Russia Downplays Danger as Phobos-Grunt Nears Re-entry

Phobos-Grunt in orbit around the Earth. (Credit: Ralph Vandeberg -- used by permission)

The latest update from Roscosmos on its failed Mars mission’s arrival back at the home office:

“The Earth’s surface can reach the remains of the spacecraft from the heat-resistant materials in the amount of the order of 20-30 pieces and total weight not exceeding 200 kg. The components of the fuel burn of the spacecraft in the dense atmosphere of the Earth at an altitude of approximately 100 kilometers.

“Radioisotope source (cobalt-57), set in one of the scientific instruments, spacecraft – Mossbauer spectrometer has a mass not exceeding 10 micrograms, a small half-life and will not cause dangerous contamination.

“Many years of international statistics shows that when leaving the orbit, spacecraft are almost always completely burned in the dense atmosphere, and their residual fragments, as a rule, do no harm.”

Oh, re-entry is likely to occur between Jan. 10 and 21, probably the 15th give or take a day. And it will come down somewhere between 51.4 degrees south and 51.4 degrees north. I’m not an expert in such things, but that sounds like most anywhere.

I’ve reproduced the full press release below.

ROSCOSMOS PR — Experts at the Space Agency are continuing to monitor the convergence of the orbit of the spacecraft (SC) “Phobos-Grunt”, which was launched into space November 9, 2011, and located at the present time in Earth orbit.

As of January 6, 2012 the spacecraft orbit parameters are:

Maximum height – 229.4 km;
Height minimum – 189.2 km;
Inclination – 51.49 degrees;
Period – 88.43 min.

Dynamics of the deceleration of the spacecraft in Earth’s atmosphere depends on a variety of technical and space factors, including those that can not be controlled by man. Chief among these is the ambiguity of the behavior of the atmosphere, exposed to significant interference from the Sun.

According to available data and preliminary estimates of experts of the Task Force for control of decay of the spacecraft “Phobos-Grunt”, the projected window is determined by the dates of its fall from 10 to 21 January 2012, approximately a central point – 15 January.

Estimated area of ​​impact residues on spacecraft today can only be defined “strip” the Earth’s surface from 51.4 degrees south latitude to 51.4 degrees north latitude. The exact spot, the date and time of their fall is possible to predict, not earlier than one day.

The earth’s surface can reach the remains of the spacecraft from the heat-resistant materials in the amount of the order of 20-30 pieces and total weight not exceeding 200 kg. The components of the fuel burn of the spacecraft in the dense atmosphere of the Earth at an altitude of approximately 100 kilometers.

Radioisotope source (cobalt-57), set in one of the scientific instruments, spacecraft – Mossbauer spectrometer has a mass not exceeding 10 micrograms, a small half-life and will not cause dangerous contamination.

Many years of international statistics shows that when leaving the orbit, spacecraft are almost always completely burned in the dense atmosphere, and their residual fragments, as a rule, do no harm.