School of Aerospace Engineering (since 1926)

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)

• 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

• 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 conceptFrom cargo , C130J, C130J-J30(with AVIO)

From high performance aircraft , Tornado(with MBDA, AVIO,Alenia Aeronautica, AM)

From San Marco to UNISAT

Unisat 26 Settembre 2000

Unisat-220 Dicembre 2002

Unisat-329 Giugno 2004

Unisat-426 Luglio 2006

• Hph (FP7): microsat for the test of an advanced propulsion system

• Lares :Satellite to measure the Lense-Thirring effect of the general relativity theory (the payload of the first VEGA launch)

Edusat : Microsatellite for high schools educational project (ASI)

Re-entryAEROFAST (FP7)1. Astrium France2. Astrium Germany 3. Deimos Portugal4. Samtech Belgium 5. INETI Poland 6. SIA, Italy7. BAS Bulgaria 8. PAS Poland 9. ONERA France 10. Kybertech Cecz11. 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 School2011-2012

TOTAL = 2.153.755 , TOTAL + TOTAL = 4.353.520

Founds given by “Sapienza” for ordinary expenses: 5000 Euro per year

Program From Amount (in Euro)

Lares Italian Space Agency 243898

Edusat Italian Space Agency 459740

National VEGA GNC MBDA 100970

Air dropped launchers

AVIO 72620

Hph European Community 358800

AEROFAST European Community 55921

Ulisse European Community 38806

Educational Project 1 MAE 822765

Educational Project 2 Sharif University 2200000

The future of the School

?

Few months ago, the Governance of “Sapienza” has “temporarily stopped”

the School for the sake of economy

Air-dropped LaunchersMethods of Design

Paolo Teofilatto

School of Aerospace Enginnering

Rome

Payload in LEO < 1000 Kg

Air-dropped Launchers

Conventional Launchers

Payload in LEO > 1000 Kg

Vega: 1500 Kg , Polar

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

4 ore

Costellation 1: three passages each hour with gaps of max 13 minutes

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)

1) Initial thrust to weight ratio (i=1,3)

2) Specific impulse (in seconds)

3) Structural mass ratio

4) Surface to weight ratio

Parameters to be optimised

00

i Tn

gm

iIsp

0

pi mu

m

0

1

2i S

m 12 parameters

Method of launcher design (2)Constraints

a) Geometric constraints

b) overall weight

c) initial conditions

d) final conditions

Cost Function

Payload mass um

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

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)

Tornado Launch System

Time [s] Velocity [km/s] Flight path ang. [deg] Event0 0,26 35 Separation

30 3,26 30 First stage burn out31 3,26 30 Second stage ignition76 4,25 20 Second stage burn out

264 4,12 8 End of 1st coasting368 7,00 5 Third stage 1st burn out672 6,80 1 End of 2nd coasting679 7,20 0 Third stage 2nd burn out

Overall 3 stage mass before ignition 406 Kg

Propellant for orbit acquisition 260 Kg

In orbit mass (included 3° stage structural mass) 146 Kg

Nominal Trajectory: 500 Km , circular

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

• Cargo aircraft:

- heavier weight then bigger payload

- more difficult release manoeuvre (?)

Vozdushny Start (Air Start).A Antonov - Polyot study : carrier aircraft An-124Polyot 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.

Lanciatore

Postazione operatore

Piattaforma di lancio

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.