LAPLander”Light Airbag Protected Lander”

- A REXUS 7/8 Proposal –

ESA-ESTEC Presentation5 Feb. 2009

TEAM OVERVIEW

General and Scientific issuesTorbjörn Sundberg,

PhD student,Space and Plasma Physics, KTH

Aerodynamic issues and modelingXin Li,

Aerospace Master, KTH

Mechanics and Design:Matías Wartelski,

Aerospace Engineering, KTH,

Mechanical Engineering and Materials Science, Ecole des Ponts ParisTech

Christian Westlund,

Aerospace Engineering, KTH

Electronics and softwareMalin Gustafsson,

Electrical Engineering, KTH

Joakim Sandström,

Electrical Engineering, KTH

Oliver Neuner

Electrophysics Master, KTH

The Royal Institute of Technology (KTH)

One-third of Sweden’s technical research and engineering education capacity at university level, with 12,000 undergraduate students and 1,400 PhD students

Department of Space and Plasma Physics

Long-standing expertise in experimental studies of space plasma, withinvolvement in missions such as Cluster, MMS and Bepi Colombo.

Scientific Background• Plasma exhibits complex interactions on various scales.The near earth environment is one of the best places for studying plasma physics.

• Auroral and ionospheric research are areas where important results can be achieved with sounding rockets

• To characterize the electrodynamics of the ionospheric plasma, in-situ measurements of electric and magnetic fields, and plasma parameters are needed.

Technological BackgroundMulti-point measurements are in the forefront of space research

• Satellite constellations i.e. Cluster (4), and Themis (5)

• Sounding rockets Cascades-2 (5 payloads)

A compact and lightweight payload for measuring electric and magnetic fields would directly allow truly multipoint measurements

- Bandwidth limitations requires recoverable payloads

- SCALE boom deployment system developed at KTH makes a compact electric field instrument possible on small spinning payloads

SCALE

The LAPLander”Light Airbag Protected Lander”

Prototype of a small lightweight sounding rocket payload, capable of high resolution measurements in the ionosphere.

Features:

- Small (6-7 cm high, 25 cm diameter)

- Ejectable and Recoverable

- Lightweight (2-3 kg)

- On-board data collection

- Sensors for flight diagnostics

- Prepared for future electric field measurements in the ionosphere

1) Payload is successfully ejected from the main rocket, localized and recovered.

2) The collected data are recovered and the payload’s behavior is evaluated.

3) Payload dynamics is understood in terms of theoretical predictions and simulations

4) The payload has suffered only a limited amount of damage and can be reused in future missions.

Project Success Criteria

Facilities and support

Wind Tunnel WorkshopElectronics lab

Supervision and support:

Nickolay Ivchenko, Department of Space and Plasma PhysicsPeter Fuks, Department of Electromagnetic EngineeringDan Borglund, Department of Aeronautical and Vehicle Engineering

MECHANICAL DESIGN

Payload design

- Central electronics box

- 4 dummies of the SCALE E-field instrument

- Heat shields on top and bottom

- Disposable hatches on the sides

Payload decentLanding speed

of 24 m/s

Max temp of ~300 C for only some

seconds

Inflatable structure• For deceleration and impact protection• Lightweight solution using minimal space

Four Ring Protection

Umbrella-like design helps deceleration

and fall stabilization

Very efficient vertical protection

Low gas volume needs (~3-4 L/ring at 1 bar)

Deceleration

Impact test

Descent with parachute

Inflation options

• Compressed gas (CO2, N2…):

Example: CO2 cartridges

- Simplest and most viable solution for low gas volumes. Technology used for bicycle pumps, Soda Streamers, etc.

ELECTRONICS

System overview

Batteries (10.8 V)

DC/DCconverter

Deployment system

Altimeter

Central Unit(FPGA and

Microcontroller)

Memory

Cornell GPS SMILE

Radio transmitter

Satellitetransmitter

Accelerometer

Gyroscope

Temperature sensors

GPS

Timeline of operation1 Trajectory phase

Starting from launch, the sensors start gathering data and store it in the system memory.

• Cornell GPS, Space-grade GPS needed for trajectory phase, an in-kind contribution from Cornell University, USA, is a system available for us.

• Cornell GPS and accelerometer give independent acceleration measurements

• Gyro, magnetometer and Cornell GPS provide independent attitude measurements.

• Multiple temperature sensors characterize thermal behaviour in different parts of the payload. Batteries

(10.8 V)

DC/DCconverter

Deployment system

Altimeter

Central Unit

Memory

Cornell GPS SMILE

Radio transmitter

Satellitetransmitter

Accelerometer

Gyroscope

Temperature sensors

GPS

Timeline of operation

1 Trajectory phase

2 DeploymentAt 2-5 km the central unit activates the procedure that deploys the airbags. Cornell GPS will run until its dedicated memory is full (approx. 600 seconds), all other sensors are active until after landing.

Batteries (10.8 V)

DC/DCconverter

Deployment system

Altimeter

Central Unit

Memory

Cornell GPS SMILE

Radio transmitter

Satellitetransmitter

Accelerometer

Gyroscope

Temperature sensors

GPS

Timeline of operation

1 Trajectory phase

2 Deployment

3 RecoveryAfter 1500 sec, the data acquisition is stopped, and the localization system is activated. The radio beacon and satellite transmitters operate at low duty cycle, taking turns transmitting to avoid interference and limit peak power consumption.

• Radio transmitter sends a identification signal and GPS position in the UHF band. Range estimated to 25 or 50 km depending on transmission frequency.

• Satellite transmitter sends GPS position via communication satellites to mail or SMS.

Batteries (10.8 V)

DC/DCconverter

Deployment system

Altimeter

Central Unit

Memory

Cornell GPS SMILE

Radio transmitter

Satellitetransmitter

Accelerometer

Gyroscope

Temperature sensors

GPS

Sensors• Accelerometer

ADXL180, Range ~ ± 50 g, accuracy ~ 0.125 g.

• GyroscopeThree orthogonally mounted ADXRS300.

• Temperature sensorsA few Pt1000 together with electronics. Range -50 - +500 °C.

• AltimeterMS5540, Range ~ 0 - 30 km, accuracy < 30 m.

• GPSWhen on the ground, a conventional GPS module is used to obtain the payloads position

• SMILEAn in house designed magnetometer that will be used to reconstruct the attitude of the payload, by referring to its orientation in the geomagnetic field.

• Cornell GPSA novel dual-antenna GPS attitude system. All data from this unit will be reconstructed post flight.

MS5540 altimeter

ADXRS300 Gyroscope

SMILE magnetometer - KTH

In kind contribution of KTH, Sweden

20x20x20 mm fluxgate sensor

0.1 nT bit resolution

250 samples/sec

To fly on NASA Cascades-2 sounding rocket.

For LAPLander: new PCB layout – combined withcentral unit PCB

Cornell University GPS attitude sensor

In kind contribution of Cornell University, USA(prof. P. Kintner, S. Powell, E. Lundberg)

Uses two antennas to determinephase difference of GPS signalIndependent attitude information, to sub-degree accuracy

Test flown on SCIFER-2 NASA rocket

Two PCBs on LAPLander11.4 Mbit/sec raw data for postflight analysis

Localization systemBoth the radio- and satellite transmitter uses patch antennas

• Radio transmitterRange estimated to 50 km for 433 MHz

or 25km for 915 MHz

TX8000 transmitter:• Max. power output: 0.5 W• Data rate 10Kbps

• Satellite transmitterThis technology is used for tracking containers, wild animals etc.

Two possible operators: Thuraya or Globalstar correspond-ing to two possible modules: Thuraya Module or STx2

Both transmitters uses frequencies around 1.6 GHz.

TX8000 Transmitter

STx2 transmitter

Core systems

• BatteriesThree Saft LSH 26180 with 3.6 V and 1.2 Ah will be used as power source.

• Central Unit

An Actel ProASIC FPGA and an 8051 Atmel CPU

• DC/DC convertere.g.: TMR 1211

• MemoryNAND01G-A, 1Gbit per chip

LSH 26180

Power budget

Trajectory phaseCentral unit - sensors 0.8 W SMILE 0.5 WCORNELL 1.5 W

total 2.8 W x 1500 s = 4.2 kJ

Recovery phasecentral unit - GPS 0.5 WSTx2 transmit 2 s / 10 min x 1.6 WTX8000 transmit 2 s / 1 min x 2.1 W

total about 2 kJ/h

batteries supply 3x (3.6*1.2 Ah) = 46 kJassuming 50% efficiency 23 kJrecovery phase > 9h.

Electronics box

Batteries,Satellite module

Electronics box

Batteries, Satellite module

Radio transmitter

Electronics box

Batteries,Satellite module

Radio transmitter

Central unit PCB

Electronics box

Batteries, Satellite module

Radio transmitter

Central unit PCB

Cornell GPS

Electronics box

PROJECT DETAILS

Scientific outcome• Design to be used for future multi-point

measurements in the Ionosphere.

• The dynamics of the payload will be analyzed and compared to simulations

• Data and design to be used as course material for advanced courses in Spacecraft Dynamics, Rocket Science and Aerodynamics

• The design is to be presented at ESA-PAC 2009

• The students are enrolled in ”Project Course in Space Plasma Physics, advanced level” for spring 2009 (12 ECTS). Torbjörn Sundberg will devote 20% of his time to the project during 2009.

This gives a total of ~52 man weeks before the Critical Design Review.

• Most students are available throughout 2009 for the construction phase. The studens will be given the possibillity of extending the work into Master Thesis Projects (30 ECTS).

Time Plan

Time Schedule

Outreach – ”KTH on the inside”• An advertising campaign initiated by KTH• Three projects to be selected to promote science and

technology to the general public• LAPLander in the final selection round

Final projects selected by public vote, ongoing online at www.kthpainsidan.se14 Jan. – 10 Feb.

Currently on place #2. (As of Jan 31)

Outreach • Information on the project has been advertised at KTH and Ecole des Ponts,

ParisTech

• Article in the student magazine ”Osqledaren” to be published spring 2009, a second following the launch. ”Osqledaren” reaches a broad group of students and will help to promote space research.

• The Public Relations Officer at the school of Electrical Engineering will help with providing contacts with the local media and newspapers.

• Project homepage at www.spp.ee.kth.se/rexus

• Article to be published in the Fudan University Technique magazine, China

Budget• Electronics

– Sensors 500 €– Radio system 1000 €– Circuit board manufacturing 1000 €

• Mechanics– Airbags 100 – 1000 €– Inflation 500 – 4000 €– Materials 500 €

- The expected costs are within the frame of the budget available- Construction will be done in-house - The Cornell GPS and SMILE are in-kind contributions

Required assistance

- Launch signal to initialize system

- System for payload ejection

- Helicopter transport for payload recovery

- General advise from you

Dank U wel, Grazie, Tack, Merci, Danke, Gracias,Thank you