Add one more problem to the beleaguered Japanese Mars probe, Nozomi. There are worries in some science quarters that the troubled spacecraft could possibly contaminate Mars.
Nozomi will find itself at the red planet in December, years behind its originally intended arrival time. The spacecraft has been beset by multiple woes. A thruster problem prevented the probe from attaining the correct speed during an early swingby of Earth. That forced ground teams to script an emergency flight plan for Nozomi.
Slipping through space, Japan's Nozomi was also beat up by a burst of solar flares, damaging its heating system and causing a loss of communication between Earth and the probe. Mission control experts were eventually able to make long distance repairs to the craft.
On June 19, 2003, Nozomi made another swingby of Earth. That slingshot maneuver boosted the probe's speed and put it on a final heading for Mars.
Fuel gauge on low
But now with its onboard fuel supply gauge reading low and plagued by a power short, Japanese space engineers are attempting to repair Nozomi's electrical problems as the probe glides ever closer to Mars.
According to experts familiar with the Japanese space probe's overall condition, none of its instruments can provide data with the current power-short situation. Spacecraft handlers are slated to recycle the onboard hardware electronics about a 1,000 times in hopes of clearing the short.
At issue is will Nozomi provide science data if it is successfully placed into orbit around Mars? Furthermore, can Nozomi be nudged into an orbit that will avoid an imminent crash on Mars? Lastly, if the craft cannot produce any science, why bother to orbit Mars when it might contaminate the planet?
Mars scientists and experts in the field of planetary protection suggest that Nozomi is not likely to present a biocontamination hazard to Mars. It is that "not likely" that constitutes concern. On one hand, the spacecraft has had years of radiation soaking in transit. Also, if the probe were to accidentally smack into Mars from a highly elliptical orbit, the super-hot atmospheric plunge would likely eradicate most other microbial contamination.
Despite this, however, some within the Mars science community stress the importance of Japan acknowledging the possibility of contamination, then work to demonstrate why this won't happen -- or take steps not to put Nozomi into Mars orbit in the first place.
Making sure the spacecraft are as biologically clean and contamination-free as possible before they leave Earth is NASA's planetary protection policy. NASA's policy is based on the most recent understanding of planetary conditions and biology
Hope for useful data
Nozomi, also called Planet-B, is the first Japanese Mars orbiter. It was launched some 5 years ago, on July 4, 1998 from Japan's Kagoshima Space Center, under the auspices of that country's Institute of Space and Astronautical Science (ISAS). Its mission is to orbit Mars and gather data on Martian upper atmosphere and its interaction with solar wind for up to two years.
With a price tag of $88 million, Nozomi, or "Hope", has been just that. Japanese scientists are hoping the craft can get to Mars and provide useful data.
"The Japanese have a real challenge with Nozomi," said John Rummel, NASA Planetary Protection Officer at the space agency's headquarters in Washington, D.C. "It is unlikely for technical reasons that they will put it into Mars orbit if the instrument-data cannot be received. But if they do they will have to put extra effort into extending Nozomi's orbital lifetime to achieve the non-contamination objectives required by international consensus," he told SPACE.com.
Meanwhile, Nozomi faces a shortage mode failure within the secondary part of one power supply. Both heater control electronics and mode control of telemetry system are connected to that power supply. ISAS experts are committed to resolving the problem before Mars orbit insertion.
According to ISAS scientist, Hajime Hayakawa, Nozomi's onboard camera remains in operational mode and is able to get images at Mars. However, to transmit the images to Earth, the craft's power shortage must be fixed, he told SPACE.com via email. Regarding concerns that Nozomi might impact Mars, the scientist said that a small amount of propulsive energy is available to assure Nozomi will not impact Mars, even if the craft's problems are not fixed.
Issues regarding Nozomi and planetary protection are sure to be addressed by a new Japanese space agency to be born on October 1, just months prior to Nozomi's arrival at Mars. The National Space Development Agency of Japan (NASDA) is merging with the Institute of Space and Astronautical Science (ISAS) and National Aerospace Laboratory of Japan (NAL) to create the Japan Aerospace Exploration Agency.
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