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lpnpQR rOYi0WS the QdVOUItQ~OQ and
liaitoeiom OR OlQCtriC pnowlalon for
1 iqlhemaa che roctar i zed by o nnunch inam
ln tho DO0 to 100 Rg ran$@. 'Bna coneidyra?d
dyotooa include ion propuioion, nrcjvee,
and ntotionary plasma thruntorn eor
Bitfornone applications GUC~ ne drmg
coopnnneion, orbit raisinq, Pdnrlr ?rimming
of orbital parameters, and variauo crbit
tranofors.
ElQCtrk propuloion provldaa nubstnntiel
oann onviqo nm3 turna out eo bo on
onablbmg tochnolbgy for ceetnln I lightoat
aiseiono. TRO conatrainte reoirlPIn9 eron
DC ~ V O R linitations onbomrd small
@gtolllktQQ QrO dincuseod, QlOw W i t h the
inplicotiono on candidate tochnoloqios and
systoa aolutlons. A review ol nenr terra
prooptivoa of lou power ion Phrueatero.
lor lightmats applications, concludes the
paper.
1. I~WCTIOW
Rscont adtvencsa in electric propu?sion
hsvo finally lad to consider Len une POP
coanorcinl qoootationary communication
satallitss etationkeeplng. For rsuclz
function, ion thrusters, statlonary pleme
thruotera (SpT) and arcjete ore currently
boing planned on board uavnrel now
setollitea. Tho main at?rtiction of
eloctric thruitoro lice In their hiqh
OXheU8t VQlOCity which 15 aovorel ti%iiOS
that oP convent.iona1 chemical thrurstero.
"he najor benefit is represontad by tho
gropllant mass reduction for orbit
control eaeko. I
Eleceric propuleion is QAOO being
tonnidlorad for other near earth propulsion
bpglicotions, 000 n.9. (I], in pareicular
for orbit tranefer .and manoauvering of
large spcecraftr and for scientific and
interplanatary BiO8ione.
Tor what concern8 the ulectrlc propulsion
appliceelona to liqhtsats, norno initial
work raoulto from the open literature, BB)B
e.g. [I], but no specific plana ora known
to tho authorQ about actually inplononting
electric propuleion onbomrd lightmato.
Thio io quit0 surprising bocmuocr, in viov
of tho specific conetreinto of s~all
satollito@, electric propulaion may be
conoidorcpd an *enabling* eochnology
without which a number of appltcatlonm
would br alnomt unfoamibla.
Ubat:erfc Propuleion for Lightoato:
A R~MIoQ! of ?$plicotionka and Mvantaqes
6. mrrotea
Alhnbo 8pQXiO 8.p.A.
via BQCCO!PUPO a4, 00131 w-, Italy
C. Cirri, C. Matticeti
Proel Industria
v.10 Machiav$illi 29, 5017q ril'enze, Italy
24- I
Tho paper rsviown the koy features of
oloctric peopuloion in the specific
context bf DC-power limited liqhtsats
cheractorlzod by a launch mess rnnqe in
tho 300 to 800 K9, which is most
eppropnieeo for Q number of 'professional*
applications, including clvil and defense
ones.
Tho nein reason to consider electric
peopuloien le to reduce the total
oubnyeten mass for propuls1m-related
tnoka, tho iaaximizlnq the payload to
leunch DblDQ ratio while stayinq within the
leunch mas8 bounda otated above. However,
oloctric propulnion can be a viable
appeoach only Lf the power requirements
aPQ 8100 compatlble with tho DC power
lioitationa, conoiderinq that the liqhtsat
pow0r plane is normally dcslqned to
oupport the payload operation in normal
ado. WO will llait our conelderations to
throo E. R. technologies: ion propulsion,
Stationary Plasma Thrusters, and arcjets.
Yn tho low-power ranqe of Interest for
lrghtoats, typical performance arc given
@ in Table 2.-1 which envelopes the
characteristice of a number of existing
devicoo. WO main Electric Propulsion
applications are considered:
- orbit kaeping, which incluCos drag
conpnaotion, fine trimming of orbit
prnraooeoeo and, for liqhtsats in
oynchronous orbit, etation-keepinq. These
gropuloion tasks are normally concurrent
with payluad oporation. Therefore 2. P.
oppllcotione aro mainly power limited,
bssides being a100 mass limited in order
to rsoult conpatitive with chemical
propulsion. To exemplify, we will assume
to slloceto 30 Kg and 300 W to such E.P.
functionmi
.'+- orbit lbnoouvering, which includes orbit
s!~jr8ioing,
circular to e1 1 iptical orbit
.tronofer, and orbits c!rcularization.
Thooo . propulsion tasks are performed
outoido payload operation. Therefore the
full lightoat DC power, normally used to
supply tho payload in normal mode, can be
wade availabla, for Eloctric propulsion.
TypiC8lly, ono pay allocate 60 Kg and up
to 1200 W of DC p e r to E.P. functions.