Launch News (Failure) Phobos-Grunt and YingHuo-1 atop Zenit-2 on November 8/9, 2011

[garyw]

What about keeping this craft in leo till the next window opens?

Thats about two years. In that time the probe would need to be kept from re-entering which costs fuel and I don't know how long the upperstage fuel can last. I assume it's solid as there has been no talk about cryo boil off.

 

[SiberianTiger]

Thats about two years. In that time the probe would need to be kept from re-entering which costs fuel and I don't know how long the upperstage fuel can last. I assume it's solid as there has been no talk about cryo boil off.

The least scientific thing that can be done, given assumptions:

1) The probe can fix its attitude and do burns with its main engine;
2) There are no reachable targets beyond Earth's gravity well;

Is to put it into a highly elliptical orbit (or a Solar-centric orbit with returning back in about one year), separate modules one by one, tests the spacecraft's controllability in different stages of flight, and ultimately, bring the return vehicle for reentry and recover the capsule.

(and save the poor dormant Tardigrades locked inside! :facts

 

[dgatsoulis]

About 15 minutes ago, I copied Ph-G's orbital elements from here in Orbiter. (Close enough).

Here is the scenario

BEGIN_DESC
Contains the latest simulation state.
END_DESC

BEGIN_ENVIRONMENT
  System Sol
  Date MJD 55890.4242208673
END_ENVIRONMENT

BEGIN_FOCUS
  Ship GL-01
END_FOCUS

BEGIN_CAMERA
  TARGET GL-01
  MODE Cockpit
  FOV 60.00
END_CAMERA

BEGIN_MFD Left
  TYPE Map
  REF Earth
  POS 0.00 0.00
  DISP 1711
END_MFD

BEGIN_MFD Right
  TYPE Orbit
  PROJ Ship
  FRAME Equator
  ALT
  REF Earth
END_MFD

BEGIN_SHIPS
GL-01:DeltaGlider
  STATUS Orbiting Earth
  RPOS -1425943.54 328672.12 -6497348.20
  RVEL 4542.125 6201.659 -716.146
  AROT -59.35 47.54 -117.53
  VROT -0.08 -0.06 0.17
  AFCMODE 7
  PRPLEVEL 0:1.000000 1:1.000000
  NAVFREQ 402 94 0 0
  XPDR 0
  GEAR 1 1.0000
  AAP 0:0 0:0 0:0
END
END_SHIPS

BEGIN_ExtMFD
END

If someone can provide the dv budget, i think this would make an excellent challenge.

EDIT: Remember to go to the editor and apply the "now" date.

 

[SiberianTiger]

Thanks, dgatsoulis!

If someone can provide the dv budget, i think this would make an excellent challenge.

The Main Propulsion System (stage 1) has:

Engine S5.92.00000-0-01 having two thrust modes:

• High Thrust: 19,777 ± 981 N (2,016 ± 100 kg of force) @ 3,901 m/s ISP
• Low Thrust: 13,842 ± 1,471 N (1,411 ± 150 kg of force) @ 3,185 m/s ISP

Can be ignited up to 50 times.

The propellant reserves are like in the table:

Primary tank assembly with additional vessels:|
* "Atin" Oxidizer (tanks O1,O2)|4,675 kg
* UDMH Fuel (tanks G1,G2)|2,340 kg
Discardable tanks assembly:|
* "Atin" Oxidizer (primary tank)|2,004 kg
* UDMH Fuel (tanks G1,G2)|997 kg

Plus, it uses pressurized Helium for feeding of the engine:
134 litres at the main assembly + 63,2 litres at the discardable tanks.

Initial mass of the whole spacecraft at launch: 13,505 kg

Could not find the dry mass of the discardable tanks straight away.

Transfer-Orbital Module (stage 2) has:

Main engine assembly:
4 * 11D458F (4 * 382.4 N (39 kg of force), @ 2,982 m/s (304 kg of force*s/kg) ISP)

RCS engines facing -X axis:
4 * 11D457F (4 * 53.9 N (5.5 kg of force), @ 2,845 m/s (290 kg of force*s/kg) ISP )
4 * 17D58EF (4 * 12.45 N (1.27 kg of force), @ 2,551 m/s (260 kg of force*s/kg) ISP)

RCS engines facing +X axis:
4 * 11D457F (4 * 53.9 N (5.5 kg of force), @ 2,845 m/s (290 kg of force*s/kg) ISP )

Plus there are 8 * 11D457F to facilitate rolls.

Total fuel reserve 185.6 kg
Total oxidizer reserve 343.4 kg

Mass: less than 550 kg

Returned Module (stage 3) has:

Engine Thrust: 124.6 N
ISP: 3,002 m/s
Dry Mass: 139 kg
Propellants mass: 135 kg

Is it good enough info to calculate the total delta-V budget?

 

[SiberianTiger]

http://ria.ru/science/20111125/497887350.html

ESA specialists will not resume attempts to communicate to Phobos-Grunt before Monday

17:06 25/11/2011

"We are taking a time out till Monday. Over the last days, Phobos-Grunt operations had been the top priority. Other important tasks has grown overdue. This is why these weekend the station's personnel will be reallocated to other programs" - said Pischel.

 

[SiberianTiger]

By the way, despite http://astrojava.com/ballistic-trajectory-planner is not working because Oracle suspended signing for jolt libraries used in this application, I've been able to assemble a working app out of jars on my hard drive (a with Win32 natives).

Sadly, I have no spare time to play around with this cool application. But ready to share one with someone who wants.

 

[dgatsoulis]

...Is it good enough info to calculate the total delta-V budget?

Thanks!
Here is a rough estimate just for the main engines of stages 1 & 2 and please correct me if i'm wrong.
Mo=drymass , M1=drymass+propelantmass

Stage 1: For dry mass i'll just subtract the total of the propelant reserves from the total weight of the ship.
dv=ln(Mo/M1)*excaust-v = ln((13505-4675-2340-2004-997)/13505)*3901= 5279.79 m/s (high thrust)
dv=ln(Mo/M1)*excaust-v = ln((13505-4675-2340-2004-997)/13505)*3185= 4310.72 m/s (low thrust)
This is without taking into account the (Mo) weight of the pressurized helium and the discardable tanks.

Stage2: Mo = 550kg M1 = 550+185.6+343.4=1079kg
dv=ln(Mo/M1)*excaust-v = ln(550/1079)*2982= 2009.48 m/s

Total dv from (HT)1+2 = 5279.79+2009.48= 7289.27 m/s
Total dv from (LT)1+2 = 4310.72+2009.48= 6320.20 m/s

 

[N_Molson]

Is it good enough info to calculate the total delta-V budget?

Stage 1 fuel mass :

Main : 4675+2370+134 = 7179 kg

Torus : 2004+997+63.2 = 3064.2 kg

Total : 7179+3064.2 = 10243.2 kg

Stage 1 empty mass : 13505-10243.2 = 3261.8 kg

Let's assume that the torus tank mass is 10% of its fuel mass.

Torus empty mass : 3042*0.1 = 304.2 kg

So we have to consider the first stage divided in two "substages".

Dv of the "Torus stage" :

DvTs = 3901*ln*(13505/10440.8)
DvTs = 1003.8787_ m/s

Dv of the "Main stage"

DvMs = 3901*ln*(10136.6/2957.6)
DvMs = 4804.9214 m/s

Total Dv for the first stage :

DvS1 = 1003.8787_ + 4804.9214
DvS1 = 5008.8001 m/s

Edit : :ninja:

 

[SiberianTiger]

http://www.esa.int/SPECIALS/Operations/SEMQTNZW5VG_0.html

ESA station unable to establish new link with Phobos-Grunt

25 November 2011
UPDATE After establishing contact with Russia's Phobos-Grunt Mars mission earlier this week, ESA's tracking station in Australia received no signal from the spacecraft last night. ESA engineers are investigating the cause in close collaboration with Russian mission controllers.

Despite listening intently during four scheduled communication passes during the night of 24–25 November, ESA's 15 m-diameter dish antenna at Perth, Australia, did not receive any signals .

The slots for communication, timed to coincide when Phobos–Grunt was passing over in direct line-of-sight with the station, began at 20:12 GMT and ran until 04:04 GMT. Each lasted just 6–8 minutes, providing very limited windows for sending commands and receiving a response.

"Our Russian colleagues provided a full set of telecommands for us to send up," said Wolfgang Hell, ESA's Phobos–Grunt Service Manager, "and Perth station was set to use the same techniques and configurations that worked earlier. But we observed no downlink radio signal from the spacecraft."

ESA's contact with the Mars mission on the night of 22 November marked the first receipt of spacecraft data since contact was lost shortly after separation from the launch vehicle was confirmed on 8 November.

One piece of positive news: observations from the ground indicate that the orbit of Phobos–Grunt has become more stable.

"This could mean that the spacecraft's attitude, or orientation, is also now stable, which could help in regaining contact because we’d be able to predict where its two antennas are pointing," said Manfred Warhaut, ESA's Head of Mission Operations at the European Space Operations Centre, Darmstadt, Germany.

"The team here at ESOC will do their utmost to assist the Russians in investigating the situation."


UPDATE 25.11 14:30 GMT - The next scheduled communication slot for ESA's Perth station is set for the night of 25 November, when it will again be allocated to support Phobos–Grunt.

 

[Izack]

That's that, folks.

 

[SiberianTiger]

That's that, folks.

It has been many times "that" before. At this point all I can say that the spacecraft has a sort of malfunction and behaves erratically.

Last news from telemetry decoding was that that BKU (computer) used to be powered and online.

 

[dgatsoulis]

If only the little guy could manage to stay in a stable orbit and reestablish communication, there is a nice Earth->Venus->Earth->Mars (after 1 orbit)->Phobos trajectory comming up on March 12th 2012.

Earth departure March 12 2012
Venus flyby June 26 2012
Earth flyby April 27 2013
Mars September 10 2015(low dv encounter, after coasting once around the Sun).

The dv budget should be sufficient.

 

[SiberianTiger]

If only the little guy could manage to stay in a stable orbit and reestablish communication, there is a nice Earth->Venus->Earth->Mars (after 1 orbit)->Phobos trajectory comming up on March 12th 2012.

Earth departure March 12 2012
Venus flyby June 26 2012
Earth flyby April 27 2013
Mars September 10 2015(low dv encounter, after coasting once around the Sun).

The dv budget should be sufficient.

Precious, thanks! :thumbup:
If only my name were Putin, I'd demand Lavochkin to hear what you say. :lol:

 

[RisingFury]

Precious, thanks! :thumbup:
If only my name were Putin, I'd demand Lavochkin to hear what you say. :lol:

You're talking about sending a dysfunctional probe on a ride across the solar system, that it wasn't even designed to do. This isn't Orbiter, where the DG can go anywhere...

 

[T.Neo]

You're talking about sending a dysfunctional probe on a ride across the solar system, that it wasn't even designed to do. This isn't Orbiter, where the DG can go anywhere...

Just because it isn't a fictional spaceship with implausible performance doesn't mean that it is suddenly extremely limited, by extremely limiting limitations given to it by you.

 

[RisingFury]

Just because it isn't a fictional spaceship with implausible performance doesn't mean that it is suddenly extremely limited, by extremely limiting limitations given to it by you.

Again, I bow before your infinite wisdom, knowledge and experience. I will forget about the current malfunctions of PhG and pretend we can make it do things it wasn't designed for and survive.

 

[Urwumpe]

Just because it isn't a fictional spaceship with implausible performance doesn't mean that it is suddenly extremely limited, by extremely limiting limitations given to it by you.

To be fair, RisingFury is right in this case - you can't keep the probe in LEO for weeks. That it is still alive enough that a chance to rescue it exists, is a miracle and pretty rare. Usually, the batteries would already be drained, this time the deployed solar arrays help, but it is not known how good they help.

May 2012 is too late, a trajectory by Venus is also no real option, since the solar arrays might age too fast close to the sun. Also, the RCS of the spacecraft is designed for a different mission - the heavy full fuel tank means that the RCS propellant will get consumed much faster as with the planned mission, the bigger torques by gravity and atmosphere will do their best to also consume RCS propellant.

If you can't get the probe revived and dispatched to a mission in mid-December 2011, the probe is dead. Close, but no cigar in that case.

 

[RisingFury]

I'd also imagine that the Earth->Venus->Earth->Mars trajectory would require a lot more mid course corrections than a direct Earth->Mars flight. Even if there wasn't this extra mass being tugged around, I'd imagine the RCS fuel would run out, or be extremely limited.

 

[Ghostrider]

Well, better to send it somewhere than let it crash IMHO. Unless you have a worthy target on the ground...

 

[RisingFury]

Well, better to send it somewhere than let it crash IMHO. Unless you have a worthy target on the ground...

Not true. There's no guarantee that the probe would last in good condition until any launch window opened. It wasn't even designed for LEO communications in mind. If you boost its orbit, you only risk losing contact and having it crash later.

Unfortunately I agree that a controlled reentry is the best option here. There's even a chance - though low - that parts of the probe could be recovered for analysis.