Fond mem­o­ries of a trail­blazer

Mercury (Hobart) - - NEWSFRONT - MARTIN GE­ORGE Space

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).

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