Phobos over Mars
Phobos 2 was launched on July 12, 1988 on its way to orbit
Along with its sister craft,
Phobos 1, it was part of the first mission in what was to be a new wave of Soviet Mars exploration.
This new wave was not to be. Phobos 1 failed on its way to Mars due to a ground controller error.
By the time Phobos 2 reached Mars, its main antenna had failed, forcing it to trickle back data at a
small fraction of the intended data rate. And its computers were near failing. The Phobos probes
had three identical computers which controlled them. For every operation, the craft would do what
at least two of the three computers would tell it to do. Not long into the mission, the first computer
failed. As Phobos 2 approached Mars, a second computer began to falter. Three months after
arrival,it failed as well. The one remaining computer could not beat the two votes of the failed
computers, and thus could not control the spacecraft, which lost contact with earth on March 27,
1989. In 1991 the Soviet Union itself collapsed. Along with it, the funding for planetary exploration
disappeared. Onemore spacecraft from the new series, known as Mars '96 was launched, but its
upper stage failed sending it plunging back to earth. This marked the end of Soviet Planetary
exploration. Before Phobos 2 failed, it did manage to send some images and other data back from
Mars. This page contains some of the images it sent back. The above image is a rather dramatic image
of Phobos hanging over the limb of Mars. It was taken by the Videospectrometric System (VSK), the
CCD imager on Phobos 2. Like the other images in this page, it was created from red and blue images
with an artificial green image to produce color. It also had a monochrome high resolution channel which
could be overlaid with color data from the wide angle imagery. The first image below is a visible light
image from Thermoscan, which scanned Mars in infrared and visible light. The color data is from VSK
images. The rest of the images are all fromthe VSK. I hope to eventually construct a page with more
of the Thermoscan images. The VSK series begins with an image of Mars alone. This is followed by an
image of Phobos over Mars. The next few images show Phobos and Mars in the same frame. The last
images show Phobos by itself. The Phobos 2 CCD chip brightness built up so that if the image was fairly
full the side of the image that read out last was often nearly or completely washed out. I seriously question
whether or not Phobos 2 could have ever sent back the spectacular high resolution images it was
supposed to. Most of the images that had completely filled frames at least partially washed out, so
coverage would likely have been spotty.
Despite the limitations of the VSK, it returned some dramatic shots of Mars and Phobos. I have
worked to clean them up to give the best idea possible of what the view might have been like from the
spacecraft. A lot of work has gone into this page so please refrain from using these images without
contacting me first as they are copyrighted. Also, they are highly compressed for faster download.
If you need the original .tiff files, I can send them to you.
The end of the Valles Marineres System and the chaotic terrain to th east of it.
Mars without Phobos from the VSK.
Phobos over Tharsis
This image of Phobos over Mars is arguably the
beautiful dramatic view Phobos 2 ever returned.
Phobos over the limb of Mars.
A more distant view.
Mars in the above frame is largely washed out by the signal buildup.
with Mars in the upper left corner.
This view was the last wide angle view taken by Phobos 2 before it failed.
Phobos from a distance
The large crater Stickney can be seen at the top.
This image shows a half-sunlit Phobos, with the dark site faintly glowing by Marsshine.
Moving in close to Phobos, with Stickney in the shadows on the right.
Closing in on
This is the
image of the Phobos 2
mission (~40 meters/pixel). The famous grooves from
the Stickney image can be seen at the left. This was the
last image from Phobos 2, and thus the last image from
the Soviet planetary program
Looking on to Jupiter. During the time shortly after Phobos 2
several test images were taken. This is one of them. It shows a distant, gibbous
Jupiter from Mars orbit.
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© Copyright 2003 Ted Stryk
Use of these images requires permission of the author. email@example.com