Object of Study:
     Mars' upper atmosphere and its interaction with the solar wind.

Date Launched:
     January 3, 1998

Landing Date:
     December 1, 2004

Mission End:
     Early 2006

Current Location:
     En route to Mars

Launch Vehicle

M-5 rocket

Launch Site

Kagoshima Launch Center, Japan

Space Craft Description

The Nozomi orbiter is a 0.58 meter high, 1.6 meter square prism with truncated corners. Extending out from two opposite sides are solar panel wings containing silicon solar cells which provide power to the spacecraft directly or via Ni-MH (nickel metal hydride) batteries. On the top surface is a dish antenna, and a propulsion unit protrudes from the bottom. A five meter deployable mast and a 1 meter boom extend from the sides, along with two pairs of thin wire antennas which measure 50 m tip to tip. Other instruments are also arranged along the sides of the spacecraft. Planet-B transmitter power is 2.5 W. The spacecraft can transmit in S-band (2293.89 MHz) at 35 dBm and in X-band (8410.93 MHz) at 37.6 dBm.

The 14 instruments carried on Nozomi are an imaging camera, neutral mass spectrometer, dust counter, thermal plasma analyzer, magnetometer, electron and ion spectrum analyzers, ion mass spectrograph, high energy particles experiment, VUV imaging spectrometer, sounder and plasma wave detector, LF wave analyzer, electron temperature probe, and a UV scanner. The total mass budgeted for the science instruments is 33 kg. Radio science experiments will also be possible using the existing radio equipment and an ultrastable oscillator. The total mass of Nozomi at launch including 282 kg of propellant was 540 kg. [Source: NSSDC]

Mission Description

Nozomi (Japanese for Hope and known before launch as Planet-B) is a Mars orbiting aeronomy mission designed to study the martian upper atmosphere and its interaction with the solar wind and to develop technologies for use in future planetary missions. Specifically, instruments on the spacecraft will measure the structure, composition and dynamics of the ionosphere, aeronomy effects of the solar wind, the escape of atmospheric constituents, the intrinsic magnetic field, the penetration of the solar-wind magnetic field, the structure of the magnetosphere, and dust in the upper atmosphere and in orbit around Mars. The mission will also be returning images of Mars' surface.

The arrival of Nozomi at Mars has been delayed four years from its originally scheduled rendezvous in 1999 in order to conserve fuel. The spacecraft used more propellant than planned in a course correction maneuver on 21 December 1998 after the 20 December Earth flyby left the craft with "insufficient acceleration". The spacecraft will continue in a heliocentric orbit until it encounters Mars in December of 2003.

  • Launch into Earth orbit: July 3, 1998, 19:12 UT
  • First lunar encounter swingby: Sept 24, 1998, 11:52 UT
  • Second lunar encounter swingby: Dec 18, 1998, 11:10 UT
  • Final Earth escape kick maneuver to Mars transfer orbit: Dec 20, 1998, 11:36 UT
  • Mars orbit insertion date: Jan 2004

[Source: NSSDC]


(ISA) Ion Spectrum Analyzer - Hayakawa H. (ISAS)
(ESA) Electron Spectrum Analyzer - Machida S. (Kyoto U.)
(EIS) Electron Ion Spectromete - Kikuchi J. (Waseda U.)
(XUV) Extreme Ultraviolet Spectrometer - Yamashita K. (Nagoya U.)
(PWS) Plasma Wave and Sounder Experiment - Ono T. (Tohoku U.)
(LFA) Low Frequency Wave Analyzer- Matsumoto H. (Kyoto U.)
(MGF) Magnetic Field Measurement - Yamamoto T. (ISAS)(deceased)
(PET) Electron Temperature Probe - Oyama K. (ISAS)
(UVS) Ultraviolet Imaging Spectrometer - Fukunishi H. (Tohoku U.)
(MIC) Mars Imaging Camera - Mukai Tadashi (Kobe U.)
(TPA) Thermal Plasma Analyzer- A. W. Yau (Canada)
(IMI) Ion Mass Imager - R. Lundin (Sweden)
(MDC) Mars Dust Counter - E. Igenbergs (Germany), Sasaki S. (U. of Tokyo)
(NMS) Neutral Mass Spectrometer - H. Niemann (U.S.A.)
Radio Science Experiment

Status Page

21 October 1998: Mission Update [CSA]

3 July 1998: Canadian Probe Launched to Mars, press release, Canadian Space Agency

1 July 1998: NASA instruments on Japanese Planet B spacecraft will aid studies of Martian upper atmosphere, NASA press release

26 November 1997: Japan's Mars probe in final tests, NASA GSFC






Spacecraft undergoing integration onto M-5 launch vehicle (image 1) [ISAS]

Spacecraft undergoing integration onto M-5 launch vehicle (image 2) [ISAS]

Spacecraft undergoing integration onto M-5 launch vehicle (image 3) [ISAS]

Nozomi Launch [NASA NSSDC]

First Nozomi image of Earth and the Moon [NASA NSSDC]

Nozomi spacecraft (Drawing) [NASA NSSDC]

Nozomi Hobbles On

Nozomi -- Japan's first mission to Mars - completed a successful second swingby of Earth last Thursday but damage to a heating system responsible for keeping the spacecraft's fuel from freezing may impede it from establishing an orbit around Mars in January - or ever.

Artist's depiction of Nozomi in orbit around Mars.

Named after the Japanese word for hope, Nozomi now needs all it can get. Originally scheduled to begin returning data on the Martian atmosphere in October 1999, the $88 million (11 billion yen) spacecraft is five years late and in serious trouble.

The spacecraft burned too much fuel during its first swingby of Earth in December 1998, and didn't have enough speed to continue on its planned course. To save the mission, Japanese scientists decided to take a longer flightpath that required two additional, gravity assist passes around Earth to give the spacecraft the needed boost to get to the Red Planet by early 2004.

While the use of gravity assist swingbys has become fairly routine in space exploration, what isn't all that common is the unanticipated burst of solar energy that zapped Nozomi as it approached the Earth for its second swingby. Not only did the solar flare cut off communication with the spacecraft, it damaged the heating system that keeps the fuel from freezing.

Communication has been restored, but the heating system has not been - and may not be able to be repaired. If too much fuel remains frozen at the time Nozomi reaches Mars, it could just continue on, sailing right on past the planet, scientific instruments, obviously in tow.

Yasunori Matogawa, director of Japan's Kagoshima Space Center told the BBC News Online last Tuesday: "I think there is a 50% chance of succeeding in mending the Nozomi spacecraft based on the information I have at the moment."

The daunting challenge Nozomi now confronts is yet another reminder of just how difficult space exploration can be, and, in particular, just how difficult it is to send a spacecraft to Mars. To date, nearly two of every three missions has failed.

If Nozomi can be repaired, it is scheduled to drop into orbit in late December or early January, around the same time as Mars Express/Beagle 2 and the Mars Explorations Rovers -- Spirit and Opportunity.

No one in the space community however wants to see any of one of this fleet of Mars probes fail for the simple reason that together they would represent a much greater accomplishment, indeed, a monumental triumph for all humanity. If these five spacecraft arrive intact and in good working order, they will join Mars Global Surveyor and 2001 Mars Odyssey, already in orbit, for the first-ever New Year's celebration from Mars.

For more information got to Exploring Mars at :

Canada's Nozomi spacecraft may miss its target -- Mars

Tom Spears

Canwest News Service

OTTAWA -- Canada's first space mission to another planet -- a science instrument riding on a Japanese probe heading to Mars -- is likely doomed as the Nozomi spacecraft is escaping control and may miss Mars completely.

Nozomi has been flying for five years and has already missed Mars once. It carries a Canadian-built instrument that would measure the gases in Mars' thin atmosphere. Nozomi is designed to orbit Mars.

But Japan acknowledges it can barely control Nozomi, and the spacecraft may crash on Mars within a few weeks, or miss the planet and drift aimlessly around the sun forever.

Nozomi means "Hope," and the little spacecraft could use some.

It has experienced a series of failures that kept it from reaching Mars on its first trip. Unfazed, its operators swung it around for a second pass at the Red Planet, but now say the probe is in its "final challenge" and may never arrive.

Translation: Nozomi, and the Canadian-built Thermal Plasma Analyzer, may continue a tradition of man-made probes that don't survive the trip to the bad-luck planet.

Canada's instrument is the country's first participation in a mission to another planet. In theory, once Mars orbit is established, the Thermal Plasma Analyzer will be extended out from the satellite on a boom, and its measurements of the Martian atmosphere will begin.

It is designed to measure low-energy particles and gases considered vital to the understanding of the origin and composition of the Martian atmosphere. Other instruments will study the magnetic field of Mars and take pictures of the planet's surface.

The Canadian Space Agency is funding this research. It involves scientists from the University of Calgary (the co-Principal Investigators of the TPA are Dr. Andrew Yau and Dr. Greg Garbe, professors of physics and astronomy at the University of Calgary), as well as scientists from the Universities of Alberta, Western Ontario, and Victoria. Others on the research team include scientists from Hokkaido, Nagoya and Tokyo.

Nozomi's troubles began in December 1998 during an Earth fly-by that was to "slingshot" the craft toward Mars, and arrive there in October 1999.

But the plan went wrong. A stuck valve forced controllers to do extra manoeuvres, leaving Nozomi too low on fuel to steer safely into orbit around Mars at the scheduled arrival time.

The Nozomi team was forced to steer a more indirect path, and the probe is now closing in on Mars, and is due to arrive next month. As well, the probe's main transmitter stopped working, so scientists now depend on a backup.

Also, a large solar flare a year-and-a-half ago damaged its power system.

Nozomi isn't dead yet. On Friday the Japanese Space Agency had this to say:

"Nozomi right now is under 'the last challenge' to repair its malfunction on which must be concentrated all [the] task force of scientists and engineers of Nozomi mission team until its outcome is clearly known. Upon recovering from the damage, we will then work on putting the probe to orbit around Mars and resume its exploration."

But if they can't repair the damage they will steer away from Mars. "Nozomi will, after once approaching Mars, escape from Martian gravitational sphere to become an artificial planet going around the orbit of the sun forever."

The Ottawa Citizen

© Copyright 2003 Vancouver Sun

Japanese space program in trouble

Associated Press

Its Mars probe is wandering off course. Its weather satellites are breaking down. And its latest attempt to put a pair of spy satellites into orbit ended last weekend in a fireball, costing an estimated $110-million Canadian.

While rival China is basking in the glory of its first manned space flight, Japan's new space agency is off to a decidedly inauspicious start.

“Is this the best we can do?,” an editorial in the Asahi Shimbun asked after an H2-A rocket carrying the two spy satellites failed to launch properly and was detonated in mid-air over the remote Tanegashima Space Centre.

The failure was especially disappointing because it followed five consecutive successful liftoffs for the H2-A, a two-stage rocket designed by Japan to show off its technical prowess. The H-2A has served as the country's primary launch vehicle for several years.

Officials would not comment on the likely impact of the failure until they complete an investigation. The H2-A was destroyed minutes after liftoff Saturday because a booster on the side failed to detach itself, pulling the rocket off course.

“We are investigating what happened,” said Hiroaki Sato, a spokesman for JAXA, Japan's space agency. “We still don't know how this will affect future launches.”

Created in October to streamline and focus a space bureaucracy previously comprising three separate agencies, JAXA is finding success hard to come by.

Japan's highest-profile project, the Nozomi Mars probe, is due to reach the Red Planet this month after a five-year journey, but officials say it is off course and may not achieve orbit. They plan to try firing its engines next week in a last-minute effort to fix its trajectory and save the mission.

Just over a month ago, communications were lost with Midori 2, an environmental observation satellite. The launch of an H-2A carrying a multipurpose weather satellite to replace one that malfunctioned several years ago is scheduled for January or February, but that, too, is now looking iffy.

“We'll just have to wait and see,” Sato said.

The H2-A failure, the first launch since JAXA was created, comes after a series of glitches forced the liftoff to be postponed three times.

“It's very unfortunate,” Prime Minister Junichiro Koizumi said. JAXA chief Shuichiro Yamanouchi apologized for “failing in this very important mission.”

Although Japan put its first two spy satellites into orbit in March, mainly to keep watch on neighbouring North Korea, it can obtain photos only every other day, a problem that the second pair of satellites would have solved.

An official with the cabinet's Satellite Intelligence Centre, insisting on anonymity, said the government would make do with the current pair for the time being. But he added that launches scheduled for 2005 and 2006 may advanced to compensate for the loss of the second pair.

Officials fear Japan's space program, already struggling to make the most of its limited resources, could face further budget cuts if the launch-pad disappointments continue.

JAXA operates with about 1,800 employees and an annual budget equivalent to $2-billion (U.S.), about one-tenth of NASA's. China's budget is a secret, but it is believed to have spent more than $2.8-billion on its manned space program alone.

Since sending its first man into space on Oct. 15, China has launched three satellites into orbit. In all, it has had 32 successful launches since October, 1996, Including the manned mission.

China has also said it probably will put two more astronauts into orbit within the next two years on the country's second manned mission, and its aerospace officials have said they planned to launch a space station within 10 years.

“Japan could put a man in space in five years if it wanted to,” said Saburo Matsunaga, assistant professor of aerospace engineering at the Tokyo Institute of Technology. “But Japan doesn't have the luxury to do things like that at the moment.”

Still, Mr. Matsunaga said, Tokyo's record has been good overall.

“For the small number of launches Japan has done, the country has a high rate of success,” he said. “The U.S., Russia and China have experimented a lot with military-purpose space projects, some of which are totally covert missions, and have failed many times.”