Quick Facts Sheets
Revision Three
Below is a copy of the Quick Facts Sheet of the third
revision picosatellite. Each of the subsystems are linked to this
page.
| Artemis is the second undergraduate
satellite project at Santa Clara University. It is part of the Santa
Clara Remote Extreme Environment Mechanism
(SCREEM) laboratory, which was started to investigate and design various
mechanisms to survive extreme environments. These environments include
the vacuum of space and the depths of the ocean.
As one of the three picosatellite providers for Stanford's
Orbiting Picosat Automatic Launcher (OPAL)
project, the Artemis group is using a low cost, quick prototype process
to continually explore the limitations of picosatellites. The expected
period for integration and test with OPAL starts in May and the expected
launch date is in September 1999.
|
||||||||||||||||
| Mechanical
Structure
Material: Aluminum 6061-T6 Length: 8 +/- 0.003 inches Width: 1 +/- 0.003 inches Height: 3 +/- 0.003 inches Bevels: 1/16-inch, 45 degrees on the longest 8 edges 0.1" radius on 4-1" edges Volume: 24 cubic inches Weight: 611.87 grams Center of Gravity: less than 0.75 inches from center Our picosatellites use GaAs solar cells with two secondary AA Nickel-Cadmium batteries (rated at 1.25 Volts and 800 mA-Hrs) for an extended lifetime. A LM2621 DC-DC converter from National Semiconductor is used for regulation. The Basic Stamp II will monitor the battery voltage via an additional comparator to determine the power status of the picosatellites. The Basic Stamp II PIC processor provides the necessary functionality to check for adequate battery supply, read sensors, read and log pulses from the VLF receiver, transmit using FSK modulation, and receive commands sent from ground. The Basic Stamp has been flown in space and is designed to operate under extreme conditions.
The picosatellites will transmit and receive over amateur radio frequencies. For the downlink, we will use the 2-meter amateur band with transmitter circuitry based around the Motorola MC13176 at 1200 baud and has the capability to transmit at 200 mW. For the uplink, our receiver is based on a single chip, the RX 1000, from RF Monolithics. The receiver will receive in the 2-meter band at 1200 baud. |
VLF (Very Low Frequency) Receiver The main payload onboard our satellites are the VLF receivers, a science payload in conjunction with the STARLab at Stanford University. It is a simplified version of conventional VLF circuit that is able to detect VLF signals using a 1-meter whip antenna. Our two picosatellites have different VLF thresholds, 100mV and 10mV. Our mission is to simultaneously record VLF data with our two picosatellites. From comparison of the two data sets, we can approximate the occurrence and amplitudes of horizontal and vertical lightning. Four IR/Visible phototransistors are onboard each of the picosatellites. Each phototransistor is perpendicularly placed on an 8"x1" or 3"x1" face. This will provide some rough attitude determination functionality. The attitude sensor data will be taken immediately before and after the VLF data is taken, thus providing a more accurate picture of the picosatellites' positions with respect to the atmospheric perturbations measured by the VLF payload. Rubber ferrite magnets are on board to control the spin axis, aligning it relative to the Earth's magnetic field. This control will enhance the data accumulation for the VLF experiment. Contact Us
|
|||||||||||||||
Please click below to view the Quick Facts Sheet of our
revision one and revision two picosatellites:
Revision One
Contact us: artemis@scudc.scu.edu
HOMEPAGE | MISSION & OBJECTIVES | ABOUT US | SYSTEMS | SPONSORS | LINKS | SCREEM