This document contains summaries of 3 seminar topics: 1. Figuring out the moon - Computer simulations have helped understand the moon's weak and variable magnetic field by modeling a blanket of material that briefly insulated the lunar core. 2. The internet on Mars - Plans are underway to establish an interplanetary internet by connecting individual planet networks through gateways and using a bundle protocol for long distance data transfer. 3. Satellite tracking - Over 5,000 satellites are tracked using telemetry, which measures conditions from space and monitors satellite performance, and networks of ground stations that communicate with and control satellites.

1. SEMINOR
ON
IT IN SPACE
Submitted By:
Y.Naresh
M.C.A (|III semester)
Roll no: Y4MC14009
Submitted To:
Department of Computer Studies
Mahatma Gandhi College (PG courses)
Edulapalem, Guntur-522 019.
FIGURING OUT OF THE MOON

2. If space has always been an enigma for mankind, then the moon has always
served as the first post for any attempt at understanding or exploring deeper space.
All ventures into outer space, ranging from exploratory fly-bys to managed flights, have
first been tried out of the moon. Like in most other areas, space research is also moving
into larger-scale simulations using powerful computers . in fact given the high cost , and
often the impracticability of conducting live experiments, space research had moved into
computer-based simulation long before most other streams.
Everything from flight paths of futer rockets to the theories on the origin of
the universe and its evolution are today computer simulated.consider the case of the
magnetic file around a planet. Like with everything else in space research . let take the
moon as our example the moon’s magnetic field is very feeble when compared to that of
the earth. Also unlike on the earth, it varies widely from point to point. This much is
known from the measurements taken by spacecraft that flew by or landed on the moon.
Now ,why is this so? The obvious conclusion is that the moon does not have a fluid core
like what the earth has, but has localized magnetic sources. What, during the course of
the moon’s evolution, could have caused this? This is where computer simulation can
provide an answer. And an answer has been recently found. Reaearch at the university of
California, Berkely, have modeled a blanket of dense material that would briefly insulate
and even heat the lunar core, before bobbing to the surface to allow a brief period of rapid
heat flux and core convection
The calculations were run on Cray T3-E 1200 located at NASA’s Goddard
space flight center in greenbelt, MD which was taken offline at the end of last year. We
performed the final calculations last spring on 128 processors of the Cray. We were
running case of about 20 GFlops for 10 hours each. We ran about 10 cases for our final
results.
The software is our (written in Fortran) which uses MPI and has been
developed over the past 15 years, primarily by John Baumgardner at Los Alamos
National Laboratory. It is portable and has run on every operating system. We are
currently running it on Beowulf clusters running Redhat linux and also on the earth
simulator in Japan, which uses HPUX. The machine at NASA Goddard ran a flavour of
Unix. The software was developed for modeling the earth’s interior, but has also been
applied to mars and the moon. One of the basic tents of space research is that projects
could take many, many year to reach completion. About this specific problem, stegman
says the problem was first looked at 15 years ago by BAUMGARDNER. Recent
technical advancements allowed us to look at this problem again, beigining in mid 2000.
the actual time spent working on the project was about 2 years.
Where does it go from year we are thinking about the evolution of mars and
the earth, using what we have learned about the moon. Fortunately, we now have access
to even faster computers, which we have need in order to study these larger planets.
Like they say in star trek, space exploration is about boldly going where no man has
before. And, it takes a computer to take you there.
THE INTERNET ON MARS

3. The internet is slated to go over and above this world, the first target being
mars, to be followed by Jupiter and its moon, europa.
This idea of talking the internet to the space comes from the need for a low
cast and high reliability inter planetary network. It is not that there was no
communication earlier.when
Countries started sending probes into the space,each used a unique set of
protocols to communicate with the earth. This was done using the deep space
network(DSN) developwd by NASA. Since these probes communicated with same
ground stayions, the need for common protocol increased with time. Taking the internet
to space is the offshoot of this need for standardization. The inter planetary
network(IPN),a part of jet Propulsion Laboratory(JPL),is managing this program.
But how will this be implemented? One can plan how the internet will work
on the earth because of its fixed size and the fixed positions on which the data has to
travel. Now, for the implementation on the planets will be connected through individual
dedicated getways. The individual networks can follow their own protocols,but these
protocols will end at the gateway. By keeping the internets of all the planets
separate,engineers will not have to make long service calls. Besides they will not have to
send a database of 20-million dotcom names to mars periodically
These gateways will work on a bundle based protocol, which will reside over
the transport layer to carry data from one gateway to another. This gateway may not be
on the surface of a planetary body;it can be a spacecraft in orbit,too.At at the moment a
bundle protocol will be needed because the data will need to travel huge distances,and
sending small packets of data may not be feasible. Instead, this data will be collected and
sent in a bundle, as a big burst of data,to the next gateway.
Regarding mars, jpl plans to put many microsats around it and a bigger
marssat acting as a gateway to the earth. Managing the individual planet internets is not a
big problem as it can be managed in more or less the same manner as the earth’s network.
It is developing
The interplanetary backbone network(IBN),however, which requires the
biggest effort. The use of standarda-based technology in space will mean that the
commercial vendors can be used to provide the equipment, which will drastically
decreases the equipment and manpower cost needed in space communication.
Sounds too good to be true?well,there are thorns to content with too. At the
moment the communication links from the space to yhe earth are very cumbersome with
three satellite clusters placed around the world. The biggest problem is the bandwidth.
Thw other biggest hindrance is the astronomical distance between the two planets. This
can result in long delays,for example, a round trip transmission from earth to mars may
exceed 40 mins. Even if the distance is managed there can be instance when the
communication is not possible at all when the planetsare on the opposite sides of the sun.
Beside the natural factors of distance,we cannot overlook the potential of the hacker
community,which is quite strong on our planet. One this kind of technology is
functional,its security will be a big issue.

4. Satellite Tracking
Today there are more than 5,000 satellites in our space . These are kept track
of by telemetry and control systems.
October 4 1957 Sputnic the first artificial earth satellite was launched by the
USSR, and thus began the space age. Now , 45 years after, there are more than 5,000
satellites in outer space,and tracking and controlling them is big work. Thousands of
observatories, computers,communication systems and human beings work round the
clock,around the earth, to keep their satellites in proper condition and on the right path.
Telemetry, tracking and control are three major functions that make this happen.
Satellite telemetry is measuring the conditions in the atmosphere and oceans
from outer space using artificial satellites, and monitoring the performance and condition
of rockets, spacecraft and satellites that send information about their own performance,
flight path and other data to earth. With this, the earth stations keep track of the
spacecraft’s condition in outer space and able to control it from the ground. This
processing has to be done in real time using real time systems . this means developing
high performance and robust systems that will work in extreme conditions and constraints
of space, weight and power in satellites. Earth stations, too , demand a high degree of
expertise and planning while developing such systems.
A basic telemetry system consists of s measuring instrument, transmitter and
receiving station. The measuring instruments are sensors that measure the amount of a
physical attribute and transform the measurement to an engineering unit value. This is
multiplexed as a single data stream, formatted and then transmitted using radio or
microwave signals .
Hence measurements can be made at remote or inaccessible spots, and the
data collected is transmitted equipment for monitoring, display recording and analysis,
On the ground, the receiving station receives the signals transmitted by the satellite,
which are then sent for processing. The ground system makes sense of the enormous
amount of data received and presents it in a user-friendly manner to the operators. They
use a variety of display objects-like strip charts, bar charts, vertical maters, crossplots and
analysis programs like excel or high level analysis, languages to evaluate archived
data,extract results and generate repports. A satellite’s conditions is also monitored in real
time so that decisions regarding its operation and path can be taken instantaneously in
case of a problem. The display systems run on both UNIX and PC platforms. The
communication systems for interfacing with ground stations network and the real time
processing of satellite data generally use UNIX. The communication system uses TCP/IP
protocol for data transfer between computers on the ground station networks. The data is
stored on disks or tapes as files, but other alternatives are relational database like MS
Access and oracle schudling system generate operation schudles and allocate network
resources for satellites supported by the ground station.
Web-based telemetry solutions enable such activities using a web browser ,
and can be used from any machine on the ground system network. You can get some
from www.netacquire.com.

5. In India the ISRO telemetry tracking and command networks does these. It
provides mission support to satellites and launches vehicle missions, and has a network of
ground stations across the country and abroad that provide valuable inputs for controlling
India satellites.
Hubble control systems

6. The hubble space telescope(HST) is a large optical telescope. It orbits the
earth and takes detailed pictures of stars,galaxies and solar-system objects..where ever is
out there.The
HST uses an elaborate spacecraft-management system to keep it afloat and
working.In this respect, it is nodifferent from other spacecraft.The main elements of the
system are the computer support system module and the advanced tracking and data relay
satellite(TDRS)series.The computer support system module contains devices and systems
needed to operate the hubble telescope.This serves as the master control for
communications, navigation,power management,etc.The TDRS series accepts Hubble’s
Information for relay to the ground controllers at the space telescope operations control
center(STOCC) in greenbelt,Maryland,us.Similarly,the TDRS also provides high band
width communication support to the international space station(ISS) and some other
satellites up there
7000 variables of real time information from the hubble telescope are
transmitted to the geo-synchronous tracking and data relay satellite
system(TDRSS),from which they are downlinked to the ground station at white
sands,new Mexico,and then relayed to the Goddard space flight center in Maryland using
what is known as the comtrol center system(CSS).Further data analysis is done using the
space telescope science data analysis system(STSDAS).The ccs front-end uses java
applets that let engineers control and monitor hubble from the earth.The ccs user interface
has two parts:The first is control,where the telescope can be commanded to select new
targets;and the second is data visualization,where the user can view telemetry and
engineering data either archived or being streamed down in real time from the spacecraft.
The ccs applets establish a direct network connection to a NASA host,where
a middleware serever connects to the exciting server system.This allows anyone with
access privileges on the internet to view the engineering data is being continuously
transmitted by the spacecraft, and even to obtain a personalized,configurable view of this
data.the server code written in c++.
The ccs is used to handle communication between hubble and the ground
stations for spacecraft commanding and health and safety analysis. The architecture for
this is a typical secure network.The data sent from telescope is analyzed using the
STADAS,which is powerful set of tools that support software used to calibrate and
analyze data.A companion package,tables ,is a set of tools for creating and manipulating
tabular data,reading and writing flexible image transport system(FITS) the widest used
data format used for astronomical images –immages and tables,and creating customizex
graphics.STADAS and TABLES are layered on the image reduction and analusis
facility(IRFS) software from the national optical astronomy observatories.STADAS and
TABLES run in tandem with IRAF.
The space telescope engineering data store(STEDS) isintended to serve as a
common data source for all the telemetry data for all the hubble subsystems.its design
uses a typical middleware-enabled three tire model,and it is plat from independent as it
has to be accessed over the internet.The telemetry data stream from hubble is transferred
to the front end processor(FEP) vis nascom.Fep provides a communication interface
between the vehicle and ground control and captures all the downlinked data.It then for
forwards it to the attached all points archive, which interacts with the web server to

7. produce a web-browser output for a client machine,and through the middleware c++
server to process the applet GUIs.
CONTROLLING SPACECRAFT
COMPUTING FOR SPACE SHUTTLE AND PATH FINDER
SHUTTLE
300 major electronic black boxes,300 miles of electrical wiring,120,400,
wire segments,
6,491 connectors wiring and connectrs weight approximately 7,000 pounds,
wiring
Alone weighing approximately 4,600 pounds.seems daunting/ in fact, they
are allApart of the space shuttles avionics systems the lifeline of the shuttles wayback in
1988.Other data processing systems consist of five general purpose computers mass
storage, a time shared computer data bus network for communication between the
computers. AS of all five GPCs were IBM AP-101S computers.Before that they were the
IBM AP-101Bs. The older GPCs had non –volatile memory ,but with the AP 101s the
shuttle computers moved to volatile memory with battery back up.Each of the GPCs
consists of a central processor. Unit and an input /output processor.the first four systems
comprise thePASS[primary avionics software system] it may seems surprising that
NASA uses ancient computers, but they do so because of a very reasons; these computers
have been thoroughly tested .such reliability is extremely necessary when dealing in
mission-critical operation.
GPC is loaded with different soft war created by adifferent coany but
performing the same functions and operation. This software is the Backup Flight
system[BFS]. The BFS monitors the other GPC to keep track of the current state of the
vehicle . if required the BSF can take over control of the vehicle upon the press of a
button . theBSF also performs the system management functions during ascent and
entry .BFS software is always loaded into the fifth before flight but any of the five GPCs
could be made the BFS GPC if necessary .NASAis developing shuttle upgrade project to
install a vehicle health monitor [VHM] system.the VHM system will be used to detect
troubleshoot and resolve hardware problems during and after fight .to match the hardware
the software is also written and verified meticulously.the shuttle control software has
some 420,000 lines of code.the software is subject to countless hours of verification and
testing.yet, there are flaws.ther are still bugs in the code but when compared to other
software they are very less.thetwo companies involved in the shuttle software creation
were IBM Federale systems and Lockheed Martin.When information and voice is
scrambledfor security so there is a computer onboard to decrypt this data so that the
astronauts can read it or herd the voice from mission control in Houston, Texis.once the
data is decrypted there are other computersonboard that controle the attitude , velocity
,temperature,and toilet/bathroom systemjust to name a few.Acomputer called the ground
communication logic controller[GCIL] receives this data and then routes it to the
appropriate computer system to perform one of this function .Houston , Texas controls

8. most of the computers onboard from the grond itself because the crew has experiment
and science data to collect and sometimes cannot be responsible for all functions.
PATHFINDER
The path finder mission that put a rover,sojourner of mars was
conceptualized in 1992. Traditionally, spacecraft landed on alien territory by the means
of rockets(the Viking mission to mars). The path finder mission was a technological first,
in demonstrating a low cost landing mechanism by the means of parachutes and airbags
as suspension. Given the distance mars from the earth, the timetaken by the signals from
nars to reach the earth is about 10 mins. It was launched on December 4, 1997 abd, after
nearly seven months of space travel reached mars. The path finder mission also carried a
rover, soujourener to mars. The payload also included an alpha proton X ray spectrometer
to anlyze the elemental composition of the soil on mars, to act like an on- site goeligist.
As mentioned, the time lag for signals to reach the earth was around 10 mins. So; some
amount of autonomous control had to be built into the system. After landing it took
another 2 martin days to get the rover functional and it remained so for the next three
months. During these three months sojourner sent back over 2.6 billion bits of data. It
also did 20 soil analysis tests during this time the computing power behind the rover is a
radiation protected IPM RISI 6000 single chip CPU. The complete mars path finder flight
computer had 128 MD DRAM. The code was developed using Vx works as the real time
OS and the good old C and assembly for coding.
The communication between the lander and the rover is not exactly rocket
science. The protocol using a simple acknowledge/negative acknowledge
algorithm(where the data was received or not). A CRC check is done on the receiving
side to validate the transmission. The maximum frame size used was 256 bytes. Such
methodology is nothing but the more commonly used protocol striped to bare minimum.
IMAGE FORMATS

9. Satellite images of the earth have been easily and commercially available for
some time now. Originally, they were the purview of the military some of the better
known satellites known that are used for this purpose are IKONOS which captures 1-
meter resolution images, the INSATAs, the US landsat canadas RADARSAT and the
European space agency’s ERS satellites.
These are archived and distributed in various formats. We may be familiar
with some of these formats, while some are specifically developed to handle extra
information.
For browsing, common formats-GIF and JPEG-are used. But for archiving
the data, the files are stored on digital linear tapes(DLT) in the framed raw expanded data
format(FRED). This raw image format is considered a ture ‘digital negative’, which
records data over a wider bit range (typically 10 or 12 bits) than JPEG or 8-bit TIFE.
Satellite images are used for a variety of end uses, and to suit their requirements, images
are stored in formats that can also provide lots of additional information.
Superstructure Format: this is one such format, developed by the landsat ground
station operators working group (LGSOWG). The committee for earth observation
satellite (CEOS) has adopted it to exchange data between different users. The
superstructure format has the provision to include ancillary data pertaining to the image
file, like mapping or other geographic information, and hence is most suitable for
applications where further processing has to be performed on the images.
GeoTIFF: this enhanced version of TIFF contains all the information necessary for
converting the iamage co-ordinates to geographic and cartographic co-ordinates.
DIMAP with GeoTIFF: digital image MAPping is a metadata format designed to
document to document digital image maps using XML. The underlying image format is
GeoTIFF. Spot image, satellus and CNES ( the French national space agency) have
developed DIMAP. It is and open initiative. Any one can contribute modifications to the
format.
Band Interleaved by line(BIL): this is one of the oldest format used for space imaging.
It treats each line as separate storage units. The bright values for each line is stored one
after another. It is practical to use this format if all bands in an image are to be used.
National Imagery Transmission Format(NITF): This is a US standard per digital
imagery used by the intelligence community, the department defense, and elated
departments and agencies of governments.
Flexible image transport system (FITS) is an archive and interchange format
for astronomical data files. Originally designed for transfer of images, FITS is now
widely used as an astronomical data transfer format.
SPACE COMMUNICATION PROTOCOLS

10. Earlier satellites used customized systems for communication with each
mission or set of missions being more or less self-contained, and no one thought of
interpretability with other systems now as the cooperation among the agencies and
nations grow, interpretability becomes important.
Recognizing the fact, NASA, US defense department and national security
agency of the US have jointly designed specified, implemented under testing a set of
protocols called space communications protocols standards (SCPS).
The SCPS suite currently has four modules : file handling, transport, security
and network. Instead of being an entirely new system, it is a new version of the existing
standards (TCP/IP, file transfer protocol ) optimized for wire less networks and satellite
links. So, to the end user, the new standard functions the same as TCP/IP.
The SCPS addresses layers three through seven of the OSI model. Its major part covers
layers three and four of the OSI model and the IP and TCP layers of the TCP/IP protocol
suite.
SCPS-File protocol (SCPS-FP): File transfer protocol coordinate the movement of files
between systems. SCPS-FP is derived from FTP with extensions to support the
movement of file records, addition of integrity checking, and resume support after
interruption.
SCPS-security protocol (SCPS-SP): It operates between the transport protocol (SCPS-
SP) and network protocol (SCPS-NP) and provides authentication, access control,
integrity and confidentially. It uses a variety of existing security protocols such as
SP3/NLSP, IETF IP security.
SCPS-network protocol (SCPS-NP): Network protocol route data through the
intermediate systems to the destination. It functions as the IP (internet protocol ) with the
additional capability of supporting both fixed routing and connectionless routing of
packets through space and wire less data link. SCPS-NP also offers multiple routing
options and supports packet life time control.
SCPS-transport protocol (SCPS-TP): Transport protocol support end to end
communications between systems ie, systems active only at end points and not
intermediate routers. SCPS-TP is the most prominent part of the protocol suite since it
gives major performance improvement in the space environment. SCPS-TP is a modified
version of TCP (transmission control protocol) but the terrestrial environment for which
TCP was designed is markedly different from that of space. As an example,
Performance tests of SCPS-TP vs TCP-show that SCPS-TP is well suited to the long
delay, high bit-error rate environments of satellites with a performance improvement by a
factor 10 and more.
READY FOR THE COUNTDOWN

11. A satellite launcher like the PSLV as thousands of subsystems that have to
system properly for a launch to be successful. These rocket systems are monitored by
embedded systems. As countdown to lift off approaches, all of these have to be
monitored and decisions on weather to continue with the launch or to abort need to be
taken in real time.
For this real time, embedded systems find extensive use in pre-launch check
out systems.In the case of launch agencies like ISRO, they independently create the
checkout software required to run launcher systems and rockets are expand on the work
of collaborating agencies. In the case of launch agencies like Ariane, the check out
systems could be developed by third party contractors.
For example the checkout systems for the Atlas V rocket were done by L-3
communications. The amount of information picked up by these systems is too much and
too complex to be comprehended in their alphanumeric form, or by one person. So the
data is distributed over a network to many controllers, who view the information
graphically. Change in parameters would be indicated in a change of parameters or colors
and other such graphical alerts or even audible alerts.
Wisdom of the Ancients

12. space exploration has its origin in astronomy, which in turn has its roots in
mathematics. Both astronomy and mathematics have their roots in antiquity and all
ancient civilizations have been fairly advanced in booth these sciences. So a study of the
ancient texts, particularly in astronomy from different civilizations , may be worth the
while for any one with more than a passing fancy in the space sciences.
The Aryabhatiyam, written around 499 AD, is perhaps the oldest these. This
mathematical –astronomical treatise of 121 sloaks is supposed to be surprisingly accurate
in its calculations when compared to measurements made possible by modern
instruments. If ancient llanguages are not your staple ,many of them are available in
translations. And then there are many derived works and even the modern ones. Erich
von Daniken’s Chariots of the gods is, of course the , the classic here. The spaceships of
the prophet Ezekiel by Josef F Blumrich was with NASA and was involved in the design
of the Saturn V rocket and Skylab . his book investigates the similarities in the biblical
chariots seen by the prophet and modern-day space ships, and whether Ezekiel did indeed
see alien spacecraft.
Costliest: June 4 1996 the first launch of Ariane 5. 40 sec after liftoff, the rocket
broke up,taking down with it $500 million worth of launch vehicle and satellite(s). the
enquiry commission appointed to look into the incident concluded that it was a software
error. The interial reference system requires some computations done to align it till about
9sec before lift off. To avoid complications if a lift off is aborted, the computations
continue till 50 secs after liftoff but are useless. This system was used in the ariane 4
series and was reused without rechecking in ariane 5. B ut ariane 5 had a completely
different set of flight parameters, leading to an error being fed to the computations for the
IRS, well into flight this error, in turn , made the IRS change the flight path of the vehicle
drastically,leading to it disintegrating. Talk resuing software
Satellite: on October 22 2001 PSLVC3 took off form sriharikotha, successfully
launching TES,PROBA and BIRD into space. PROBA weighs in under a hundred kilos,
but it is unique in many ways. One of the unique factors about PROBA is that it is
hooked on to the internet . images taken by the cameras on PROBA will directly go to a
web server at its controller center in Redu,Belgium. The images become directly
available to users from this web server, as soon as it comes in from the satellite.
Webserver: UoSat-12 launched on april 21 1999 has the world first web server
in space . on jan 25 2001 HTTP was used to transfer data from the satellite to the ground.
AIST-1 launched by the same company in December 2002 is the internet protocol for
routine in orbit operations AISAT-1 implements the CCSDS( consultative committee for

13. space data systems) CFDP(file delivery protocol), operating over an IP link at 8 mbps to
deliver payload data to the ground.
Internet2: the world’s largest radio telescope at Arecibo , Pueto Rico sifts through
800 terabytes(819gb or 840 million MB) of data from deep inside the universe each day.
It can gather 40 megabytes of data per second. To handle the enormous data-transmission
requirements, it has been using a super high-speed internet2 connection since late 2001.
Internet2 is an initiative to build quality of service into the internet by providing
dedicated backbone connectively to academic and other research-intensive internet usage.
The connection is 155 Mbps over a T3 carrier. One famous application of the
Arecibo radio telescope is the SETI project, which uses it to monitor radio signals
coming from space to search of extra-terrestrial life.
Traffic: if think that satellite are only for cutting edge work or for military uses, it is
time for you think again. Computers can combine with satellite to perform some fairly
mundane tasks also. Like monitoring traffic congestion. This was tried out by the
European space agency between march 1999 and November 2002 in Rotterdam and Den
Haag districts of Netherlands. A computer each was installed on to 15 postal service
vehicles. Using GPS and a mobile communication system designed to communicate
directly with satellites, data from these computers was transmitted to a central
monitoring facility. This helped them in understanding traffic congestion patterns better
than with traditional systems which measure traffic only at specific points along selected
routes. There is no need for interaction between the driver and the computer in the
vehicle. This method can be extended for fleet management , break down support, theft
protection etc, based on a network of satellites.