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IKAROS JAXA Solar Sail mission
elakdawalla
post Jan 26 2011, 09:49 PM
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Mine was taken from the press kit too -- I think yours has more pixels but is just upsampled. Which is not to say that upsampling to make the image occupy more space on the screen doesn't help in interpreting the image; I just don't think it actually contains any more data.


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pandaneko
post Jan 27 2011, 02:32 PM
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QUOTE (elakdawalla @ Jan 27 2011, 05:23 AM) *
Based on @ikaroskun's tweets I'm pretty sure this is the largest size available -- if I am translating correctly, it took days or weeks to even download thumbnail images at IKAROS' current distance from Earth.


I have always thought how lovely this child of yours is, whenever you posted something... It reminds me of my life with my own kids, who are all grown up by now. People go through life stages, I think... That apart, yes, you are right with your translation, the low bit rate transmission and all that.

I will translate the report you mentioned from tommorrow on as it does not seem to contain complicated pages, unlike those of Akatsuki. Why not? I myself want to know what has happened with this thing...

Pandaneko
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pandaneko
post Jan 30 2011, 02:26 PM
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What is to follow from now for some time is my translation of IKAROS report.

This is a strange report, for a start, it does not have an outline page, and secondly, and here, I am simply guessing from one abbreviated character string printed at the top right corner of this report that this report was comissioned to one person at JAXA, Dr Osamu Mori, and thirdly, its refrence number is 4-2, perhaps suggesting that there are other reports that JAXA do not carry on their regulaer web pages.

Anyway, the first page, page 1 goes like this.

Comissioned report 4-2

Report on the termination of the regular operation of the small solar power sail engineering test spacecraft.

26 January 2011 (Wed)

JAXA
Dr Osamu Mori

P
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Paolo
post Jan 30 2011, 02:38 PM
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can't wait to read the rest of the translation! many thanks in advance Pandaneko!
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pandaneko
post Jan 31 2011, 12:53 PM
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Page 2: IKAROS report

0: Today's reporting items

We have been operating the small solar power sail engineering test spacecraft for the last 6 months, and we herewith confirm mission achievements based on the results so far and at the same time report on the latter part of the (continued) mission envisaged.

1: Mission objectives and significance

objectives

1.1 This is a front loading project for reducing the cost of development for the next project that we wish to run.

1.2 We wished to confirm the possibility of solar sailing and at the same time check on the power generation on the sail surface for the future hybrid propulsion system (no ion engines used this time)

IKAROS = Interplanetary Kite-craft Accelerated by Radiation Of the SunPage 2

P
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pandaneko
post Jan 31 2011, 01:20 PM
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Page 3: IKAROS report 4-2

1. Mission objectives and significance

The following 4 items are the main objectives


1. Large membrane expanstion (objective 1)

1.1 Extend a large 20 m membrane using the mechanism (similar) to be used with future spacecraft under zero gravity and in vacuum

1.2 Evaluate the extension mechanism and the result of expansion and relate the obtained data to analysis model

2. Power generation using the power sail

2.1 Generate power with the thin film solar power generator and confirm power generation through on-the-membrane harness

2.2 Obtain data of the generated power and evaluate characteristics

3. confirm acceralation by the solar sail membrane and check the obtained data agains the actual orbital measurement data (distance change rate by distance measurement data) (objective 2)

3.1 (there is something here, but I cannot read it, P)

3.2 Evaluate the acceralation capability and reflect the result into the orbital caluculation methods for reaching the target astronomical objects

4. Obtain navigation techiniques by solar sail operation

4.1 Confirm orbit determination techniques under solar acceralation

4.2 Confirm active control methods of photon acceralation direction vector by sail manipulation under photon pressure and obtain navigation techniques using the rsult

Objective 1: minimum success

Objective 2: full success

P
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pandaneko
post Jan 31 2011, 01:49 PM
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Page 4:

2: Result confirmation of mission requierments

(here, I do not wish to retranslate objectives carried before, so I will be brief with objective items as they are exactly the same, P)

2.1 Sail expansion:

complete, leading mass seperation on 26 May, primary expansion on 2-8 June, secondary expansion on 9 June and sail expansion was manitained after that by spin

2.2: evaluation

evaluation of spin and expansion and reflecting to expansion simlulation: achieved, we confirmed general agreenment between simulation and the real data obtained, and checked on the discrepancies and reflected them into the analytical model・. ,.

3: solar power generation

complete, on 10 June power generation was confirmed

3.1 interplanetary solar panell chracreristics evaluation, this was done once per week and compared with ground tested deterioration data<


HERE, I GIVE UP for this evening, because I thought that this page was a simple table page and that I could copy and paste and overwrite, but it is not that easy as its layout is messed up a lot. I will try again tommorrow.

P
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nprev
post Feb 1 2011, 02:07 AM
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Pandaneko, by all means please take your time...and thank you for this!!! smile.gif


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pandaneko
post Feb 1 2011, 01:11 PM
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I will start from page 4 again. One thing that bothers me is that nowhere on this report submission it says submission was made to the Space Activities Comission (SAC) and the strange reference number, 4-2. I have a feeling that this is not an official report, rather internal, perhaps, and also interim, just to say, at this stage, something for the public at large.

Anyway,

Page 4 of the report 4-2 is as follows (this is a 30 page report)

2. Confirming results of the mission requests

1. Expansion of the large area membrane

1.1 Expand the 20 m (diagonal) membrane in vacuum and under zero gravity using the mechanism similar to that to be used with future space probes.

Completed: (I will come to definition at the end of this page, P)

Leading mas seperation on 26 May, primary expansion during 2-8 June, and final expansion on 9 June, and after that expansion was spin maintained

1.2 Evaluate expansion behaviour and expanded status and reflect the findings into the analytical model for expansion simulation.

Achieved: (I will come to definition at the end of this page, P)

We confirmed that observed expansion behaviour was more or less consistent with our prior simulation. We also evaluated discrepancies and refelected them into the analytical model.

2. (this 2 is within the header 2. that is, subsection 2, P) Power generation by the solar power sail

2.1 Generate power with the thin film solar power generation system, through the membrane harness, and confirm it by IKAROS itself

Completed:

power generation was confirmed on 10 June

2.2 Obtain relevant data of the solar cells on the membrane and grasp their characreristics

Achieved:

We conducted about once per week evaluation and compared the data with predicted deteriooration curve and grasped the characteristics

3. Confirm acceralation by the solar sail

3.1 Confirm solar sail's acceralation effects by orbit determination (measued distances and distance change rates)

Completed:

We observed photon induced acceralation and confirmed that the resultant propulsion was within the designed values.

3.2 Evaluate acceralation ability and reflect obtained data into the orbit determination methods for reaching target astronomical bodies

Achieved:

Optical characteristics were inorporated into the attitude orbital dynamics and established the optical method for parameter determination

and refelected those into the orbit planning system

4. Obtain navigation techniques with the solar sail

4.1 Confirm orbit determination techniques under photon induced acceralation

Achieved:

We have built a photon induced acceralation model and established the orbit detemining method including tracking, and actually operated the model with IKAROS.

4.2 Establish active control methods for photon induced vector treatment by the sail and the navigational techqniques by using those control methods

Achieved:

We confirmed that we can achieve required and planned orbit control by active sail attitude manoever. We conducted this relative to Venus and are satisfied with the results.

Glossary:

Achieved: mission requests jhave been more or less met and addtional analysis (including data from continued operation) may lead to further results

Completed: all of mission requests have been met perfectly

P
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pandaneko
post Feb 2 2011, 09:41 AM
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Page 5:

2: operational procedures and confirmed results against mission requirements

(on the diagram) red blacket relates to the first few weeks in search of a minimum success, whch is the extention of the membrane and power generation and the blue bracket relates to the following 6 months in search of a full success, which is to verify the acceralation by the sail and to gain navigational skills

(Here, character strings are numbered from 1 to 5 and these are)

1. launch (21 May) and spin seperation of the craft (5 rpm)

2. initial checking and spin-up (25 rpm)

3. solar sail extension (2.5 rpm, 2-9 June), power generation on 10 June, and spin rate adjustment (1-2.5 rpm)

4. acceralation by the sail (9 July)

5. orbit control and navigation skills (December 2010)

Page 6:

2: Membrane extension (attitude data)

1. leading mas seperation on 26 May, primary extension during 2-8 June, and final extension on 6 June. Extension mechanism wroked well and spin behaviour was more or less consistent with expectation.

2. Departing camera was used on 14 and 19 June and captured the sail image and confirmed no anomaly.

(there are 3 graphs here, from left to right, and these are)

1. leading mas seperation
2. primary extension, and
3. start of final extension

With these graphs vertical axes on left are the spin rate around Z-axis, and that on the 3rd graph on the right is the angular velocity (red for X-axis and blue for Y-axis)

Page 7:

2: sail extension images

There are 6 images here, those on left were taken by the engineering camera on board and those two on the right were by the departing camera.

4 captions for the engineering camera, clockwise, are:

1. after leading mas seperation
2. during primary extension
3. after final extension
4. after primary extension

The caption for the departing camera images is "confirmation of liquid crystal device", ON is specular reflection and OFF is diffuse reflection

Page 8:

2: Power generation by the sail

We conducted a verification test on 10 June, followed by about once/week of characteristics evaluation and confirmed that the data was more less consistent with the predicted values obtained on the ground.

There is one table and one graph here on this page.

The header row for the table at top, from left to right says;

number, membrane section measued, Isc, Pmax, Imp, and temp

The second row has only one character string and that is the predicted value.

With the graph on right the caption on top is I-V characteristic.

These measurements were taken at 22:50 on 10 June, 2010, at 1.05 AU, earth distance of 7860133 km, sun angle at 13 deg, spin rate at 2.5 rpm.

Pandaneko
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pandaneko
post Feb 3 2011, 10:21 AM
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Page 9:

2: Verification of photon acceralation

2.1 We confirmed photon acceralation by Doppler measurements.

2.2 Estimated propulsive power was in agreenment with the designed value.

2.3 We measured photon proplusion at different AUs and at different sun angles. Cumulative photon acceralation reached 100 m/s.

(2 graphs here)

One on left is the Doppler measurement history.

Vertical axis on left is the difference of IKAROS between two cases where photon pressure is present (actual measued values) and where photon pressure is absent (calculated values) in mm/s.

Horizontal axis is the time line around the final extension on 9 June 2010.

The caption at the bottom of this particular graph says "Estimated (from Doppler effects) photon pressure= 1.1 nM"

There are chrracter strings on this graph, top one says "execution of final extension at 09:36 UTC" and the one below it says "time region where data is missing due to swtich over to oneway Doppler mode".

The other graph on the right is the cumulative photon acceralation, vertical axis on left is just that, horizontal axis is the time line between 22 May and 8 December. The caption at bottom of this graph says "We achieved 100 m/s by November".

Page 10:

2: Navigational skills obtained with the solar sail

2.1 With the liquid crystal device we conducted device checking and attitude control experiment and confirmed that expected control ability was achieved.

2.2 IKAROS flew by Venus at 80,000 km on 8 December and it was a day later than AKATSUKI because we conducted a non-balistic flight by the solar sail on way. Akatsuki was led to the sun side of Venus and IKAROS to the night side.

(with this page 10, we have 2 graphs and one image)

With the leftmost graph the vertical axis is the sun angle (its title is the spin rate during control mode, by the way) and the horizontal axis is the time line in UST, starting at 12:00 on 12 July.

The character string in the top box is "control start", bule dots are before the start of control mode and red dots are taken during this control mode operation. Solid line is the expected sun angle without control.

The chenck of caption below it says" gievn the initial evaluation which took into account the sun distance and the sun angle we confirmed that over 90% of attitude control accuracy was achieved".

The second graph is as follows.

The character string in red at top says "nearest approach to Venus at 07:39 UT and IKAROS is moving to the left.

Then, the image, and this is before image processing.

(To me, it does not look fully extended. It looks like a dried jelly fish thrown up on a beach..., P)

Page 11:

3: Outline of follow-up operations

3.1 duration: until about end March 2012 (and we will be making a decision on further follow-up operation at that time)

3.2 DSN station: Usuda 64 m

3.3 Objectives:

We wish to gain further insight into solar sail navigation which we hope will contribute to the development of next project.

3.3.1 Solar power sail mission: 4 new themes and 3 continuing themes
3.3.2 With optional devices (GAP, ALDN, VLBI) current mission will continue
3.3.3 Evaluation of newly developped devices, such as liquid/gas equilibrium thruster, MGA, mission system electicity

PANDANEKO
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pandaneko
post Feb 5 2011, 09:37 AM
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Page 13:

3: Continued mission plan (themes related to the main mission)

3.1: large membrane extension

Continuation theme 1:

Evaluate the extended state and check up on mechanical deterioration of the sail surface

New theme 1:

Proactively pull out the membrane behavoiur and shape changes and construct a dynamic model of the extendes state

3.2: Power generation

Continuation theme 2:

evaluate the capacity and monitor system deterioration

3.3: Verification of acceralation by the sail

Continuation theme 3:

Evaluate its ability and dependency on reflection characteristics and deterioration, and attitude dependecy on membrane shape during photon acceralation

New theme 2:

Improve, given membrane shape changes, the the seperation accuracy of photon reflection and areas concerend, and use the data to construct an optical parameter model of the membrane

3.4: Navigational skills:

New theme 3:

Make use of the increasing distance between Earth and IKAROS, to evaluate the orbit determination accuracy under photon pressure andacceralation

New theme 4:

Evaluate the long term control/guidance characteristics per each orbit revolution

NOTE 1: With all of these themes they are expected to be completed by 31 March 2012, and contribute to the next step in development for the project targetted at Jupitor and the Troia group of asteriods

NOTE 2: Mission included in the continuation plan should contribute to the studies of large membranes, orbit determination/control under solar photons. These will be useful for other purposes and projects.

Page 13:

3: Comments on new themes included in the continued operation

New themes 1 and 2:

These should contribute to the studies of large membrane structure.

We confirmed, from regular operation so far, that changes in sun angle and spin rate will lead to membrane shape changes and that solar photon pressure does contribute to membrane behavoiur.

With this in mind, we will proactively alter the combination of sun angle and spin rate in order to;

1. construct a dynamic model of the extended membrane structure

2. consttuct an optical parameter model of the membrane

New themes 3 and 4:

These will contribute to the studies of orbit determination and guidance under photon pressure.

Given increasing changes in the relative positions of Earth and IKAROS compared with those during the initial regular operation we will make use of them in order to;

1. evaluate orbit determination accuracy under photon acceralation (accuracy decreases as the distance increases)

2. Evaluate long term controlability (evaluate orbit info per every revolution around the sun)

P
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pandaneko
post Feb 6 2011, 09:29 AM
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Page 14:

3: Orbit plan (from launch to Venus)

launch: 21 May 2010
nearest approach to Venus: 8 December 2010

(There are 2 graphs here and this page must be self-explanetary, P)

Caption at the top of the left graph says "Nearest approach to Venus on 8 December 2010", and the caption at bottom is "launch on 21 May 2010". At the centre is the sun, Venus green, earth blue.

Caption at the top of the right graph is "Sun-Earth fixed system". At the centre is the sun and Venus green, and the character string just below IKAROS (in red) is the Earth

Page 15:

3: Orbit plan (from nearest approach to Venus to the end of fiscal 2011)

Black square: nearest approach to Venus on 8 December 2010
Black diamond: 31 March 2012

(There are 2 graphs here)

With the left graph the sun is at the centre and the caption at the top is "nearest approach to Venus on 8 December 2010"

With the right graph the caption at the top is "Sun-Earth fixed system", sun at the centre, Earth is the blue dot on the right, IKAROS movement in red.

Page 16:

3: Orbit plan (from fiscal year end of 2011 to the furthest point)

black diamond: 31 March 2012
black star: 6 December 2012

(There are 2 graphs here)

2 captions at the bottom of the lefthand graph, the left one says "furthest point on 26 December 2012" and the one on the right says "31 March 2012".

With the right hand graph, my earlier comments apply.

Page 17:

3: Operational policy for the latter half of IKAROS operation

Given the limited coms capacity our operational policy is as follows:

3.1 February 2011:

attitude/orbit determination (new themes 3 and 4, continuation 3)

confirmation of sail extension and power generation (continuation 1 and 2)

GAP operation and reproduction of ALDN observation data

3.2 May, June 2011:

attitude/orbit determination (new themes 3 and 4, continuation 1 and 2)

confirmation of sail extension and power generation (continuation 1 and 2)

reproduction of GAP, ALDN data, engineering experiment with VLBI

attitude/orbit determination upon changing spin rate and sun angle (new themes 1 and 2)

3.3 July 2011 and beyond:

We will make our judgement based on the results obtained by June.

Current tentative plan is as follows:

We are going to change the spin rate and the sun angle over a very wide range and;

1. If we can improve coms status we will try a longer operation by economising on fuel.

2. If we cannot improve coms status asa result we will still try to economise on fuel and try to maintain MGA's link attitude.

P
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pandaneko
post Feb 8 2011, 08:56 AM
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I now realise that I made a simple mistake with my earlier translation.

Page 17 should have been page 18. And Troia group of sateroids should have been Trojan group of asteroids, I think.

Anyway, page 17 should have been as follows, P

Page 17:

3: Latter mission operational plan

Continue with optional devices mission

1. GAP: GAP= GAmma‐ray burst Polarimeter

This device comprises of a refelector at the centre, surrounded by 12 pieces of fluorescent light detector, intended to measure polarisation of Ganma ray bursts.

2. ALLADDIN= Arrayed Large‐Area Dust Detector for INterplanetary Space

This device is intended to record collision occurence times, maximum signal value and signal decay so that data will contribute to spatial distribution analysis of space dusts in the region nearer to the sun than earth.

3. VLBI= Very Long Baseline Interferometry

This will make use of quasors in the far distance in order to measure precise IKAROS positions using delta VLBI technique. Regular measurements will be made with future missions.


Results so far of these optionnal devices:

1. GAP, ALDN, VLBI are all normal and producing data, however

2. because we concentrated our resources on system operation as the first priority we have not had enough time with these divices. So, our current intention is to use them as long as we could.

P
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pandaneko
post Feb 8 2011, 09:05 AM
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Page 19:

4: Supplementary information

What is the solar sail?

1. Solar sail: is a craft which makes use of solar photons for propulsion.

2. Solar power sail: is, in addition to the sail membrane itself, solar power generation devices are attached to the sail surface

If we combine ion engines and solar power sails we should be able to navigate into regions much further away from the sun. We will be trying out this idea with our next mission targeted at the Trojan group of asteroids and Jupitor.

P
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