From: roelle@uars_mag.jhuapl.edu (Curtis Roelle)
Subject: Re: Japanese 1990 Lunar Probe
Organization: Johns Hopkins University
Distribution: sci
Date: 12 Nov 92 14:47:18 GMT

baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes:

>In article <BxKFIA.5Er.1@cs.cmu.edu>, 0004244402@mcimail.com (Karl Dishaw) writes...
>>I saw a UPI dispatch saying that Japan launched two satellites to the 
>>Moon in January 1990, but there wasn't anything in the FAQ about them.  
>>Does anybody know what happened on that mission and whether they got 
>>any useful data?
>> 

Regarding useful data.  As I recall it was an engineering mission more
than a science mission.

>I wrote this about the Japan probes a year and a half ago.  I've also
>appended Yoshiro Yamada's post on a later lunar fly.

>                            HITEN STATUS REPORT
>                               March 8, 1991

>     Japan's small Moon probe, Hiten, made its seventh lunar flyby on March 3,
>passing about 13,300 km from the Moon.  JPL's Deep Space Network is tracking
>the spacecraft.  On February 28, the 34 meter Goldstone antenna supported
>ranging tests on Hiten, and were successful.  On March 1, the same antenna was
>used to collect 24 minutes of ranging and doppler data.

>     Hiten was launched into Earth orbit on January 24, 1990.  The spacecraft
>was then known as MUSES-A, but was renamed to Hiten once in orbit.  The 430 lb
>probe looped out from Earth and made its first lunary flyby on March 19, where
>it dropped off its 26 lb midget satellite, Hagoromo.  Japan at this point
>became the third nation to orbit a satellite around the Moon, joining the
>Unites States and USSR.

>     The smaller spacecraft, Hagoromo, will remain in orbit around the Moon.
>An apparently broken transistor radio caused the Japanese space scientists to
>lose track of it.  Hagoromo's rocket motor fired on schedule on March 19, but
>the spacecraft's tracking transmitter failed immediately.  The rocket firing
>of Hagoromo was optically confirmed using the Schmidt camera (105-cm, F3.1) at
>the Kiso Observatory in Japan.

Although the photograph confirmed firing of the rocket for lunar orbit
insertion, there is no direct evidence proving that Hagoromo entered
lunar orbit, or that it still remains in lunar orbit.  This is
according to Robert Farquhar and David Dunham, who were both with
NASA-Goddard at the time.  Radio contact with Hagoromo was never
regained, and the spacecraft is too small to be observed visually from
Earth.  Hagoromo is "assumed" to be in lunar orbit, but the fact
that the transmitter failed when the rocket was fired raises some
doubt.
 
>    Hiten will continue to make lunar flybys on a regular basis, typically
>once a month.  According to Takahiro Yamada at ISAS,  Hiten will be performing
>aerobreaking experiments on March 19 and 30.  These experiments will be done
>using the atmosphere of the Earth.  The next lunar flyby is scheduled for
>April 26.

[Hitten Ephemeris, and Yohiro Yamada's post -- deleted]

Japan has a second spacecraft that is busy making swingbys of the Earth
and moon.  The Geotail spacecraft has made two passes of the moon, with
several more planned. Even-numbered lunar encounters are passages on the 
moon's leading edge which removes orbital energy from the spacecraft.  
Odd-numbered lunar encounters are passages on the trailing edge which cause
Geotail to gain energy.  Last week Geotail came back home for a perigee
passage at Earth.  Here is Geotail's schedule over the next couple months, 
from information provided by David Dunham:

			GEOTAIL ENCOUNTERS:

			NOV 5	Perigee 
			    8	Lunar #3
			Dec 10	Apogee 
			Jan 10  Lunar #4
			    12  Perigee

Curt Roelle
roelle@sigi.jhuapl.edu