[FPSPACE] Russian Segment SM Engine burn soon -- last one went verybad

[James Oberg]

Burn has occurred -- question is, was it a lot smoother
than last time? Recall that neither NASA nor Tsup-M gave
a truthful account of how rough the Jan 2009 burn actually was,
not even in the On-Orbit Status reports, not until video of the
massive internal shaking leaked out many days later. Their 
information release performance was shameful. And as far as I can 
tell, TsUP-M and Roskosmos has NEVER acknowledged ANY
problem with that burn, except to hint yesterday that today's burn
would be performed with improved mathematical models. The issue is --
such powerful rhythmic vibrations can create mechanical fatigue damage in
major structural components -- and may well have reduced overall 
station lifetime significantly. 

Is today's report of burn duration a correction of yesterday's
report that it would last "54 seconds"? The NASA burn data (planned delta-V) at
http://spaceflight1.nasa.gov/realdata/sightings/SSapplications/Post/JavaSSOP/orbit/ISS/SVPOST.html
does say 'seconds'.



ISS Up Almost 2 Km

Moscow Interfax-AVN Online in English 1225 GMT 22 Jan 10

   MOSCOW. Jan 22 (Interfax-AVN) - The orbital altitude of the International Space Station (ISS) was raised 1.75 km on Friday, Russian Mission Control spokesman Valery Lyndin told Interfax. 
   "The average height of the station's orbit has been raised 1.75 km," Lyndin said.
   The two engines of the Zvezda service module were turned on to conduct a preliminary adjustment at 12:06 p.m. Moscow time and were on for 54 minutes, Lyndin said.
   The adjustment was automatic and did not involve the crew, Lyndin said.
   On January 24, Mission Control will conduct the main adjustment, which will increase the ISS's orbit by another 5 km.
   The orbital adjustment needs to be conducted to enable the ISS to dock with the Progress cargo spacecraft, whose launch is scheduled to take place at Baikonur on February 3, and the manned Soyuz spacecraft, which will head to the ISS in April, Lyndin said.
  ----- Original Message ----- 
  From: James Oberg 
  To: fpspace at friends-partners.org 
  Sent: Friday, January 22, 2010 12:03 AM
  Subject: [FPSPACE] Russian Segment SM Engine burn soon -- last one went verybad




  The Russian Segment of the ISS will light both Service Module engines at 0906 gmt Friday, Jan 22, for about 55 seconds, in the first of two orbit boost burns. This is the first time since the burn one year ago that resulted in alarming vibrations within the ISS. According to TsUP-M the math models of the ISS mass properties have been improved. Let's watch and listen to A/G comments.



  Details of the Jan 22 maneuver:

  http://satobs.org/seesat/Jan-2010/0059.html

  and the January 24 maneuver:

  http://satobs.org/seesat/Jan-2010/0081.html

   

  Jan 2009 story here: Shaking on space station rattles NASA

  Vigorous vibrations caught on video during orbital reboost last month

  http://www.msnbc.msn.com/id/28998876/  [including on-board video]

  updated 8:27 a.m. CT, Wed., Feb. 4, 2009



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