Communicating with a Mars probe can be a little like talking to the dead. Depending upon how far apart Mars and Earth are at any given moment, it will take anywhere from 4 to 20 minutes for a light-speed radio signal to traverse the distance. What’s breaking news or an imminent danger when the spacecraft sends out its signal can be long over — for better or worse — by the time we learn about it.
That’s what made things so harrowing just after 1:17 AM EDT on Monday, August 6. It was at that moment that the Curiosity rover was supposed to touch down on the Martian surface after a journey of more than eight months. The Earth and Mars were about 154 million miles (248 million km) apart, which meant the transit time for a message was 13 minutes and 48 seconds. If the rover crashed — a real possibility considering it would be slamming into the atmosphere at 13,000 mph (921,000 k/h), slowing down via a combination of air resistance, a parachute and retrorockets. In addition, the rover was relying on an untried, hovering sky crane to winch it the final 25 ft. (7.6 m) to the ground — no one would know until 1:32 AM. Every bit of happy news Curiosity was beaming back about its progress could already have been trumped by a disastrous finish.
(Cover Story: Live From Mars)
But the news that did finally arrive in Mission Control at NASA’s Jet Propulsion Laboratory was exactly what the mission managers had been hoping to hear: “Touchdown confirmed!” flight dynamics engineer Allen Chen called. “We’re safe on Mars!”
That kind of announcement is the reason space geeks get out of bed in the morning — and it’s one of the reasons the United States travels to distant worlds in the first place. But it’s hardly the only reason.
For all of Mars’s desert-like appearance, it was once a warm and watery place, with its surface still scored by ancient riverbeds, dry seas and empty oceans. Traces of water remain on the Martian surface and buried underground, and that makes the Red Planet one of the best places in the solar system to look for life — and certainly the closest. Even if nothing is living there now, the one billion years Mars is thought to have been wet would have been sufficient for life to have emerged and briefly thrived. Microbial fossils and other organic remains may still be there to mark its passing.
The one-ton, SUV-sized Curiosity will study the possibility of Martian biology — as well as the planet’s chemistry, geology and meteorology — with a suite of 10 instruments weighing a collective 15 times more than the entire scientific payload of any previous rover. A gas chromatograph, mass spectrometer and laser spectrometer will look for telltale isotopes, gasses and elements, especially methane and other carbon compounds. A mobile arm with multiple tools gives Curiosity Swiss army knife dexterity and its 17 cameras make it the sharpest-eyed spacecraft ever launched.
While the rover will help answer a wealth of questions about Mars, it raises some troubling ones about Earth — and the United States in particular. Why does a country that can pull off this kind of engineering legerdemain have such a hard time doing the easy stuff — maintaining its terrestrial infrastructure, addressing climate change, simply stepping out of the toxic swamp of domestic politics enough to keep the FAA funded and the lights on in Washington? The successful landing of the rover is what smart looks like, what visionary looks like. A country that can pull that kind of thing off should be capable of well-nigh anything. The commitment and competence we bring to the Red Planet could also be applied to the blue one.