Richard Lawrence - The Mammoth Book of Space Exploration and Disaster

A lot of people say can you see anything else in the daytime on the Moon – can you see stars? The answer to that is yes – if you shield your face and eyes from all the reflected light around you can see stars in the daytime on the Moon – not as brightly as at night of course.

Lindsay:

A visit to the North Massif during the third geological excursion during day three and a visit to the Sculptured Hills and the Van Serg Grater brought to an end the last journey on the surface of the Moon in the twentieth century. By this time both Cernan and Schmitt were weary, aching, and rubbed raw trying to follow all the planned instructions and changes relayed up from the geological experts gathered at Mission Control in Houston.

Houston called to the moonwalkers, “Okay, you guys, say farewell to the Moon.”

Cernan replied, “Bob, this is Gene. I’m on the surface… as we leave the Moon at Taurus-Littrow, we leave as we came, and, God willing, we shall return, with peace and hope for all mankind.

Gene Cernan turned to climb the ladder and spotted a plaque mounted there by a Grumman factory worker and repeated the inscription aloud, “Godspeed the crew of Apollo 17.” He then climbed up the nine steps of the Lunar Module’s ladder to become the last person in the Apollo Program to leave the lunar surface. At the top he paused and looked around.

“I felt excited that we had been there, but disappointed that we had to leave. Jack Schmitt and I described that valley that we landed in as our own private little Camelot. We knew once we left we would never come back. It was our home – it was a uniquely historical place no man had ever been before in the history of life on this planet of ours. You were there – you made your imprint. You would think that would be enough, but there was so much to do. Then you do leave and you remember all the things you wished you would have done – little things or big things or whatever. It was hard to leave but it was time to leave. I always thought that if I knew things were going to go so well I wish I could have stayed another week or two. But you do know the longer you stay the more vulnerable you might become to problems that might come to keep you from getting home.”

On Earth Mission Control read a statement from President Nixon:

“As Challenger leaves the surface of the Moon we are conscious not of what we leave behind, but of what lies before us.” So, as the last words exchanged between the Moon and Earth echoed around the world, what were the people of Planet Earth who were listening thinking?

It seems everybody remembers the first step on the Moon, and of course that is what the people on Earth commemorate, but few can remember the last person to pull his boot off the surface of the Moon in the twentieth century.

At 4:54 pm on 14 December the last unofficial words spoken on the Moon’s surface were heard: “Okay, Jack, let’s get this muther outta here,” as Cernan flicked the yellow ignition switch and red flames ripped into the lunar surface. Shredded gold foil from the descent stage glinted in the boiling cloud of gray dust shooting out from under the engine bell housing. The Stars and Stripes whipped madly in the rocket’s exhaust, then relapsed into a permanent stillness as the rocket’s red glare dwindled into the distance above, and winked out. The dust drifted down to settle over the discarded twentieth century artefacts. The last of the aliens had gone.

Apollo 17 returned to Earth to splash down in the Pacific at 1:24 pm spacecraft time on 19 December. The crew of Apollo 17 were welcomed back with a big party on the carrier USS Ticonderoga , and entered the record books with the longest manned flight to the Moon, the heaviest swag of lunar samples, the longest activity time on the lunar surface with the greatest distance travelled, the longest time in lunar orbit, the greatest distance travelled and the only Saturn V night launch.

The Skylab project grew out of a number of proposals dating back to the idea of an orbiting solar observatory which had been suggested in 1962, and von Braun’s ideas of the 1940s. George Mueller suggested the concept of using the casing of one of the lower stages as a space lab. Such a project would extend the life of the manned space flight network.

Skylab was made up of the Saturn Workshop (SWS), 15 metres long with a diameter of 6.7 metres. The SWS connected with an Airlock Module (AM) connected, in turn, to a Multiple Docking Adapter (MDA), 5.2 metres long by 3.2 metres in diameter. The MDA had two ports: one to to dock the visiting command module and one for rescue. The docking port allowed the astronauts access and also contained the control and display panels for the Apollo Telescope Mount (ATM). The four diagonal solar wings provided the power for the telescope and part of the power for the SWS, most of which would come from the solar panels mounted on beams which would extend at 90° from the SWS itself.

The Skylab 1 mission was launched on 14 May 1973. Lindsay:

Skylab 1 was the last Saturn V launched in the twentieth century. With the regular stunning successes of the Apollo launches, it was expected to be another copybook mission. It was – until just after launch. On a nice warm spring day, right on time, the SIC first stage thundered into life on Pad 39A at the Kennedy Space Center and lifted smoothly into the air. It looked another perfect launch, then 63 seconds later the flight engineers were startled to see their telemetry giving strange indications from the micrometeoroid shield and part of the solar array – it looked as though they had initiated deployment early. Atmospheric drag had torn the shield loose and a portion had jammed one of the workshop solar wings, and severely damaged the other solar wing. The staging rocket’s blast then tore the wing from its hinges and flung it into space to be lost.

Just over ten minutes after launch Skylab entered a nearly circular orbit above the Earth, and manoeuvred around until its centreline pointed to the centre of the Earth. Unlike Apollo, which rolled around on its way to the Moon to keep the temperatures evenly spread around, Skylab remained in one attitude throughout the orbit, the heat and cold being controlled by a micrometeorid shield using black, white and aluminium paints painted in a carefully tailored pattern to control heat losses and gains. This shield was lost, so the surface of the workshop was left exposed to the Sun, and the temperatures rose 93°C above the designed limits.

It is interesting that Skylab became overheated out in space – because Apollo 13 became unbearably cold when in trouble. Why the difference? First it should be understood that a passive body in space absorbs and radiates heat. If these are not equal the body will heat up or cool down to a stable temperature where the heat being received equals the heat loss, providing the conditions remain constant. Although there are other factors, the simplistic explanation is Skylab lost its temperature controlling thermal heat shield which was carefully designed to balance the heat absorption and losses in its planned environment. The Laboratory was also orbiting very close to Earth. As the Earth radiates roughly the same amount of heat it receives, particularly in the infrared band, Skylab was receiving heat energy from both the Sun and Earth while in daylight, so its temperature went up.

Apart from being away out in space beyond the Earth’s reflected heating influence, Apollo 13’s electrical equipment was shut down to an absolute bare minimum, so again the carefully planned temperature control for its environment was out of balance. With the lack of internal heat being generated by the spacecraft’s electronics, Apollo 13’s temperature went down.