I was thinking that it would make a great demonstration if Ikaros could be maneuvered to rendezvous with Akatsuki at some point during the next few years... but yeah: just tossing around hypotheticals.

Before the demise of Akatsuki I was not terribly interested in this craft. I just thought of it as a planar object going around in space. Now, I just wonder, do they at JAXA know where it is going? Or, are they supposed to know where it is going?

With every other space craft people who sent them out there must have pre-determined flight plans for them to follow, including when the project is supposed to end. For instance, Prof Kawaguchi with Hayabusa, he apparently said he considers that the end of Hayabusa project is when international calls are invited later this year. That is simple and clear.

With this planar space craft I have not been able to find anything about its future whereabouts. I am just intrigued to know what is going on...By the way, there was an article in yesterday's Asahi newspaper about a space net that JAXA want to send up into near earth orbits in a few years time to capture space debris and burn them out with the net on destructive re-entry.

Pandaneko

IKAROS took this self-portrait with Venus in the background! (Darn it, JAXA... Release a larger size of this image)

Thanks to Emily for the heads-up: http://www.planetary.org/blog/article/00002892/

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.

Here's a larger version of the IKAROS-Venus pic...taken from the JAXA press kit

http://www.jaxa.jp/press/2011/01/20110126_sac_ikaros.pdf

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.

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

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

can't wait to read the rest of the translation! many thanks in advance Pandaneko!

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

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

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

Pandaneko, by all means please take your time...and thank you for this!!!

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

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

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

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

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

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

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

Page 20:

4: Supplementary information

Significance of solar power sailing:

This is expected to lead to flexible operation of probes.

It is also expected to provide enough electrical power in the vicinity of Jupitor and beyond.

P

Page 21:

There are graphs and other structures with this page, but they are self-explanetary. So, my translation is only about IKAROS specs, as follows.

Main body size: 1.6 m in diam. and height 0.8 m

Membrane size:s 20m by 20 m, and membrane thickess of 7.5μm

Mass: 308kg, of this 16kg is the membrane mass

Orbit: direct flight to Venus

Orbit determination: range fidings and Doppler measurements

Attitude control: by spin

Propulsion: vapour and liquid equilibrium thruster and gas jet thrusters

Mission duration: longer than 6 months

Comms: 2 LGAs and 1 MGA

P

I will skip pages 22 and 23 as they are too obvious.

Page 24: Supplementary info on GAP

1. Small table header from left to right:

GRB name, trigger time, distance, alpha, beta, angle of entering, simultaneous observation

2. With the 3 graphs here vertical axis is intensity, horizonrtal time in seconds

Main text (jist of it) as follows:

GAP is a ganma ray burst polariser detector. It also achives simultaneous Compton scattering counting.

Power was switched one month after launch. Data is stored in memory and sent back to earth. No mulfunction to date. GAP detects polarisation of megnetic field.

P

Page 25:

4: Supplementary info on GAP

(Here, I am only translating gists of what this page says, P)

Primary objective of GAP is to measure polarisation of ganma ray bursts and try to understand the mechanism. However, it is only 4 months in operation and we have not yet meaure enough of these bursts.

Following report (what follows?, P) is based on the collaborative work with all those GRB satellites around the world with a view to determining the directions of these bursts.

Earlier page's list has data from Russian Konus satellie (K), US Fermi satellite (F), and US-Italy Swift satellite (S). For example, the burst, GRB 100826A (detected on 26 August 2010) was determined to be within the region surrounded by the blue frame with the graph here. Due to polarisation measurements IKAROS is providing additional accuracy.

P

Page 26:

4: Supplementary info on VLBI (multi tone transmitter)

Result of of experiments:

Succeeded in obtaining about 20 times more accuracy of orbit determination compared with earlier JAXA measurements (Hayabusa and AKATSUKI), with the thermal noise level of 50 pico seconds.

Objectives of the experiments:

This is a mission devoted to try out DDOR(Delta differential one-way range) techniques. Basically, very far radio emitting stars are used and the very long baseline interferrometry and triangulation is involved. Participants are as follows:

University of Tasmania: Hobart26m
DSN: DSS34 34m,DSS45 34m, DSS43 70m
ESA: Cebreros 35m New Norcia 35m
ATNF: Mopra 22m, ATCA 22m
Shanghai Observatory: Urmuchi 25m, Shanghai 25m, Konmei 40m
Japan, 32m, 34m, 34m and 64 m)

NASA JPL is quite active in this technology, and for instance, NASA DSN were deeply involved, when required, with DDOR determination of Akatsuki, almost everyday. Collaboration has been done before, but we lacked this essential element, multi tone transmitter, and this time we developped a dedicated transmitter and used it with 8 organisations' 15 antennas with 24 pases.


Comparison (orbit information) between Akatsuki and IKAROS data is as follows:

Akatsuki:

precision : (thermal noise) 700 pico seconds
accuracy : 1 to 2 nano seconds

IKAROS:

precision: (thermal noise) 50 pico seconds
accuracy: 50 to 150 pico seconds

This comparison was made around August 2010

P

What follows from page 27 on, I find it very difficult to translate (technical terms, mainly), but I will give it a try in the belief that even if my translation is not good some people with background knowledge may find them useful.

Page 27:

4: Supplementary info on VLBI multitone transmitter

We developped a DDOR digital base band converter (64 Msps/16 ch/4 bit, 4096 Gbps). 2 graphs here, one on left is the result obtained by this digital wideband system, and one on right is the data recorded by conventional analogue/narrowband system.

With conventional recording system you need to combine a couple of 8 MHz bandwidth analogue signals. The right graph indicates that the gain and the phase within the band are not flat enough.

With this new system it becomes possible to use weak qasor signals as calibrators and that will be useful with future wideband DDOR systems using Ka band.

Page 28:

4: Supplementary info on VLBI multitone transmitter

There is one graph on this page, which came from the observation made on 29 July 2010, using Usuda-Canbera baseline for VLBI observation.

Vertical axis is the delay residual (whatever it means, P) in nano seconds. Horizontal axis is the time ellapse from the start of observation in seconds.

Upperleft character string says "Lizzard constellation's star BL's delay residual"

Character string down right says "delay residual of quasor J1425-2513"

Character string to the left os it in blue says "delta DOR observed quantity"

The bottommost character string says "IKAROS delay residual"

There are 2 texts here on this page, the first one being explanation of the chart itself, and the second one is on future operations from now on. And, I am now going to paste those text down here for further translation. If it does not go well, then I will send this up anyway and try to upload another post.

On the graph, 6 groups of dots (I find only 5, P) relate to IKAROS' VLBI delay residual and those 3 upper left and another 3 upper right exists in the vicinity of IKAROS on the "star sphere surface" (I do not know the word for this, P)

These two are the delay residuals of the astronomical bodies whose positions are accurately known. IKAROS' plot is based on range/Doppler measurements and if its orbit determination is correct IKAROS' delay residual should be on the same line as these of two astronomical bodies'.

However, these are not in line, clearly suggesting a bias coming from orbit determination error not accurately estimated by range/Doppler measuments.


ΔDOR observation quantity: (-7.83 ns±50ps)

With these two astronomical bodies we see that , despite weak signals from quasor producing a lot of noise, delay residuals are on the same line, suggesting that bias due to the presence of atmosphere etc has been successfully removed.

Operations from now on:

Compared with bus system antennas VLBI transmitter has a narrower bandwidth and future observation oppotunities are limited and measurment accuracy is not large. However, we will continue to operate the system because we expect to be using this system with our future missions a lot regularly and we need to improve on the system such as pipelining and semi-automatic operation.

Observation so far has given us a lot of quality data for orbit determination and we should be able to come up with detrmination accuracy of a few centimeters, compared with a few meters accuracy required for deep space orbit determination.

We will also be making use of near Earth satellites for further improvements on accurate orbit determination.

P

Page 29:

4: Supplementary info on ALADDIN

ALADDIN = Arrayed Large Area Dust Detectors in INterplanetary space

Mission objectives:

Cosmic dusts detector engineering tests, to be used for future Jupiter exploration and other outer planets, also to be used in near Earth orbits.

Device composition and arrangement:

1. 0.3% of the sail membrane (0.54 square meters)
2. Piezo-electric thin film elements of 2 different thicknesses at 9/1000mm and 20/1000mm in 4 channel arrangement at the sensing part (ALDN-S at 40g) and detection part (ALDN-E at 210g)

P

Page 30:

4: Supplementary info on ALLADIN

Operational results:

1. Operation started on 21 June 2010.

All 8 channels detected cosmic dusts, more than 100 of them within the duration of acumulative 25 days startong on 30 June.

2. Study of distance dependency of cosmic dusts in the solar system

We are getting more accurate data by cumulative 24 hours of observation.

(End of IKAROS report, 4-2)

P

domo arigato gozaimasu, Pandankeo, I have really enjoyed your translation!



I think they are referring to the quasar "BL Lacertae"

Thanks, Paolo

I am taking a little time off at the moment, but I will come back with the newsletter translations soon.

Since it contains different topics and since I do not wish to be a new topic starter I am thinking how best I might do this. However, I can assure you that these newsletters do make some interesting light readings.

While at work I always enjoyed these, and I would have thought they no longer existed...

P

just one question: what are they talking about when speaking of "1970", "1990" etc in page 30?

Thanks and apologies for not translating fully. You can actually ask for further translations any time you wish.

The top graph is cosmic dusts distribution in space nearer to the Sun than the Earth.

Vertical axis is the flux and the horizontal is heliocentric distance in AU.

Character string at the top left of this graph is IKAROS (2010), down below it in red is Helios 1 (1970's) and just to the right of it is the counting by Galileo (1990's).

Two characters at the bottom left is : Venus orbit, right : Earth orbit

There are two small graphs at the bottom and one on left is IKAROS orbit, and the one on the right is IKAROS orbit with respect to the Sun-Earth fixed frame of reference.

Here below, I will paste the main text and hope it will succeed.

Page 30: Supplementary information on ALDN

Operational results:

(1) Large area dust counter started operation on 21 June 2010. Dusts larger than a few micron size were recorded on all of the 8 channells. A little more than 100 dusts were counted during 25 days starting on 30 June and this number is larger than the count recorded by a German counter (MDC) on board NOZOMI during 45 months from August 1998.

(2) Study of dusts distribution dependence on heliocentric distance

Earlier countings during 1970's and 1990's were somewhat uncertain in accuracy in time resolution. IKAROS data seems to show a continuous rise in the flux as we approach Venus. We may get more information as we continute to operate IKAROS.

P

Paolo

I am afraid I am giving up the idea of translating this newsletter, simply because I found that I cannot copy texts. I have been trying for the last few days all of my tricks for copying, but to no avail.

If you or any other Forum collegues find something to be translated with any other items (as long as it is not too much) I will be willing to do so. I am a very fast translater (actually, very, very fast...) as long as I can copy and paste and overwrite.

Apologies once again and I will sit back for the moment and enjoy posts. My next main interest is ATRO-G, as it will not go far away from earth.

Pandaneko

a good resume of the IKAROS missions, its technologies and its results so far (in English)
http://www.isas.jaxa.jp/e/forefront/2011/tsuda/index.shtml

IKAROS had kinda fallen out of my brain! That article put it back in.

Thanks Paolo

Aviation Week is running more or less the same story: Japanese Researchers Controlled Solar Sail

Thanks Paolo! I saw the Aviation Week story and came directly here to see if anyone had a link to Yuichi Tsuda's paper and, as always, UMSF came through.

The sheer, simple elegance of this experimental spacecraft has always left me almost speechless. Integrating propulsion, power generation, attitude control, and science instrumentation into the sail was simply brilliant and a huge step beyond what any other solar sail experimental craft have been designed to do. I am so glad to see that JAXA and the IKAROS team have achieved all their goals and that so many of their concepts have been proven viable.

It is without a doubt the crowning achievement of JAXA to date IMO. It may well be the most important spacecraft of the last decade in terms of spacecraft propulsion and control. I look forward to their follow-on spacecraft that will build on this success and add an Ion engine.

Ikaros reversed its spin yesterday: http://www.jaxa.jp/projects/sat/ikaros/index_e.html

if I understand correctly today's release, IKAROS has been put into hibernation owing to the large distance from the Earth and Sun, making communication difficult and owing to the quasi-depletion of its reserves of gas for attitude control
http://www.jspec.jaxa.jp/ikaros_channel/bn018.html
pandaneko, can you confirm?

Yes, Paolo, but not in one go、I am afraid. I will translate the whole lot in parts. First, the introduction.


Updated 6 January 2012.　

About the result of reverse spin operation of IKAROS and transfer into heybernation mode

We have been analysing the result of above reverse spin operation carried out on 18 October 2011 and we are now able to offer detailed information about this reverse spinning.

Also, we are informing you that we have confirmed that IKAROS has entered into a hybernation mode, and this is judged from the operation records up until now, by 6 January 2012 (instruments shut down because of the decrease in the power generated).


◆ Result of the reverse spin operation

On 18 October 2011 IKAROS sfifted into the reverse spin status without any hitches. Its data is carried on the table 1 as follows.

P

thanks pandaneko. there is also an English release at http://www.jaxa.jp/projects/sat/ikaros/index_e.html but it seems to lack some of the details of the Japanese version

The table in question is a regular matrix, 3 columns and 7 rows. Members are as follows.

C1R1: Item of evaluation.
C2R1: Before reverse spin operation
C3R1: After reverse spin operation

C1R2: Spin rates
C2R2: 0.17 rpm
C3R2: - 0.24 rpm

C1R3: Spin rate changes
C2R3: about 0.1 rpm (decreasing)/ day
C3R3: about 0.1 rpm (increasing)/day

C1R4: Sun angle
C2R4: tendency to increase
C3R4: tendency to decrease

C1R5: Sun-IKAROS distance
C2R5: 0.72 AU
C3R5: 0.72 AU

C1R6: Earth-IKAROS distance
C2R6: 1.10 AU
C3R6: 1.10 AU

C1R7: Remainning fuel
C2R7: about 2 kg or less (note: 20 kg at launch)
C3R7: reverse spin used a few hundred gramms of fuel

By the way, IKAROS is a kite and the kite in Chinese characters consists of a wind component and a width (or, span) component. I think it is lovely.

P

The rest of this release follows below.


◆ About the shitft into hibernation mode

Ikaros' behaviour after the reverse spin operation is now known to be like:

(1) Owing to the gradually increasing reverse spin rate the sun angle has been increasing and IKAROS has transferred from Solar photon pressure priority (*1) navigation mode to inertial guidance priority navigation mode (*2).


(2) IKAROS is currently flying on an elliptical orbit around the Sun, and its Solar distance in AU will continue to increase until March 2012 when it passes the furthest point from the Sun.

(3) Due to above (1), (2) a decrease in power is expected. As a result of this, if the generated power is less than the consumption power, then IKAROS will go into hibernation mode (i.e., shutting down instruments on board)

(4) Even if we tried the spin rate down operation (or, attitude control) by gas jet control our conclusion is that we will not be able to obtain dramatic changes as the remaining amount of fuel is so low.



（*1） Solar photon pressure priority mode:

IKAROS' attitude is strongly influenced by the Solar photons. Membrane is facing the Sun.


（*2） Inertially guided direction priority mode:

IKAROS' increasing spin rate is forcing IKAROS to take up the attitude (orientation) that is strongly influennced by this spin rate change. In the case of IKAROS, it is the increasing Sun angle.

Based on these behaviours we have not attempted any attitude control since early December and have simply continued to obtain the attitue data as the Sun angle increased, trying to check on the health of IKAROS.


Consequently, we are pleased to inform you that IKAROS has entered into hibernation mode by today.

From now on, we will try to investigate the possibility of signal reception once after the hibernation.

End of this release

P

if you want to test your karaoke skills here, freshly released, is a IKAROS-dedicated song!!!
http://www.jspec.jaxa.jp/ikaros_channel/bn019.html

What follows is not a direct response to yours as above, but to another of yours that followd this. IKALOS operational status as in late April 2012 at ISAS(JAXA) operation room and that goes as follows:


However, IKALOS still seems to be in heybernation. Next operational contact is scheduled to be for 8 May.

I am KY from the team IKALOS. I offer my greetings from the team.


I am pleaased to say that thanks to your and all other people we have been able to finish the latter half of the operation ( from January 2011 to March 2012) without any hitches. I thank you profoundly for this. I really mean it.

We continued our dialogue with various sections within JAXA and I am pleased to say that now we will be able to continue with our operation of IKALOS from next fiscal year on. This is making it possible, if IKALOS comes back from its current heybernation, to monitor its membrane shape data and attitude control data. Our team is very pleased with this possibility.

For your information, you can look at these contents at (PDF only)


　
　　↓↓↓
　http://www.mext.go.jp/b_menu/shingi/uchuu/017/gijiroku/1316992.htm
　
　（Ministry of Education HP, 10th Space Activities Commission 2012）


　

IKALOS as of 17 April 2012
Solar distance: 1.06AU
Earth distance: 229134867km, longtitude=-14.4°, lattidue=-8.2°
Distance to Venus: 1.61AU(240444296km)
Attitude：Spin rate= ** rpm, Solar angle= ** deg

Today's IKAROS
Sun Distance: 1.06AU
Earth Distance: 229134867km, RA=14.4deg, Dec=-8.2deg
Venus Distance: 1.61AU(240444296km)
Attitude: Spin Rate= ** rpm, Sun Angle= ** deg

(all this does show that my translation is not professional!!!)

Pandaneko

Science results from the ALADDIN dust monitor onboard IKAROS regarding the cosmic dust flux
in the inner solar system presented at 2012 LPSC:

http://www.lpi.usra.edu/meetings/lpsc2012/pdf/1632.pdf


Tolis.

if I understand the latest blog entry, IKAROS has responded to a command to switch on its transmitter last 6 September
http://www.isas.jaxa.jp/home/IKAROS-blog/i...php?itemid=1000

That's not how I read it; it seems to talk about "the search continues" and "why we keep looking" and the orbit info is "for reference only."

I hope pandaneko or someone else speaking Japanese can help

Paolo, it looks like I have to apologize; I think you were right. I'm asking for help translating this update:
http://www.jspec.jaxa.jp/ikaros_channel/
Here's how Google does it, which in fact sounds like IKAROS has been heard from: