March 1980:Cosmos 146 and 154

The flights of the two Soviet spacecraft Cosmos 146 and 154 in March and April 1967 have always been obscure with respect to both purpose and mission profile. Several authors have speculated about the purpose of these missions. The two main theories are:

Both flights were near lunar velocity Earth-orbit re-entry tests of an unmanned prototype of the Zond manned circumlunar spacecraft. As support for this hypothesis the fact that some of the objects resulting from these launches disappeared from orbit within one and two days respectively is often cited.

Both flights were unsuccessful circumlunar tests of the Zond spacecraft. According to this theory the Earth-orbit escape manoeuvre failed.

The following account analyses the flights of these satellites using available orbital data and amateur radio observations made in Europe at the time. An attempt is made to clarify the obscure mission profiles of these spacecraft and various new hypotheses of the nature of these flights are discussed. These partly contradict the aforementioned speculative classifications.

Cosmos 146

Three or possibly four objects were associated with the launching of Cosmos 146 as shown below:

Spadats no.

Lifetime

—

1 day?

2815

1 day

2705

8.3 days

2709

8.7 days

These lifetimes have been obtained from NORAD decay notes. The two objects decaying within one day have earlier been considered the main objects, but a close look at the orbital history and radio tracking data made available recently shows that one of the longer-lived objects, probably 2705, was the main object.

Figures used by Grahn show the orbital period and heights for object 2705 which seems to have manoeuvred extensively during the first 2.5 days of the mission. A smaller disturbance in the natural decay pattern,possibly indicating a manoeuvre, is seen 4.5 days after launch. Bulletin 1 of the object 2709 was issued 2.5 days into the flight which could indicate that the appearance of this object was associated with the termination of manoeuvres at this point.

Signals from one of the objects associated with this launch were reportedly received by two sources, Oslender in Bad Godesberg (Federal Republic of Germany) and the now defunct tracking station of the East German Astronautical Society (DAG, Deutsche Astronautische Gesellschaft), Junge Welt (Young World) in Berlin. Bulletins from Oslender’s tracking log also shows that signals from a possible space object were regularly received on 20.008 MHz ten times during the period 11-15 March 1967. A comparison between these reception times and the over-the-horizon passages of objects 2705 and 2709 shows fair agreement (of a kind often experienced later during Soyuz flights which also still use this frequency. The long reception times of the signals when the spacecraft reaches Europe resembles the procedure used for the shortwave transmitters on early Soyuz and Soyuz-type unmanned missions. The shortwave transmitter is mainly used to obtain housekeeping telemetry during periods when line-of-sight contact with Soviet tracking stations' is impossible.

Oslender’s and DAG’s reports of signals are completely< independent sources and therefore tend to support each other. Object 2705 or 2709 could be the source of the signals. Before 0000 Z on 13 March it seems that these two objects were joined together during the extensive manoeuvring period of the mission.

In summary the mission of the main Cosmos 146 object can be described by the following table:

Orbit: 185-350 km (max. eccentricity)

Manoeuvres: Yes. for 2.5 days

Lifetime: 8.3 or 8.7 days

Frequency: 20.008 MHz

Cosmos 154

Four objects have been associated with the launching of Cosmos 154. According to NORAD decay notes the following table describes the lifetime of these objects:

Spadats no.

2745

2746

2747

2748

Lifetime

2 days

10.97 days

2.3 days

1 day

The most accurately known decay time is that of object 2746 which is given as 1221 Z±5 minutes on 19 April 1967 at which time the spacecraft was at approximately 50°N,30°W, i.e. over the Atlantic Ocean. Whether or not this represents a natural decay or an intentional ocean recovery is not known.

The radio tracking log of Oslender’s listening post in Bad Godesberg for 10-13, April 1967 shows eight receptions of signals on 19.995 MHz attributable to Cosmos 154. A comparison between the reception times and the periods when object 2746 was above the local horizon in the Bad Godesberg area shows excellent agreement.

No notes as to the signal character are available in Oslender’s log. However, a hitherto unidentified reception of FSK-PDM signals on 19.995 MHz made in Stockholm, Sweden by Grahn early on 12 April 1967 can probably be attributed to object 2746. This strong, almost "line-of-sight-strength”, transmission lasted for about 7.5 minutes and occurred between the signals from the penultimate and recovery revolutions of Cosmos 154, which also transmitted FSK-PDM on 19.995 MHz. The fact that no note as to signal character was made in Oslender’s log also tends to indicate that the signal was of an ordinary and well-known nature and therefore did not need special mentioning.

The Cosmos 154 mission was probably mainly carried out by object 2746, which can be described in the following terms:

Orbit: 185-215 km (max. eccentricity)

Manoeuvres: None

Lifetime: 10-97 days

Frequency: 19.995 MHz (FSK-PDM)

It is tempting to assume that this mission represents in some way an Earth-orbital test flight of the Zond space vehicle. On the other hand the orbit of Cosmos 154 also resembles that of Soyuz 1. Its frequency (19.995 MHz) does not agree with that of Soyuz but with that announced for Cosmos 133, often regarded as the first Soyuz precursor.

Cosmos 146 on the other hand, showed extensive manoeuvreability and used a typical Soyuz frequency. It is therefore not unnatural to consider the possibility that this flight could represent a thorough flight test of the Soyuz propulsion system in preparation for the Soyuz 1 flight five weeks later. However,the notion that Cosmos 146 is a Soyuz precursor contradicts a generally held opinion that Cosmos 146 was a large object launched by a D-vehicle not used for Soyuz-type payloads.

These theories are offered here for what they are, hypothetical speculations. Nevertheless, it seems likely that Cosmos 146 and 154 carried out missions of different nature. Such a conclusion is in contradiction to earlier theories as to the nature of these very obscure but historically important spacecraft.