Another Notable 2017 Space Anniversary:
I
n this account of the rather incredible (in the true sense of
the word) achievements of Cassini and Huygens in September this
year it would be remiss of us NOT
to mark an even more incredible
anniversary also occuring this year
– that of the launch of the first manmade Earth satellite, Sputnik 1, by
the Soviet Union on October 4, 1957.
Arguably the only comparison
between Sputnik and Cassini is that
they were both launched into space!
Where (huge) Cassini has been responsible for virtually continuous
transmission of data and pictures
since its launch, the tiny Sputnik (a
585mm, 85kg sphere) was capable of
“only” transmitting a series of beeps
as it orbited the Earth.
Thousands of amateur radio operators listened out for the faint signals from Sputnik on 20.005MHz
(close to the 21MHz amateur band
and well within the capabilities of
most amateur equipment using that
22 Silicon Chip
band) and 40.002MHz (a VHF signal
requiring more specialised receiving
equipment).
What those thrilling at the sound of
those 0.3s pulses didn’t know was that
they were also listening to the first data
from space: Sputnik’s radio signals
from its one watt, 3.5kg transmitter
were encoded with (quite elementary!)
telemetry data, not only initially telling
controllers of the satellite’s successful deployment but during the flight,
information on the electron density
of the ionosphere along with satellite
temperature and pressure.
After several unsuccessful test firings of R-7 launch vehicles, Sputnik
was carried aloft on an 8K71PS rocket
(itself a modified R-7) from Site No.1
at the 5th Tyuratam proving ground in
Kazakh SSR (now known as the Baikonur Cosmodrome), at 19:28:34 UTC.
The control system of the Sputnik
rocket had an intended orbit of 223
by 1,450km, with an orbital period of
101.5 minutes; the actual orbit turned
out to be 223 x 950km with an orbit
every 96.2 minutes.
There are several reasons for this
difference – remember that even with
the brightest minds in the Soviet Union working on the project, much of
the work was theoretical, unproven
technology.
Not all to plan!
Even the launch didn’t go exactly
to plan: a booster failed to reach full
power at lift-off, causing the rocket to
tilt over at 2° just six seconds after liftoff. The booster reached full power just
one second before the launch would
have been automatically terminated.
This would have caused the spacecraft
to crash close to the launch pad.
Then 16 seconds into the flight, a
fuel regulator in the booster also failed,
resulting in excessive fuel consumption and 4% higher than expected engine thrust.
This resulted in termination of the
thrust one second early – hence the
siliconchip.com.au
60 Years since Sputnik
different orbit than expected. However, at 19.9 seconds after engine cutoff, the second stage separated and the
radio transmitter was automatically
activated, indicating a successful deployment.
Engineers listened to the “beepbeep-beep” for two minutes, until the
craft disappeared below the horizon.
They waited some 90 minutes until
Sputnik was once again in “view” and
confirmed radio reception, before calling Soviet premier Nikita Khrushchev.
TASS, the Soviet news agency, then
announced to the world the successful
launch and deployment.
Strangely enough (considering the
times) it took some time for the Soviets to start making any real propaganda mileage out of Sputnik. But in the
USA, the launch was met with some
fear and trepidation with the realisation that they had, at least then, lost
the lead in the “space race”.
Three week life
Sputnik had a design battery life of
just 14 days – it continued to trans-
mit for three weeks until its battery
finally gave out. But the craft itself
continued to orbit the Earth (where
it could often be seen, depending
on its height) for another three
months, until it re-entered the
Earth’s atmosphere and burned
up on January 4, 1958, having
completed 1,440 orbits.
How many Sputniks?
While there was only one Sputnik
to claim the title of “the first”, there
were at least three (and possibly more)
duplicates built. One of these, a complete system, is in the “Energia” corporate museum just outside Moscow,
where it is viewable by appointment
only.
Another is in the Museum of Flight
in Seattle, Washington – while it has
been authenticated (and even shows
some signs of wear) it doesn’t have
any internal components. And there
are said to be at least two other duplicates in private collections.
There are dozens of “replica” Sputniks in various museums and collec-
tions around the world – one even in
Australia at Sydney’s Powerhouse
Museum.
And there were three studentbuilt one-third scale Sputniks deployed from the Mir space station
between 1997 and 1999 (the first
launched to mark the fortieth anniversary of the original Sputnik).
Yet another “went down with the
ship” when Mir burned up on its
controlled re-entry on March 23,
2001.
SC
Image Credit: http://unusualsuspex.deviantart.com/art/Sputnik-1-Tech-Readout-new-470662574
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