point on the Moon!

Layers near Apollo 15 Landing Site

LROC Explores Apollo 15 (YouTube Video)

Hadley Rille and the Mountains of the Moon

Follow the Tracks

Published by J. Stopar on 18 June 2014