MISSION TO MARS

Scientists are now able to explore the unknown with innovative technologies that can determine whether or not there is the possibility of life on other planets, particularly Mars. Through recent voyages to our neighboring planet, scientists have had a taste of the dream, and now want more.

NASA is planning a mission for the fall of 2009 to send a machine, called Mars Science Laboratory rover, to Mars. The purpose of this rover is to carry scientific instruments designed to gather information on the past and present habitability of Mars. By studying the composition of rocks on the planet, scientists believe they have the ability to determine facts about the climate history, the origin of life on Earth, and the possibility of Martian microbial life.

An engineering model of Mini-Corer was installed on JPL's field test rover, FIDO, to facilitate basic mission operation testing. The model currently resides at JPL.

The rover will be capable of conducting complex scientific tests with instruments such as spectrometers and a periscoping camera to gather information for rock selection and navigation. NASA has employed Honeybee Robotics Spacecraft and Mechanisms Design Company to develop and test the apparatus needed for analysis of the makeup of rock specimens.

DEVELOPING THE MINI-CORER

For the upcoming Mars Science Laboratory mission, Honeybee has designed a mechanism that will manipulate and move 74 cups of Mars dirt that will be taken to multiple science stations. Each sample will be hermetically sealed into an oven, which will bake the dirt so scientists may analyze the gases that burn off. This instrument, the Mini-Corer, will represent 85% of all the science the Mars Science Laboratory mission will perform.

By studying the composition of rocks on the planet, scientists believe they have the ability to determine facts about the climate history, the origin of life on Earth, and the possibility of Martian microbial life.

The Mini-Corer, formally known as the Miniature Rock Coring and Rock Core Acquisition and Transfer System, was originally designed for the 2003 NASA Mars Exploration Rovers Mission, but was not sent. It will be a part of the 2009 mission, however. Its purpose is to acquire rock cores for examination by other instruments prior to transport, and to store cores for sample return.

In order to qualify devices, tests are conducted to simulate the conditions that mechanisms will be subjected to in space. Cold temperature may cause the material to shrink. Vibration must not interfere with product quality and functionality. Before the machine even reaches space, it must be able to withstand the 62Gs produced by the launch. Honeybee does the calculations and analysis to ensure proper performance, including tests in a thermal-ac chamber with temperatures as low as -70°C.

Corporation's double wide bushing provides more stiffness and rigidity than two standard width bushings.

THE DETAILS

The Mini-Corer is about the size of a shoe box, and will be made of albemet (a combination of aluminum and beryllium). There is a smaller box inside, which double-seals the Mini-Corer to prevent dust from plaguing the gears and bearings. When the Mini- Corer drills into a rock, the large box doesn't move. The shaft that spins and cores the drill is attached to the smaller box. The smaller box houses the motors and gears, and can slide up and down up to 6 in. on two NB Corporation SMS10WUU double-wide linear bearings. It has two linear slide rails and one threaded acme screw that moves the smaller box within the larger. The double linear slide allows for a more distributed load.

The Mini-Corer is an arm-mounted, stand-alone device, requiring no additional arm actuation once positioned and preloaded. A compact internal lowmass transmission provides all the motor power used by the tool mechanism. Shown with different end effectors and bits.

The double-wide bushings have a diameter range of 3.175mm to 50.8mm (0.125 in. to 2 in.). Their standard width bushings come in lengths from 12.7mm to 203.2mm (0.5 to 8 in.). The coring bit is 5cm long, with an 8mm diameter. The Mini-Corer weighs less than 2.8Kg (6 lbs) and measures less than 270mm (10.6 in.) x 112mm (4.4 in.) x 100 mm (4 in). It is expected to take samples of 25mm long and 8mm diameter from a single hole of a hard rock.

The Mini-Corer is an arm mounted, stand-alone machine, requiring no additional arm activation once placed and preloaded. An internal low-mass transmission provides all the motor power used by the tool mechanisms. It is able to drill 25mm into basalt in less than six minutes while taking up under 10 watt-hours of power. Carbide cutting teeth enable the unit's power needs to be low, because they require a minimum of torque.

The Mini-Corer is able to self-preserve by changing its own bits as they get dull. This feature was accomplished without the addition of extra motors to the design. The same devices that function as a coring tool were adjusted to let the mini-corer drop worn bits and put on new ones. Testing indicated that 8mm carbide drill tips begin to dull after drilling ten 30mm cores into basalt with over 100Mpa of compressive strength. Engineers designed the Mini-Corer to use its bit change-out system to replace worn bits so it can maintain high coring and abrasion penetration rates.

Through the combined efforts of this machine and numerous other highly-advanced devices that will accompany the Mini-Corer on the Mars Science Laboratory mission, scientists hope for a breakthrough in understanding life here on Earth, as well as the possibility of life on Mars.