Author Topic: Planned and actual locations of spacecrafts landings  (Read 42718 times)

Online Comga

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Re: Planned and actual locations of spacecrafts landings
« Reply #40 on: 07/02/2012 04:40 PM »
Anik: Do you have planned vs actual coordinates for TMA-03M ?

There was a post on the Live thread by Chris Bergin saying "Digital Autopilot test".  Is the deorbit and landing system a new digital system or a legacy analog system? (Apolgies if I am repeating a previous question, but this seems to go against my recollection.)
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline anik

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Re: Planned and actual locations of spacecrafts landings
« Reply #41 on: 07/02/2012 06:31 PM »
Soyuz TMA-03M:
Planned point - 47°18' N, 69°34' E; 150 km SE of Dzhezkazgan.
Actual point - 47°20'56.3" N, 69°32'47.4" E; 146 km SE of Dzhezkazgan.
6 km N.

There was a post on the Live thread by Chris Bergin saying "Digital Autopilot test"

It means that Kononenko has tested RODK mode (manual orientation in digital contour) after undocking and it does not relate to deorbit and landing.

Offline AnalogMan

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Re: Planned and actual locations of spacecrafts landings
« Reply #42 on: 07/02/2012 06:45 PM »
Soyuz TMA-03M:
Planned point - 47°18' N, 69°34' E; 150 km SE of Dzhezkazgan.
Actual point - 47°20'56.3" N, 69°32'47.4" E; 146 km SE of Dzhezkazgan.
6 km N.

Updated chart - latest landing marked in red (click image to enlarge).  This landing has the smallest distance between planned and actual of all the spacecraft listed in the chart title.
« Last Edit: 07/02/2012 06:49 PM by AnalogMan »

Online Comga

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Re: Planned and actual locations of spacecrafts landings
« Reply #43 on: 09/18/2012 05:09 AM »
New landing, same request :-)
Anik: Do you have planned vs actual coordinates for TMA-04M ?
The English audio said "bull's eye landing."  It sure looked like calm winds.
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline anik

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Re: Planned and actual locations of spacecrafts landings
« Reply #44 on: 09/18/2012 05:57 PM »
Soyuz TMA-04M:
Planned point - 51°00' N, 67°14' E; 86 km NE of Arkalyk.
Actual point - 50°59'11.6" N, 67°15'22.2" E; 85 km NE of Arkalyk.
2 km SE.

Offline AnalogMan

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Re: Planned and actual locations of spacecrafts landings
« Reply #45 on: 09/18/2012 06:27 PM »
Updated chart - latest landing marked in red (click image to enlarge).  This landing has the second smallest distance between planned and actual of all the spacecraft listed in the chart title.

EDIT: corrected coordinates on graph
« Last Edit: 09/18/2012 11:15 PM by AnalogMan »

Offline patchfree

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Re: Planned and actual locations of spacecrafts landings
« Reply #46 on: 09/18/2012 10:01 PM »
Updated chart - latest landing marked in red (click image to enlarge).  This landing has the second smallest distance between planned and actual of all the spacecraft listed in the chart title.

It would be interesting to mark in red all the soyuz TMA-0XM landings to answer the question: is the new Soyuz series more precise?
I think not because the landing accuracy is more related to winds the day of landing.
« Last Edit: 09/18/2012 10:03 PM by patchfree »
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Offline AnalogMan

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Re: Planned and actual locations of spacecrafts landings
« Reply #47 on: 09/18/2012 10:36 PM »
Updated chart - latest landing marked in red (click image to enlarge).  This landing has the second smallest distance between planned and actual of all the spacecraft listed in the chart title.

It would be interesting to mark in red all the soyuz TMA-0XM landings to answer the question: is the new Soyuz series more precise?
I think not because the landing accuracy is more related to winds the day of landing.

Here you go (TMA-M TMA-02M TMA-03M & TMA-04M in red)

EDIT: corrected coordinate of latest point
« Last Edit: 09/18/2012 11:16 PM by AnalogMan »

Online Comga

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Re: Planned and actual locations of spacecrafts landings
« Reply #48 on: 09/18/2012 10:53 PM »
Soyuz TMA-04M:
Planned point - 51°00'          N, 67°14'        E; 86 km NE of Arkalyk.
Actual point     - 50°59'11.6" N, 67°15'22.2" E; 85 km NE of Arkalyk.
2 km SE.
Updated chart - latest landing marked in red (click image to enlarge).  This landing has the second smallest distance between planned and actual of all the spacecraft listed in the chart title.

Anik said the offset was to the Southeast, but with almost no latitude (N-S) error.  As I read your plot it shows the offset to the Northwest.  Am I reading it wrong?  Are you plotting in in a way that is intuitive to you but not to me?

I also show this to be THE smallest offset, 2.2 km (with 1.1 km uncertainty due to the single arc-minute precision of the target).  This is less than the previous minimum of 2.7 km I calculated for TM-14.
« Last Edit: 09/19/2012 12:11 AM by Comga »
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline AnalogMan

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Re: Planned and actual locations of spacecrafts landings
« Reply #49 on: 09/18/2012 11:13 PM »
Soyuz TMA-04M:
Planned point - 51°00'        N, 67°14'        E; 86 km NE of Arkalyk.
Actual point   - 50°59'11.6" N, 67°15'22.2" E; 85 km NE of Arkalyk.
2 km SE.
Updated chart - latest landing marked in red (click image to enlarge).  This landing has the second smallest distance between planned and actual of all the spacecraft listed in the chart title.

Anik said the offset was to the Southeast, but with almost no latitude (N-S) error.  As I read your plot it shows the offset to the Northwest.  Am I reading it wrong?  Are you plotting in in a way that is intuitive to you but not to me?

I also show this to be THE smallest offset, 2.2 km (with 1.1 km uncertainty due to the single arc-minute precision of the target).  This is less than the previous minimum of 2.7 km I calculated for TM-14.

My error - I pasted N & E values the wrong way around into my spreadsheet!  Thanks for spotting.

I also make this latest landing the nearest to its planned point after correcting.

(I will correct my original posts)

Online Comga

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Re: Planned and actual locations of spacecrafts landings
« Reply #50 on: 09/19/2012 12:18 AM »
Thanks, AnalogMan.  That makes sense now.  However a real nit-picker would note that the azimuth of the offset is shown around 135 deg, but should be near 95 deg.  Fortunately, we don't know any people THAT picky.  ;)

With the second SpaceX COTS landing being roughly 8 km off target, and that not well established, their precisions and that for the new TMs is comparable. 
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline AnalogMan

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Re: Planned and actual locations of spacecrafts landings
« Reply #51 on: 09/19/2012 11:25 AM »
Thanks, AnalogMan.  That makes sense now.  However a real nit-picker would note that the azimuth of the offset is shown around 135 deg, but should be near 95 deg.  Fortunately, we don't know any people THAT picky.  ;)   

Not sure I understand your comments about the azimuth of the offset.  From my spreadsheet offsets are 1.60 km East, -1.49 km North, giving a distance of  2.19 km and azimuth of 133.0 degrees.  If I enter Anik's planned and actual landing coordinates in Google Earth and use the built-in ruler to measure between them, I get a distance of 2.19 km and a heading of 133.1 degrees.  Where are you getting the 95 degrees from?
« Last Edit: 09/19/2012 11:28 AM by AnalogMan »

Online Comga

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Re: Planned and actual locations of spacecrafts landings
« Reply #52 on: 09/19/2012 02:32 PM »
My mistake.  Did the calculation in my head and got a difference backwards, 11.6" vs 48.4"
You are correct.
And I really like your graph.  Here's my magnitude plot:
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Online Comga

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Re: Planned and actual locations of spacecrafts landings
« Reply #53 on: 11/19/2012 10:10 PM »
NASA post of an aerial shot of the Soyuz TMA-05M spacecraft shows what appears to be a huge skid mark.  This suggests high winds.

Do we have the landing offset, and was it much larger than the previous precise landing?

PS I still have not seen a good number for SpaceX COTS-2+, or CRS-1 but saw a Twitter post that implies it was close:
"If we keep landing this precisely, we're going to have to start issuing the recovery team titanium umbrellas. #Dragon"
« Last Edit: 11/19/2012 10:11 PM by Comga »
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline anik

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Re: Planned and actual locations of spacecrafts landings
« Reply #54 on: 11/23/2012 03:11 PM »
Soyuz TMA-05M:
Planned point - 51°01' N, 67°12' E; 88 km NE of Arkalyk.
Actual point - 51°03'13.3" N, 67°08'24.6" E; 91 km NE of Arkalyk.
6 km NW.

Offline jcm

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Re: Planned and actual locations of spacecrafts landings
« Reply #55 on: 11/23/2012 03:41 PM »
Soyuz TMA-05M:
Planned point - 51°01' N, 67°12' E; 88 km NE of Arkalyk.
Actual point - 51°03'13.3" N, 67°08'24.6" E; 91 km NE of Arkalyk.
6 km NW.

Thanks!
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Offline AnalogMan

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Re: Planned and actual locations of spacecrafts landings
« Reply #56 on: 11/23/2012 06:05 PM »
Here's my updated scatter graph using Anik's data.  I've picked out the most recent landings in different colors (TMA-05M is in red).  Click image to enlarge.

Despite all the talk of the late 'chute opening causing a less accurate landing, the data says otherwise.
« Last Edit: 11/23/2012 06:05 PM by AnalogMan »

Online Comga

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Re: Planned and actual locations of spacecrafts landings
« Reply #57 on: 11/26/2012 07:59 PM »
This 2010 post said:

Quote
http://www.roscosmos.ru/main.php?id=2&nid=10734
"GLONASS/GPS navigation equipment will be installed on Russian crew vehicles Soyuz in 2012, Interfax informs.
The first GLONASS’ed Soyuz TMA-05M will fly in 2012. Navigation equipment will be located on the Soyuz descent capsule, with the aim to use it for defining landing coordinates.
The coordinates are further to be relayed for the MCC and rescue teams via KOSPAS-SARSAT, providing the opportunity to define landing spot and maintain crew rescue promptly.
Navigation equipment will be also introduced in the Soyuz GNC system in three years. This will help defining Soyuz orbital parameters and avoid using ground stations. "

The ground stations in question are those whose only function is to provide the Kama-N radar for orbital parameter determination. The voice/data/command stations will still be required."

Was this in fact the case, and was the new system effective?
The landing offset may have been the largest or the four TMA M series capsules.
Is the Soyuz landing system now down the the fundamental limit of weather, where winds add more variance to the landing location than the control systems?

What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline Lewis007

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Re: Planned and actual locations of spacecrafts landings
« Reply #58 on: 11/29/2012 03:26 PM »
Soyuz TMA-05M:
Planned point - 51°01' N, 67°12' E; 88 km NE of Arkalyk.
Actual point - 51°03'13.3" N, 67°08'24.6" E; 91 km NE of Arkalyk.
6 km NW.

NASA's ISS on-orbit status report of Nov 19 gives different numbers:
"the capsule landed at 51º01' N 67º09' E ... about 2 miles off-target, 87 km from Arkalyk"
http://www.nasa.gov/directorates/heo/reports/iss_reports/2012/11192012.html

why the difference?

Offline anik

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Re: Planned and actual locations of spacecrafts landings
« Reply #59 on: 11/29/2012 05:38 PM »
why the difference?

51º01' N, 67º09' E are planned coordinates before Soyuz TMA-05M undocking.

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