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Japan admits its Mars probe is failing

Japanese space officials have finally confirmed that their Mars-bound Nozomi probe is teetering on the brink of failure.
An artist's illustration shows the Japanese Mars probe known as Nozomi ("Hope"). The spacecraft went off-course after its launch five years ago.
An artist's illustration shows the Japanese Mars probe known as Nozomi ("Hope"). The spacecraft went off-course after its launch five years ago.
/ Source: NBC News

After months of silence and a week of hopeful half-truths, Japanese space officials have finally confirmed that their Mars-bound Nozomi probe is teetering on the brink of failure in its five-year quest to explore the Red Planet.

During this voyage, Nozomi became the first space vehicle to make an Earth-Mars-Earth round trip after navigation and power problems thwarted mission managers’ original plans. Ingenious flight planning and fine-tuned space navigation gave the probe an unprecedented second chance to reach Mars. But that space odyssey now appears doomed.

by the Japanese Aerospace Exploration Agency described how the probe “right now is under ‘the last challenge’ to repair its malfunction.” JAXA said the mission team would concentrate on the repair effort “until its outcome is clearly known.”

This concentration was offered as an explanation for why nobody could tell the public plainly what was really going on until now.

“As long as [the] team is at work,” the statement read, “please give us a little more time until around Dec. 10. When final result is known, we are ready to explain everything plainly.”

Spaceflight operations veterans have told that refusing to give up despite the odds is a proper approach. However, they expressed dismay at Japan’s lack of candor with the public — especially as it may raise false hopes that will be later be dashed.

Mars flotilla
The Nozomi orbiter is one of four spacecraft that are due to converge on Mars in the next two months. The other three probes — the European Space Agency’s Mars Express and NASA’s two Mars Exploration Rovers — are still on track and in good working order, according to the latest status reports. Mars Express is due to enter Martian orbit on Christmas Day and send a British-built Beagle 2 lander to the surface, while the NASA rovers should arrive on Jan. 3 and Jan. 24.

Rumblings about Nozomi’s problems percolated through the press last week. The mission’s project manager, Hajime Hayakawa, told a reporter in Tokyo that his team still was trying to fix the probe’s malfunctioning electrical circuits. But he admitted that “if we can’t fix Nozomi’s problems in time, it is very likely that it won’t be able to enter Mars’ orbit.”

“At this point, we don’t know the percentage of its chance of successfully entering into a Mars orbit,” Hayakawa said.

Also last week, spacecraft manager Ichiro Nakatani assured the California-based that “Nozomi is just on the right orbit to reach Mars on Dec. 14 (JST).”

“It is true that we have a problem with one of the subsystems, and we are now in the process of recovery operation,” Nakatani said.

Neither official provided an assessment of the likelihood of a successful recovery. But The Associated Press quoted Firouz Naderi, NASA’s manager of the Mars Exploration Program at the Jet Propulsion Laboratory, as saying that Nozomi “most probably won’t make it.”

He was further quoted as saying, “The obituary is not out yet, but you can hardly detect a pulse now.”

Damage by solar flare
Sources within the planetary science community have told privately that the probe’s power control system was severely damaged by a solar flare a year and a half ago. This would prevent the probe from sending science data — and it also affected the operation of propellant tank heaters, which are supposed to keep the liquid fuel from freezing as the spacecraft recedesfrom the sun. If the fuel is frozen, the spacecraft’s main rocket cannot not fire, and the probe cannot be placed into orbit around Mars as planned.

Beginning last summer, Japanese ground control engineers have been sending repeated commands to the power control system, hoping that it would shift into a configuration to accept and obey commands. But after thousands of radioed commands from Earth, the probe remained unresponsive.

Not even foreign scientists with instruments aboard the Nozomi probe were kept informed of the progress of the recovery attempt. Finally, at a space conference in Houston this week, the director of JAXA’s Washington office, gave a gloomy assessment of Nozomi’s chances.

“It’s hard to recover the system,” Masato Koyama told the audience, in response to a direct question about the probe’s status. He told conferees he did not think the recovery would succeed.

Friday’s JAXA statement denied one Tokyo press report that probe was doomed to impact Mars and possibly contaminate the planet. Such a scenario would violate an international “space quarantine” treaty.

“The truth is that Nozomi will, if going as it is, approach Mars on Dec. 14 by 894 kilometers [559 miles], passing above Martian surface at its closest approach,” the statement said, “but there would not be excluded a theoretical possibility of colliding with Mars by more or less 1 percent, if we take the error of orbit determination into account.”

“If not restored,” the statement continued, “we will try to adjust the closest approach as far as possible from 894 kilometers. In this case, Nozomi will, after once approaching Mars, escape from Martian gravitational sphere to become an artificial planet going around the orbit of the sun forever.”

Names in orbit 
Onboard the probe is an aluminum plate etched with the names of people who responded to a pre-launch campaign to “send your names to Mars.” Instead of reaching Mars, the statement said, “The names of 270,000 people will keep on circling around the sun for hundreds of million years.”

Nozomi was launched in mid-1998 and first flew past Mars late the following year. However, it was unable to enter its planned survey orbit, and instead had to circle back around the sun, fly past Earth twice to shift its orbit, and then head for Mars a second time.

JAXA’s statement showed that controllers have not yet given up hope for Nozomi (which actually means “hope” in Japanese).

“We believe what the mission team can do is not to give up, but to do the best until the very last moment,” JAXA said. Mission managers would not admit defeat until Dec. 9, five days before the scheduled arrival, when a small rocket burn planned to trim the approach path would instead be used to divert the probe as far away from Mars as possible.

So for now, neither the Nozomi probe, nor the hopes of its operators and the thousands of ordinary Japanese whose names are carried on it, are yet irretrievably lost.

James Oberg, space analyst for NBC News, spent 22 years at the Johnson Space Center as a Mission Control operator and an orbital designer.