ALTEA data handling

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Advances in Space Research 37 (2006) 1710–1715

ALTEA data handling

L. Di Fino a, F. Belli a, V. Bidoli a, M. Casolino a, L. Narici a,*, P. Picozza a, A. Rinaldi a,D. Ruggieri a, V. Zaconte a, S. Carozzo b, W.G. Sannita b,c, P. Spillantini d, V. Cotronei e,

E. Alippi f, G. Gianelli f, A. Galper f, M. Korotkov g, A. Popov g, V.P. Petrov h,V.P. Salnitskii h, S. Avdeev i, W. Bonvicini j, G. Zampa j, N. Zampa j, R. Vittori k,

C. Fuglesang l, D. Schardt m

a INFN and University of Rome Tor Vergata, Department of Physics, Via della Ricerca Scientifica 1, 00133 Rome, Italyb Neurophysiopathology-DISM, University of Genoa, Genoa, Italy

c Department of Psychiatry, SUNY, Stoony Brook, NY, USAd Department of Physics, University and INFN, Florence, Italy

e Italian Space Agency, Rome, Italyf Alenia Spazio S.p.A. – Laben, Milan, Italy

g Moscow State Engineering Physics Institute, Moscowh Institute for BioMedical Problems, Moscow, Russia

i Cosmonaut, Russian Space Corporation �Energia� by name Korolev, Korolev, Moscow region, Russiaj Department of Physics, University and INFN, Trieste, Italy

k ESA Astronaut and INFN, Perugia, Italyl ESA Astronaut, Royal Institute of Technology, Stockholm, Sweden

m GSI/Biophysik, Darmstadt, Germany

Received 14 October 2004; received in revised form 21 January 2005; accepted 31 January 2005

Abstract

The ALTEA program is an international and multi-disciplinary collaboration aimed at studying particle radiation in space envi-

ronment and its effects on astronauts, in particular the anomalous perception of Light Flashes. This paper describes ALTEA space

facility scheduled to fly in the International Space Station (ISS) after July 2006, what kind of data are produced and how data are

transmitted to Earth, processed and analyzed.

� 2006 Published by Elsevier Ltd on behalf of COSPAR.

Keywords: ALTEA; Cosmic rays; Data handling; ISS; Light flash

0273-1177/$30 � 2006 Published by Elsevier Ltd on behalf of COSPAR.

doi:10.1016/j.asr.2005.01.105

Abbreviations: ALTEA, Anomalous Long Term Effects on Astronauts; ASI, Italian Space Agency; ASMP, Asymmetric MultiProcessor; BEU,

Brain Explorer Unit; BNL, Brookhaven National Laboratory, Upton, NY, USA; CNSM, Central Nervous System Monitoring; DAU, Data

Acquistion Unit; DOMSAT, Domestic Satellite; DOSI, Dosimetry; DSP, Digital Signal Processing; EEG, ElectroEncephaloGraph; GSI, Institute

for Heavy Ion Research, Darmstadt, Germany; HIT, Heavy Ion Therapy; ISS, International Space Station; LET, Linear Energy Transfer; LOR,

Line Outage Recorder; LTU, LapTop Unit; MARS, Microgravity Advanced Research and Support; MICE, Mice Irradiation with Concurrent

Electrophysiological monitoring; MIP, Minimum Ionizing Particle; MSFC, Marshall Space Flight Center; OBT, On Board Time; PBU, Push Button

Unit; POIC, Payload Operations Integration Center; RIC, Rack Interface Controller; SDS, Silicon Detector System; SDU, Silicon Detector Unit;

SGS, Space-to-Ground Subsystem; SSCC, Space Station Control Center; TDRSS, Tracking and Data Relay Satellite System; UHB, User Home

Base; USOC, User Support and Operation Center; VSU, Visual Stimulator Unit; WSC, White Sands Center.* Corresponding author. Tel.: +39 0672594519; fax: +39 062023507.

E-mail address: [email protected] (L. Narici).

mailto:[email protected]

L.D. Fino et al. / Advances in Space Research 37 (2006) 1710–1715 1711

1. Introduction

The length of manned space flights (operations in the

International Space Station (ISS) or the planned journey

to Mars) will significantly increase in the near future.

Anomalous Long Term Effects on Astronauts (ALTEA)is an international and multi-disciplinary program

aimed at studying the effects of particle radiation on

the Central Nervous System during long manned mis-

sions on board ISS, in particular the anomalous percep-

tion of Light Flashes (Casolino et al., 2003). ALTEA

includes a space facility scheduled to fly and operate in

the ISS after July 2006 (Narici et al., 2003).

This paper describes what kind of data are producedby this facility and how data are transmitted to Earth,

processed and analyzed; it consists of five main sections.

In the first section a quick overview of the apparatus and

its main scientific objectives are presented. The second

section deals with different experiment configurations

and data produced during ALTEA space experiments.

Third section is about audio and video requirements.

Fourth section describes in details data path duringtransmission from ISS to ALTEA User Home Base

(UHB) in University of Rome Tor Vergata. Last section

gives a hint about processing and analysis of ALTEA

scientific data.

Fig. 1. Schematic view of ALTEA facility: it is possible to see all

ALTEA devices attached to Express Rack during CNSM mode;

technical specifications are given for each component. In the upper left

corner a 3D view of ALTEA inside ISS.

2. ALTEA facility: general description

ALTEA is a multi approach program. It consists of

various experiments both laboratory based and onboard

ISS. Ground experiments are:

� ALTEA-MICE (Sannita et al., 2004): started in 2001

at GSI and BNL

� ALTEA-HIT: started in 2004 at GSI

� ALTEA-Biophys: started in 2003 at GSI

Space experiments are:

� Alteino (Casolino et al., 2002): onboard ISS since

April 2002

� ALTEA Light Flash Questionnaire (Fuglesang et al.,

2004): started in 2003

� ALTEA-Space: scheduled to fly in December 2005� Other future uses of the ALTEA Facility (ALTEA-

3D, ALTEA-Shield, etc.)

ALTEA-Space will measure on board ISS the parti-

cles passing through the brain of the astronauts and

monitor the cortical electrophysiological activity and

the visual system functional status. The goal is to define

and measure electrophysiological descriptors of brainfunctioning and to correlate their dynamics with space

environments (Narici et al., 2004). Measures of re-

sponses to proper visual stimuli will permit to assess

the visual system status. It will also operate in un-

manned mode to allow long term measurement of parti-

cle fluxes inside the ISS.

The ALTEA facility (see Fig. 1) is composed by:

� Data Acquisition Unit (DAU)

� Silicon Detector System (SDS) – composed by 6 par-

ticle detectors (SDU)

� Brain Explorer Unit (BEU) – 32-channel ElectroEn-

cephaloGraph (EEG)

� Visual Stimulation Unit (VSU)

� Push Button Unit (PBU)

� LapTop Unit (LTU)

The Data Acquisition Unit (DAU) is connected with

the 6 Silicon Detector Units (SDU) and with the Visual

Stimulation Unit (VSU). The DAU and the LapTop

Unit (LTU) are connected via TCP/IP with the ISS

using the Rack Interface Controller (RIC) connections.

ALTEA is an autonomous experiment from the point of

view of the interaction with Ground: no remote controlis foreseen and just an initial and guided participation of

the astronaut to experiment set-up is required. All data

from ALTEA are in the form of Express Rack Teleme-

Table 1

Structure of an Express Rack Telemetry packet

Table 2

Telemetry data: main data types are reported together with packet size

and frequency of acquisition

Telemetry data type Packet size

(bytes)

Frequency of

acquisition

Science SDS data 122–1266 Event driven

Service data 24 Event driven

Nominal housekeeping 232 10 Hz

EEG data 1074 1024 Hz

Health & status 34 1 Hz

1712 L.D. Fino et al. / Advances in Space Research 37 (2006) 1710–1715

try packets. In Table 1 the structure of a telemetry pack-

et is described. In Table 2 various kinds of telemetry

data are reported together with packet length and

frequency of acquisition. Scientific telemetry data and

service data generation depend on instrument

operating mode and on involved subsystems. SDS gen-

erates periodic scientific data only in calibration mode,

otherwise data generation is triggered by particledetection.

3. Experiment configurations and expected data rates

The two main ALTEA-Space configurations are

named Dosimetry (DOSI) mode and Central Nervous

System Monitoring (CNSM) mode and they are, respec-tively, unmanned and manned operative modes. AL-

TEA will continuously operate in DOSI mode for a

period of one increment without human intervention.

There will be six interruptions corresponding to the

CNSM sessions. During DOSI mode ALTEA measures

radiation fluxes on board ISS. Only Silicon Detector

System (SDS) is switched on and data are downloaded

in real-time, without any local storage. Expected datarate is about 0.65 Mbps, so the estimated storage size

for the whole increment is about 1.3 Tb. Second opera-

tive mode is CNSM. Six 90-min sessions are planned as

follows: an astronaut will wear the EEG cap, insert his/

her head in the SDS and will signal perceptions of Light

Flashes with a pushbutton while SDS will measure cos-

mic rays flux through his head, so that it will be possibleto study concurrently the passage of cosmic radiation

through the brain, the functional status of the visual sys-

tem and the electrophysiological dynamics of the corti-

cal activity. Data are stored on the ISS laptop.

Expected data rate is 1.4 Mbps and each session is ex-

pected to take up about 1.5 Gb. Data are then down-

loaded off-line and erased from the laptop only after

positive transmission check.

4. Audio and video

To assure optimal setup of the experiment, real-time

audio and video communications are required. The

audio will be a bidirectional system, while video will

be a one-way system from ISS to earth. Fig. 2 shows aschematic view of experiment timeline in which audio

and video communications are reported: we asked

for recorded video during the entire system setup

and during CNSM setup, while realtime video and

audio will be used only in the last 10 min of system

setup and the first 15 min of CNSM setup. A second

astronaut will help the subject during part of the CNSM

sessions.

5. ALTEA data flow

This section deals with transmission of data from the

Payload on board ISS to the ALTEA UHB, where data

are stored and analyzed. Composition of Space Segment

and Ground Segment are described together with Trans-mission Bands used for communications and data distri-

bution between different segments. In Fig. 3 there is a

block view of the entire data flow.

5.1. Space data segment

5.1.1. Onboard ISS

ALTEA is installed in an Express Rack, that providesstandard and simple interfaces to payloads, and it com-

municates over a local LAN to the RIC. The RIC is con-

figured as a passive server and provides the

communication link between payloads and the Space

Station data system and ground controllers. The RIC

will route the payload data in packets (Express Rack

Packets), with headers to identify the payload (see Table

1), and it will transmit them through the Space Stationdata system. All communications onboard ISS are based

on TCP protocol.

Fig. 3. Schematic view of ALTEA data flow: data are produced by ALTEA facility on board ISS (Section 5.1.1), then transmitted through TDRSS

and WSC (Section 5.1.2) to NASA Ground Segment (Section 5.2.1) and finally to Italian Ground Segment (Section 5.2.2).

Fig. 2. Schematic view of ALTEA experiment timeline: it is possible to see recorded video during the entire system setup and realtime video and

audio communications during part of the setup.


5.1.2. TDRSS and WSC

All ISS communications to Earth are vehiculated by

Tracking and Data Relay Satellite System (TDRSS).TDRSS consists of 6 satellites in geosynchronous orbits

and a dedicated ground station. The main task of the

TDRSS is to provide communication and tracking ser-

vices for ISS and other low-earth orbit spacecrafts.

TDRSS operates as a repeater, relaying signals to and

from the ground station. No data processing is done on-

board the TDRSS.

The ground station that monitors and controls thesatellites is the White Sands Ground Terminal in New

Mexico. White Sands Center (WSC) has a Line Outage

Recorder (LOR) that records data in case a connection

between WSC and one of the NASA centers fails. If thathappens, WSC can play back the data when the connec-

tion is restored.

5.1.3. Data transmission bands

Transmission Bands used for communications and

data distribution between Space Segment and Ground

Segment are S-band and Ku-Band.

S-band data is relayed to/from ISS via TDRSS.S-Band carries primarily core system data down and

1714 L.D. Fino et al. / Advances in Space Research 37 (2006) 1710–1715

commands up. S-Band operates at 2065.0 and

2085.6875 MHz and it is used for the forward and return

link to ISS.

Ku-Band is used as a return data link and data is sent

from the ISS Space-to-Ground Subsystem (SGS) to

White Sands via TDRSS. Data are then sent to thecontrol centers, and finally to remote users. Ku-Band

operates at 13,775 and 15003.4 MHz and primarily

carries High Rate Payload Data, Digital Video (video

is converted from analog to digital onboard and sent

down as a part of the Ku-Band data) and Core Playback

Data.

5.2. Ground data segment

5.2.1. NASA ground segment

The two main nodes of NASA Ground Segment are

Space Station Control Center (SSCC) at Johnson Space

Center and Payload Operations Integration Center

(POIC) at Marshall Space Flight Center (MSFC).

Planning and procedure data are exchanged between

SSCC, POIC and the Italian Ground Segment. Audiocoordination is used between sites on the ground. The

POIC is responsible for scheduling, managing, and con-

trolling the Space Station onboard payload data and

video systems. ALTEA data is received at MSFC�sPOIC that has the overall responsibility for payload

ground data distribution. At MSFC there is also the

capability to monitor vital payload information. Beside

ALTEA scientific data, other kind of data will be dis-tributed: ISS System Telemetry, Air-to-ground Audio

and Air-to-ground Video. Data are distributed to

remote sites using UDP protocol.

Fig. 4. Schematic view of ALTEA UHB: it is possible to see the structure of

the storage server and the devices for communications and data presentatio

5.2.2. Italian ground segment

Data are transmitted to Italian Segment from the

Italian Space Agency (ASI) Gateway (USA) through

the ASI-Net backbone to the Microgravity Advanced

Research and Support (MARS) Center in Naples that

operates as ASI Italian User Support and OperationCenter (USOC) and that is responsible for the opera-

tions of the Italian Payloads onboard ISS. Finally data

reach ALTEA UHB.

5.2.3. ALTEA UHB

ALTEA UHB will be able to monitor experiment, to

store and to analyze collected data. UHB configuration

will be the following (see Fig. 4):

(1) One Data Storage Server (with redundant disk

array).

(2) One or more multi-processor workstation for

Scientific Data Analysis.

(3) One Video-Conference workstation for video-con-

ference communications with NASA.

(4) One Voice-Loop workstation for audio-communi-cations with ISS.

(5) One wide screen monitor/video projector to

display ISS real-time video or scientific data.

We are considering the use of multi-processor Linux

workstations with specially developed Asymmetric Mul-

tiProcessor (ASMP) real-time kernel and dedicated Dig-

ital Signal processing (DSP) boards for real-timeanalysis. ASMP kernel allows to entirely dedicate one

or more processor to specific tasks, reducing overhead

due to standard system operations.

the User Home Base with the private LAN, the analysis workstations,

n.


6. ALTEA data analysis

6.1. DOSI analysis

In DOSI mode Health & Status and Housekeeping

data such as voltages, currents and temperatures willbe monitored to ensure proper functioning of all the

instrumentation and to allow emergency deactivation

or to shut down any system or subsystem. Off-line anal-

ysis of scientific data will be able to process scientific data

relative to SDS subsystem, performing pedestal subtrac-

tion, adaptive pedestal correction, bad data rejection,

particle track reconstruction, released energy calcula-

tion, Linear Energy Transfer (LET) calculation, nuclearspecies discrimination, relative and absolute nuclear

abundances calculation, differential and integral radia-

tion fluxes calculation and statistics on particle direction.

In addition to this some ancillary data of the ISS (posi-

tion, altitude and inclination) will be correlated with

ALTEA data to obtain information about radiation

fluxes in different geomagnetic zones. Work is in progress

to process a subset of these operations in real-time, in or-der to issue space radiation warnings to the crew.

6.2. CNSM analysis

In CNSM mode, all subsystems will be switched on,

and in addition to previous ones there will be data from

EEG and Push Button Unit (PBU). CNSM data will be

analyzed off-line to measure the energies and trajectoriesof the cosmic particles passing through the astronaut�s

brain concurrently with his brain electrophysiological

dynamics. Particle trajectory and absorbed doses in

brain will be calculated and the correlation between

the energy released in different cortical regions and

changes in the electrophysiological signal will be stud-

ied. This will allow to define new risk parameters linkedto the interaction in space between ion passages and

brain functions.

Acknowledgement

ALTEA is funded by the Italian Space Agency.

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ALTEA data handling