VEGA
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VEGA |
Avio (Advanced
Vision Into Aerospace) * European Launch Vehicle (ELV S.p.A.)
The European Space Agency will definitely proceed with the development of the
VEGA (Vettore Europeo
di Generazione Avanzata) launcher using Ariane booster technology. VEGA is a three-stage
launch vehicle using solid motors. The first launch is planned for 2007. It is planned
that Arianespace would operate and commercialise the launch service from Kourou.
Prime contractors will be FiatAvio and EADS. VEGA will consist of three solid propellant
stages and a liquid propellant upper stage. The first stage P80 Advanced Solid Booster
will also be used to increase the performance of the Ariane 5 in its twin-solid
rocket booster system, with new features such as a new gimballing nozzle. The second
stage will be Italy's Zefiro motor. The third stage be a modified Zefiro booster
and the upper stage an Attitude and Vernier Upper Module with storable propellants.
VEGA will be able to place about 1.5 tons into an SSO. The final decision on the
development of the small launcher VEGA is expected to be taken in October 1999 by
the ESA Council.
After about two years of defination
and consolidation activities, the current VEGA configuration, including the new
P80 FW first stage, two additional solid-propellant stages Zefiro (the
Zefiro motor development was initiated by FiatAvio under company funding and contracted
by the Italian Space Agency) as, respectively, second and third stages, and
the AVUM upper modul, had been established and was ready for development as an ESA
program. The specified mission for VEGA is: launch of a payload of up to 1500 kg
into a circular 700 km-altitude polar orbit. VEGA will be able to launch satellites
for a wide range of missions and applications, into orbits with a range of inclinations
from 5.2 degrees to SSO, with altitudes between 300 and 1500 km, and with payload
masses ranging between 300 and 2500 kg from Kourou. VEGA is designed as a single-body
vehicle composed of three solid-propulsion stages, an additional liquid-propulsion
upper module, and a fairing for payload protection. The three solid stages perform
the injection of the upper composite into a low-altitude orbit. The upper module,
called AVUM ( Attitude and Vernier Upper Module), is used to improve the accuracy
of the primary injection, to circularize the orbit, and to perform the empty-stage
to deorbiting manoeuvre.
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First stage: The first stage is based
on the adoption of the new P80 FW solid-rocket motor being developed through
a parallel Program slice. P80 FW Technology Choises: CFRP monolithic carbon
fibre case, HTPB 1912 propellant. The P 80 FW maximum vacuum thrust is 3015
kN. The nozzle has a throat diameter of 496 mm and an expansion ratio about
1: 16. The nominal firing time is about 110 seconds. In addition to the P80
motor, the first stage is composed of the structural elements needed to connect
it to the second stage (interstage 1/2 aft part) and to the ground infrastructure
(interstage 0/1), and to host the stage avionics. Those airframes are aluminium
shells. The rear skirt (interstage 0/1) is a cylindrical structure, while the
interstage 1/2 is a conical structure. |
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Third stage: The VEGA third-stage propulsion is based on a solid-rocket motor
with a propellant mass of 9.5 tons, known as Zefiro SRM and derived from Zefiro
16. Zefiro 9 employs a carbon-epoxy filament-wound case, HTPB 1912 composite propellant,
and a moving nozzle based on flexible-joint technology. Its maximum vacuum thrust
is 317 kN, respectively. The nozzle has a throat diameter of 164 mm and an expansion
ratio of 1: 56. The nominal firing time is about 119 seconds. An interstage connects
Zefiro 9 to the AVUM, and hosts the stage avionics and the main safeguard unit.
Upper stage: The AVUM (Attitude and Vernier Upper Module) upper stage is
composed of two different sections, one hosting the propulsion elements (APM= AVUM
Propulsion Module), and one dedicated to the vehicle equipment bay (AAM= AVUM Avionics
Module). The APM provides attitude control and axial thrust during the final phases
of flight. The total propellant loading will be between 250 and 500 kg, depending
on the launcher configuration definition and the mission to be performed.
Upper composite: The upper composite includes the payload adapter and the fairing.
The upper-stage configuration imposes the use of a conical structure in order to
provide the required payload standard interface of 937 mm diameter. The reuse of
an existing Ariane adapter is foreseen. For the fairing, a two shell configuration
has been selected, with a 2.6 m external-diameter cylindrical part and a total height
of 7.9 m � including a 3.5 m cylindrical part. The structure is made of two composite
shells, composed of aluminium honeycomb and carbon skins.
