STEREO : мимо Луны - и к Солнцу!

Автор Имxотеп, 28.10.2006 00:18:24

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Alex_II

Аэрокосмическое агентство NASA восстановило утраченный контакт со своим космическим аппаратом STEREO-B, который считался утерянным с 1 октября 2014 года, когда команда на Земле не получила очередную порцию данных, собранных в рамках космической миссии по наблюдению за Солнцем. Спустя 22 месяца ученым неожиданно удалось вернуть связь с космическим аппаратом, когда Deep Space Network (система NASA для отслеживания космических миссий) смогла уловить радиосигнал.
http://hi-news.ru/space/nasa-vosstanovilo-svyaz-s-poteryannym-2-goda-nazad-kosmicheskim-apparatom.html
И мы пошли за так, на четвертак, за ради бога
В обход и напролом и просто пылью по лучу...



Nick123 nick

Отличный сайт заходите не пожалеет. Вот ссылка http://slotmachine24.ru

Boo

Давненько спма здесь не было. Осторожно, там ещё и вирусня может лезть!
Аффтар, съешь еще этих мягких французских булочек да выпей царской водки!

instml

#65
Работа между прочим кипит...

http://stereo-ssc.nascom.nasa.gov/new.shtml

http://forum.nasaspaceflight.com/index.php?topic=2443.240

August 27, 2016

BEHIND observatory status: Avionics off, uncontrolled attitude, complex rotation about the principal axis of inertia. Current orientation supports nearly continuous communication near the edge of the + Z LGA with some solar array input. Propulsion tanks are frozen. Secondary battery and propulsion tank heaters are on in between DSN tracks."

IEM = Integrated Electronics Module
FDF = Flight Dynamics Facility
LGA = Low Gain Antenna
DSN = Deep Space Network

August 28, 2016


BEHIND observatory status Unknown state of power, uncontrolled attitude, complex rotation (~14 minute rotation with the previous ~2 minute rotation) about the principal axis of inertia. Current orientation may support communication near the edge of the + Z LGA with some solar array input.

August 28, 2016


BEHIND observatory status Unknown state of power, uncontrolled attitude, complex rotation (~14 minute rotation with the previous ~2 minute rotation) about the principal axis of inertia. Current orientation may support communication near the edge of the + Z LGA with some solar array input. Propulsion tanks are frozen.


August 30, 2016


The DSN detected the carrier signal again from STEREO Behind on the morning of Tuesday, August 30. More details to follow.


August 31, 2016

On Tuesday, Aug 30, the DSN once again detected the downlink carrier signal at 1321z from STEREO BEHIND. The signal was intermittent with a peak level of -159 dBm. FDF analysis of the Doppler residuals shows the signal fluctuating at ~140 seconds and a spin-axis to Earth angle of ~36 degrees. Note that the TWTA was only on for 30 minutes to conserve battery state of charge. A more stable uplink is required to load parameters necessary for conducting an autonomous momentum dump to re-establish attitude control. From Friday's IEM power on, four additional telemetry packets were processed (one was a duplicate) and will be distributed. The reaction wheel latching relays were commanded off along with all unnecessary power loads.
Go MSL!

instml

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Спойлер


#241 by DaveS on 27 Aug, 2016 15:00
From http://stereo-ssc.nascom.nasa.gov/new.shtml:

"August 27, 2016

The primary propulsion tank heaters (~30W) were enabled at 1530z on Friday, Aug 26. During the second track, after the IEM was powered, the downlink signal would drop out periodically. From analysis of the Doppler residual data from the FDF, the rotation is more complex, there is an ~14 minute rotation with the previous ~2 minute rotation. This appears to have shifted the spin axis from 10.5 deg to 22 deg. Three packets of critical telemetry were received. From this very limited data, as expected, the observatory is quite cold, with the battery at 30% state of charge and generating power to support ~150W. From the propulsion tank pressures, the tanks appear to be frozen; however, no temperature data were received. The Sun angle averaged ~ 60 degrees. As the main bus voltage was 24v and falling, the transmitter was powered off early. While early in recovery, 2 of 11 battery cells appear not to be functioning. Verified that the increased battery charge rate command to C/4 was received. From engineering team discussions, it was decided to power off the IEM and power on the secondary battery heater to allow the battery to recharge. The secondary propulsion tank heaters were also powered on to continue thawing of the hydrazine.

BEHIND observatory status: Avionics off, uncontrolled attitude, complex rotation about the principal axis of inertia. Current orientation supports nearly continuous communication near the edge of the + Z LGA with some solar array input. Propulsion tanks are frozen. Secondary battery and propulsion tank heaters are on in between DSN tracks."

#242 by WindnWar on 27 Aug, 2016 17:30
So it looks like the plan is to thaw the fuel tanks and warm up the battery so it can charge faster while trying to narrow down the rotation in order to figure out the series of thruster firings needed to stop the spin and re-point the craft for power generation and communications but doing so in a manner that doesn't exhaust the battery.

I wonder if the star tracker will work again?

Until the tanks are warmed up I assume they won't know how much fuel remains either.
#243 by denis on 27 Aug, 2016 17:43
Quote from: WindnWar on 27 Aug, 2016 17:30
So it looks like the plan is to thaw the fuel tanks and warm up the battery so it can charge faster while trying to narrow down the rotation in order to figure out the series of thruster firings needed to stop the spin and re-point the craft for power generation and communications but doing so in a manner that doesn't exhaust the battery.

I don't think they would do that (the part in bold).
They have figured out the spin is too high for the reaction wheels to spin it down, so they need a thruster control AOCS mode, which is why they are thawing the propellant before trying to recover attitude control.
Once it's done, they'll switch to some safe/initial acquisition AOCS mode that will kill the spin and orient the solar panel towards the Sun (using gyros and sun sensors + thrusters). No need to compute any series of thruster firing on ground.

Edit:
Quote from: WindnWar on 27 Aug, 2016 17:30
I wonder if the star tracker will work again?
I would be more concerned about the reaction wheels, as their lubricant could be frozen with possibly pretty bad impact on the bearing.

Something similar (a "deep freeze" for an extended period of time) happened on SOHO years ago but the wheels survived. Their behaviour (friction torque) was pretty bad after "de-freeze" apparently, but then went back to normal. They are still working fine up to now.
On the other hand, all the gyros (mechanical at that time) died from this episode. Probably less of an issue with modern solid-state gyros.
#244 by WindnWar on 28 Aug, 2016 16:16
Not as promising news in the latest update.

 August 28, 2016

On Saturday, August 27, during the evening recovery track, no downlink signal was received after repeated commanding the transmitter on. Battery recovery commands were sent for the last hour of the support.

On Friday evening, as battery voltage was decreasing from the three telemetry packets received, the transmitter was powered off early. However, the downlink signal was lost 6 minutes earlier than expected. It is speculated that with the complex roll, which resulted from powering on the IEM, the battery voltage may have collapsed at some point.

BEHIND observatory status Unknown state of power, uncontrolled attitude, complex rotation (~14 minute rotation with the previous ~2 minute rotation) about the principal axis of inertia. Current orientation may support communication near the edge of the + Z LGA with some solar array input.
#245 by DaveS on 29 Aug, 2016 00:01
Latest news:
August 28, 2016 update


Today, the DSN created a new acquisition sequence for only sweeping a 3 kHz range about the best lock frequency. This was used successfully during the morning Goldstone support to repeatedly sweep and send battery recovery commands. It was agreed to continue battery recovery tonight and on a 4 hour support on Monday. The carrier recovery is scheduled for Tuesday during a 4 hour support with radio science receivers recording.


BEHIND observatory status Unknown state of power, uncontrolled attitude, complex rotation (~14 minute rotation with the previous ~2 minute rotation) about the principal axis of inertia. Current orientation may support communication near the edge of the + Z LGA with some solar array input. Propulsion tanks are frozen.
#246 by DaveS on 30 Aug, 2016 14:56
August 30, 2016

The DSN has been able to extract 5 additional telemetry frames from Friday's IEM power on. These frames are being processed and the telemetry from the 5 critical packets will be distributed. An updated recovery plan was developed and discussed during the daily telecon. On Tuesday, carrier recovery will be commanded, attempting to power on the TWTA. If the downlink signal is detected, the TWTA on time will be limited to ~21 minutes, which is 1.5 times the period of the beat frequency of rotation and nutation. The reaction wheel latching relays will be commanded off. If no signal is detected, the battery recovery commands will be sent for the remainder of the support and the next day's support will be shortened to 4 hours. This operational cadence will continue until BEHIND is restored to active attitude control or the DSS-63 time ends on Sep 11th.

BEHIND observatory status: Unknown state of power, uncontrolled attitude, complex rotation (~14 minute rotation with the previous ~2 minute rotation) about the principal axis of inertia. Current orientation may support communication near the edge of the + Z LGA with some solar array input. Propulsion tanks are frozen.
#247 by DaveS on 30 Aug, 2016 18:38
August 30, 2016 update

The DSN detected the carrier signal again from STEREO Behind on the morning of Tuesday, August 30. More details to follow.

[свернуть]
Go MSL!

instml

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( 2 )

http://forum.nasaspaceflight.com/index.php?topic=2443.240

Спойлер


#248 by DaveS on 31 Aug, 2016 15:50
August 31, 2016

On Tuesday, Aug 30, the DSN once again detected the downlink carrier signal at 1321z from STEREO BEHIND. The signal was intermittent with a peak level of -159 dBm. FDF analysis of the Doppler residuals shows the signal fluctuating at ~140 seconds and a spin-axis to Earth angle of ~36 degrees. Note that the TWTA was only on for 30 minutes to conserve battery state of charge. A more stable uplink is required to load parameters necessary for conducting an autonomous momentum dump to re-establish attitude control. From Friday's IEM power on, four additional telemetry packets were processed (one was a duplicate) and will be distributed. The reaction wheel latching relays were commanded off along with all unnecessary power loads.
#249 by DaveS on 01 Sep, 2016 15:02
September 1, 2016

Five telemetry frames were received on Wednesday, August 31. With a good signal level, -159 to -164 dBm and a ~3 minute period, there was continuous communications with the TWTA on for 30 minutes. Subsequent analysis showed that the telemetry from the PDU was stale, so there was no sun vector. From the one sample, the battery appears to be charging with the TWTA on, with battery pressures 634 psi and 19 psi, and main bus voltage at 24.9v. As the uplink was good, the mission operations team began loading uplink time consuming commands to EEPROM, i.e., autoexec macro 1 and bad gyro data parameter to EA and G&C. The S/C emergency was reinstated (had ended at midnight) and a 6.2 hour DSS-14 support was added starting at 1815z. As the signal had sufficient margin, the downlink rate was increased to 35 bps, which provides one (1 packet/frame) every 102 seconds. Eight good telemetry frames were received, including 3 memory dump packets and one temperature packet. Unnecessary systems that were found to be on were turned off to decrease the load on the battery. The 3 loads to EEPROM were verified from dumps received.
#250 by DaveS on 01 Sep, 2016 20:06
September 1, 2016 update

Today, during 4 brief TWTA sampling periods this morning, communications are still continuous with the carrier signal fluctuating between -158 dBm and -164 dBm. The battery charge rate increased to C/4 for approximately 4 hours during the track this morning increasing the battery pressure by ~50 psi. An autonomous momentum dump parameter was loaded, dumped, and verified to EA RAM and EEPROM and G&C EEPROM. Detailed power subsystem telemetry was received and cell #6 and #9 (2 out of 11 cells) are indicating 0 volts. Propulsion tanks are slowly warming and have increased by ~2 deg C. IMU2 was powered on briefly and initial indications show that it is healthy and was used to confirm the estimated system momentum level (high). 54 telemetry packets were received. From the Doppler data analysis by the FDF, the nutation is slowing and returning to the previous spin axis orientation.

Progress continues on developing the plan and procedure to re-establish attitude control with very limited battery capacity by conducting an autonomous momentum dump in EA mode, powering on reaction wheels, and promoting the observatory to Standby mode.
#251 by avollhar on 05 Sep, 2016 18:42
For tomorrow, the DSN schedule looks exciting:

Behind  2016-09-06 10:00  2016-09-06 16:45  06h45m  D63  9  MOMENTUM DUMP  
Behind  2016-09-06 18:05  2016-09-06 21:00  02h55m  D26  8  SSR PB/UNATT 160

Source: (http://stereo-ssc.nascom.nasa.gov/plans/dsn_schedule.shtml)

Which basically means mission control will try to fire the attitude control thrusters to get rid of excessive momentum, try to advance to earth-pointing 3-axis stabilisation with the momentum wheels and switch the downlink rate to 160 kbit/s (last entry 2nd line, compared to current 35 bit/s emergency mode). Best of luck!

[свернуть]
Go MSL!

instml

http://forum.nasaspaceflight.com/index.php?topic=2443.240

#253 by avollhar on 06 Sep, 2016 18:38
From http://stereo-ssc.nascom.nasa.gov/minutes/weekly_20160906.txt

* The reaction wheels came online for 1.3 hours yesterday (Sep 5) due to an
  expected feature in the flight software autonomy rules.  This perturbed the
  spacecraft attitude again.  Subsequent observations appear to show that the
  perturbation is dampening out again, and may be better tomorrow.  Currently,
  the spacecraft is able to receive short commands, but telemetry lock is not
  yet stable.  The solar array is stable, and the batteries continue to charge
  up.  The propulsion is being warmed.  The IMU only has two usable axes out of
  three to assist in reorienting the spacecraft.  The IEM is on, as are three
  heaters.  The spacecraft emergency is still in effect.  Depending on the
  telemetry link, the maneuver to despin the spacecraft and repoint it at the
  Sun may occur tomorrow (Sep 7).  The plan is to despin the spacecraft
  sometime this week, as Behind's orbit continues to change the spin angle
  relative to the Sun and Earth.  After attitude control has been achieved, the
  MOC will continue with checking out the spacecraft and slowly bringing the
  instruments online.  A schedule for this will be sent out later.
Go MSL!


ЕвгенийС

А почему не обсуждается наличие инопланетных кораблей обнаруженных на снимках аппаратов Stereo?
Например ролики на ю-тубе:
https://www.youtube.com/watch?v=NtqVzvmZyoE
https://www.youtube.com/watch?v=Z_tgCSlXyDM
https://www.youtube.com/watch?v=A9ShzD2lxcA
"– Это водка? – слабо спросила Маргарита.
Кот подпрыгнул на стуле от обиды.
– Помилуйте, королева, – прохрипел он, – разве я позволил бы себе налить даме водки? Это чистый спирт!" (с)

Дмитрий Виницкий

Потому что дурдом в другом месте.
+35797748398

ЕвгенийС

ЦитироватьДмитрий Виницкий пишет:
Потому что дурдом в другом месте.
А, это всё типа подделка? А как-же ссылки на реальные фото из архива НАСА?
"– Это водка? – слабо спросила Маргарита.
Кот подпрыгнул на стуле от обиды.
– Помилуйте, королева, – прохрипел он, – разве я позволил бы себе налить даме водки? Это чистый спирт!" (с)

Дмитрий Виницкий

Это ссылки пациентов из дурдома для пациентов той же палаты.
+35797748398

Chilik

А интересно, люди, которые верят в инопланетян на снимках НАСА и люди, которые верят в то, за что моментальный пожизненный бан на форуме - это одни и те же люди, или нет?

Константин

Игровой клуб Вулкан имеет приятный и понятный интерфейс, огромное собрание азартных игр и только щедрые бонусные выплаты. В казино Вулкан возможно все. Все игры этого заведения можно четко описать, как реальный способ для удовлетворения потребностей и получения денежного дохода. Казино Вулкан просто создано для того, чтобы радовать посетителей 24 часа в сутки игровыми автоматами от популярных фирм. Отправиться в путешествие во времени, прокатиться на необитаемый остров и поохотиться на зловещих вампиров под покровом ночи - вот мечта каждого игрока.

IQpant

ЦитироватьКонстантин пишет:
Игровой клуб Вулкан имеет приятный и понятный интерфейс, огромное собрание азартных игр и только щедрые бонусные выплаты. В казино Вулкан возможно все. Все игры этого заведения можно четко описать, как реальный способ для удовлетворения потребностей и получения денежного дохода. Казино Вулкан просто создано для того, чтобы радовать посетителей 24 часа в сутки игровыми автоматами от популярных фирм. Отправиться в путешествие во времени, прокатиться на необитаемый остров и поохотиться на зловещих вампиров под покровом ночи - вот мечта каждого игрока.
Модератор! АУ!!! Вампиры в топик пролезли! Причём, неоднократно!

zandr

https://ria.ru/science/20170328/1490921814.html
ЦитироватьУченые обнаружили у Cолнца признаки планет
РИА Новости. Американские ученые зафиксировали на Солнце волны Россби, раньше это явление встречалось только на Земле. Подробные результаты исследования с описанием открытия опубликованы в журнале Nature Astronomy.
Волны Россби на Земле встречаются над океанами и в умеренных широтах атмосферы и сильно влияют на погоду. Их особенность состоит в том, что они создают возмущения в воздушной оболочке нашей планеты, а на Солнце наблюдаются в виде изменений магнитного поля в умеренных широтах солнечной атмосферы, что ведет к колебаниям космической погоды.
Открытие стало возможно с помощью трех космических аппаратов — SDO (Solar Dynamics Observatory) и STEREO (Solar TErrestrial RElations Observatory), — которые позволили ученым изучать единственную звезду Солнечной системы в ракурсе 360 градусов. Раньше такие исследования были невозможны, так как с Земли было видно лишь одну сторону Солнца.
На Земле волны обнаружил в конце 1930-х годов метеоролог Карл Густаф Арвид Россби, в честь него и назвали это явление.