A Venus probe stumbles - and I happen to listen in!

Expecting a companion to Venus 7

Venera 7 (left) was launched from Baikonur on August 17, 1970 at 0538 UT. The previous set of Venus probes from the Soviet Union, Venus 5 and 6 had been launched 5 days minus 36 minutes apart. If a companion spacecraft was planned for Venus 7 it should have been launched from Baikonur at 0502 UT on August 22, 1970. Indeed, something was launched at 0505 UT that day and announced by Moscow at midday as Kosmos 359 in a 210-920 km orbit at a 51 degree inclination.

My radio tracking station in the countryside

That morning I was at my parents summer house about 150 km north of Stockholm. I had set up a modest listening post there concentyrartiong on the range of frequencies which were under strong interference in Stockholm. This included the 61-76 MHz band of Soviet VHF telemetry which was effectively masked by TV tranmissions in Stockholm. Earlier during the summer of 1970 I had succeeded in locating strong telemetry transmissions from recoverable reconnaisance satellites in the Kosmos series at 66.0-66.5 MHz.

This particular morning, a Saturday, I was on weekend leave from the Army, where I was serving my term as a conscripted soldier. I had left the base in the nearby city of Uppsala and was twidlling my radios. I had a two-elent Yagi for TV channel 4 and a frequency converter that brought the 66 MHz band into the tuning range of my old Lafayette HE-30 shortwave receiver. I also had an Eddystone EC-10 receiver humming away, tuned to the Soviet space frequency band just below 20 MHz. (By the way, the EC-10 had OC71 and OC171 transistors - germanium transistors!!!!)

At 0706 UT I had picked up signals on 19.995 MHz typical of those coming from the recovery capsule of Soviet reconnaisance satellites. I phoned Geoff Perry and 0800 to find out that these had been heard for several days and were probably from recovery team practice. After hanging up I started the VHF rig and just aimlessly tuned around. It was fun hearing VHF/FM broadcast stations in the Baltic states suddenly appearing for a second or so being bounced across the Baltic by meteor trails.

A buzz from orbit

All of a sudden, at 0816 UT I heard a rapidly fading buzz on 66.2 MHz, very similar to the signals from the recon satellites. The fade rade was 1.3 fades per second. It disappeared at 0819 UT. There were no more signals that day. Was this the Venus probe? Well, during the following week, I received orbital information about Kosmos 359 from Geoff Perry and the table below shows that the satellite wss indeed above my horizon precisely when I heard the buzz on 66.2 MHz.

SATELLITE: Kosmos 359
SITE: Skutskar Lat: 60.39 Long: 17.25
 
Date Time UT Latitude, N Longitude, E Altitude
(km)		 Range
(km)		 Azim Elev
1970 Aug 21 08:16:00 46.22 18.19 221 1617 177.3 0.7
1970 Aug 21 08:17:00 47.85 23.52 224 1492  161.0 2.1
1970 Aug 21 08:18:00 49.20 29.18 230 1498 143.3 2.2
1970 Aug 21 08:19:00 50.23 35.11  236 1634 127.3 1.1

What did I hear and what happened?

Kosmos 359, a failed Venus probe, probably separated from the fourth stage of the booster. This last stage, with the Venus probe still attached, was what was called Sputnik 7 by Soviet authorities back in early February 1961.

In a book by Alfred J. Zaehringer, "Soviet Space Technology", published in 1961, Sputnik 7 was said to have had a transmitter on 66.2 MHz. So, what I probably heard was the escape stage that had not finished its burn. When you look at the map of the ground track and the radio horizon from my location (left) you realize that a stroke of sheer luck made me hear the signals. Maximum elevation 2.2 degrees!

The flight profile of Venus 7 reveals what was planned for the Venus probe (V-70 no. 631) that became Kosmos 359. The fourth stage of the Molniya booster ignited 81 minutes after launch from Baikonur and fired for 244 seconds. The map below shows where this woul have taken place in the case of Kosmos 359. If a ship was placed in the Gulf of Guinea it could have caught the start fo the burn and when Yevpatoria acquired the craft the burn would have been completed, unless a ship was stationed in the Mediterranean! Well, the burn was not completed and the batteries in the fourth stage lasted until the next pass over Europe when attitude control had been lost and the craft was tumbling wildly.


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