Apollo 15 Mission Provided Lessons for Future Exploration
During the summer of 1971, Apollo 15 took America's lunar landing program to the next level. With more science and the addition of the Lunar Roving Vehicle, or LRV, it was the most complex mission to date. The flight would also help pave the way for exploration years into the future.
The two previous lunar missions included a pair of moonwalks by the astronauts. Apollo 15 Commander David Scott and Lunar Module, or LM, Pilot James Irwin would have three, each utilizing the electric-powered, four-wheel-drive Lunar Rover to travel 17 miles around the landing site.
Command Module Pilot Alfred Worden remained in lunar orbit, operating orbital sensors in a Scientific Instrument Module mounted in the spacecraft's service module while circling the moon for 74 orbits over 145 hours. Worden also deployed a small sub-satellite which was left in lunar orbit.
With months of preparation and training complete, Apollo 15's Saturn V rocket thundered off Kennedy Space Center's Launch Pad 39A on July 26, 1971.
"I'll never forget that morning and the power of the rocket that you assembled for us," Irwin said addressing Kennedy employees during a visit in March of 1987. "It was an exciting mission to explore the mountains of the moon."
Apollo 15 was headed for a landing site surrounded by the Hadley-Apennine Mountains to the south and east and the deep, canyon-like Hadley Rille to the west. Lunar geology training was stepped up in hopes that Scott and Irwin might find rocks and soil samples that could unlock secrets of the origins of the moon.
While the geology training took place in exotic places such as the California desert and Hawaii, many of the simulations for the moon walks occurred in a field near what is now Kennedy's Operations and Checkout Building. The site would come to be known as the "rock pile."
Tons of volcanic cinders, rocks and boulders were unloaded in the area to make it resemble the lunar surface. The site allowed astronauts preparing for lunar missions to develop procedures and practice using the geology tools. Since Scott and Irwin used the area to practice driving the Lunar Rover, the area was also dubbed the "rover racetrack."
Lessons learned from those early days of developing Kennedy training sites for exploring beyond low Earth orbit are now being applied to possible ventures to Mars or a return to the moon.
When the Apollo lunar modules descended, astronauts could take control to avoid hazards on the surface. But as the experience of two flights shows, additional aids may have helped.
"On two Apollo missions, the LM landed on a ten-degree slope," said NASA Test Director Greg Gaddis. "We believe that if one had landed on a slope greater than 12 degrees, they might not have been able to take off."
As future spacecraft are being designed for destinations beyond Earth, NASA's Project Morpheus, led by the Johnson Space Center, involves developing a prototype lander to demonstrate technologies aiding in hazard avoidance. The Morpheus lander arrived from Johnson to Kennedy on July 27.
"The Autonomous Landing and Hazard Avoidance Technology, or ALHAT, being developed by NASA and tested with Morpheus is designed to detect rocks, slopes and craters whether assisting robotic or human space missions," said Gaddis Kennedy's Morpheus test site manager.
Just north of Kennedy's Shuttle Landing Facility runway, a rock- and crater-filled planetary scape has been built so engineers can test the ALHAT system's ability to provide the required navigation data and test the Morpheus vehicle's ability to negotiate away from risks.
Image above: This panoramic view shows the Project Morpheus prototype lander's simulated planetary landscape on July 13 built for testing the lander's Autonomous Landing and Hazard Avoidance Technology. Image courtesy of Greg Gaddis/NASA
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"We want to see if the new technology can identify hazards and avoid them while landing in a safe area," Gaddis said.
On Apollo 15, Scott and Irwin safely landed between mountain ranges and a rille on July 30. Their ambitious schedule included three moonwalks totaling 10 hours, 36 minutes of setting up experiments, collecting rocks and testing the new lunar rover.
"On the second day, we drove up the side of a mountain about a thousand feet," Irwin said. "We saw a rock sitting on another almost free of dust. It seemed to be saying, ‘I'm here, take me!'"
Upon seeing the rock, Scott knew the geology training had paid off.
"Guess what we just found," he radioed to Mission Control. "I think we found what we came for."
It was a white anorthosite rock weighing about half a pound. Geologists dubbed it the "Genesis rock" as it turned out to be more than four billion years old.
"It would help scientists understand the early history of the moon and maybe the early history of Earth," Irwin said.
During the return flight back to Earth, Worden became the first to perform a spacewalk outside of Earth orbit. With Irwin assisting in the command module hatch, Worden retrieved film canisters from the Scientific Instrument Module.
After splashdown in the North Pacific Ocean on Aug. 7, 1971, the crew was recovered and taken aboard the recovery ship, the USS Okinawa, after a mission lasting 12 days, seven hours.
Apollo 16 and 17 would fly similar missions in 1972 with three moon walks, use of the lunar rover and a spacewalk during the return trips. The lessons learned preparing for these missions will continue to prove valuable as NASA plans for future flights beyond Earth.
NASA's John F. Kennedy Space Center