The Universe

THE UNIVERSE

The galaxy is included in the universe. It is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, an important but poorly understood component tentatively dubbed dark matter.

THE MILKY WAY

The milky way galaxy is the spiral galaxy which is known as home for other billons of star in the galaxy.. Like other spiral galaxies, the milky way has a bulge, a disk and a halo. Although all are parts of the same galaxy, each contain different objects. The halo and central bulge contain old stars and the disk is filled with gas, dust and young stars. The Milky Way Galaxy is at least 5 billion years older than the Sun.

Nebulae

A nebula is an interstellar cloud of dust, hydrogen gas, helium gas and plasma. In these regions the formations of gas, dust and other materials "clump" together to form larger masses, which attract further matter, and eventually will become big enough to form stars. The remaining materials are then believed to form planets, and other planetary system objects. Many nebulae form from the gravitational collapse of gas in the interstellar medium or ISM. As the material collapses under its own weight, massive stars may form in the center, and their ultraviolet radiation ionises the surrounding gas, which creates plasma, making it visible at optical wavelengths. An example of this type of nebula is the Rosette Nebula or the Pelican Nebula. The size of these nebulae, known as HII regions, varies depending on the size of the original cloud of gas, and the number of stars formed can vary too. As the sites of star formation, the formed stars are sometimes known as a young, loose cluster. Some nebulae are formed as the result of supernova explosions, the death throes of massive, short-lived stars. The material thrown off from the supernova explosion is ionized by the supernova remnant. One of the best examples of this is the Crab Nebula, in Taurus. It is the result of a recorded supernova, SN 1054, in the year 1054 and at the centre of the nebula is a neutron star, created during the explosion.

Supernova

A supernova (pl. supernovae) is a stellar explosion. Supernovae are extremely luminous and cause a burst of radiation that often briefly outshines an entire galaxy, before fading from view over several weeks or months. During this short interval, a supernova can radiate as much energy as the Sun could emit over its life span. The explosion expels much or all of a star's material at a velocity of up to a tenth the speed of light (30,000 km/s), driving a shock wave into the surrounding interstellar medium. This shock wave sweeps up an expanding shell of gas and dust called a supernova remnant.

The earliest recorded supernova, SN 185, was viewed by Chinese astronomers in 185 AD. The brightest recorded supernova was the SN 1006, which was described in detail by Chinese and Arab astronomers. The widely observed supernova SN 1054 produced the Crab Nebula. Supernovae SN 1572 and SN 1604, the last to be observed with the naked eye in the Milky Way galaxy, had notable effects on the development of astronomy in Europe because they were used to argue against the Aristotelian idea that the universe beyond the Moon and planets was immutable

 

Aurora

The Aurora Borealis shines above Bear Lake

 

Aurora Australis in Antarctica

 

Red and green Aurora in Fairbanks, Alaska

The phenomenon of aurora is an interaction between the Earth's magnetic field and solar wind. The aurora is a common occurrence in the Poles. It is occasionally seen in temperate latitudes, when a strong magnetic storm temporarily expands the auroral oval. Large magnetic storms are most common during the peak of the eleven-year sunspot cycle or during the three years after that peak. However, within the auroral zone the likelihood of an aurora occurring depends mostly on the slant of IMF lines (the slant is known as B_z), being greater with southward slants

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Short Quiz

1. The formation of Aurora is an interaction between _________and _____________.

2. Historically, galaxies are being categorized according to their apparent shapes, which are _____________, _____________ and_______________.

3. Milky Way Galaxy is approximately ___________ years older then the Sun.

Reference

http://en.wikipedia.org/wiki/Aurora_(astronomy)

http://en.wikipedia.org/wiki/Galaxy

http://en.wikipedia.org/wiki/Nebula

http://en.wikipedia.org/wiki/Milky_Way

Information prepared by Yien Peng.

Technology and Communications - WiMAX

What Is WiMAX?

 

WiMAX, meaning Worldwide Interoperability for Microwave Access, is a telecommunications technology that provides wireless transmission of data using a variety of transmission modes, from point-to-multipoint links to portable and fully mobile internet access. The technology provides up to 3 Mbit/s broadband speed without the need for cables. The technology is based on the IEEE 802.16 standard (also called Broadband Wireless Access). The name "WiMAX" was created by the WiMAX Forum, which was formed in June 2001 to promote conformity and interoperability of the standard. The forum describes WiMAX as "a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL".

WiMAX is not a technology, but rather a certification mark, or 'stamp of approval' given to equipment that meets certain conformity and interoperability tests for the IEEE 802.16 family of standards. A similar confusion surrounds the term Wi-Fi, which like WiMAX, is a certification mark for equipment based on a different set of IEEE standards from the 802.11 working group for wireless local area networks (WLAN). Neither WiMAX, nor Wi-Fi is a technology but their names have been adopted in popular usage to denote the technologies behind them. This is likely due to the difficulty of using terms like 'IEEE 802.16' in common speech and writing."

The bandwidth and reach of WiMAX make it suitable for the following potential applications:

Þ Connecting Wi-Fi hotspots with each other and to other parts of the Internet.

Þ Providing a wireless alternative to cable and DSL for last mile (last km) broadband access.

Þ Providing high-speed mobile data and telecommunications services (4G).

Þ Providing a diverse source of Internet connectivity as part of a business continuity plan. That is, if a business has a fixed and a wireless internet connection they are unlikely to be affected by the same service outage.

Þ Providing Nomadic connectivity.

WiMAX base station equipment with a sector antenna and wireless modem on top

Broadband Access Many companies are closely examining WiMAX for "last mile" connectivity at high data rates. This could result in lower pricing for both home and business customers as competition lowers prices. In areas without pre-existing physical cable or telephone networks, WiMAX will, it appears, be a viable alternative for broadband access that has been economically unavailable. Prior to WiMax, many operators have been using proprietary fixed wireless technologies for broadband services. WiMAX subscriber units are available in both indoor and outdoor versions from several manufacturers. Self install indoor units are convenient, but the subscriber must be significantly closer to the WiMAX base station than with professionally installed units. As such, indoor installed units require a much higher infrastructure investment as well as operational cost (site lease, backhaul, maintenance) due to the high number of base stations required to cover a given area. Indoor units are comparable in size to a cable modem or DSL modem. Outdoor units allow for the subscriber to be much further away from the WiMAX base station, but usually require professional installation. Outdoor units are roughly the size of a textbook, and their installation is comparable to a residential satellite dish. Limitations A commonly held misconception is that WiMAX will deliver 70 Mbit/s, over 70 miles (112.6 kilometers). Each of these is true individually, given ideal circumstances, but they are not simultaneously true. In practice this means that in Line of sight environments you could deliver symmetrical speeds of 10Mbps at 10Km but in Urban Environments it is more likely that 30% of installtions may be Non Line of sight and therefore Users may only receive 10Mbps over 2Km. WiMAX has some similarities to DSL in this respect, where one can either have high bandwidth or long reach, but not both simultaneously. The other feature to consider with WiMAX is that available bandwidth is shared between users in a given radio sector, so if there are many active users in a single sector, each will get reduced bandwidth. However, unlike SDSL where contention is very noticeable at a 5:1 ratio if you are sharing your connection with a large media firm for example WiMax does not have this problem. Typically each cell has a 100Mbps backhaul so there is is no contention here. On the radio side in practice many users will have a range of 2,4,6,8 or 10Mbps services and the bandwidth can be shared. If the network becomes busy the business model is more like GSM or UMTS than DSL in that it is easy to predict the capacity requirements as you sign more customers and additional radio cards can be added on the same sector to increase the capacity. Mobile applications Some cellular companies are evaluating WiMAX as a means of increasing bandwidth for a variety of data-intensive applications; indeed, Sprint Nextel has announced in mid-2006 that it will be investing about US$ 3 billion in a WiMAX technology buildout over the next few years. In line with these possible applications is the technology's ability to serve as a high bandwidth "backhaul" for Internet or cellular phone traffic from remote areas back to an internet backbone. Although the cost-effectiveness of WiMAX in a remote application will be higher, it is not limited to such applications, and may be an answer to reducing the cost of T1/E1 backhaul as well. Given the limited wired infrastructure in some developing countries, the costs to install a WiMAX station in conjunction with an existing cellular tower or even as a solitary hub are likely to be small in comparison to developing a wired solution. Areas of low population density and flat terrain are particularly suited to WiMAX and its range. For countries that have skipped wired infrastructure as a result of inhibitive costs and unsympathetic geography, WiMAX can enhance wireless infrastructure in an inexpensive, decentralized, deployment-friendly and effective manner. Technical info WiMAX is a term coined to describe standard, interoperable implementations of IEEE 802.16 wireless networks, in a rather similar way to Wi-Fi being interoperable implementations of the IEEE 802.11 Wireless LAN standard. However, WiMAX is very different from Wi-Fi in the way it works. MAC layer In Wi-Fi the media access controller (MAC) uses contention access — all subscriber stations that wish to pass data through a wireless access point (AP) are competing for the AP's attention on a random interrupt basis. This can cause subscriber stations distant from the AP to be repeatedly interrupted by closer stations, greatly reducing their throughput. This makes services such as Voice over IP (VoIP) or IPTV, which depend on an essentially constant Quality of Service (QoS) depending on data rate and interruptibility, difficult to maintain for more than a few simultaneous users. In contrast, the 802.16 MAC uses a scheduling algorithm for which the subscriber station need compete once (for initial entry into the network). After that it is allocated an access slot by the base station. The time slot can enlarge and contract, but remains assigned to the subscriber station which means that other subscribers cannot use it. The 802.16 scheduling algorithm is stable under overload and over-subscription (unlike 802.11). It can also be more bandwidth efficient. The scheduling algorithm also allows the base station to control QoS parameters by balancing the time-slot assignments among the application needs of the subscriber stations. Physical layer The original WiMAX standard (IEEE 802.16) specified WiMAX for the 10 to 66 GHz range. 802.16a, updated in 2004 to 802.16-2004 (also known as 802.16d), added specification for the 2 to 11 GHz range. 802.16d (also known as "fixed WiMAX") was updated to 802.16e in 2005 (known as "mobile WiMAX"). and uses scalable orthogonal frequency-division multiplexing (OFDM) as opposed to the OFDM version with 256 sub-carriers used in 802.16d. This brings potential benefits in terms of coverage, self installation, power consumption, frequency re-use and bandwidth efficiency. 802.16e also adds a capability for full mobility support. The WiMAX certification allows vendors with 802.16d products to sell their equipment as WiMAX certified, thus ensuring a level of interoperability with other certified products, as long as they fit the same profile. Most interest will probably be in the 802.16d and .16e standards, since the lower frequencies suffer less from inherent signal attenuation and therefore give improved range and in-building penetration. Already today, a number of networks throughout the World are in commercial operation using certified WiMAX equipment compliant with the 802.16d standard. Advantages over Wi-Fi Þ The WiMAX specification provides symmetrical bandwidth over many kilometers and range with stronger encryption (TDES or AES) and typically less interference. Wi-Fi is short range (approximately 10's of metres) has WEP or WPP encryption and suffers from interference as in metropolitan areas where there are many users. Þ Wi-Fi Hotspots are typically backhauled over ADSL in most coffee shops therefore Wi-Fi access is typically highly contended and has poor upload speeds between the router and the internet. Þ It provides connectivity between network endpoints without the need for direct line of sight in favorable circumstances. Þ The non-line-of-sight propagation (NLOS) performance requires the .16d or .16e revisions, since the lower frequencies are needed. It relies upon multi-path signals, somewhat in the manner of 802.11n. Spectrum Allocations issues The 802.16 specification applies across a wide swath of the RF spectrum. However, specification is not the same as permission to use. There is no uniform global licensed spectrum for WiMAX. In the US, the biggest segment available is around 2.5 GHz, and is already assigned, primarily to Sprint Nextel and Clearwire. Elsewhere in the world, the most likely bands used will be around 3.5 GHz, 2.3/2.5 GHz, or 5 GHz, with 2.3/2.5 GHz probably being most important in Asia. In addition, several companies have announced plans to utilize the WiMAX standard in the 1.7/2.1 GHz spectrum band recently auctioned by the FCC, for deployment of "Advanced Wireless Services" (AWS). There is some prospect in the U. S. that some of a 700 MHz band might be made available for WiMAX use, but it is currently assigned to analog TV and awaits the complete rollout of digital TV before it can become available, likely by 2009. In any case, there will be other uses suggested for that spectrum if and when it actually becomes open. It seems likely that there will be several variants of 802.16, depending on local regulatory conditions and thus on which spectrum is used, even if everything but the underlying radio frequencies is the same. WiMAX equipment will not, therefore, be as portable as it might have been - perhaps even less so than WiFi, whose assigned channels in unlicensed spectrum vary little from jurisdiction to jurisdiction. The actual radio bandwidth of spectrum allocations is also likely to vary. Typical allocations are likely to provide channels of 5 MHz or 7 MHz. In principle the larger the bandwidth allocation of the spectrum, the higher the bandwidth that WiMAX can support for user traffic. Standards The 802.16 standard IEEE Std 802.16e-2005, approved in December 2005 follows on from IEEE Std 802.16-2004, which replaced IEEE Standards 802.16-2001, 802.16c-2002, and 802.16a-2003. IEEE Std 802.16-2004 (802.16d) addresses only fixed systems. 802.16e adds mobility components to the standard. IEEE 802.16e IEEE 802.16e-2005 (formerly named, but still best known as, 802.16e or Mobile WiMAX) provides an improvement on the modulation schemes stipulated in the original (fixed) WiMAX standard. It allows for fixed wireless and mobile Non Line of Sight (NLOS) applications primarily by enhancing the OFDMA (Orthogonal Frequency Division Multiple Access). SOFDMA (Scalable OFDMA) improves upon OFDM256 for NLOS applications by ü Improving NLOS coverage by utilizing advanced antenna diversity schemes, and hybrid-Automatic Retransmission Request (hARQ) ü Increasing system gain by use of denser sub-channelization, thereby improving indoor penetration ü Introducing high-performance coding techniques such as Turbo Coding and Low-Density Parity Check (LDPC), enhancing security and NLOS performance ü Introducing downlink sub-channelization, allowing administrators to trade coverage for capacity or vice versa ü Improving coverage by introducing Adaptive Antenna Systems (AAS) and Multiple Input Multiple Output (MIMO) technology ü Eliminating channel bandwidth dependencies on sub-carrier spacing, allowing for equal performance under any RF channel spacing (1.25-14 MHz) ü Enhanced Fast Fourier transform (FFT) algorithm can tolerate larger delay spreads, increasing resistance to multipath interference On the other hand, 802.16-2004 (fixed WiMAX) offers the benefit of available commercial products and implementations optimized for fixed access. Fixed WiMAX is a popular standard among alternative service providers and operators in developing areas due to its low cost of deployment and advanced performance in a fixed environment. Fixed WiMax is also seen as a potential standard for backhaul of wireless base stations such as cellular, WiFi or even mobile WiMAX. SOFDMA and OFDMA256 are not compatible so most equipment will have to be replaced. However, some manufacturers are planning to provide a migration path for older equipment to SOFDMA compatibility which would ease the transition for those networks which have already made the OFDMA256 investment. This effects a relatively small number users and operators. HIPERMAN The equivalent of 802.16 in Europe is HIPERMAN. The WiMAX Forum is working to ensure that 802.16 and HIPERMAN inter-operate seamlessly. WiBro Korea's electronics and telecommunication industry spearheaded by Samsung Electronics and ETRI has developed its own standard, WiBro. In late 2004, Intel and LG Electronics have agreed on interoperability between WiBro and WiMAX. WiBro has South Korean government support with the requirement for each carrier to spend over US$1 billion for deployments. The Koreans sought to develop WiBro as a regional and potentially international alternative to 3.5G or 4G cellular systems. But given the lack of momentum as a standard, WiBro has joined WiMAX and agreed to harmonize with the similar OFDMA 802.16e version of the standard. What makes WiBro roll-outs a good 'test case' for the overall WiMAX effort is that it is mobile, well thought out for delivery of wireless broadband services, and the fact that the deployment is taking place in a highly sophisticated, broadband-saturated market. WiBro will go up against 3G and very high bandwidth wire-line services rather than as gap-filler or rural under-served market deployments as is often exampled as the 'best fit' markets for WiMAX. Associations   WiMAX Forum The WiMAX Forum is "the exclusive organization dedicated to certifying the interoperability of BWA products, the WiMAX Forum defines and conducts conformance and interoperability testing to ensure that different vendor systems work seamlessly with one another." Those that pass conformance and interoperability testing achieve the "WiMAX Forum Certified" designation and display this mark on their products and marketing materials. Vendors claiming their equipment is "WiMAX-ready", "WiMAX-compliant", or "pre-WiMAX" are not WiMAX Forum Certified, according to the Forum. WiMAX Spectrum Owners Alliance - WiSOA WiSOA is the first global organization composed exclusively of owners of WiMAX spectrum. WiSOA is focused on the regulation, commercialization, and deployment of WiMAX spectrum in the 2.3–2.5 GHz and the 3.4–3.5 GHz ranges. WiSOA are dedicated to educating and informing its members, industry representatives and government regulators of the importance of WiMAX spectrum, its use, and the potential for WiMAX to revolutionize broadband. Competing technologies WiMAX is a framework for wireless development based on a forward-looking core set of technologies. More recently 3GPP cellular's 4G, 802.22 Cognitive Radio RAN (Rural Area Network), and 802.20, the High Speed Mobile Broadband Wireless Access (MBWA) Working Group, have shifted toward use of similar constructs of multi-channel scalable OFDM, HARQ, FEC, MIMO-AAS and other complementary technologies as are part of WiMAX. Within the marketplace, WiMAX's main competition comes from widely deployed wireless systems with overlapping functionality such as UMTS and CDMA2000, as well as a number of Internet oriented systems such as HIPERMAN and WiBro. Cellular Phone Systems 3G and 4G Both of the two major 3G systems, CDMA2000 and UMTS, compete with WiMAX. Both offer DSL-class Internet access in addition to phone service. UMTS has also been enhanced to compete directly with WiMAX in the form of UMTS-TDD, which can use WiMAX oriented spectrum and provides a more consistent, if lower bandwidth at peak, user experience than WiMAX. Moving forward, similar air interface technologies to those used by WiMAX are being considered for the 4G evolution of UMTS. 3G cellular phone systems usually benefit from already having entrenched infrastructure, being upgrades from earlier systems. Users can usually fall back to older systems when they move out of range of upgraded equipment, often relatively seamlessly. In addition to obvious competition, in some areas of the world the wide availability of UMTS and a general desire for standardization has meant spectrum has not been allocated for WiMAX: in July 2005, the EU-wide frequency allocation for WiMAX was blocked by France and Finland, where manufacturers have invested heavily in UMTS technology. In September 2006, frequency bidding in Malaysia was stopped and any allocation of WiMAX has been suspended indefinitely. The ITU has, however, advised agnostic use of spectrum for IMT-2000 and is considering WiMAX as an alternative specified use for IMT-2000 and IMT-Advanced. Growing interest among operators is building for 'technology agnostic' allocation of spectrum in which operators are free to make best use of their large investments and insure against regulated obsolescence. Internet Oriented Systems Early WMAN standards, the European standard HIPERMAN and Korean standard WiBro have been harmonized as part of WiMAX and are no longer seen as competition but as complimentary. All networks now being deployed in Korea, the home of the Wibro standard, are now WiMAX. As a short-range mobile internet solution, such as in cafes and at transportation hubs like airports, the popular WiFi 802.11g system is widely deployed, and provides enough coverage for some users to feel subscription to a WiMAX service is unnecessary. Comparison Comparison of Mobile Internet Access methods Standard Family Primary Use Radio Tech Downlink (Mbps) Uplink (Mbps) Notes 802.16e WiMAX Mobile Internet SOFDMA 70 70 Quoted speeds only achievable at short range more practically 10Mbps at 10Km. HIPERMAN HIPERMAN Mobile Internet OFDM 56.9 56.9 WiBro WiBro Mobile Internet OFDM 50 50 Short range (<5km) UMTS W-CDMA HSDPA+HSUPA UMTS/3GSM Mobile phone CDMA/FDD .384 3.6 .384 5.76 HSDPA downlink widely deployed. Roadmap shows HSDPA up to 28.8Mbps from the basestation . Users can expect downloads of 400 to 600Kbps but around 100Kbps uplink speeds. UMTS-TDD UMTS/3GSM Mobile Internet CDMA/TDD 16 16 Reported speeds according to IPWireless LTE UTMS UMTS/4GSM General 4G OFDM/MIMO (HSOPA) >100 >50 Still in development 1xRTT CDMA2000 Mobile phone CDMA 0.144 0.144 Obsoleted by EV-DO EV-DO 1x Rev. 0 Rev. A CDMA2000 Mobile phone CDMA/FDD 2.45 3.1 0.15 1.8 Proposed Rev. B improves downlink to nearly 5Mbps. Notes: All speeds are theoretical maximums and will vary by a number of factors, including the distance from the tower and the ground speed (i.e. communications on a train may be slower than when standing still.) Usually the bandwidth is shared between several terminals.

A pre-WiMAX CPE of a 26 km connection mounted 13 meters above the ground (2004, Lithuania).

Illustration of a WiMAX MIMO board

Is WiMAX new?

When did it start?

WiMAX is relatively new in terms of a standards initiative - and in particular, the launch of numerous WiMAX technologies supporting chipsets by Forum members. However, much of the technology being incorporated into the IEEE 802.16 technology set is existent in the industry today and well tested. A number of best of breed broadband radio manufacturers have been offering various elements used in WiMAX for several years as proprietary technology. However, vendors rarely offered consistent iterations of radio modulation and other techniques---ensuring that solutions had to be specific to a single vendor. This is especially true on the fixed wireless side. And even more so for unlicensed band fixed wireless. However, mobile broadband wireless technologies suffered from the fragmentation of multiple proprietary approaches.
This means that much of the technological capability of WiMAX is relatively mature. In fact, the radio vendors who are members of the forum have deployed equipment in over 125 nations around the globe with trials and deployments exceeding 275. The combination of these advanced technologies into two standards packages for Fixed and Mobile broadband wireless combined with new generation optimized chipsets and tested and certified interoperability between radio manufacturers deliver a robust and powerful technology. This capability can match or exceed the performance and cost factors of other broadband technologies. This can all be achieved without traditional wireline tethers.
On the horizon, plans are to expand the WiMAX product capability as well as the early underpinnings of the next version of WiMAX, which will incorporate increasingly newer technologies. Also, the next major version of the 802.16 standard 802.16m, is already in the process of being defined. This version will offer even better throughput, spectral efficiency and capabilities along with increased interoperability.

Reference

Wikipedia

www.palowireless.com

Short Quiz

Fill in the blanks.

1. provides up to 3 Mbit/s broadband speed without the need for cables.

2. WiMAX provides between network endpoints without the need for direct line of sight in favorable circumstances.

3. In line with these possible applications is the technology's ability to serve as a high bandwidth " " for Internet or cellular phone traffic from remote areas back to an internet backbone.

4. WiMAX is a for wireless development based on a forward-looking core set of technologies.

backhaul	framework	proprietary
broadband	WiMAX	connectivity

 

Answer:

1. WiMAX

2. connectivity

3. backhaul

4. framework

Information prepared by Mei Ing

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Technology and Communications – RazakSAT

1. ) RazakSAT

Malaysian agencies requiring satellite image currently rely upon image data and information provided by satellites manufactured and operated by foreign international companies. Due to the orbit in which such satellites are located, the images provided are neither timely enough nor does it cater to Malaysia's specific use and need. A Medium Aperture Camera Satellite (RazakSAT(TM)) Malaysia's own small satellite will be able to provide specific and timely data for its users in Malaysia as well as being able to cater to the needs of countries located on the equatorial belt.

 

The RazakSAT(TM) spacecraft is a small LEO satellite. It carries an electro-optical payload, a Medium-sized Aperture Camera (MAC) a pushbroom camera with 5 linear detectors (1 panchromatic, 4 multi-spectral). The RazakSAT(TM) satellite will be operated through its ground segment in Malaysia, consisting of a Mission Control Station (MCS) and Image Receiving and Processing Station (IRPS). ATSB's engineers are operators at the MCS and they will execute RazakSAT(TM)'s mission plan, command generation and telemetry receiving, archiving and analysis. The IRPS will receive and archive images for post processing and distribution to the users. The development of the RazakSAT(TM) system is a collaborative programme between ATSB and Satrec Initiative Co. Ltd, Republic of Korea.

The High Resolution EO Satellite

The RazakSAT is a cost-effective 180kg mini satellite capable of high resolution Earth Observation missions.

The satellite will be launched in early 2009. The design and manufacturing process of this satellite follows the exacting and rigorous established standards of space programs. Using these standards, the RazakSAT has passed through the phases of Engineering, Qualification and Flight Models.

The primary payload of RazakSAT is a high resolution Medium-Sized Aperture Camera or MAC. The satellite is three-axis stabilized and has a comprehensive sensor suite including space borne GPS receiver, star tracker, fiber optic gyroscopes, magnetometers, fine and coarse sun sensors. Satellite actuator systems, which include reaction wheels and magnetorquers, allow accurate positioning of the satellite.

The combination of high resolution and large attitude maneuverability allows RazakSAT to provide highly customised and configurable imaging missions according to customer requirements.

In brief, the specifications of RazakSAT are as follows:

Orbit	Near Equatorial Low Earth Orbit (NEqO) at 685km 9° inclination
Mechanical Configuration	Ø1200mm x H1200mm hexagon type; 180 kg mass
Power Generation	Greater than 300W at end of life
Playload Features	Medium-sized Aperture Camera Panchromatic : 2.5m ; Multi-spectral (4-bands) :5.0m
Imaging Capacity	20 km swath by 500 km strip for total area of 10,000 km2
Data Down Link Rate	30 Megabits per second single channel

After years of postponement, RazakSAT, Malaysia's first remote sensing satellite, will be blasted into space from Kwajalein Island on April 21.The island is part of the Marshall Islands leased to the United States.

Science, Technology and Innovation Deputy Minister Fadilah Yusof said the satellite was scheduled to be flown via a Royal Malaysian Air Force (RMAF) C130 aircraft from Subang to the Bucholz Army Airfield, Kwajalein on March 21.

"The aircraft carrying the satellite will be making temporary stops in Kota Kinabalu and Guam during the journey to Kwajalein," he told a press conference at the Astronautic Technology (M) Sdn Bhd (ATSB) near here on Thursday.RazakSAT, which is also Malaysia's second low orbit microsatellite, was developed through a colloboration of ATSB with Satrec Initiative Ltd of South Korea.

The 180kg satellite is expected to be carried into space on a Falcon One rocket owned by United States' Space Exploration Technology (SpaceX) from Kwajalein.The 2.5mm Medium Sized Aperture Camera on the satellite is expected to provide high resolution images of Malaysia that can be applied to land management, resource development and conservation, forestry, fish migration and security.

According to Fadilah, RazakSAT, also the nation's first observatory satellite, would be launched to an orbital location specifically for Malaysia, to be known as the Equatorial Orbit.He said the orbital location would enable observation to be made on the earth surface more often, as compared to other observatory satelites, that is, five to six times daily, during daylight.

"Compared to TiongSAT1, which was launched in 2006 and which was more experimental in nature, RazakSAT is considered a functional satellite in monitoring the earth's surface and environment," said Fadilah, adding that the satellite was built at a total cost of RM150 million.

Fadilah said for the first time, together with RazakSAT, two other satellites meant for educational purposes CubeSAT and InnoSAT would also be launched.Meanwhile, Fadilah said Malaysia had the necessary expertise and capacity to develop its own satellite for sale to other countries."There is already a demand from countries like Iran to purchase satellites developed by ATSb," he added.

 

 

 

Reference

http://www.astb-malaysia.com

http://www.astb.com

Wikipedia

Short Quiz

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Multiple Choice Questions

1.) What is the mass of RazakSAT?

A. 160 kg B. 170 kg

C. 180 kg D. 190 kg

2.) When did RazakSAT launched?

A. 21 April 2009

B. 8 March 2009

C. 14 February 2009

3.)  Where will be RazatSAT blasted?

A. Langkawi Island

B. Kwajalein Island

C. Hawaii Island

4.)  What type satellite of RazatSAT?

A. Communication satellite

B. Observatory satellite

C. Navigation satellite

Answer

1. C
2. A
3. B
4. B

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Information prepared by Mei Ing

What is H1N1?

What is H1N1 Flu?

H1N1 flu is a respiratory disease of pigs caused by type A influenza that regularly causes outbreaks of influenza among pigs. H1N1 flu viruses do not normally infect humans; however, human-to-human spread of H1N1 flu virus is occurring, similar to the spread of regular seasonal flu viruses.

What causes H1N1?

It was caused by a particular strain of the influenza virus, just like any other flu. This particular strain (Influenza A, Novel H1N1 or 2009 Swine Flu virus) originated in pigs (swine) but has changed itself to be infective to humans.
Swine flu is a virus that originally infected only pigs and they spread it from one infected hog to other hogs the same way it spreads in people, by direct contact or by droplets holding the virus in the air after a pig coughed or sneezed. Because pigs are physiologically very similar to humans, when they have been living closely with humans, some microbes that can infect them are able to be changed or mutated into strains that people can catch. These types of diseases that we can get from animals are called zoonotic diseases.

What are the symptoms of H1N1?

The symptoms of H1N1 flu in people appear to be similar to the symptoms of regular seasonal flu and include:

• fever of more than 100 degrees Fahrenheit
• cough
• sore throat
• muscle aches
• headache
• chills
• fatigue
• diarrhea
• vomiting

Initial outbreaks

It is not known where the virus originated. Analysis has suggested that the H1N1 strain responsible for the current outbreak first evolved around September 2008 and circulated in the human population for several months before the first cases were identified as being due to a new strain.

Mexico

The virus was first reported in two U.S.children in March, but health officials have said that it apparently infected people as early as last January in Mexico. The outbreak was first detected in Mexico City on March 18, 2009 where surveillance began picking up a surge in cases of influenza-like illness. "In early April, Mexico had noticed that it had high numbers of serious respiratory illnesses and some deaths. It began sending samples to Canada and the United States, asking for help genotyping the new virus." Health Secretary Jose Angel Cordova confirmed that a 4-year-old boy was part of an outbreak in Veracruz state that began in February. Residents of the town of Perote worried at the time that they had contracted a new and aggressive flu, and publicly demonstrated against the pig farm they initially blamed for their illness. It was only after U.S. labs confirmed a swine flu outbreak that Mexican officials sent the boy's sample in for testing, and it tested positive for swine flu. While there was speculation that the outbreak may have started at the pig plant in Veracruz, the plant owners said that no pigs had tested positive for the virus.

After the outbreak was officially announced, Mexico immediately requested material support from the U.S. and worked closely with the CDC and Canada, sending them suspected samples for testing. Soon after, the CDC helped Mexico build their own lab capability to do faster diagnosis and confirmation of the H1N1 virus in Mexico. According to one commentator, "in the face of mounting hysteria, the response of both Mexico and the United States was an almost perfect display of the cooperation and partnership . . . ." Within a few days Mexico City was "effectively shut down," and some countries hastily canceled flights to Mexico while others halted trade. Although many in the U.S. called for shutting the border to help contain the spread, President Obama rejected the idea and Homeland Security Secretary Janet Napolitano called it "pointless," as the virus had already crossed into the U.S., and felt that "closing the border would have done nothing more than wreak economic havoc on both economies."

Prevention

 

What can I do to protect myself from getting sick?

There is no vaccine available right now to protect against novel H1N1 virus. There are everyday actions that can help prevent the spread of germs that cause respiratory illnesses like influenza.

 

Take these everyday steps to protect your health:

• Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
• Wash your hands often with soap and water, especially after you cough or sneeze. Alcohol-based hand cleaners are also effective.
• Avoid touching your eyes, nose or mouth. Germs spread this way.
• Try to avoid close contact with sick people.
• Stay home if you are sick for 7 days after your symptoms begin or until you have been symptom-free for 24 hours, whichever is longer. This is to keep from infecting others and spreading the virus further.

Other important actions that you can take are:

• Follow public health advice regarding school closures, avoiding crowds and other social distancing measures.
• Be prepared in case you get sick and need to stay home for a week or so; a supply of over-the-counter medicines, alcohol-based hand rubs, tissues and other related items might could be useful and help avoid the need to make trips out in public while you are sick and contagious.

What is the best way to keep from spreading the virus through coughing or sneezing?

If you are sick, limit your contact with other people as much as possible. If you are sick, stay home for 7 days after your symptoms begin or until you have been symptom-free for 24 hours, whichever is longer. Cover your mouth and nose with a tissue when coughing or sneezing. Put your used tissue in the waste basket. Then, clean your hands, and do so every time you cough or sneeze.

 

 

 

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Short Quiz

1. H1N1 flu is a respiratory disease of pigs caused by type A influenza that regularly causes outbreaks of influenza among pigs.

2. Symptoms of H1N1 are cough, sore throat, muscle aches, headaches and fever of more than 100 degrees Fahrenheit.

3. The outbreak was first detected in Mexico city.

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Information prepared by Choo Teng

Health

HEALTH

Introduction for HEALTH

Health is generally defined as being "a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity" according to the World Health Organization (WHO).

In 1986, the WHO, in the Ottawa Charter for Health Promotion, said that health is "a resource for everyday life, not the objective of living. Health is a positive concept emphasizing social and personal resources, as well as physical capacities." Classification systems such as the WHO Family of International Classifications (WHO-FIC), which is composed of the International Classification of Functioning, Disability, and Health (ICF) and the International Classification of Diseases (ICD) also define health.

Overall health is achieved through a combination of physical, mental, emotional, and social well-being, which, together is commonly referred to as the Health Triangle.

Aspects of health

1. Physical health

Physical fitness refers to body health, and is the result of regular exercise, proper diet and nutrition, and proper rest for physical recovery.

A strong indicator of the health of localized population is its average height or weight, which generally increases with improved nutrition and health care. This is also influenced by the standard of living and quality of life. Genetics also plays a major role in people's height. The study of human growth, its regulators, and implications is known as Auxology.

2.) Mental Health

Mental health describes either a level of cognitive or emotional well-being or an absence of a mental disorder. The World Health Organization defines mental health as "a state of well-being in which the individual realizes his or her own abilities, can cope with the normal stresses of life, can work productively and fruitfully, and is able to make a contribution to his or her community”. However, despite official definitions, the term mental health, and the question of whether or not an individual is 'mentally well', remains a subjective assessment.

Maintaining health

Achieving health and remaining healthy is an ongoing process. Effective strategies for staying healthy and improving one's health include the following elements:

1. Social Activity

Personal health depends partially on the social structure of one's life. The maintenance of strong social relationships is linked to good health conditions, longevity, productivity, and a positive attitude. This is due to the fact that positive social interaction as viewed by the participant increases many chemical levels in the brain which are linked to personality and intelligence traits.

2. Sports Nutrition

Sports nutrition focuses the link between dietary supplements and athletic performance. One goal of sports nutrition is to maintain glycogen levels and prevent glycogen depletion. Another is to optimize energy levels and muscle tone. An athlete's strategy for winning an event may include a schedule for the entire season of what to eat, when to eat it, and in what precise quantities (before, during, after, and between workouts and events).

3. Hygiene

Hygiene is the practice of keeping the body clean to prevent infection and illness, and the avoidance of contact with infectious agents. Hygiene practices include bathing, brushing and flossing teeth, washing hands especially before eating, washing food before it is eaten, cleaning food preparation utensils and surfaces before and after preparing meals, and many others. This may help prevent infection and illness. By cleaning the body, dead skin cells are washed away with the germs, reducing their chance of entering the body.

4. Stress management

Prolonged psychological stress may negatively impact health, such as by weakening the immune system and mind. Stress management is the application of methods to either reduce stress or increase tolerance to stress. Relaxation techniques are physical methods used to relieve stress. Psychological methods include cognitive therapy, meditation, and positive thinking which work by reducing response to stress. Improving relevant skills and abilities builds confidence, which also reduces the stress reaction to situations where those skills are applicable.

Reducing uncertainty, by increasing knowledge and experience related to stress-causing situations, has the same effect. Learning to cope with problems better, such as improving problem solving and time management skills, may also reduce stressful reaction to problems. Repeatedly facing an object of one's fears may also desensitize the fight-or-flight response with respect to that stimulus—e.g., facing bullies may reduce fear of bullies.

Prolonged hours of surfing on the Internet is a major concern that can affect the eyes significantly.^[White backgrounds on computer screens with a viewing distance of less than 14 inches is known to increase strain, mental fatigue and temporary di-chromatic visions in a normal healthy human being. Trying to opt for black or any non-white backgrounds can help in reducing eye strain in front of PCs.^]

5. Health care

Health care is the prevention, treatment, and management of illness and the preservation of mental and physical well being through the services offered by the medical, nursing, and allied health professions.

6. Workplace wellness programs

Workplace wellness programs are recognized by an increasingly large number of companies for their value in improving the health and well-being of their employees, and for increasing morale, loyalty, and productivity.^] Workplace wellness programs can include things like onsite fitness centers, health presentations, wellness newsletters, access to health coaching, tobacco cessation programs and training related to nutrition, weight and stress management. Other programs may include health risk assessments, health screenings and body mass index monitoring.

Prepared by Jacklyn

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Short Quiz

1. How can we define health?

2.What are the elements of effective strategies for staying healthy and improving one's health?

3. What are the two aspects of health?

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Answers

1. Health is generally defined as being "a state of complete physical, mental, and social well-being.

2.

Social Activity

Sports Nutrition

Hygiene

Stress management

Health care

Workplace wellness programs

3. Physical health & mental health