Fond memories of a trailblazer

TIME marches on. This coming week, we will celebrate the 60th anniversary of the launch of the very first artificial satellite of the Earth.

It was called Sputnik 1, and it was launched by the Soviet Union from Kazakhstan.

Being the very first, it is unique in a list of space achievements, because one cannot really compare it with anything else.

Sputnik changed the world in a way not even achieved, in my opinion, by the landing of Neil Armstrong and Edwin Aldrin on the moon in 1969.

It was Sputnik that started it all, beginning what many call the “space age’’, and it gave the US a shock.

The Soviets had achieved something that the US had not, even promoting it as evidence that their political system was superior.

The events of the next dozen years made it a very exciting period as the two superpowers were involved in a race to get people to the moon, even though the reality of the race was not apparent for many years afterwards.

This week’s thoughts, though, will certainly concentrate on Sputnik itself.

Sputnik was a very simple satellite, a sphere only 58 centimetres in diameter but with a mass of 84 kilograms, quite heavy for its size.

Its elliptical orbit around the Earth took 96.2 minutes, varying in height above the Earth’s surface between 215km and 939km.

It was not quite the same as the expected orbit, calculated in advance by Soviet cosmonaut-to-be Georgi Grechko, but it mattered little: an object was now in orbit, and that was that.

Sputnik helped our understanding of the Earth’s atmosphere and the layer of charged particles called the ionosphere.

However, it is remembered far more for the fact that it was simply there, in space, orbiting the Earth.

To make sure of things, the Soviets designed Sputnik so that it would transmit a signal every six-tenths of a second. Nobody could deny the Soviets their claim to be the first nation to place an object into Earth orbit.

There are, of course, many people alive today who remember the famous 1957 event, and I am sure that during the next week there will be friends who exchange stories about what they saw in the sky.

Not only did Sputnik transmit a radio signal to prove its existence, but the launch also resulted in the visibility to the unaided eye of an orbiting object.

Many people saw a point of light moving across the sky, and were fascinated to “know’’ that they had seen Sputnik.

However, Sputnik itself was at best barely visible to the unaided eye. Although it was quite reflective, its diameter of only just over half a metre did not allow it to reflect enough sunlight to be easily seen.

Very much brighter than Sputnik itself was the last stage of its rocket, which was also in Earth orbit, and which was what most people actually saw.

In Tasmania, there was a lot of interest in the world’s first artificial satellite.

Dr Bruce Scott, senior lecturer in physics at the University of Tasmania, popularised the event by delivering many lectures on the subject across the state.

Of particular note are photographs taken by University of Tasmania photographer Tom McMahon.

Time exposures of the night sky today regularly show the trails of light of orbiting objects, but in 1957 it was especially exciting that McMahon had captured the trail of Sputnik — or, at least, part of its rocket.

On the nights of October 7 and 10, McMahon, in Hobart, aimed his camera towards a carefully planned direction in the sky and exposed his photographs, which showed the hoped-for trails of light. Some of the stars in the pictures, which appear as short trails due to the Earth’s rotation, were labelled.

The October 7 image, which appeared in an article in the scientific journal Nature on October 26, is probably the earliest photograph of an artificial object in orbit. It was, at the time, assumed to be the rocket, but the faintness of the trail indicates that it may have been Sputnik itself.

The October 10 image was certainly of the rocket, because it was much brighter and showed a trail of varying brightness as it tumbled.

Sputnik orbited for three months, burning up in the atmosphere in early January 1958.

It didn’t last long, but its impact on the world was enormous. Martin George is manager of the Launceston Planetarium (QVMAG).