How To Avoid a Very Expensive Loss
The failure to boost Russia’s Phobos-Grunt (“Phobos-Soil”) sample return mission out of Earth orbit is only the latest blow for the newly mishap-prone Russian space program. The Russians claim it may still be possible to salvage the mission — and some of their spacefaring credibility — by uploading new software, but few if any outside observers agree.
The loss of this automated spacecraft will affect the wider space community, and ironically human space exploration will suffer the most.
In 54 years of spaceflight, remarkably few examples of extraterrestrial materials have been brought to Earth for study. The vast majority of existing samples date from the Apollo flights to the Moon, and it is now clear that Apollo did not produce a collection representative of the Moon’s many landscapes and resources.
In a dramatic and marginally successful mission, Japan retrieved a few tiny grains of dust from an asteroid and returned them to Earth on June 13, 2010. The United States is planning a similar project that should collect a larger sample. Cometary and interstellar dust, as well as particles from the solar wind, have been obtained by free-flying spacecraft.
Large, pristine samples, collected from bodies outside the Earth-Moon system that are potentially useful to human explorers, are not yet available for study. There is far too little “ground truth” data to back up orbital observations.
Phobos-Grunt was to change that. This elaborate Russian mission was to collect 15 to 20 samples totaling up to 200 grams, though less than 100 grams was probably more realistic. The samples would come from some of the most exciting territory in the inner solar system — the innermost of the two martian moons, Phobos and Deimos.
This was an extraordinarily high-risk mission. Failing to learn from the experience of others, Russia loaded too many experiments on a single overly complex spacecraft, including a Chinese orbiter unrelated to the primary mission. It may have launched with inadequate testing, and in retrospect parts of the spacecraft appear poorly designed.
Vladimir Popovkin, the head of the Russian federal space agency, Roscosmos, was quoted by Space News’ Peter B. de Selding as implying the Russians have received enough telemetry to show the spacecraft is alive and may be healthy. Ground-based observers have reported that it appears to be stabilized and not tumbling.
Nonetheless, reliable communications have proved impossible, possibly because a full fuel tank is blocking uplinks to the low-gain antenna, according to “an informed source” quoted by Russian space journalist Anatoly Zak. This tank was designed to be ejected after the two trans-Mars burns that have not taken place, which would have allowed the antenna to be used. Likewise, the short seven-minute communications sessions available to the Russians complicate efforts to upload new software.
The probable loss of Phobos-Grunt is a major blow to Russia’s ambitions in space. To the rest of the space community, losing the science planned on and near Phobos hurts most. Two hundred grams is a very large sample for modern laboratory equipment to study. For comparison, it is about half to two-thirds the size of the total sample contemplated in many NASA Mars sample return proposals.
More importantly, unlike prior Soviet retrievals from the Moon, this was to be an intelligently collected sample. The mother craft would spend up to nine months mapping potential landing sites for safety and interest with panoramic cameras and other instruments. The lander would spend a few days to a week on the surface, evaluating the site with cameras, spectrometers, a gas chromatograph, a seismometer, radar, a microscope and other instruments before selecting multiple rocks and patches of regolith. A robot arm (one of two) with a cylindrical scoop would have delivered each specimen to the return vehicle, where a piston would force it out of the scoop.
Just a few grams, if successfully collected and returned to Earth, would provide enough material for meaningful analysis by more than one laboratory. Material impact-splashed from elsewhere on Phobos — and from Deimos and even Mars — might well have been included. Phobos is probably a captured asteroid, and it is certainly an asteroid-like object. It is far larger and more diverse than any body likely to be sampled by a near-Earth asteroid mission. In a single flight, a successful Phobos-Grunt might have achieved some of the goals of both an asteroid mission and the proposed Mars sample return.
The results could have provided definitive evidence for water, carbon-bearing compounds, heavy metals and other elements useful for human exploration of Mars and for activities back in Earth orbit. Located high in the Mars system’s gravity well, these resources would be more accessible from Earth than the lunar surface and many near-Earth asteroids.
A successful Phobos-Grunt mission could demonstrate that many resources required by human explorers do not have to be lifted from Earth. It is hard to think of a goal in space more important to humanity’s future.
Where do we go from here? If Phobos-Grunt does fail to leave Earth orbit, reflying the mission should be a top priority of all the world’s space communities. The Russians should be encouraged to try again with a greatly simplified spacecraft. Other spacefaring nations can and should help, providing money, technology and, most importantly, hard-won skills in spacecraft testing and reliability. In particular, the United States might offer a4 or Atlas 5, ultra-reliable launch vehicles with high-energy upper stages that have yet to fail.
Recovering from Phobos-Grunt is an opportunity for the entire world to cooperate on a mission of great importance to humanity’s future in the solar system.
Donald F. Robertson is a freelance space industry journalist based in San Francisco. For further examples of his work, see www.DonaldFRobertson.com.