Six Wheels on Martian Dirt!
by Emily Lakdawalla on August 6, 2012
Holy frak, it worked.
It’s now five hours since Curiosity successfully landed on Mars (at 10:32p.m. Pacific time, August 5) and it’s still hard to believe that the whole thing worked so flawlessly. And here we are: a new wheel on Mars. Presumably the other five wheels are firmly on soil as well!
I live-tweeted the landing and it amazed me how everything unfolded so perfectly. Here are my tweets from all of E, D, and L — the fiery entry protected by the heat shield; the descent (first under parachute, then on rockets); and the skycrane-assisted landing. Almost all of these are quotes from the mission controllers. The hashtag, #MSL, is short for Mars Science Laboratory, the mission’s formal name, and was much easier to type than “Curiosity.” You can relive these same minutes by watching this video.
ENTRY INTERFACE!! #MSL
“Standing by for start of guided entry” #MSL
“Nav can see the atmosphere in the doppler.” “Vehicle has reported via tones that it has started guided entry.” #MSL
#At this time the vehicle is beginning to steer its way to the target and its starting its first bank reversal.” #MSL
“First bank reversal complete. We have passed peak deceleration. We are seeing G’s on the order of 11 or 12.” #MSL
Bank reversal 2 is starting! We are now getting telemetry from Odyssey! #MSL
“We have a connection but we do not have any data yet.” “Oh, there we go.” #MSL
“We are receiving MEDLI data.” End of range control, error minus 1.2 kilometers.” #MSL
The visualization is now running on live data from Odyssey. #MSL
The MEDLI instrument measured heating through the heat shield. #MSL
We’re going about Mach 2.4 at an altitude of 17 kilometers.
Vehicle is reporting heartbeat tones again. Everything is fine. Standing by for parachute deploy. #MSL
We’ve begun entry balance mass jettison. #MSL
PARACHUTE DEPLOY! #MSL
Thrusters have been reenabled. We are decelerating.
WE HAVE ACQUIRED THE GROUND WITH THE RADAR #MSL
Lost X band tones due to Earth setting below Curiosity’s horizon
Down to 90 meters per second
Down to 86 meters per secon at an altitude of 4 km and descending #MSL
WE ARE IN POWERED FLIGHT!!! #MSL
Altitude of 1 km and descending at 70 m/s #MSL
500 meters altitude
“We’ve found a nice flat place.” #MSL
SKYCRANE HAS STARTED! #MSL
Descending at 0.75 m/s as expected
WE ARE FREAKING ON MARS!!!!!!!!!
Trusty old Odyssey. Odyssey is a Mars orbiter now 11 years old, the longest-lived spacecraft ever at Mars, through which a goodly proportion of Spirit and Opportunity’s data has come to Earth. She’s been showing signs of age recently; one of the three reaction wheels she uses to control her orientation in space has gotten sticky, and she’s been switched over to her backup. This happened only weeks ago, which caused quite a bit of heartburn, because Odyssey had to execute a quick roll right before the landing in order to be able to pick up the signal and relay it to Earth continuously. Without Odyssey, we wouldn’t have had real-time information on the landing. But that wonderful old ship performed her duty, relaying Curiosity’s signals to Earth loudly and clearly throughout the descent — and after.
It was through Odyssey that we received Curiosity’s first photos from Mars. They are not art. But they are beautiful in their way, confirmation that we have once again accomplished what was science fiction only fifty years ago. We have built an intelligent, autonomous robot and sent it to another planet. Curiosity’s wheels are now firmly on Martian soil, ready to launch a whole new adventure.
We’ll get better images from Curiosity over the coming days. Much better. The Hazcams are engineering cameras designed to help us check out the equipment. Soon we’ll see HD, color images and even movies from the higher-resolution science camera.
As if all of this weren’t enough, another amazing feat was pulled off last night, by a third robot: Mars Reconnaissance Orbiter. The newest and largest of Earth’s fleet of Mars orbiters, MRO is equipped with an incredibly powerful camera called HiRISE that images Mars in excruciating detail. Tomorrow, we can hope to see HiRISE photos of Curiosity and some of her spent landing hardware sitting on the surface. Today, though, we have one of the most amazing images in the history of space exploration: an action shot of a spacecraft descending to the surface of another planet shot by another spacecraft moving perpendicular to it at a relative speed of thousands of kilometers per hour. Just think about that, will you?
The engineering feats pulled off today are arguably among the most difficult ever attempted by humans. And we did it. We actually did it.
The question is if we’ll do it again. Right now, there are no plans to return more wheels to the Martian surface. It may seem early to be talking about the next mission when this one just landed. But it’s not. It takes a decade or so to get a mission of this complexity from idea to the launch pad. For some missions, it takes another decade or more after launch to reach its destination. Curiosity is the last flagship mission in NASA’s planetary mission line. We’re not developing any more.
It’s not because there’s not more to do. It’s because there isn’t enough money. This is an expensive mission, with a price tag of $2.6 billion. Still, that’s just $7 per taxpayer. I know I think it’s worth it. Do you?