Moon Society congratulates Japan on successful launch of Kaguya probe towards the Moon

September 15, 2007 Yesterday, JAXA, the Japanese Space Agency had another significant success. The massive 3 ton Kaguya probe, carrying two subsatellites, was successfully into a complex set of trajectories which will bring it into lunar orbit by October 3rd.

Kaguya is the first of the "Lunar Decade" salvo of International lunar missions. China is set to follow later this year with Chang'e 1, India plans to launch its Chandrayaan-1 early next year, followed by NASA's Lunar Reconnaissance Orbiter and its piggyback Lunar CRater Observation and Sensing Satellite (LCROSS). If all goes well, 2007 and 2008 will see the greatest amount of lunar activity since the Apollo Moon program ended with the return of Apollo 17 in December, 1972, 35 years earlier. All of these new probes are designed to fill in critical gaps in the knowledge we now have of the Moon, helping all four nations better plan manned landings in the 2020s.

The most recent lunar probe, SMART-1, as had its recent predecessors, Clementine and Lunar Prospector, had already given us much new information about the Moon.

One used to hear the shallow witticism about the Moon, "been there, done that." It is obvious that lunar scientists behind these recent and upcoming probes do not share that attitude. We continue to learn more about the Moon, and our picture of our neighboring world becomes more complex, captivating, and, for the prospects of permanent human presence and settlement, more promising.

Japan is not a newcomer to planetary space. In 1985, Japan launched two comet probes, Sakigake and Suisei to comet Halley; in 1990 Hiten/Muses A/Hagoromo (failed subsatellite) into a lunar trajectory; in 1998 Nozomi which failed to reach Mars; and finally in 2003-2006 Hayabusa to asteroid Itokawa. While the success of the Sample Return part of this mission is still in doubt, the encounter with Itokawa itself was an astounding feat.

Kaguya has an ambitious science program.

By the use of a subsatellite it will release as a relay, Kaguya hopes to accomplish the first live-time gravity mapping of the lunar farside.

Kaguya's 15 instruments will also study the composition and topography of the lunar surface down to a resolution down to 10 m resolution, and map the lunar magnetic field and plasmasphere. It is hoped that Kaguya's observations will shed further light on the origin of the Moon as a companion of Earth.

The probe should produce the first really good altimetry data and lunar topographic map with vertical resolution as high as 5 m (16 feet) from which we could begin to plan transportation corridors for roads and railroads.

Kaguya will be able to study the impact of the Sun on the Earth by observing both auroras of the North and South Poles at the same time from the Moon.

Its radar sounder will probe the top 20-30 km (12-19 miles) of the lunar crust. There is no indication I can find whether its resolution will be high enough to detect voids on the scale of lunar lavatubes. If so, that would be a tremendous plus.

More technical information about Kaguya/Selene

Kaguya won't reach lunar orbit until October 3 and won't begin its science operations until October 21.

Here is the planned timeline:


Date / Time (UTC)

Adjustment Maneuver of Revolution Period

Sept. 19, 00:46:01

LOI Conditions Adjusting Maneuver

Sept. 30, 18:56:01

Lunar Polar Orbit Insertion (LOI)

Oct. 3, 21:01:01

Relay Satellite Release

Oct. 9, 00:46:01

VRAD Satellite Release

Oct. 14, 05:37:01

Science observations begin in a circular polar orbit
100 km (62 miles) above the lunar surface

Oct. 21, 10:27:01

Graphic illustration of its orbital adjustments during this period

Before reaching its planned 100 km high orbit, Kaguya will release the relay satellite and then the VRAD satellite at 2,400 and 800 kilometers (1,500 and 500 miles), respectively.

Of course, as always, a successful launch and insertion into its initial trajectory, does not guarantee a successful mission for any probe. The Moon Society and the Lunar Community in general, will be watching closely. We wish NAXA a fully successful mission.

A lot is at stake. For those of us who live in a country where plans are always tentative because they are subject to fickle political processes, we are encouraged by the efforts of our fellow spacefaring nations. No matter what happens to the politically fragile Vision for Space Exploration, thanks to Japan, India, China and NASA's own now uncancelable Lunar Reconnaissance Orbiter, we are guaranteed a fascinating and encouraging few years. And beyond that, we look forward to successful European and American Student Moon Orbiters (ESMO, ASMO.)

The results of these probes will heighten global interest in Moon, not only as an object of scientific curiosity, but as a source of resources with which to tackle seemingly intractable problems here on Earth.

At 3,000 kg, 6,600 pounds, Kaguya is the most massive scientific payload ever launched to the Moon. Compare these weights: Lunar Prospector 158 kg; Clementine 227 kg: SMART-1 367 kg; Lunar Reconnais-sance Orbiter 2180 kg (with LCROSS 880 kg hitchhiker = 2,360 kg; Chang'e-1 2350 kg; Chandrayaan-1 523 kg.

With Kaguya coming so soon on the heels of a highly successful SMART-1 mission, lunar exploration is on a roll!









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