Back in space

An hour after the telecast, Duke asked the crew to participate in an experiment using a laser. ‘‘If you have got Earth through any of your windows, or in the telescope, would you so advise?’’

‘‘I’ve got you in the telescope,’’ Collins replied.

‘‘We have a blue-green laser that is to flash at a frequency of on-for-a-second, off – for-a-second. It’s from the McDonald Observatory near El Paso, Texas, which should be just on the dark side of the terminator. Would you take a look and see if

you can see it.” Collins agreed. “McDonald reports there is a break in the clouds,” Duke announced a few minutes later, “and they’re beaming it through.” Observing nothing through the telescope, Collins switched to the magnifying sextant, with no better result. Armstrong joined him. Aldrin reported, “Neither Neil nor Mike can see it. We did identify the El Paso area, and there did appear to us to be a break in the clouds there.’’ However, at their distance from Earth, the beam would be just a few thousand feet across, and was very likely not illuminating the vehicle.

Half an hour later Duke signed off, “The White Team bids you good night.’’

“You earned your pay today, Charlie,’’ Aldrin said.

As the Black Team began the ‘graveyard’ shift, with Gerry Griffin standing in for Glynn Lunney as flight director, the astronauts finished miscellaneous chores, had supper, and settled down for their second sleep period, this time with Aldrin as the watch-keeper. By this time, Apollo 11 was 137,219 nautical miles from Earth, and travelling at 4,132 feet per second.