There was a brief TV news coverage on Hayabusa 2 on NHK here yesterday. It said that in order to accelerate the development of Hayabusa 2 a new project manager was appointed. He is Prof Hitoshi Kuninaka of JAXA (that is ISAS). He was apparrently responsible for the development of ion engines used on Hayabusa 1.

Prof Makoto Yoshikawa of NAO (National Astronomical Observatory) is no longer the PM for Hayabusa 2 ? In any event the news also said that fabrication of Hayabusa 2 components is progressing rapidly in time for sending it out in December 2014.

The TV also showed the impact simulation, very briefly, 2 ,3 seconds. There was a clear and large fireball in mid air (it did look like an explostion, not a firing of a projectile) , and also an explosive impact on the asteroid surface. I am not sure if there was a time lapse between them as the video was so brief. I am more and more confused by this...

P

Is Prof. Kawaguchi involved in Hayabusa-2 at all?

Good question and I am even more confused by all this. My Google alert today (local Kyodo Tsushin, a news provider like AFP), I think, gave me an e-mail (2012/09/15 16:56) and it says Hayabusa 2 is progressing steadily under the direction of Prof Makoto Yoshikawa. My earlier posting was based on the NHK news which I saw on 17 September.

Since I am not exactly sure about the difference between PI and PM both of them may still be involed, but probably not Prof Kawaguchi.

This Google alert of 15 September also gave me a clue to what I had been wondering about. It says that a mass (not an explosive mass) will collide with the asteroid by the force of an explosion. This may be in line with the simulation video I saw.

There was a fireball in mid-air and it was spherical in shape. The explosion on the ground was hemispherical. This, to me, seems like a very inefficient of digging a hole in the crater. Perhaps, there is a very good reason?

P

Hayabusa 2's structure complete http://www.jaxa.jp/projects/sat/hayabusa2/...What%27s+New%29

That's great news. I wish JAXA posted higher-res versions of their photos with their articles....

high resolution pics are on JAXA digital archive
http://jda.jaxa.jp/category_p.php?lang=e&a...mp;page_pics=50

Thanks, Paolo

I also found an intersting article, which I have translated as follows. Its origin is given at the top of my translation. In it, P stands for pictures and G stands for graphics. Some of these are actually texts and they are too small to be properly recognied, so I have not translated these.

Here it goes, from P

http://news.mynavi.jp/articles/2012/12/28/...usa2/index.html


JAXA demonstrates Hayabusa-2 flight model to the press

On 26 December JAXA displayed the flight model currently under construction at its Sagamihara campus (ISAS campus). It is a succesor to Hayabusa which landed on
an asteroid caIled Itokawa and returned to Earth in June 2010. It was shown to the press at the time when only its main body frame and solar pannells are complete.

P-1:　Hayabusa 2 shown here. It looks very different from its final form of completion.
P-2:　This a 1/20 scale model. A cylindrical device shown in the middle of its body is the impacter.


Another point of difference is its increased length (or height)

Hayabusa 2 measures 1.0mx1.6mx1.25m and weighs 600kg including fuel. As its predecessor it is intended to carry out a sample return mission. Launch timing of December
2014 is assumed. If successful it will return at the end of 2020.


The model shown this time is the completed body frame with its solar pannels plus dummy weight components. Dummy weights are attached to ensure same weight
and same centre of gravity during the vibration tests currently being conducted.


P-3: Shown from behind the probe. Body and solar pannels are flight ready. Main body is composed of 8 alminium honeycombe pannels (6 outer and 2 inner pannels).
P-4: Holes are meant to hold iron engines. Shown in front is the dummy iron engine weight and fuel tank dummy weight is seen at the end of the hole.


P-5: A pipe like object is seen sticking out. This is a dummy middle gain antenna.
P-6: Seen from the left. 3 solar pannels per one wing are folded and obstructing the view of the side of the main frame.


P-7: The device with an ambrella like object is the sampler horn. This sampler horn also is a flight model. A cylinder shown in front is the sase for Minerba 2
(mini-rover)
P-8: Sampler horn seen from the other side. Since three minerba 2 rovers will be on board there is also another cyliner on this side.


P-9: We could not get the front view of of the main body. Dummy weight of the return capsule is only just shown here.
P-10: The model is placed on the vertical vibration tester. Red cable leading from the probe is for acceleration sensors. In front is the horizontal vibration
test bed.


Main points of difference from Hayabusa are as follows.


G-1: On board device comparison (1)
G-2: On board device comparison (2))


Conspicuous in its external appearance is the two high gain flat antennas in place of the usual parabolic antenna. Of these one is intended as with Hayabusa for X-band
(7-8 GHz) range, but the other one is for Ka band (32 GHz) range to ensure higher comms. speed and to secure higher degree of redundancy.


Vital to the return journey is the fuel efficient iron engines. Same number of four engines will be on board. However, propulsive power of each unit has been
increased from 8mN to 10mN.

New device that attracted our attention is the impacter. This device will accelerate a 2 kg copper collider (liner) to a few km velocity by explosion of an explosive
and collide with the asteroid surface, creating an artificial crater of a few meters in diamter. This will make it possible to sample prestine inner materials not
affected by solar corrosion.

There is no significant change made to the sampler horn. One small change is the nails added to the inner surface of the horn tip in order to increase the amount of
samples. The number of projecter has been increased from 3 to 4. Sample containing room is now divided into 3 sections (previously 2 sections).

With Hayabusa there was only one mini rover called Minerba which faild to land on Itokawa. With Hayabusa 2 there will be three of these of similar size and these will
be collectively called Minerba 2. In addition another small lander called MASCOT developped in Europe will be on board.


Hayabusa was intended for sampling from an S type asteroid. Hayabusa 2 will ber flying to a C type asteroid 1999JU3 where existence of organic materials and water
is expected. As a result observation devices will include a near infrared spectrometer and mid infrared camera. Of these Hayabusa did have a near infrared spectrometer,
but observation range has been changed so that water absorption band can be seen.

Main body frame looks similer in size, but it is longer by 15cm in the height direction. Its weight is also heavier bby 100kg in order to cope with the increased
number of devices.

2 years to launch, no time to loose

Expected launch timing is December 2014, but if JAXA fails to make it next launch timing will be 10 years later, making continuiation the whole project impossdible.

Sample return from type C asteroids will be scientifically significant. However, many of them exist in the main belt between Mars and Jupiter and they are
too far from here and Hayabusa class probes will not be able to cope with the mission. 1999JU3 just happens to be in near earth orbit, making it about the only type C
asteroid.




G-3: With Hayabusa 2 there are 3 points of significance
G-4: Mission scenario is different



G-5: Selection of target asteroid. 1999JU3 has been selected.
G-6: With 1999JU3 we still do not know its exact shape.


Project manager, Prof Hitoshi Kuninaka of JAXA (ISAS) stresses emphatically that they will to stick with the launch in December 2014. Theoretically speaking,
there are windows in June and December of 2015. However, arrival timing of June 2018 cannot be moved and the delayed launch will mean that much harsher operation
of iron engines.





P-11: Hayabusa 2 project manager, Prof Hitoshi Kuninaka. He was in cgarge of iron engines with Hayabusa.

December 2014 launch means 80% operation rate. However, the launch in Decmber 2015 will require 96% operation rate, meaning rest time of only 7 hours per week.
Communication with the earth station alone will require 5 to 6 hours and that means almost limiting conditions in case of troubles.

Right now, Hayabusa 2 is located at the Sgamihara campus of JAXA (ISAS), but very soon after the year end 2012 it will be transported to Tsukuba Space Center
to undergo accoustic tests. It will then be returnd to Sagamihara in mid January 2013 to undergo electricl tests and other component tests. Then, from October
2013 its final configuration will start, to be flight ready by summer 2014.

Thank you for yet another update pandaneko, appreciated. =)

Today, I actually managed to find an answer to this question of mine. It is revealed in a document presented at an annual ISAS conference of almost exactly one year ago. Since it is a short 10 page document I will fully translate it and post it tommorrow, I think.

P

Today, I actually managed to find an answer to this question of mine. It is revealed in a document presented at an annual ISAS conference of almost exactly one year ago. Since it is a short 10 page document I will fully translate it and post it tommorrow, I think.

P
[/quote]ause of that

As it turned out this is a 20 page document, and not because of that I have not been able to translate the whole pages. So, I am uploading that has been translated so far, as follows. P

My notation is as follows.

Squares on the original PPT files are designated as S (such as S1, S2 etc) and the diamonds are designated as d (such as d1 and d2 etc).

Title page

Hayabusa 2 collision device (S1-07)

5 January 2011
Hayabusa 2 project - collidding device subsystem
T Saeki (JAXA)

P-1 (page one)
Page title: Hayabusa 2 project

S1: With Hayabusa 2 we intend to create an artificial crater by making a colliding body collide with an asteroid.

S2: We will observe thus created crater and subsequently try to sample soils in the crater.



On this page there are 3 boxes as follows. They correspond to Launch, Re-entry, and Sample analysis. Also,
there are three pictures.

Picture -1 at the top is qualified as :

Remote sensing observation (optical cameras, infra-red spectrometer, LIDAR (distance measurement)) etc
＝＞ investigation of the asteroid characteristics
Asteroid observation from vicinity, small rovers, sampling of surface materials

Picture -2 in the middle is qualified as:

Carrying out the collision operation

Picture -3 down at the bottom is as follows:

Observation of crater formation by cameras and sampling of prestine materials (extra bonus if successful)

P-2
Page title: Hayabusa 2 colliding device

S1: SCI(Small Carry-on Impactor)

S2: Create an artificial crater by a collision process

d1: Acceleration by rocket motors etc will mean longer acceleration distances and neccesitate guidance,
leading to system becoming too complicated.

S3: Use an explosion formed intrusion mass which can be created in a very short time so that the colliding device itself willl not neeed to
control its own attitude and carry out guidance.

d2: Acceleration of a metal object by an explosive charge
d3: Ultra-short time acceleration: (up to 2km/s in 1ms or less)
d4: Less contamination of the soil because explosion itself will not crate the crater
d5: Casing material will fly away by the force of explosion

P-3
Page title: Colliding device configuration (graphics and from left to right, section or areawise)

Re-entry vehicle (pale blue area on the left)
and it includes cameras

Remaining area(s) to the right of the re-entry vehicle depicts the collision device which includes:

A: Seperation mechanism (which, I think, is slightly tinted)

and its collision device interface section contains wired interface, pyros for seperation and seperation connecter spring


B: Collision device body

and this consists of :

B-1: Collision controller which includes:

temp. monitors, heaters, power source circuits, sequensers, seperation detecting sensors, primary batteries, ignition/safety mechaism,
heat controlling materials

B-2: Collision explosive section which contains:

relay explosive (ignition explosive?), main explosive charge and a metal liner

P-4
Page title: Mass etc

S1: Mass: Less than 20kg (including seperation mechanism)
S2: Physical size: 300mm diamter x 300mm height
S3: Location: Z face of the probe (inside the rocket coupling ring)

P-5
Page title: Seperation mechanism

S1: Spin seperation (same as Hayabusa)

d1: Collision device itself is not equipped with an attitude control system. Mothership will direct the device.
d2: Spin will be given becuse of the long time before collision (40 minitues) after seperation to maintain its attitude.

P-6
Page title: Outline of collision operation

S1: Colliding device will scatter small fragments in all directions (with velocities up to a few km/s). In addition, landing on the asteroid surface will mean
soil scattering. For this reason, the probe will hide behind the asteroid immediately after the seperation.

(after this, there are 3 boxes as follows)

Box 1: Debris avoidance operation: Hide behind the asteroid.

Box 2: Avoiding high speed ijecta by hiding behind the asteroid: Hide behind the asteroid.

Box 3: Avoiding low speed ijecta: Keep enough distance from the asteroid if they are doing regular orbital flying. At ultra high altitudes
they will have very small velocities and impact effects will be minimal and the probability of collision itself will be very small.

thank you for your translation, pandaneko, as usual
can you share the link to the document you are translating?

From "Small carry-on impactor of Hayabusa2 mission"

A schematic of the shaped charge penetrator, a model, and a test impact.

More pictures at the link.

Click to view attachment

EDIT: The model pictured above is captioned: "Small model of the explosive part. Weight of the explosive is about 150 g." The schematic below is captioned: "Shape of explosive part. It has a liner face in the shape of a shallow dish. The weight of the explosive is about 4.5 kg." So it seems the actual impactor will have 30 times the explosive as the model.

Click to view attachment

Quote removed - Mod


Thank you very much for this. I am particularly grateful because I now seem unable to access the original source file. It was:

http://ae86.eng.isas.jaxa.jp/sss12/paper/s...20202232209.pdf and when I try it I am refused access and one of the advices given is the cache file below, but it does not carry pictures and schematics.

http://webcache.googleusercontent.com/sear...20202232346.pdf

However, I pasted texts into my memo pad. I think some of these are still useful without picture reference and I will try to translate them this evening. In any event "centsworth_II" information is sufficient for us to understand impact operation, I think.

P

Quote removed - Mod

This, actually is far better than the pictures and schematics carried in the document I was using. For instance, All I could find as the liner shape was a simple vertical line because only a cross section schematic was there in the document I was translating. Here, you can see a lot more.

Anyway, I have been yapping about this mid spce explosion for a long time, thinking that such an explosion cannot possibly send the colliding mass in the right and accurate direction. I am now a lot happier.

In case anybody is interested I am pasting the remaining pages of translation as follows. P

P-7
Page title: Collision operation

Outline:

1.Mothership descends to the asteroid with the collision device pointing to the asteroid
2.Seperation at an altitude of approx. 500m
3.Horizontal evacuation maneuver
4.DCAM seperation
5.Vertical evacuation maneuver
6.Detonation. Timing is by a pre-set timer. Timer is activated on detecting seperation.

P-8
Page title: Evacuation time

Time between seperation and detonation:

If too short then delta V required for evacuation will get larger. If too long the error in colliding position will get larger,
making the collision point area lager and/or fall to the asteroid before detonation

(I remember there was a couple of pictures here, P)

P-9
Page title: Evacuation maneuver and collision accuracy

Time from seperation to detonation: 2400 seconds, collision point accuracy (radius) of approx. 200m, evacuation delta V is approx. 10m/s


P-10
Page title: Explosive section:

Shape: conical
Liner: Copper without oxygeon
Explosive charge: HMX type PBX
Mass: Approx. 9kg (explosive charge alone is 4.5kg)

P-11
Page title: Liner flight

Liner shape: Shell type.
Deformation time: < 0.5ms
Relative collision velocity: > 2000m/s.
Mass: > 2kg.

P-12

Liner into sand experiment

P-13

1/2 scale model tests

P-14

1/2 scale model flight tests (continued)


P-15

1/2 scale model flight tests (continued)

P-16
Page title: Long flight tests

Test flight distance of approx. 100m

P-17
Page title: Long flight tests (continuation)

Collision body : 1/1 scale model was used and it was confirmed that its intended flight shape was
successfully formed by explosion

P-18
Page title: Long flight tests (continuation)

Deviation from designed flight path of less than 1 degree confirmed, velocity also confirmed

P-19
Page title: Long flight tests (continuation)

Observation of ejecta was carried out

P-20
Page title: Summary

Designed results confirmed and further improvements will be made.

Below is just for your information.

March edition of Scientific American (Japanese version) apparently gives the names of those involved in Hayabusa 2 as follows.

Project manager is Prof Hitoshi Kuninaka of JAXA (ISAS).
Project scientist is Prof Seiichiro Watanabe of Nagoya University. His main interest is planet formation.
Mission manager is Prof Makoto Yoshikawa of JAXA (ISAS and National Astronomical Observatory)

P

On my way back from a gym session I walked into a library and amazingly found the March edition of this Scientific American!

There was a short article in it with some photos. Photos apart, what caught my eyes were:

1. There will be a small camera to televise the moment of crater creation.
2. There will be 4 reaction wheels (instead of 3 on Hayabusa), all supposedly trouble free because JAXA now know what went wrong with Hayabusa reaction wheels.
3. Improved (on Akatsuki's) chemical engines.
4. More powerful (+ 20%) ion engines.

P

Is the reason for the reaction wheels failure available to the public ?

I have no idea and the article did not mention the reason. If there are JAXA reports on this issue I am sure there are reasons given there, but finding those reports is a big problem, I think. By the way, Hayabusa 2 will definitely go in 2014 as the funding has been secured. There have been many newspaper reports on this.

P

Ah, so the explosive device is not "fired" at the asteroid, so there would be no kick-back. The main vehicle starts moving toward the target, releases the impactor, and then moves away, leaving the impactor to continue on toward the asteroid.

What follows is from MSN-Sankei newspaper dated 07:58 (local) on 18th March 2013.

JAXA announced that they will use part of the contributions from the general public (approx. JPY 20.000.000) for the flight of Hayabusa 2 in order to install an additional camera at the bottom of the main body so that sampling process can be viewed from the earth.

P

Wow! Now that's dedication to PR!
Yes, it's not entirely unprecedented (Junocam, etc.), but seeing such support for outreach is very reassuring.

Most impressive to see that outreach in this case is a two way street. Public donations used for a high public interest instrument. Similar to the Planetary Society's Mars Microphone. I have a feeling (hope) that the camera will be a more integrated instrument that will actually be used as opposed to the microphone which was more like a hitchhiker that mission planners were reluctant to turn on.

Impressive outreach indeed, but let's be careful when analyzing the reasons why instruments are included or omitted. Integration is sometimes more art than science; designers are wary of add-ons, and rightly so.

Hayabusa 2 Name and Message Campaign

http://www.jaxa.jp/press/2013/03/20130329_hayabusa2_e.html

I love these send your name things. I can show support and almost be immortal. GO JAXA!

You can now submit your name on the Japanese version of JAXA's Hayabusa 2 page:

http://153.122.7.196/form/

(Deadline: Juy 16 - 12:00 PM JST)

The English version should be up on The Planetary Society's website this Saturday (April 13)

You can now submit your name on The Planetary Society's website:

http://www.planetary.org/get-involved/messages/hayabusa-2/

I have checked with JAXA HP in English, but I could not find immediately if what follows is actually carried there. So, just in case, what follows is from Nihon Keizai Shimbun dated 23 April.

"JAXA are inviting 2 piggy-back interplanetary space probes:

JAXA announced on 23 April that they will invite 2 piggy-backs to be launched with Hayabusa 2 on their H2A rocket. Invitation period is by the end of May and selection will be made at the end of June. 2 space probes of each less than 50 kg are invited. Hayabusa 2 itself will weigh 600 kg."

This makes me think and wonder as follows.

1. Can anybody make proposals so quickly?
2. This must be just powdering operation and the infomation has been circulating within intimate circles, both domestic and intrernational, for a long time.

P

" 2 piggy-backs to be launched with Hayabusa 2 "

I thought the ATOM (Mars aero-capture mission ) would be one of those missions?
I read something about it in 2012.

according to this presentation (undated but named "fall 2012")

I honestly don't think so, just a proposal can take up to a year to get a heads up. Then they would have to build it.

Even if some agency or university were sitting on one suitable unlaunched craft/probe, they would have to practically carry it out the door directly for intergation and testing.
So it sound like a nice offer, though one without actual candidates, now that delays have created a vacant spot - perhaps even two.

Is it also too late to use those 50 kilos on Hayabusa 2 itself, somehow? Or is this offer specifically for other craft on the same launcher? I mean it would be a waste to just let an opportunity like this go.

Sure, but it would be a risk to rush a development & integration effort with too little time for testing before the launch date. Let's see what they do.

for more info on the Mars aerocapture demonstrator see this JAXA presentation

Aviation Week and Space Technology reports that Japan will be cutting back on its space plans and, "But former high-priority goals to promote environmental monitoring, human space activities and putting robots on the Moon are now much lower priorities and will have to fight for funding." I don't know how this will affect Mars plans. Hayabusa-type missions are apparently still planned.

Hayabusa 2 will be accompanied in solar orbit by two microspacecraft, PROCYON and Artsat 2 and possibly also by Shin'en 2.
The most interesting of the bunch is PROCYON which, among other things, will demonstrate imaging techniques during at least one but possibly up to three close flybys of small NEOs
a presentation of the mission and spacecraft is available here

a rather detailed description of PROCYON (in Japanese) is available here

Re above I have just translated this article and the first few pages (up to page 5) are as follows. The rest can be uploaded within the next week, I think. (P)

Contents of Presentation
• Significance and possibility of hyper minitualisation in deep space exploration

* Reference in Space Science and Probe Roadmap
• What is hyper minitualisation?
• Status of hyper minitualisation space probe industry
• Mission possibilities in hyper minitualised deep space probes

* PROCYON- 50kg class hyper minitualised deep space probe
• Mission outline
• Probe system outline
• Development
• Development schedule



P-2

(continue from page 2)

Significance in minitualisation and hyper minitualisation

What follows are some of the remarks made in the Space Science Probe Roadmap. Here, Importance of minitualisation of satelliets and space probes is recognised.
• with a view to realising low cost and high frequency space science missions using improved Epsilon rockets we should aim at minitualisation and improvements of satellites and space probes
• improved Epsilon rockets should be able to send out small solar system probes more frequently...
• future visions of space probes and satellite systems...through innovation, minitualisation, and weight reduction in probe architecture we should aim at more advanced and flexible missions

Ｐ-3

•Objectives in minitualisation include frequent missions under budgetary and costing constraints. However, it does not mean "minitualisation=conpromise in sceince results (should not)

---> what should then we be doing?

Hyper minitualisation=Innovation (diagram header)

Horizontal axis: system scale and number of functions etc.
Vertical axis: costs, weight, development length etc.

horizontal dotted lines in red: limit of costs and weights etc.

3 character sets in square from top to bottom are:
No innovation
Innovation speed: low
Innovation speed: high

(Annotation along the dotted lines in black from LL to UR)

more functional!
more advanced missions!
more... more...

P-4

Annotation along the dotted lines in red from LL to UR
innovation in minitualisation
(such as introductionof highly advanced techniques) etc.)
more advanced missions made possible!





P-5

Second portion of the translation as follows. Page 5 to page 10. (P)


Examples of innovation in hyper minitualisation
(page header)

similar accuracy in positional astronomy (characters to the right of left larger photo, above arrow)

HIPPARCOS (ESA) >1ton, 1989 (left photo)

Nano-JASMINE (Univ. Tokyo) 33kg, 2014 (right photo)

"achieved mass reduction to 1/30 via progress and revolution in technology"
(not at the expense of function or capability)




P-5
Towards hyper mini satellites: Hodoyoshi project
・aiming at education/engineering experiments: learning from failures

(first 4 lines in the top left yellow square as follows)
・unpractical S/N ratio and comms. capability etc.
・trial and error (time consuming at times)
・no standardisation - one product only

(next 4 lines in the bottom left yellow square as follows)
・practical level capability and reliability
・development of small yet functional devices­
・systematic developmental methodology
(being sure of end products)
・standadizing on software and satellite components etc.
(applicable to other uses)
aiming at low costs and shorter development period
P-6
(character sets below top right photo as follows)
angular resolution of 30～1000m
10 kbps

(character sets below bottom right photo as follows)
angular resolution of 2.5～200m
100 Mbps

(No need to translate page 7)

(four character sets from top to bottom)
Catalogue of onboard devices (Hodoyoshi project)
Ultra minituare electric propulsion
Radiation hardened ultra small onboard computer
Ultra small attitude control devices
(such as iW，CG，C，CQ

P-8
(No need to translate page 9)

Significance of ultra minitualisation in deep space probes: even lighter and even deeper

(character set on the graph, top right)
（figure: courtesy of ISAS)
(characters along the solid lines from top to bottom)
reinforcement LEO 3 ton class
reinforcement LEO 2 ton class
4th stage
(character set lower right at top as follows)
50kg class, Ultra small probes X 4
(character set lower right at bottom as follows)
50kg class, Ultra small probes, C3 approx.40 (Ceres)
(and at the very bottom as follows)
(C3：how much deeper can we throw into?)


P-10

Thank you very much for the translations!

Translation of pages 10 to 15. More will follow. P

Significance of ultra minitualisation in deep space probes: even lighter and even deeper

(character set on the graph, top right)
（figure: courtesy of ISAS)
(characters along the solid lines from top to bottom)
reinforcement LEO 3 ton class
reinforcement LEO 2 ton class
4th stage
(character set lower right at top as follows)
50kg class, Ultra small probes X 4
(character set lower right at bottom as follows)
50kg class, Ultra small probes, C3 approx.40 (Ceres)
(and at the very bottom as follows)
(C3：how much deeper can we throw into?)


P-10
Ultra small deep space probes - mission varieties (1)

＊ Piggy back on larger space probes and missions
– examples: IKAROS (on Akatsuki)，PROCYON（on Hayabusa 2)
– frequency is minimal, but offers precious opportunity despite the lack of merit arising from low cost and high frequency potential

＊ Piggy back on GTO (geostationary transfer orbit) missions
–small kick stage (approx. a few 100kg) added to the top of launcher is used to insert small probe into orbits outside gravity (C3>0) after main satellite insertion into GTO
– after that the probe will move into its own mission orbit by EDVEGA etc. (electric propulsion as used in Hayabusa)

Ｐ-11


Ultra small deep space probes - mission varieties (2)

＊ single probe launch by low cost, medium rocket (Epsilon)
– insertion into orbit which reaches ultra far astronomical object making use of its light weight (approx. 50kg)
– conducting risky project as precursor to future medium to large missions

＊ cluster of probes launched by medium, low cost rocket (Epsilon)
–simultaneous launch of ultra light probes by a single rocket
– insertion into far reaching orbit is not possible, but individual orbit manuevability can secure limited mission　freedom and variation (--> leading to low cost and frequent deep space missions


P-12

Technologies required for lutra small deep space probes
(header)

• electricity generation very far from Sun --> ultra light weight power generating system (above all photos)
• highly efficient and small propulsion system for orbital manipulation (above middle two photos)
• overall weight reduction in bus related devices >> (attitude control system, power system, computers etc.)
(above bottom three photos)

(and at the very bottom)
Component technologies for ultra small deep space probes are becoming available

P-13

Presentation contents
• Possibility and significance of ultra small deep space probes
• References made in space science and probing roadmap
• What is meant by "Ultra small probes"?
•Current status of ultra small probe industry
• Mission varieties and realisability of ultra small deep space probes
• PROCYON- 50kg class ultra small deep space probes
• Mission outline
• Outline of probe system
• Development
• Development schedule

P-14

Outline of PROCYON mission
(PRoximate Object Close flYby with Optical Navigation)
Mission sequence
Dec 2014: launch, followed by a series of various component engineering test missions
Dec 2015: Earth swingby
After Jan. 2016: Planetary flyby mission

Outline of mission components

1. 50kg class ultra small deep space probe bus technology testing (nominal mission)
(contents in bottom left square)
a. orbit determination, comms., attitude control, temp. control, and power generation in deep space
b. orbit manipulation in deep space by ultra small electric propulsion system
2. Verification of deep space probing technologies
(contents in bottom right square)

(Advanced mission: additional mission components)

c. comms. by highly efficient X-band power amp. using GaN
d. VLBI navigation in deep space
e. flyby around asteroids using combined radio and optical wave navigation
f. asteroid flyby in ultra proximity and at high velocity using line of sight tracking

＜Outline of ultra close, high velocity asteroid flyby＞
(explanation on the right handside picture of probe)

Relative velocity in flyby
> a few km/s

Minimum approach distance
a few 10km

line of sight control

Flyby at ultra close range and obtain high resolution pictures by mirror driving on board and line of sight tracking feedback of pictures

End of P-15

thank you Pandaneko, and welcome back!

More pages (18,19,20,22) to follow. P

(No need to translate pages 16 and 17)

System configuration

Hodoyoshi satellite system is used for the main system components of power and EDHS/EAOCS.
(Tuning and improvements for deep space mission will be conducted for PROCYON)

①Comms. system (ISAS)
②Propulsion system (Univ. Tokyo and ISAS)
③ Mission system (Univ. Tokyo, Meisei Univ, Rikkyo Univ)
(optical camera for asteroid observation)
(geo-corona imager)

P-18
Ultra smal comms. system for deep space probes
We are developping ultra small X-band comms. system which is compatible with other deep space probes such as Hayabusa

Specs. of PROCYON communication system
目仕様
Frequency band is X, category B
Uplink frequency: 7.1 [GHz]
Downlink frequency: 8.4 [GHz]
Coherent ratio: 749/880
Output power: larger than 15W
Command bit rate: 15.625, 125 [bps], 1 [kbps]
Telemetry bit rate: 8 [bps] 〜4 [kbps]
Maximum communicable distance: larger than 2 [AU]
Orbit determination: R&RR
Grund stations: Usuda and Uchinoura
P-19
HGA(PZ plane)
MGA(MZ plane)
LGA(PZ,MZ plane)

Unified propulsion system of ion thruster and cold gas jets
(what follows is the character strings inside top square)
Unified propulsion system using Xe based electrical propulsion (small acceleration and high specific impulse) and cold gas jet system for attitude control (RW unloading)+ orbit conrol (acceleration)

(middle table contents as follows)
Probe total mass: 60 kg
Xe mass: 2.5 kg
MIPS specific impulse: 1200s
MIPS propulsion: 300×10-6N
CGJ specific impulse: 25s
CGJ propulsion: 11×10-3N

(below satellite picture, colours correspond)
Ion thruster thrust direction
CGJ is used together with RCS for orbit control

(character string at very bottom)
Ion thruster for Hodoyoshi satellite

P-20

(No need to translate page 21)

Mission System

（Optical navigation and flyby camera）

• Imaging system for high speed/ultra close flyby

• Realise angular resolution even by the small satellite borne telescope required for optical navigation during close flyby of asteroid

• Realise high speed changes in line of sight by controling the rotation of part of the telescope system (driving mechanism) through image feedback

Optical system
High speed line of sight changes by driving mirorr rotation
→capable of tracking asteroid before and after closest approach
(inside top right square)
Optical system capable of observing objects as dim as magnitude 12 despite 50mm aperture and 150mm focal length
(inside bottom right square)
Driving mechanism capable of controling the rotational angle around optical axis of the telescope
P-22

(end of pages 18, 19, 20, and 22)

Pandaneko, just wanted to thank you for yet another superb effort to help us English speakers understand yet another JAXA mission; it's very much appreciated!!!

What follows is the rest of my translation. P

Development teams

Joint project by JAXA (ISAS) and Tokyo University community

aiming at entirely new form of deep space exploration (ultra small deep space probe) by bringing together knowhows (ultra small satellite technology/deep space probe technology)

(System: Univ. Tokyo/ISAS)
(Ground operation: ISAS)　　　　　　　　　　　


Propulsion system: Univ. Tokyo/ISAS

SAP opening: Nihon Univ.

Mission system: Meisei Univ./Univ. Tokyo

Science instrument: Rikkyo Univ.

Comms. : ISAS

DH system: Tokyo Science Univ.

P-23

Development schedule

Flight model of each device is currently being manufactured in time for flight model integration in April 2014

Nearer events:

System structure model/thermal model testing (mid Jan. to Feb.)
Compatibility testing Usuda and Uchinoura ground stations (mid to end Feb.)

(what follows is the translation of characters inside the chart)

The character above 7 8 9 10 11 12 1 2 3 refers to fiscal 2013 and the numbers correspond to July (7), August, September up to March (3)

The character above 4 5 6 7 8 9 10 1112 refers to fiscal 2014 and the numbers correspond to April(4), May, up to December (12)

(Hereafter the chart is regarded as a matrix and from left and from topwise:)

(C1:R1) :system
(C1:R2): device
(C2:R1): design
(C2:R2): tests
(C2:R3): newly developped devices
(C2:R4): devices already developped
(C4,5,6:R1): system design
(C5,6,7,8:R3): BBM/EM manufacturing/test
(C8,9,10,11:R3): FM manufacturing （some devices）
(C5,6,7,8,9:R4): FM manufacturing/environment test （some devices）

(and finally, diagonally across the bulk of chart from top left to bottom righ)

STM/TTM test
Usuda/Uchinoura compatibility test
prior compatibility test
all devices integration test
final overall test
margin
launch site work/loading
launch (December 2014)


P-24



Summary

• Significance and possibility of ultra minitualisation of deep space probes

– Minitualisation/ultra minitualisation is an important direction to take in order to carry out low cost and frequent science missions (as stated in Space Science Roadmap)
– What is required is not a simple minitualisation of mission and system scales, thereby making compromises in the mission results
– Ultra minitualised satellite industry has been active at innovation by introducing advanced technologies available in private industries (by improving on introduction methods), thereby making it possible to produce light weight, small, and low cost satellites with high capabilities
– Other component technologies are increasingly becoming available in order to achieve ultra minitualisation of deep space probes
– Epsilon+4th satge may be able to send ultra miniture probes into orbits of Mars and beyond re. If increased from 50kg to 100kg they are still sufficiently light for dual (tandem) probing missions．

• PROCYON: 50kg class ultra small engineering test deep space probe

– Verification of ultra small deep space probe bus system and ultra close and high speed flyby approach to asteroid
– Collaboration between university teams and ISAS/JAX with a view to achieving new form of deep space exploration
– Piggy back launch on Hayabusa 2 is expected in December 2014

Ｐ-25

Fantastic work Pandaneko. Thank you so much for translating all that information.

Paolo, thanks again for this. Do we know anything more about Artsat 2. If 2 was there 1? What was it?
Also, Is the launcher of Hayabusa 2 still going to be H2A? I am confused because I realised during
the course of my translation that they may be using this Epsilon.

As far as I know its first launch was some time last year and I am not too sure if it is reliable.
Again, it is not that important, and I am only curiious. P

pandaneko, Artsat 1 was launched in February as a secondary payload in Earth orbit. they have a good Facebook page

This really is just in case what follows has evaded the attention of colleagues so far.
I have come across an interesting short video describing activities for MASCOT.
Its URL is as follows.

https://www.youtube.com/watch?v=DbLmmvki_Bo

It is all German and yet it gives us an insight into the workings of this lander.
Actually, if you come to think about it this is all the more interesting because
with Hayabusa we had to imagine what the landing site looked like.

However, MASCOT will give us actual images and I am already very exited about this prospect. P

Yes : thanks a lot Pandaneko for your translation. What an useful work !