View source for HAMSAT

{{Short description|Microsatellite}}
{| class="infobox" style="width: 25em; text-align: left;" 
|+ <big>'''HAMSAT'''</big>
<!--
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| colspan="2" style="text-align:center;" | {{IMAGE}}<br /><small>{{CAPTION}}</small>
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|- style="vertical-align:top;"
! Organization
| AMSAT-India, William Leijenaar
http://amsatindia.org/
|- style="vertical-align:top;"
! Mission Type
| [[Communications satellite|Communications]]
|- style="vertical-align:top;"
! Satellite of
| [[Earth]]
|- style="vertical-align:top;"
! Launch
| May 5, 2005 on [[PSLV-C6]]
|- style="vertical-align:top;"
! Launch site
| [[Sriharikota]]
|- style="vertical-align:top;"
! Mission duration
| Achieved: 9 Years and 2 Months
|- style="vertical-align:top;"
! [[Mass]]
| 42.5&nbsp;kg (launch)
|- 
! colspan="2" bgcolor="#FFDEAD" align="center" | Orbital elements
|- style="vertical-align:top;
! [[Semi-major axis]]
| 7004.27&nbsp;km
|- style="vertical-align:top;"
! [[Orbital eccentricity|Eccentricity]]
| 0.0027
|- style="vertical-align:top;"
! [[Inclination]]
| 97.89 degrees
|- style="vertical-align:top;"
! Orbital Period
| 97.23&nbsp;minutes
|- style="vertical-align:top;"
! [[Right ascension]] of the [[node (astronomy)|ascending node]]
| 65.14 degrees
|- style="vertical-align:top;"
! [[Argument of perigee]]
| 222.72 degrees
|}

'''HAMSAT''', also known as '''HAMSAT INDIA''', '''VU2SAT''' and '''VO-52''', was a [[Miniaturized satellite|microsatellite]]  hat[[amateur radio satellite|a]]<nowiki/>provided [[amateur radio satellite|mateur radio satellite]] communications services for Indian and international [[amateur radio operator]]s. This satellite carries the in-orbit designation of VO-52, and is an [[OSCAR]] series satellite.

==History==
It was launched by [[PSLV-C6]] on May 5, 2005. The main payload was an [[Indian Remote Sensing satellite]], [[CARTOSAT-1]] weighing {{convert|1560|kg|lb|-1}}. HAMSAT was placed into a polar [[Sun-synchronous orbit]].

It carries two [[transponder]]s, one built by William Leijenaar (Call Sign: PE1RAH), a Dutch Radio Amateur and graduate engineering student from the [[Higher Technical Institute]] at [[Venlo]] and the other by Ham enthusiasts with help from the [[ISRO]] (Indian Space Research Organisation).<ref>{{cite web |url=http://www.isro.org/satellites/hamsat.aspx |title=HAMSAT |work=[[ISRO]] |url-status=dead |archive-url=https://web.archive.org/web/20100926103619/http://isro.org/satellites/hamsat.aspx |archive-date=2010-09-26 }}</ref> Each transponder is recognized by its beacon. The Indian transponder has an unmodulated carrier on 145.940&nbsp;MHz. The Dutch transponder is modulated with telemetry information on 145.860&nbsp;MHz. Both are linear transponders offering the CW, SSB and FM modes of amateur radio communication. They operate Mode-B for U-V operation with UHF uplink and VHF downlink.<ref name="spacetoday">{{cite web |url=http://www.spacetoday.org/Satellites/Hamsats/Hamsats2000s.html |title=Amateur Radio Satellites Roar Into The 21st Century - 2005: VuSat-OSCAR 52 HamSat |work = spacetoday.org }}</ref>

The satellite joins many previous satellites in amateur radio service; mostly launched by [[AMSAT]].

HAMSAT VO-52 failed in space on 11 July 2014, while on its 49,675th orbit, due to the failure of onboard lithium-ion batteries that have met their end of life. Although the satellite's systems and sub-systems are working normally as per the latest telemetry received, the onboard computer recurring to "Reset" mode due to the failure of batteries is hindering operation.  Hence, it was decided not to expect any more meaningful and reliable services from HAMSAT VO-52. On 21 July 2014, ISRO decommissioned ‘HAMSAT-VO52′ officially.<ref name="amsatuk">{{cite web |url=http://amsat-uk.org/2014/07/21/goodbye-hamsat-vo52-rest-in-peace/ |title=Goodbye HAMSAT-VO52 – Rest In Peace |work=amsat-uk.org|date=21 July 2014 }}</ref><ref name="amsat">{{cite web |url=http://www.amsat.org/?p=2988 |title=VO-52 "Hamsat" end of mission |work=[[AMSAT]] |date=28 June 2017 }}</ref>

HAMSAT VO-52 was designed for one-year mission life, but lasted for almost 10 years. The satellite was designed to be maintenance-free, and autonomous. It was a test bed for many new concepts such as a Bus Management Unit (BMU), lithium-ion-based power system, automatic spin rate control and spin axis orientation control (SAOC) for maintaining the satellite attitude without ground commanding. HAMSAT was known as “OSCAR-52” among Amateur HAM operators, and was popular internationally because of its high-sensitivity receiver and strong transmitter.<ref name="amsatuk"/><ref name="amsat"/>

==Specifications==

*The satellite is spin-stabilized. It spins at about 4&nbsp;RPM.
*UHF uplink and VHF downlink
*Uplink transponder frequency: 435.250&nbsp;MHz
*Downlink transponder frequency: 145.900&nbsp;MHz
*Beacon frequencies: 145.860&nbsp;MHz CW telemetry and 145.936&nbsp;MHz unmodulated carrier
*Transponder bandwidth: 60&nbsp;kHz
*Transmitter output power: 1 watt
*Antennas: VHF and UHF turnstiles
*Communication modes: CW, SSB, FM
*Electrical power: Gallium arsenide solar panels charging a lithium-ion battery
*Onboard computer: MAR 31750 processor in the spacecraft's electronic bus management unit for attitude control, telemetry, telecommand for ground control, sensor and actuator functions.<ref name="spacetoday"/>

==See also==
{{Portal|Spaceflight}}
*[[Indian space program]]
*[[List of Indian satellites]]
*[[Amateur radio in India]]

==External links==
*[https://web.archive.org/web/20100926103619/http://isro.org/satellites/hamsat.aspx ISRO: HAMSAT]
*[https://web.archive.org/web/20080731141914/http://www.amsat.org/amsat-new/satellites/sat_summary/hamsat.php AMSAT link]

==References==
{{Reflist}}

{{Indian space programme}}
{{Indian spacecraft}}
{{Orbital launches in 2005}}

{{DEFAULTSORT:Hamsat}}
[[Category:Communications satellites of India]]
[[Category:Amateur radio satellites]]
[[Category:Amateur radio in India]]
[[Category:Satellites orbiting Earth]]
[[Category:Spacecraft launched in 2005]]
[[Category:2005 in India]]