Transcript CubeSat subsystems - DTUsat CVS repository

CubeSat subsystems
Thea Falkenberg
and
Martin Sørensen
Mechanical structure
Thea Falkenberg
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AAUSat structure.
Milled from one piece.
Used last time.
Weight ~ 200 g (maybe less)
• HAUSat1
structure.
• 12 pieces.
Many screws
• weight (270 g)
• CP structure
• Triangular
assembly
• 2 main parts
• each part 4 pieces
• Easy access to all
subsystem-boards.
• Many screws (16)
• Weight: less than 300 g
• Tested
Canx-1
Cute
HAUSat-1
Radio
Thea Falkenberg
• Cubesat XI-IV: ½ wave
• AAUSat1: Two
mono & ½ wave dipole
perpendicular
• Many seem
dipole-antennas.
to have
copied Mea
Huaka’i. Two
½ wave
dipoles at 90
degrees
• Most Cubesats
uses COTS
• All use
PICOPacket
• Most use
Yaesu
because of
weight
• Some use both
(or have the
other in
reserve)
• No casings
• Slightly
modified (not
specified)
• Common idea
(maybe from
Mea Huaka’i)
• Patch
abandonned for
monopole
because of
measurement
error.
• Not updated webpage
• Pictures may be comming
• ”Next time” would push for 5/8 wave
monopole antenna, or
two 1/4 wave phased monopole
radiators. (Mike Hammer)
• Only High frequency
communication
• Only Patch antenna
• Probably discarded again
Radio summary
• All communicate at 70 cm (435 MHz); some
with uplink at 2 m (146 MHz)
• Only Ncube has (maybe) a downlink at 2,2
GHz
• Realistic power consumption seems to be ~
2,5 W in Transmit-mode and ~ 0,2 W in
Receive-mode.
• Realistic weight seems to be down to 100 g.
• Should fit on one PCB.
• The radio PCB should preferably be placed
as far away from the power PCB as
possible.
On Board Computer
Thea Falkenberg
and
Martin Sørensen
Power
Martin Sørensen
Solceller
• De fleste bruger Triple Junction Celler (> 22%)
• Standard størrelser
• Emcore & Spectrolab
Solcelle beregning for nCube
Power Point Tracking (PPT)
Ikke simpelt, men solcellernes effektivitet forøges!
Batterier
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Li-ion (en del bruger Danionics)
Kapacitet ~1500 mAh
Vægt ca. 42 g pr. styk
Voltage 3,0 – 4,2 V
Danionics batteri