TechEdSat

From Wikipedia, the free encyclopedia
Jump to: navigation, search
TechEdSat
TechEdSat.jpg
CAD Drawing of TechEdSat
Mission type Technology
Operator San Jose State University/JAXA/ÅAC Microtec/NASA
Spacecraft properties
Spacecraft type 1U CubeSat
Launch mass 1.2 kilograms (2.6 lb)
Start of mission
Launch date 21 July 2012, 02:06 (2012-07-21UTC02:06Z) UTC[1]
Rocket H-IIB
Launch site Tanegashima Y2
Deployed from ISS
End of mission
Decay date 5 May 2013
Orbital parameters
Reference system Geocentric
Regime Low Earth
Semi-major axis 6,795.131 kilometers (4,222.299 mi)
Eccentricity 0.0027290
Inclination 51.6567

TechEdSat is a 1U CubeSat built by San Jose State University students in partnership with Ames Research Center and ÅAC Microtec. Its mission is to evaluate Space Plug-and-play Avionics (SPA) designed in Sweden by ÅAC Microtec, and to perform a communications experiment utilizing the Iridium and Orbcomm satellite phone network.[2] TechEdSat was launched from Pad 2 of the Yoshinobu Launch Complex at Tanegashima on 21 July 2012, aboard Kounotori 3 atop an H-IIB carrier rocket. Kounotori 3 will carry the satellite, along with the Raiko, We Wish, Niwaka and F-1 spacecraft, to the International Space Station, from where they will be deployed via the JAXA J-SSOD deployer, from the Kibo module.[3]

TechEdSat was successfully deployed from the ISS on 4 Oct 2012 at 15:44:15.297 UTC.[4] It reentered to atmosphere on 5 May 2013.[5]

Hardware[edit]

TechEdSat Engineering Development Unit

Specifications[edit]

TechEdSat Solar Panel
  • Dimensions: 113.5 mm x 100 mm x 100 mm
  • Mass: 1.2 kg
  • Power Consumption (Safe Mode): 0.35 W
  • Power Consumption (Safe Mode, Stensat Transmitting): 3.4W
  • Power Consumption (Nominal Mode): 3.965W
  • Power Consumption (Q1000 Transmitting): 27.125W
  • Power Consumption (Q9602 Transmitting): 10.49W
  • Power Consumption (Nominal Mode, Stensat Transmitting): 7.015W
  • Solar Array (Average): 1.229W
  • Power Storage: 17 Wh

Beacon Packet Format[edit]

TechEdSat transmits a heartbeat packet over amateur radio every 4 seconds. These packets are 122 ASCII character AX.25 packets, with the following structure. Amateur band radio frequency is 437.465 MHz.[6]

Two consecutive 12 bit raw ADC Data values are parsed into one 3 byte chunk in order to save data space. Each 3 byte chunk is represented in hex by 3 ASCII characters

Byte 3 Byte 2 (Bits 7 through 4) Byte 2 (Bit 3 through 0) Byte 1
ADC Value 2 (8 MSB Bits ) ADC Value 2 (4 LSB Bits) ADC Value 1 (4 MSB Bits ) ADC Value 1 (8 LSB Bits)

The following is the tentative beacon packet format.

Name Size (ASCII Characters) Offset (ASCII Characters) Description Unit
ncasst.org 10 0 Location of spacecraft information URL
SCETTime 8 10 Spacecraft Elapsed Time seconds
5V_min 3 18 SM 5V HK min value 12 bit raw ADC
5V_max 3 SM 5V HK max value 12 bit raw ADC
5V_avg 3 24 SM 5V HK rolling average 12 bit raw ADC
5V_now 3 SM 5V HK last value 12 bit raw ADC
3V3_min 3 30 SM 3V3 HK last value 12 bit raw ADC
3V3_max 3 SM 3V3 HK last value 12 bit raw ADC
3V3_avg 3 36 SM 3V3 HK last value 12 bit raw ADC
3V3_now 3 SM 3V3 HK last value 12 bit raw ADC
Temp_min 3 42 SM Temperature HK min value 12 bit raw ADC
Temp_max 3 SM Temperature HK max value 12 bit raw ADC
Temp_avg 3 48 SM Temperature HK rolling average 12 bit raw ADC
Temp_now 3 SM Temperature HK last value 12 bit raw ADC
Curr_min 3 54 SM Current HK min value 12 bit raw ADC
Curr_max 3 SM Current HK max value 12 bit raw ADC
Curr_avg 3 60 SM Current HK rolling average 12 bit raw ADC
Curr_now 3 SM Battery Bus Voltage last value 12 bit raw ADC
VBUS_min 3 66 SM Battery Bus Voltage max value 12 bit raw ADC
VBUS_max 3 SM Battery Bus Voltage last value 12 bit raw ADC
VBUS_avg 3 72 SM Battery Bus Voltage rolling average 12 bit raw ADC
VBUS_now 3 SM Battery Bus Voltage last value 12 bit raw ADC
IBUS_min 3 78 SM Battery Bus Current min value 12 bit raw ADC
IBUS_max 3 SM Battery Bus Current max value 12 bit raw ADC
IBUS_avg 3 84 SM Battery Bus Current rolling average 12 bit raw ADC
IBUS_now 3 SM Battery Bus Current last value 12 bit raw ADC
ICH_min 3 90 SM Battery Charge Current min value 12 bit raw ADC
ICH_max 3 Battery Charge Current max value 12 bit raw ADC
ICH_avg 3 96 SM Battery Charge Current rolling average 12 bit raw ADC
ICH_now 3 SM Battery Charge Current last value 12 bit raw ADC
SA_Status 2 102 SM Solar Array Status Byte SA1: Bit 0

SA2: Bit 1

SA3: Bit 2

SA4: Bit 3

SA5: Bit 4

NON_minutes 4 104 How long the spacecraft has been in Nominal Mode minutes
NOF_minutes 4 108 How long the spacecraft has been in Safe Mode minutes
Single Errors 2 112 Safe Mode Processor Error Counter number of errors
All Errors 2 Safe Mode Processor Error Counter number of errors
All Errors 2 2 Safe Mode Processor Error Counter number of errors
CRC 4 118 CRC over all previous data bytes

CRC-16-IBM polynomial x16 + x15 + x2 + 1

0xA001 Key
Total 122 122

Launch[edit]

CubeSats deployed to orbit from the International Space Station on 4 October 2012 (from left: TechEdSat, F-1 and FITSAT-1).


References[edit]

  1. ^ Bergin, Chris (20 July 2012). "Japanese H-IIB launches HTV-3 to the International Space Station". NASASpaceflight.com. Retrieved 21 July 2012. 
  2. ^ Gunter Dirk Krebs (January 31, 2012). "TechEdSat". Gunter's Space Page. Retrieved February 1, 2012. 
  3. ^ 大塚実 (January 25, 2012). "JAXA、宇宙ステーションから超小型衛星を放出できる装置をプレス公開" (in Japanese). mynavi.jp. Retrieved February 1, 2012. 
  4. ^ "CubeSat Orbital Elements". Retrieved October 4, 2012. 
  5. ^ TechEdSat Twitter
  6. ^ "TechEdSat". IARU. April 3, 2012. Retrieved April 6, 2012. 

External links[edit]