Author Topic: LIVE: H-IIB F-6 - HTV-6 - Launch, ISS and EOM - Dec-Feb, 2016/17  (Read 43600 times)

Offline yoichi

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http://iss.jaxa.jp/en/htv/news/htv6_dom2.html

KOUNOTORI6 performed its second de-orbit maneuver for reentry
Last Updated: February 5, 2017

KOUNOTORI6 (HTV6) performed its second de-orbit maneuver for the reentry into the Earth's atmosphere at 7:12 p.m., February 5. The third de-orbit maneuver will take place at 11:42 p.m. KOUNOTORI6 is scheduled to reenter into the atmosphere at 0:06 a.m., February 6.

*All times are Japan Standard Time (JST. UTC + 9 hours)

Offline yoichi

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http://iss.jaxa.jp/en/htv/news/htv6_dom3.html

KOUNOTORI6 performed its third de-orbit maneuver for reentry
Last Updated: February 5, 2017

At 11:42 p.m. on February 5, KOUNOTORI6 (HTV6) performed the third de-orbit maneuver for the reentry into the Earth's atmosphere. The HTV6's reentry is scheduled for 0:06 a.m., February 6.

*All times are Japan Standard Time (JST. UTC + 9 hours)

Offline Olaf

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http://iss.jaxa.jp/en/htv/news/reentry_confirmed.html
Quote
Reentry of KOUNOTORI6 was confirmed

Offline JimO

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Any chance they hit the guillotine command before deorbiting, just in case? What kind of visual or radar object would the 700m tether and small end node, make?

Offline Comga

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Any chance they hit the guillotine command before deorbiting, just in case? What kind of visual or radar object would the 700m tether and small end node, make?

Scaling from the hemispherical retroreflector, which is about 175 mm across (IIRC) with 25 mm solid "corner cube" reflectors, it's well over the nominal 10 cm resolution of ground based radar.

However, none of the simple places I search (n2yo, Heavens-Above, Stuffin.space) show a separate object (2016-076B) from the launch of HTV-6.  With absolutely no information found to date, beyond the statement of having trouble, my assumption is that the tether was never released.

All that effort into the electron emitters and voltage and current monitors and the cameras and lidar, and they may have failed where so many others have, which was an inability to play out the line.


I wonder if they will get another chance on a future HTV.  Perhaps they could concentrate on just deploying the tether first, and worry about current and electro-motive forces later.
What kind of wastrels would dump a perfectly good booster in the ocean after just one use?

Offline yoichi

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result of Kounotori Integrated Tether Experiments(Japanese)

Online Chris Bergin

result of Kounotori Integrated Tether Experiments(Japanese)


Many thanks for your posts. Can you provide a short summary of that presentation in English - even just a few lines? Was it a good test?

Farewell HTV-6!

Offline Galactic Penguin SST

result of Kounotori Integrated Tether Experiments(Japanese)


Many thanks for your posts. Can you provide a short summary of that presentation in English - even just a few lines? Was it a good test?

Farewell HTV-6!

From what my extremely bad Japanese reading skills can tell, they never managed to deploy the tether, though the electron generator was tested without problems.
Chinese spaceflight is a cosmic riddle wrapped in a galactic mystery inside an orbital enigma... - (not) Winston Churchill

Offline yoichi

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by google translation

P2
We succeeded in stably generating the current flow by autonomously controlling the function of emitting electrons from the field emission type electron source and the voltage of the field emission type electron source.

We confirmed that the charging state of "KOUNOTORI" changes as expected by emitted electrons, and demonstrated the effectiveness of field emission type electron source.

P3

1. Background and results
January 28 21:35 (Japan time, same below)
Prior to endmass emission, cutting of the four bolts holding the end mass is started.
Only the No. 3 bolt does not indicate "disconnection" even if a disconnection command is sent, and sends a disconnection instruction multiple times.
After the command, after a few minutes it became "disconnected", so continue the experiment preparation.
January 28 22:35
End-mass release ready
January 29 00:08
End Mass emission command transmission. It can not be discharged.
After that, further troubleshooting was done, and until the end of the experiment on February 5,
We tried to release but could not discharge.

2. Cause investigation situation
Currently, we investigate the data obtained during the experiment and are investigating the cause.
One of the four bolts fixing the endmass is not separated and the endmass is solved
I think that the possibility that it is not released is the highest.

Offline eeergo

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Great plot by Jonathan (jcm) on Twitter about orbital decay of different ISS-related objects, including the drag sail demonstrators in HTV-6:


https://twitter.com/planet4589/status/879574752972636160


Quote from: JonathanMcDowell
New plot: orbital decay of objects ejected from ISS in 2017. Green: ISS. The blue objects are cubesats; the magenta are cubesats which successfully deployed drag devices to accelerate reentry (FREEDOM, EGG, TES5). The red line indicates the ACBM shield lost during an EVA on Mar 30. Coming down faster than cubesats but still pretty slow. The cyan line is an unidentified debris object which separated from ISS on about May 6. Notice its decay rate v similar to the ACBM shield. Note bottom of y axis is 350 km, not 0, to show different decay rates clearly. I know some of you consider this naughty graphing but IDC :-) I'm guessing (wildly) that the ROSA array will decay at a similar rate to the ACBM shield, so will be up for order 6 months. Oh, and of course the little kinks you can see in the green line at top are the ISS reboosting its orbit. There's also some false data for the most recent batch of cubesats near the start of their curves.
-DaviD-

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