Excelsior Club Presents

Excelsior Club Presents

Past and Present

CubeSat Missions

CUTE-I by Tokyo Institute of Technology, Japan

“Our Titech CubeSat project is coded "CUTE" (CUbical Titech Engineering satellite) project. "CUTE" also means our CubeSat is cute!”

Mission: Test platform based on COTS components.
Deployable solar cells, piezoelectric vibrating gyroscope (4 pcs), dual axis accelerometers (4 pcs) and CMOS camera used as sun sensor. The camera pictures could not be transmitted to the ground.
AODC: Piezoelectric vibrating gyroscope to measure angular velocity, dual axis acelerometer (used to compare to gyros), and CMOS sun sensor
Communication:

[Communication Mission] = CW-telemetry and FM-telemetry

FM transmitter transmits FM-telemetry by 2 diff protocols

change communication protocol by command uplink

[Sensing Mission] =measure acceleration, angular velocity and temperature

[Deployment Mechanism Mission] = deploy solar battery paddle by command uplink

XI-IV by University of Tokyo, Japan

Included a camera to take pictures of the earth.

AODC: Permanent magnet and hysteresis rods

Mission: Gathering the satellite health information via beacon signal

• Command uplink & data downlink

• Telemetry data broadcasting service

• On-orbit verification of the commercial-off-the-shell (COTS) components.

The true trade for the hysteresis rods came with the selection of the magnets; a damping system needed to improve the performance of the magnetic attitude control was designed and implemented with the magnets we selected.

2 failed CubeSats,

No contact established

Attitude control is accomplished by using magnetorquers. The attitude is determined by using 5 sun angle sensors, one on each face of the satellite except the payload face. The sun angle sensors are developed in MOEMS, micro optic electronic mechanical system, technology as part of the DTUsat project. A magnetometer is also included for measuring the strength and direction of the magnetic field. The magnetometer is built from 4 Honeywell sensors for redundancy. Even if one fails, it is still possible to get information on all vector composants of the magnetic field.

The primary payload is an electrodynamic tether. The tether is an unisolated copper wire of about 450 m length, picking up free electrons in the plasma trapped in the earth’s magnetic field. By emitting electrons from the satellite body, the tether (and satellite) will be positively charged. It will attract electrons, and a current will flow in the string. As the satellite, and thus the tether, moves in the magnetic field of the earth, this gives a resulting force on the satellite, as the return current will flow in the plasma. The mechanical system consisting of tether and satellite will therefore see a force in only one direction, making it possible to change the orbit without using fuel.

We will attempt to dump the satellite. This is simpler than lifting it, as the tether does not need to be isolated, and as the entire length of the wire acts as a plasma contactor. This eliminates arcing through the isolation as a failure mode. The tether itself is a 0.2 mm copper wire. It is deployed from a yo-yo-like spool, which is ejected by a spring, receiving both linear and angular velocity balanced to keep the satellite attitude stable and the tether tension low. The mechanical subsystem is very simple, and the risk of entanglement of the tether in the vicinity of the satellite is greatly reduced. The spool is braked at the end of travel by using a sticky glue to fasten the inner layers, again minimizing tension in the wire without generating space debris. The tether is electrically connected to the satellite structure. The electron emitter was projected as a chip scale device using field effects on a micrometer scale to emit electrons at low driver voltage and high efficiency. The maximum tether current using this emitter was 29 mA, which would lower the satellite orbit by 5 km/hour! However, the final metallization failed, so the tether will operate in passive mode and at considerably lower currents. Also, the tether can be shown to be dynamically unstable at this current, a problem which we have now avoided.

The mean life, the expected time before the tether is cut due to collision with space debris, for a 0.2 mm wire, is only about a week. By rolling the tether to a band of 1 mm width, the mean life could be extended to approximately 6 years, but a shipment from a Japanese manufacturer of aluminium band failed, leaving us with cupper wire as the only viable choice given our deadline.

A possible application of this device is removal of dead satellites, booster rockets etc. from orbit. If a cheap device is sold to be fitted before launch, these objects could be removed from orbit in a couple of months instead of leaving them in orbit for thousands of years.

Canadian Advanced Nanospace eXperiments

Also had magnetometers and magnetorquers

CUTE 1.7 + APD by Tokyo Institute of Technology, Japan

Lots of nano-satellites are developed all over the world and expected to be lauch into earth orbit these days. Considering the trend, much more space debris will be incresing. One of the the way to remove nano-satellites from the orbit is electro-dynamic tether technology. This mechanism aims to demonstate the electro-dynamic tether deployment for future mission, de-orbit.

This mechanism consists of inside plate and separation plate. These two plate are connected by tether. Inside plate hold the separation plate by nylon line. When the plate separates, nylon line are meltdown by nichrome coil and then three springs pushes the plate.

Data handling: Two redundant PDAs are used for datahandling. Apparently they're running Windows CE.NET!

AAUsat-2
Denmark, August 2007

• Magnetic coils and momentum wheels

– stabilize the satellite

– control of the attitude in space

• Gamma Ray Detector

AAUsat-2 by Ålborg University, Denmark Deployment Mechanism:TBA, expected 2007/8 Type:Single cubesat Mission:Detect gamma ray bursts by a gamma ray detector developed by the Danish National Space Center AODC:Magnetic based (coils) and momentum wheels Communication:TBA, but: 433-437 MHz band, 4800/2400/1200 bps AX.25 Status:Under development Link:http://www.aausatii.auc.dk/

ADCS system and a gamma ray detector, that will be activated when two-way communication is established.

Danish National Space Center

Because their high atomic number these detectors offer an excellent response to hard X-rays extending into the gamma ray band. semiconductor materials are based on CdTe or CdZnTe (tellurium) Their high average atomic number (close to 50) ensures a high sensitivity to hard X- and gamma rays and their band-gap is wide enough to ensure room temperature operation.

Delfi-C3
Delft University of Technology, Holland
June 2007

• Thin film solar cell experiment

• Autonomous wireless sun sensor

• Advanced Transceiver Experiment

Delfi-C3 by Delft University of Technology, Holland Deployment Mechanism: TBA Type: Triple cubesat Mission: Test of autonomous sun sensor using a wireless link for data transfer (915 MHz), test of new type of thin film solar cells developed by Dutch Space, and test of a high efficiency transceiver. No on-board data storage is planned. AODC: Sun sensor and by measuring input power of solar panels, and for control Communication: TBA Status: Under development Link: http://www.delfic3.nl/

permanent magnet

hysteresis rods

Thin Film Solar Cell Experiment (Dutch Space)

-photovoltaic cells is the IV curve related to the temperature

-light weight, low cost, efficient

-Resistor temperature detector

Autonomous Wireless Sun Sensor Experiment (TNO)

Advanced Transceiver Experiment (TU Delft EEMCS)

DTUsat-2
Technical University of Denmark August 2007

• Tracking of migrating Cuckoo birds

• A small 5-8 g transmitter will be mounted on a number of birds

• sun sensors, magnetometer and magnetorquers

DTUsat-2 by Technical University of Denmark Launch: TBA, expected 2007/8 Type: Single cubesat Mission: Tracking of migrating birds. A small 5-8 g transmitter will be mounted on a number of birds. The signals will be received by the satellite and returned to the groundstation. Position accuracy of the tracked birds is TBD.
The mission was chosen among these proposals at a meeting on November 10th, 2005 AODC: TBD, MEMS sun sensors, magnetometer and magnetorquers are likely Communication: TBA Status: Under development Link: http://www.dtusat.dtu.dk

KatySat 1
Kids Aren’t Too Young for Satellites Stanford University

• Educational purposes

KatySat 1 by Stanford University, USA Deployment Mechanism: P-POD Type: Single cubesat Mission: This mission is the first cubesat mission for high school students (KatySat = Kids Aren’t Too Young for Satellites).
The mission is to implement a "technically simple, fun, flexible, and affordable satellite system that will challenge and motivate young people’s interest in the fields of space, technology, and science".
KatySat will feature sensors for radiation, magnetic field, and optical (camera).
Editors note: And they call it simple? AODC: Permanent magnet (Editors note: and presumeably hysteresis rods) Communication: TBA Status: Under development Link: http://www.katysat.org/

sensors for radiation

magnetic field

optical (camera).

Club

Space camps

UCISat 1
University of California

• Camera

• Gradient stabilization

• Magnetorquers and/or magnometer

UCISat 1 by University of California, Irvine, USA Deployment Mechanism: P-POD Type: Single cubesat Mission: CMOS camera, gradient stabilization, magnetorquers and/or magnetometer for ADS AODC: Gravity gradient, mangetometer, and magnetorquers Communication: TBA Status: Under development Link: http://ucisat.eng.uci.edu/

Mars Gravity BioSatellite
MIT & University of Queensland, Australia - 2009

• *Not a CubeSat

• Martian gravity Simulation for mice

Mars Gravity by Massachustts Institute of Technology, USA and University of Queensland, Australia Launch: Funding dependent, no earlier than mid 2009.
Launch from Cape Canaveral, Florida, USA, into a 400 km circular orbit with an inclination of 31 deg. Recovery in Woomera, Australia. Baseline LV is Falcon 1 from SpaceX Type: About 400 kg, 1.2 m long, 1 m diameter Mission: Study 15 mice exposed to artificial Mars gravity during 5 weeks, after which the s/c will reenter the Earth's atmosphere and land in Australia.
Budget is around 30 million USD, including launch. AODC: Spin stabilization (for artificial gravity environment) and propulsion system Communication: TBD Status: Being planned Link: http://www.marsgravity.org

Overview
The Mars Gravity Biosatellite will carry a small population of mice to low Earth orbit aboard a spinning spacecraft creating "artificial gravity" identical to that on the Martian surface. The five-week mission will conduct the first in-depth study of how mammals adapt to a reduced-gravity environment. Groundbreaking data from this mission and its successors will be essential in determining future possibilities for human space exploration.