Curiosity on Mars
By Alyssa Keimach
With less than a month before Curiosity’s landing, Dr. David Blake gave a Benjamin Dean Lecture at the California Academy of Sciences on July 9th, 2012. A senior staff scientist in the Exobiology Branch at NASA Ames Research Center, Dr. Blake designed one of Curiosity’s science instruments, CheMin (Chemistry and Mineralogy).
CheMin will use X-ray diffraction to measure the mineral structure in samples of Mars dust: an X-ray beam shot through a dust sample will scatter in a distinctive pattern that depends on the arrangement of atoms and molecules present in the sample. CheMin also measures the energy of individual X-ray photons to determine what elements make up the sample.
Other important instruments onboard Curiosity will photograph the rover’s surroundings, drill into rock samples, look for traces of organic compounds, and conduct a variety of experiments that earned Curiosity its original name, “Mars Science Laboratory.”
The 900-kilogram roving laboratory requires a landing sequence different from previous, smaller rovers’ landings. Smaller rovers descended to the Martian surface protected by giant airbags, bouncing to a stop before deflating the airbags and beginning operations. Curiosity needs to complete an elaborate series of steps nicknamed the “Seven Minutes of Terror,” so called because NASA engineers have no way to control what happens during the seven minutes it takes the spacecraft to traverse the thickness of the Martian atmosphere. Dr. Blake showed the audience an interesting clip of the simulated landing process…
After its eight-month journey from Earth, the capsule is racing toward Mars. The Aeroshell, on the outside, includes a heat shield that protects the craft during its initial entry into the Martian atmosphere. At a designated point in its descent, the Aeroshell deploys a parachute. The heat shield drops away, and the Sky Crane carrying the rover then separates and executes a controlled descent under its own power before deploying a cable to lower the rover down to a carefully selected landing site. Flight engineers have refined Curiosity’s landing site during the eight-month voyage, pinpointing a relatively small area inside Gale Crater.
For the first few months that Curiosity is surveying Mars, Dr. Blake will live on “Mars time.” The days on Mars are about 40 minutes longer than our 24-hour Earth day, and scientists and engineers will adjust to the longer day, working on the same schedule as the rover. But all this extra time definitely adds up: Dr. Blake compares it to shifting a time zone a day for the duration of the switch, and when he practiced living on Mars time for a week, he didn’t relish the experience.
Keep up to date with Curiosity’s progress here!
Alyssa Keimach is an astronomy and astrophysics student at the University of Michigan and volunteers for the Morrison Planetarium.
Image credit: NASA/JPL-Caltech