• recupero di un razzo
• Lanciatore riutilizzabile
• dynamic analysis of a recoverable rocket
• thermal analysis of a recoverable rocket
• recoverable rocket
• recovery of a rocket
• reusable launch vehicle
• rlv
• recoverable launch vehicle
• analisi termica razzo recuperabile
• analisi dinamica razzo recuperabile
• razzo recuperabile

Re-usable launch vehicle are increasingly important in the space sector and they
could take the market lead once low refurbishment costs and high reliability are
guaranteed. This work contains the preliminary redesign and analysis of an ex-
pandable rocket to convert it into a reusable one. The objective of this thesis is to
analyze the feasibility of recovering at least the first stage, studying its descending
dynamic, assessing whether it can reach ground with vertical orientation and almost
zero speed or not. Moreover, the mechanical and heat loads are of particular inter-
est. The SpaceX’ Falcon 9 is taken as reference, being it the primary example of a
successful reusable launch vehicle and since its I-stage has been many times proved
to be recoverable. Based on their example, retro-propulsion is here used for braking
and landing of the I-stage. Once a reference mission is selected, mass and velocity
considerations are used to obtain an estimation of the propellant mass needed for
re-entry, to update the first stage structural mass to account for landing mechanism
and to calculate the new payload carriable in the same reference orbit. This is closely
connected to the re-entry dynamic for which a 2-D motion with 3 degrees of freedom
is used. Four fins located at the top of the first stage act as passive stabilizers, while
no active control system is present. The ignition of the retro-propulsion maneuver
can be selected in function of the descending Mach number and of the altitude.
Different sets of altitude-Mach number are analyzed to optimize this maneuver and
the optimal one is then used for the whole process of redesign. Lastly, a thermal
analysis on the whole object is conducted exploiting two different models -one of
which oversimplifies the retro-propulsion maneuver- and comparing them to show
how this maneuver significantly impact on the I-stage thermal loads. Apart from
the results of the specific case analyzed, what emerges from this study is a flexi-
ble code adaptable to various expandable 2-stage rockets for starting studying their
first stage redesign and re-entry. The flexibility stands in the possibility of choosing
several different reference missions through the total ∆V required for the ascending
phase. Moreover it is possible to explore different retro-propulsion maneuvers as-
sessing the mechanical and thermal loads the structure may suffer and choosing the
optimal one, therefore playing a solid work as a preliminary analysis.