Detective Story "Cosmos-2499"

Earlier this week, the network was the news about the discovery of a mysterious satellite "Kosmos-2499". A variety of sources have advanced version of the "killer satellites", "satellite-inspector", "experimental apparatus with a plasma engine" and the like interesting things. Those curious to see its orbital parameters, try to calculate the characteristic flow velocity and analyze the existing version of the appointment and equipping of a mysterious machine.

Background and correction of myths h4> First of all, it must be said that the object was the cause of suspicion 2014-028E a few months ago. May 23, 2014 launch vehicle "rumble" put into orbit three military communications satellite "Spring". Together with the upper stage "Breeze-KM" in orbit was to have four objects (2014-028A-D). However, the object was detected in five of unknown origin. It could be debris or another satellite. The second version seemed quite logical - along with three "Spring" in 2013 was put an unknown device, then get a room «Космос-2491», and in 2012 and 2008 simultaneously with the main load launched civilian vehicles "Mir" and "Jubilee." The situation became much more interesting when in June the object began to move. June 24 it lowered 4 km perigee and apogee raised by 3, 5 km. In principle, this could still be attributed to errors of publicly available orbital parameters. But in July, the orbit changes become obvious intention - Perigee fell nearly 90 miles! A unit maneuvers forced to assume that he's going to get close to the exhaust "Breeze-KM" (object 2014-028D). Indeed, November 9 unit came closer to the upper stage of one kilometer. Due to the small difference in the parameters of the orbit objects separated again, and their new rapprochement is expected in late November-early December. And journalists have raised alarm about a week after the first rendezvous.

Receive data and calculation of orbital parameters h4> What is the use of the common man United States Strategic Command? Mainly - data acquisition orbital parameters of the satellites. The fact is, they have a website http://www.space-track.org/ , which are laid out publicly available data about flying in space satellites. Anyone, after registration, can get access to this data. We use their services:



The result will be Footcloths unconvincing for the uninitiated numbers:

 1 39765U 14028E 14143.85155363 .00000010 00000-0 00000 + 0 0 18 February 39765 082.4519 349.4209 317.1560 042.8029 0018110 12.42900902 33 1 39765U 14028E 14143.93205085 .00000010 00000-0 00000 + 0 0 36 2 39765 082.4452 349.3605 316.2609 043.7103 0017028 12.42903492 40 1 39765U 14028E 14143.93205141 .00000010 00000-0 00000 + 0 0 28 February 39765 082.4533 349.3598 317.1806 042.7856 0018514 12.42904273 43  pre> This - the so-called  TLE , description format orbit space object in two rows. Save the data as a CSV file and read spreadsheet. 

First Objective - format conversion time. "14143.85155363" - this is 2014, 143 days a year, and 0, 85155363 - hours, minutes and seconds as the proportion of full-time. Using spreadsheet functions, simply get a date. 

Second Objective - to provide data on the apogee and perigee. Here we need the formula of orbital mechanics. In TLE penultimate parameter of the second line is stored frequency of revolution in revolutions per day (12.42900902). Using formulas  here , we can get the value of semi-major axis of the ellipse orbit as: 



a = (8681663.653 / n0) ^ (2/3) 

where: 

n0 - the frequency of treatment (mean motion) in revolutions per day. 



Knowing the semi-major axis of the ellipse, we can obtain the values ​​of apogee and perigee as: 



hp = a (1 - e0) - 6371 

ha = a (1 + e0) - 6371 

where: 

e0 - eccentricity of the orbit (the fifth parameter in the second row - 0018514, is converted to 0, 0018514). 

6371 - Earth's radius. 



 I did file with the calculations, format ODS , for normal maps do not try to open in Google Drive download and watch locally. 



As a result, we obtain the following interesting graph: 



 



Single emissions - probably glitches data. It is evident that the mysterious companion maneuvered very active in the summer. Let's try to calculate the cost of fuel for maneuvers. 

The calculation of fuel consumption for orbital maneuvers h4> Take here this training manual site Michigan Technical University. Make the following assumptions:

• The height apocentre considered constant.
• Changing the speed is calculated as the deceleration from a circular orbit.
  
  
  where μ - gravitational parameter (for the Earth - 398 600 4415)
  
  
  
  If there are experts on ballistics, knowing more convenient formulas, write, count.
  
  The total change in velocity 185 m / s (rough estimate). Calculations are indirectly confirmed by оценкой 190 m / s in other sources .
  
  Try to estimate fuel consumption by such maneuvers. If we assume that the satellite is the engine for high-boiling components (UDMH / AT), he took the supposed mass of the satellite in the 50 kg and a specific impulse of 3200 m / s, as in Engine" Breeze-KM », получим WolframAlpha flow in only 2, 8 kg fuel.
  
  

  The attempt to answer some questions h4>

  where to get the satellite mass of 50 kg? H5> From this mass took unnamed expert" Interfax » is not known, however, this figure is quite plausible. Spacecraft "Peace" and "Jubilee" that ran concurrent load to three "Arrow" / "Spring" had a lot of 60 and 48 kg, respectively.
  
  

  Plasma engine? H5> the latest news about the new generation of plasma engines excited the public. However, data on the satellite maneuvers do not give grounds for such conclusions. All ERE differ very little traction milliNewtons order. This draft will not allow to quickly change the speed of ~ 30 m / s, as we see it in TLE. Given that the news says an unnamed companion of ISS. Reshetnev, plasma engines can stand in the "Spring" (unlikely), or on some of the recently launched geostationary devices, such as "Meridian" or "Express-AM6", which were launched in October. The second option is the most probable - geostationary satellites, firstly, have a large number of solar energy, and secondly, the need to offset the disturbance constant moon.
  
  

  Purpose satellite? H5> The most likely that this so-called test satellite-inspector - the machine that will be able to approach the other satellite and inspect it. In favor of this version is the secrecy surrounding the "Kosmos-2499". Like satellites involved in a number of countries. For example, in 2000 the British satellite SNAP-1 , launched from the Plesetsk cosmodrome using the engine on compressed butane, photographed by satellites "Hope" and Tsinghua-1, which was launched the same launch vehicle. In the US, a similar problem was solved DART in 2006, ASTRO / NEXTSAT in 2007. China has also launched several maneuvering satellites in recent years .
  
  Next in probability option - testing a new engine for small satellites. Creating effective LRE microthrusters not easy to create powerful engines. The main problem - engine cooling. If LRE large thrust as the chamber wall material is used, such as bronze, is forced thrusters experiment with refractory rhenium and iridium.
  
  Least likely remaining options - experiments to study the possibility of repair / fueling / de-orbiting satellites exhaust their experiments with miniature TV systems and other electronics.
  
  

  Bonus h4> From "Cosmos-2499" goes telemetry, radio amateur Dmitry Pashkov it recorded and posted for all to see - you can listen to " singing "device:
  
  
  
  Maybe even enthusiasts will be able to decipher something?
  
  

  Information Sources h4> The main source of information - topic on the forum of the magazine "Space News» . Follow the news there.
  KDPV - satellite photo Tango, made flying in formation with him companion Mango, project PRISMA .
  
  Source: geektimes.ru/post/241838/