VEnUS: Vega Electric Upper Stage
Davide A. Nicolini
Vega Operational Launch System
Project Manager
Figure 7-4: EPM+, stowed into LV fairing, dimensions
Extension of Vega capabilities using
an EP module
• 
VEnUS is a 12kW Solar Electric Propulsion tug, an additional
orbital transfer kit installed on the launch vehicle payload
interface, to enable new mission types (MEO, GEO,
interplanetary) enlarging the Vega market base and
developing new services as debris or failed satellites
removal.
• 
VEnUS extends VEGA mission capability to orbits beyond
LEO:
!  Medium Earth Orbits
!  Geosynchronous Earth Orbit
!  Highly Elliptic Earth Orbits
!  Lagrange Points Halo Orbits
Extension of Vega capabilities using
an EP module
• 
ESA is running phase A with Compagnia Generale per lo
Spazio (OHB-CGS) on the autonomous orbit raising module
based mostly on off-the-shelf hardware and powered by
electric thrusters.
• 
A clear business case exists for European interplanetary
missions like Proba-3 or MEO class satellite constellation
replenishment missions (as Galileo or O3b) bringing them
within reach even using the current Vega launcher design.
High-powered
SEP
Opens Vega
to new class
of Enables
missions
Applications
currently outMultiple
of reach
Satellite)Servicing)
Payload)Delivery))
Deep)Space)Human)
Explora5on)
Commercial)Space)
Applica5ons)
ISS)
U5liza5on)
Solar)Electric)
Propulsion))
OGA)
Missions)
Orbital)Debris)
Removal)
Space)Science)
Missions)
3
Picture taken from NASA website
Missions within reach
Orbit
Orbital
elements
Application
Vega release
orbit
VENUS
Dry mass
Prop.
mass
P/L
mass
Mission
time
MEO
h = 8062km
i = 0 deg ; e = 0
O3b
h = 300 km
i = 5.2 deg ; e = 0
681 kg
421 kg
1467 kg
7.6 mo
MEO
h = 23222 km
i = 56 deg; e = 0
GALILEO
h = 300 km
i = 5.2 deg ; e = 0
681 kg
535 kg
1048 kg
7.7 mo
GEO
h = 35786 km
i = 0 deg; e = 0
Telecom, Data,
Services
h = 860 km
i = 5.2 deg ; e = 0
681 kg
551 kg
944 kg
8.7 mo
Sun-Earth L1
d = 1.491.110 km
Scientific
h = 300 km
i = 5.2 deg ; e = 0
786 kg
919 kg
834 kg
19.4 mo
Earth-Moon L1
d = 326.370 km
Scientific,
Communications,
Infrastructure
h = 300 km
i = 5.2 deg ; e = 0
* Additional tanks
847 kg
907 kg
18 mo
NEA
d = 2.047.990 km
Scientific
h = 300 km
i = 5.2 deg ; e = 0
* Additional tanks
935 kg
819 kg
19.8 mo
Active debris
removal/towing
h = 23222 km
i = 50 deg; e = 0
GALILEO FOC
01 & 02 re-orbit
h = 300 km
i = 50 deg ; e = 0
490 kg
N/A
18 mo
* Additional tanks
786 kg
786 kg
981 kg
** docking system
SEP - Enabling propulsion technology
SEP can enable high delta-V missions ( V > 2.0 km/s)
100%
3000
53,7
78,0
90%
2500
80%
1049,4
906,8
2000
Mass$[kg]
60%
50%
1616,0
78,0
Available4Satellite4mass
LV4P/L4Adapter
Mass$[kg]
70%
534,4
Module4dry4mass4w/4margin
525,0
78,0
78,0
1500
485,0
78,0
847,0
Propellant
40%
1274,9
1000
78,0
547,0
1455,0
1215,0
30%
500
20%
681,2
10%
595,3
0%
Electric4Propulsion4Module
Chemical44Propulsion4Module
SEP vs. CPS performance
comparison:
generic 4.0 km/s DV orbit raising
mission, launched by VEGA-C
Available;Satellite;mass
LV;P/L;Adapter
786,2
Propellant
718,1
230,0
0
Electric
Propulsion
Module;+;(HET)
Electric
Propulsion
Module;+;(GIT)
210,0
LISAFPathfinder LISAFPathfinder
VEGA;C
VEGA
SEP vs. CPS performance
comparison:
LISA Pathfinder mission
(S/E L1 Lagrange Point)
Module;dry;mass;w/;margin
Payload volume allocation
Vega VEnUS SEP Module
LAUNCH SYSTEM / SPACECRAFT INTERFACES CONTROL FILE
LISA Pathfinder
VG-DCI-1/50700-AE
3.6.2
CHAPTER 3
Page : 15
Issue : 1
Rev. : 2
SPACECRAFT INSIDE USABLE VOLUME (FAIRING DYNAMIC ENVELOPE)
Subject to RfW-01
Vega LPF CPS Module
Deployed and stowed configuration
Solar Array Technology Developme
Module design summary
• 
• 
• 
Solar Propulsion Sub-system:
– 
Four COPV 133 l gas tanks
– 
Two gimballed HET, 5 kW class (Hot redundancy)
– 
Two Xe Resistojet triads (for attitude control, no reaction wheel included)
– 
One PPU per thruster
– 
High pressure inlet Xe Flow Controller (piezo proportional valve based)
Power generation
– 
Flexible Solar Panels (US single source), enabling technology to allow panels
stowage
– 
17.5m2, Ø 5m, ~30 kg per wing
– 
12.5 kW BoL, ~30% power degradation at EoL
– 
“Blow-down” power management logic aimed to minimize SA over-dimensioning,
when accounting for the space radiation driven solar cell degradation:
PPU input varies from 5kW BoL to 3kW EoL, with decreasing thrust and constant Isp
Complete set of S/S for full autonomous nominal operations
– 
ACS sensing, OBDH, PCDU, TMTC, TCS, SADM, Sat Release Mech
Components layout
Proba-3 case
• 
Among currently planned ESA missions, PROBA3 fits the definition
of VENUS class of missions:
! 
Small scientific spacecraft " 540 kg launch mass
! 
High Elliptic Earth Orbit " a=36943 km, hp=600 km, ha=60530 km,
e=0.811114, i=59°, w=188°
! 
Target launch date is compatible with VENUS development schedule (2019)
Development compatible with Vega-C
qualification flight
Phase
Milestone
Duration
Start
End
-
03/2014
03/2014
Preliminary feasibility study
9 mo
03/2014
12/2014
PRR
3mo
02/2015
05/2015
SRR
3mo
05/2015
07/2015
PDR
7 mo
07/2015
02/2016
SDR
10 mo
04/2016
01/2017
CDR
10 mo
01/2017
10/2017
GQR
10 mo
10/2017
07/2018
2 mo
07/2018
09/2018
3 mo
05/2019
08/2019
KO
Phase A
Phase B
Phase C
Phase D
Phase E1
Launch Campaign
(VEGA-C maiden flight)
FQR
• ESA currently plans to continue in the 2015/2016 period
the VEnUS design up to completion of phase B
Summary and way forward
• 
Overall the technologies required have now reached the required TRL
and offer opportunities for Vega to take position on new space services
and missions
• 
Flexibility is a key feature: designed so its building blocks can be used
as SEP tug, SEP spacecraft platform or SEP propulsion module
• 
Initial design driven by a Galileo-type mission (most dimensioning)
being a clear business case, but its performance can meet farer orbits
as GEO using the module as S/C bus or as interplanetary mission (e.g.
transfer to Lagrange point orbits of scientific S/C like Proba-3)
• 
The EP module shall be designed with a low-cost approach, by making
use of existing COTS H/W as much as possible, in order to reduce
recurrent costs reducing the impact on the Vega launch service price
! 
CBE cost and target: 10% of launch service cost
! 
Competitive to Soyuz launched from Kourou