School of Aerospace Engineering (since 1926) The School has been the core of the development of aeronautics in Italy ( Guidonia Labs 1935-1942, first supersonic wind tunnel in Europe) San Marco satellites produced by the School allowed Italy to be the third nation in the world to put a satellite into orbit The School has been the only academic institution in the World to hold a launcher base platform (Malindi Kenya), till 1999 Master Degree in Astronautical Engineering (100 Students) “Laurea Speciale” in Astronautical Engineering (25 Students) Master in Satellites and Space platforms (10 Students) PhD Course in Aerospace Engineering (15 Students)

Master Degree in Astronautical Engineering The Master Degree in Astronautical Engineering has the highest rates according to students among the Sapienza courses (from the “Nucleo di Valutazione” reports) 98% of the students get the Master degree in due time 95% of the students are employed in the Aerospace area within 1 year from earning the Master degree The students are involved in the research activity of the School

From Earth to Space and back Launch Systems Satellites Re-entry Systems Human Space exploration

Launch systems Collaboration with Kosmotrass and Yusnoye (Dniepr launch vehicle) Collaboration with MBDA and AVIO:National GNC for VEGA

Air-launch concept From cargo , C130J, C130J-J30 (with AVIO) From high performance aircraft , Tornado (with MBDA, AVIO,Alenia Aeronautica, AM)

From San Marco to UNISAT 26 Settembre 2000 Unisat-2 20 Dicembre 2002 Unisat-3 29 Giugno 2004 Unisat-4 26 Luglio 2006

Edusat : Microsatellite for high schools educational project (ASI) Lares :Satellite to measure the Lense-Thirring effect of the general relativity theory (the payload of the first VEGA launch) Hph (FP7): microsat for the test of an advanced propulsion system

Re-entry AEROFAST (FP7) Astrium France Astrium Germany Deimos Portugal Samtech Belgium INETI Poland SIA, Italy BAS Bulgaria PAS Poland ONERA France Kybertech Cecz Amorim Portugal

Human Space Missions Collaboration with the Italian Air Force AeroSpace Medicine Department Two Space Medicine Classes in the Master Course “Astronautical Engineering” Space Law and Agrobiotecnology (with Aerosekur) classes Ulisse FP7 for the dissemination of the Astronautical Culture Gliosat (behaviour in space of cancer cells affected by glioblastoma)

Budget of the School 2011-2012 Program From Amount (in Euro) Lares Italian Space Agency 243898 Edusat 459740 National VEGA GNC MBDA 100970 Air dropped launchers AVIO 72620 Hph European Community 358800 AEROFAST 55921 Ulisse 38806 Educational Project 1 MAE 822765 Educational Project 2 Sharif University 2200000 TOTAL = 2.153.755 , TOTAL + TOTAL = 4.353.520 Founds given by “Sapienza” for ordinary expenses: 5000 Euro per year

The future of the School ? Few months ago, the Governance of “Sapienza” has “temporarily stopped” the School for the sake of economy

Air-dropped Launchers Methods of Design Paolo Teofilatto School of Aerospace Enginnering Rome

Conventional Launchers Air-dropped Launchers Payload in LEO > 1000 Kg Air-dropped Launchers Vega: 1500 Kg , Polar Payload in LEO < 1000 Kg

Air launched Systems: Advantages The carrier aircraft leaves the booster with a significant amount of potential and kinetic energy. The aerodynamic losses are very much reduced, since the rocket mission starts at high altitude (atmospheric density is 75% less than the sea level density) The pressure losses are reduced and the expansion ratio of the first stage nozzle is closer to the vacuum type ratio. Lower dynamical pressure and lower structural and thermal stresses allow the use of lighter materials .

Air launched Systems: Advantages Possibility to select the optimal launch condition for any mission. There is no time and space limitations on Launch Window Injection can occur directly in the orbit plane avoiding expensive out-of-plane maneuvers Reduced amount of operation and ground support. Reliability under unfavourable weather conditions. Autonomous range support activities (e.g. telemetry, tracking, flight safety). Possibility to store microsat, integrate and launch from different Air Force Bases (simultaneous launch from different sites). Readiness to launch on-demand

Example: Disaster Monitoring Constellation Helio-synchronous Constellation altitude: 678 Km 4 satellites in the same plane, phasing: 90 deg Tsinghua-1 (Cina, 50 Kg) Aisat 1 (Algeria, 90 Kg) NigeriaSat 1 (Nigeria, 100 Kg) TopSat (Surrey, 120 Kg) DMC provides very good coverage for high latitude areas The “Tsunami” (January 2005) equatorial area is visited any 12 hours

A local and dedicated costellation “Tsunami” 4 Satellites Carrier aircraft from the bases : Franch Guiana, Deutch Antille, Aden (GB), Malindi/Trapani Costellation 1: “Minimum gap” Service Costellation 2: “Max continous coverage” Service Constellation deployed in few hours

Costellation 1: three passages each hour with gaps of max 13 minutes 4 ore Costellation 2: Service 1 hour on – 1 hour off

EFA Launch System Air-Launched Rocket carried by an Eurofighter Typhoon EFA Three Stage Rocket with Thrust Vector Control TVC and four fins for safe separation by the carrier Aircraft First two stages have solid propellant third is liquid propelled Release Conditions: Altitude: 12 Km Velocity: 300 m/s Mach: 0.85 Flight Path Angle 40 degrees Carried Mass: ~ 4000Kg

Method of launcher design (1) Parameters to be optimised Initial thrust to weight ratio (i=1,3) 2) Specific impulse (in seconds) 3) Structural mass ratio 4) Surface to weight ratio 12 parameters

Method of launcher design (2) Constraints Geometric constraints overall weight c) initial conditions d) final conditions Cost Function Payload mass

Simple model and analytic formulas to have input design before numerical optimization Gravity turn trajectory Flat and not rotating Earth No atmosphere Constant Thrust-to-weigth ratio:

Analytic formulas (2) The constant A is a function of the drop conditions V0,gamma0 The final flight path angle can be derived from the burn time tb:

Analytic formulas (3) The general rocket design (first approx.) has been approached using the above formulas. The best final conditions, for instance best final velocity for each stage, can be determined as a function of the parameters of each rocket stage and of the release state conditions. Of course the constraints must be taken into account. For instance: Total mass of the rocket max diameter (then beta1 is fixed) Range of values for the specific impulses and structural parameters u are fixed by existing technology. Range of release state conditions is determined by carrier aicraft capability

Max length:6.5 m, Max diameter:1m, Max weight: 4060 Kg EFA Constraints Max length:6.5 m, Max diameter:1m, Max weight: 4060 Kg

USE OF TORNADO The rocket design for EFA launch requires some change on the EFA structure; in particular the central pylon and the landing gear must be properly modified. The Tornado aircraft is better suited for hosting big loads under the fusolage and there is room to host a larger rocket.

Rocket Design (Tornado Air-Launch)

Nominal Trajectory: 500 Km , circular Tornado Launch System Nominal Trajectory: 500 Km , circular Overall 3 stage mass before ignition 406 Kg Propellant for orbit acquisition 260 Kg In orbit mass (included 3° stage structural mass) 146 Kg

Different Concepts: “Captive on top” Global Strike Missile. A BOEING study. Carrier aircraft: F-15 Global Strike Missile is composed of stages from Minuteman II , Minotaur e Pegasus XL.

Different Concepts: “The trimaran” MLA (Airborne Micro-Launcher) A Dassault Aviation study: carrier aicraft: Rafale. Two stage rocket with two boosters

Different Concepts: Cargo Aircraft heavier weight then bigger payload more difficult release manoeuvre (?) Vozdushny Start (Air Start). A Antonov - Polyot study : carrier aircraft An-124 Polyot two-stage rocket of 100 ton. Liquid propellant (RP-LOX) Foreseen payload 3000 Kg in LEO.

Rocket on board “Space Clipper” and “Orel” Yuzhnoye sudies, carrier An-124 Rockets derived from SS-24.

Phases of rocket release Extraction Gravity Torque

Extraction Parachute TYPE V platform exiting from C130J

Stabilizer Parachute Rocket pitch oscillations after release

Aircraft instability during rocket release

Clearance maneuver

A Drop test QuickReach: An AirLaunch LLC project: carrier aicraft C-17A Quick Reach rocket weigth: 32.600 kg

Final Remarks Airdrop launcher system appear as the best systems that meet the launch on demand requirement. The complexity of the system introduces original problems in aeronautic and in missile engineering. During the preliminary design some trial and error procedures must be pursued, thus there is the need to have fast tools to discriminate rapidly among different possible solutions. In the very preliminary design an analytic approach has been pursued. The analytic results have been used as input parameters for refined numerical algorithm for the design and mission optimization.