Why NASA Should Bomb the Moon to Find Water: Analysis

NASA today announced the site of a mission that aims to send an empty fuel tank into a lunar crater to assess the amount of frozen water that is kicked up by the impact. On October 9, a kamikaze spacecraft will crash into the moon’s Cabeus-A crater, kicking up a 6-mile-high debris cloud that a follow-on craft will surf through, using infrared spectrometers and video cameras to determine how much—if any—water ice exists. A series of space-based and terrestrial telescopes will also examine the plume.

So it appears the mission is on track, but it’s been a tough summer for LCROSS. For several weeks in August, the spacecraft suffered from a strange software malfunction that caused it to consume too much fuel. After two weeks spent in an emergency mode, mission planners last week returned operations to normal. While this 240,000-mile reprogramming was underway, a chorus of online readers of mainstream science websites were rooting for the mission’s failure. These armchair space critics call LCROSS crude, violent and silly. But even a cursory look at the mission reveals a clever, scrappy mission that should be cheered instead. Here’s why we like LCROSS, and are looking forward to its date with Cabeus-A.

1) It’s a cheap, creative and scrappy mission. This is what many people want NASA projects to look like in the future.

LCROSS is a Class D mission, denoting one with the highest risk of failure. Once-in-a-lifetime missions and those with human passengers are considered Class A missions, and carry a high cost in time and money to ensure that the equipment won’t fail. The extra testing, custom-built gear and redundant equipment drives up costs to levels that give even members of Congress pause. NASA could launch more risky missions like LCROSS instead of just a handful of marquee ones, and reap more rewards even if some fail.

The cost of LCROSS is about $79 million—cheap in the spaceflight world—and its planners delivered it on budget and on time. The engineers adapted available parts and technology for their craft: commandeering an empty fuel tank for its mass, crafting an internal fuel tank from a communications satellite and copying avionics from the Lunar Reconnaissance Orbiter, which is to be delivered into the lunar orbit on the same ride as LCROSS. (The impactor mission is hitching a ride on the Lunar Reconnaissance Obriter’s launch.) LCROSS’s skeleton, an aluminum ring that looks like a section of sewer pipe with six portholes, is leftover from an Air Force project designed to release multiple satellites from a single rocket. The moon-bombing engineers cobbled these parts together to make a cheap spaceship in just two years. Some risks are worth taking: LCROSS is one of them.

LCROSS Image Gallery
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2) It will have conclusive results.

So many space missions leave people scratching their heads. Sometimes the science is obscure, or simply a preparation for some other event that may or may not occur in some future decade. For example, LRO will provide ground-breaking images of the moon, and will support any return by America, but people can rightfully ask, “Don’t we have images of the moon? And are people really going to return in 2020?” LCROSS has a specific scientific mission and a payoff that is almost immediate. In 1998 a probe called Lunar Prospector spotted tantalizing signs of hydrogen in craters at the lunar poles. But no one’s entirely sure if the hydrogen is the chemical signature of water ice, possibly deposited by comets and meteors. LCROSS should not only confirm that water-ice is on the moon, but in what quantities. Any future moon base would rely on this water, so love or hate lunar aspirations, the information will be useful.

3) The scar will be very small.

LCROSS will create a 6-foot-deep crater inside another crater on the south pole. The moon has suffered much worse from the cosmos, and this latest gouge pales in comparison. Note that there are no explosives on board—the mass of the impactor alone is enough to create a plume. Also, the craft will be empty of all fuel before impact, to keep results uncluttered.

4) Humans have been crashing things into the moon—not to mention leaving trash behind—for a long time, so what’s one more if it actually gleans some data?

There is nothing pristine about the moon. It’s lifeless surface is cluttered with spent probes, landing craft, seismic sensors and moon buggies. Every time an Apollo mission took off, the crew threw out all unneeded equipment to save weight on the return. The idea that the moon will somehow be ruined by LCROSS is bizarre. Besides, even if a fraction of previous impacts hit the moon in the future, any human traces will in time be pulverized. So the moon will recover, you thumb-sucking Luddites!