Lost Planetary Spacecraft

Introduction

Perhaps the most intriguing, but at the same time rarest objects for a satellite photographer, are spacecraft intended for interplanetary missions. In relation to this website, not meant are very long range images of probes on interplanetary trajectories that are captured as star-like objects in front of starfields. Meant are (high resolution) telescopic images of planetary probes that were stuck in Earth orbit. In spaceflight history there were several spacecraft that not left the vicinity of Earth on the way to their original destination somewhere in the solar system. Mostly were launch failures involved in which spacecraft did reach their parking orbits around the Earth but due to engine failures didn't make it out of these orbits. Chances to photograph a planetary probe are very rare but not impossible.

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Cosmos-482E - intended Venera , Photographed in Earth Orbit


Images show possibly Descent Capsule


Around 2010, I was looking for interesting objects to photograph. I observed satellites passing over the location and recorded their time and trajectory data across the sky. I noted one particular interesting object with a high angular velocity. After searching in CalSky, it turned out to be the object Cosmos 482, a failed planetary probe that made part out of the Venera family: In total 16 spacecraft that were launched by the Russians between 1961 and 1983 with destination the planet Venus. Venera spacecraft were launched in pairs with some 4 days space between them. Venera 8 lifted up on March 27, 1972 at 04:15:01 UTC while Cosmos 482 was launched on March 31, 1972 at 04:02:00 UTC. The spacecraft launched on a Molniya-M launch vehicle (with Block-NVL upper stage) from the Tyuratam Missile and Space Complex (TTMTR). The Cosmos 482 spacecraft used the 3,6 meter high bus type 3MV that was composed of an orbital compartment (core with solar panels), planetary compartment (lander) and engine unit.

Cosmos 482 looked similar to Venera 8 and was intended to become Venera 9 but it never made it out of its parking orbit around the Earth. A similar failure occured 2 years earlier with the sistercraft of Venera 7, which became Cosmos 359. Just like Cosmos 482, this spacecraft remained in an elliptical Earth orbit but Cosmos 359 decayed after more then a year. A part of Cosmos 482 is still remaining in Earth orbit for more then 45 years now.

Engine Failure

What exactly happened to Cosmos 482? Different sources mention a too short engine firing for the Block L stage burn needed to send the spacecraft on its way to Venus. Sources mention a burn of just 125 seconds instead of the required 243 seconds. As a result, the payload got stuck in an elliptical orbit around the Earth of (initially) 205 by 9.805 kilometers with 52 degrees inclination. Different sources report that after the failure, several objects were found in Earth orbit of which some already reentered within 48 hours. A story of mysterious 'space balls' found in Ashburton, New Zealand is linked to decayed Cosmos 482 pieces. The balls - titanium spheres - were found just a few days after the launch of this intended Venera probe. After research, it turned out that the found objects were spherical gas tanks and that they indeed belong to Cosmos 482 or its rocket stage. The suspicion is that at the moment of the Trans-venus injection, an explosion of the escape stage had taken place.

  Venera 8 pre-launch images. Cosmos 482 looked similar. Photo right: Venera 8 after deployment of the Antenna. There is only a small element of the spacecraft left in Earth orbit

                                   

Object E

After the launch, five pieces of Cosmos 482 were found in Earth orbit, the spacecraft Cosmos 482 itself (1972-023A), the Molniya rocket 3rd stage or SL-6 Blok I (1972-023B)
the SL-6 PLATFORM (1972-023C), the Molniya rocket 4th stage or SL-6 Blok-NVL (1972-023D), and a debris item (1972-023E). Harvard-Smithsonian Center for Astrophysics astronomer Jonathan McDowell comments on object C cataloged as PLATFORM: 'When the Soviets first started using the parking orbit technique in 1961, the US thought this object, the BOZ, was an orbiting platform from which the 4th stage was 'launched' - I guess it's not totally wrong to look at it that way'.

The
pieces B and C already reentered on respectively April 1 and April 2, 1972, shortly after launch. Fragment D (with RCS of 8,75) would have been the Block-NVL upper stage and reentered on February 20, 1983. Object A, which is believed to be the original Cosmos 482 (Venera) spacecraft bus, was in an original orbit of 205 x 9800 kilometers and decayed already on May 5, 1981. According to Russianspaceweb, the debris cataloged as object E separated from Cosmos 482 (object A) late June 1972 and thus objects A and E had a similar initial elliptical orbit.

The debris item E is still in orbit and this is the object that I photographed in recent years with the telescope. This object is currently in an orbit of 203 x 2406 kilometers (the orbit lowered with 7394 kilometers since 1972) and would have - according to available data - a radar cross section (RCS) of only 0,72 square meters. The big difference in RCS compared to the in 1981 decayed piece - which would have been 12,6 square meters - suggest that the already decayed item was the actual spacecraft bus and that Cosmos 482E (object E), the only remaining item from the launch, is only a smaller element of the spacecraft, according to experts the descent craft (the lander). Also the full-illumination brightness at perigee of -0,1 mag for the decayed piece compared to 2,3 mag for the remaining piece, strengthen these suspicions. There are also visual observation reports from the 1970's that confirm that Cosmos 482A (object A) was a bright object in the night sky.

                                                               Animation of raw frames of Cosmos-482 piece E captured June 26, 2014 with a 10 inch telescope


My own telescopic recordings of the remained piece E suggest an elongated shape. The elliptical orbit of Cosmos 482, with a lowest point of just 203 kilometers above the surface of the Earth, makes this object an interesting target for high resolution imaging during a perigee pass. After having observed Cosmos 482 several times visually, I managed to obtain first telescopic images in August 2011 and better observations in june 2014.
                  
                                                              
 
2014 Imaging Sessions of Cosmos 482

Cosmos-482 Piece E (Presumingly Descent Capsule)

In june 2014, I succeeded in capturing images of Cosmos 482 during 2 reasonably steady nights, on june 25 and june 26. Meanwhile I switched to a higher quality monochromatic camera. The best images of those sessions show a compact tiny disc, a shape that would indeed correspond to a small descent module as the lander of a Venera is. Though, interestingly, both imaging sessions tend to show also other elements, especially a more or less elongated part that seems connected to the compact object. The processings below are reprocessings of the original imaging data done in the years 2019 and 2021. The material compares averaged data of both sessions and some selected single frames of the June 26 imaging session (best seeing and most favorable pass) of Cosmos-482 object E. It is just hypothetical, but it could be a possibility that the (undeployed) parachute came out of the capsule and that this is what we see as the elongated fainter element that seems attached to the brighter compact object (presumingly the capsule).


Observations of piece E, the only remaining part of Cosmos-482 during favorable passes in 2014. The images on top show averaged data (frame stacks) of June 25 (left) and June 26 (right). Both images show a compact object with a fainter elongated part. The lower images are frames from the June 26 imaging session were seeing and pass were optimal

                                                                              Credits: TASS


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Mars / Marsmoon Probe Phobos-Grunt 

Stuck in Earth Orbit - Color Images


At the end of 2011, there was a unique opportunity to capture images of another planetary probe that was stuck in Earth orbit. Phobos-Grunt was a Russian spacecraft launched on November 9, 2011 local time with the planet Mars and its moon Phobos as a destination. The mission to Phobos was an intended sample-return mission and there was a Chinese satellite on board - Yinghuo-1 - to orbit Mars. Due to an engine failure, the probe never left its parking orbit around the Earth. It remained for 2 months in an orbit of 207 x 342 kilometers, altitudes lower then the International Space Station.

On November 29, 2011, I first had a chance to observe the stranded Mars probe in the second day of the visible observing window over the Netherlands. A previous  attempt, a day earlier failed due to bright twilight and no visual orientation. Since I track objects manually with the telescope, I need to be able to track the object visually. On the second day of the observing window, Phobos-Grunt was passing close to Altair, the  brightest star in the constellation Aquila. After a couple of clear sunny days, the edge of a front was approaching very fast from the West. I was afraid it would cover the sky just a few minutes before the greatly awaited pass of the probe. But it didn’t. Phobos-Grunt roared across the sky as bright as a star. It had an obvious reddish color visible in the tracking scope, or at least that was my impression in the few seconds of the pass, while I was concentrated at aligning the crosshairs of my viewfinder with  an object passing by with an angular velocity of 1.68 degrees per second. The probe passed by from West-Southwest, moving into Eastern direction with a 56 degrees elevation.

Locating the Spacecraft

To locate the spacecraft in what was still a considerably bright sky with the sun at -6 degrees elevation, I used a technique which recently enabled me to obtain images of the fallen satellite ROSAT, during a favorable pass in its last days before reentry. For ROSAT, the situation presented a comparable difficulty: bright twilight. The technique consists in picking up an object while it passes in front of a bright star. This time the ‘helper’ was Altair. Many frames show a striking yellow color of the main body, which probably caused the impression of a the reddish color that was obvious visually.

                                                 
Mars spacecraft Phobos-Grunt from an approach-angle, photographed in color on November 29, 2011           
             Phobos-Grunt, 2 Weeks before Reentry

Another opportunity to capture Phobos-Grunt was almost exactly one month later on December 28, 2011.
The spacecraft was going to make its last high pass over the Netherlands, and luckily enough, a clear sky was predicted, so I decided to stay up almost all night to be sure to not miss it and -in that case- to setup the equipment for high resolution imaging. I was curious about how its appearance would have be, given several reports of brightness variations, flashes, and flares over the last month. But the spacecraft showed up surpringly stable, or at least that was my impression during the few seconds of this fast pass 82 degrees high through the North, flying from West-Northwest into Eastern direction. Phobos-Grunt reentered the Earth atmosphere 2 months after launch, on January 15, 2012 over the Pacific Ocean, west of Chile.

                                            
                                 Phobos Grunt captured on December 28, 2011. Note the striking golden-yellow color of the foil in contrast to the color of the solar panels