SEDSAT-1

{{short description|American amateur radio satellite}}

{{Infobox spaceflight

| name = SEDSAT-1

| image = SEDSAT 1.jpg

| image_size = 150px

| image_caption = SEDSAT-1 satellite.

| mission_type = Communications

| operator = AMSAT

| website =

| COSPAR_ID = 1998-061B

| SATCAT = 25509

| mission_duration =

| spacecraft_bus =

| manufacturer = University of Alabama

| dimensions = {{convert|32.13|x|32.13|x|35.43|cm|in|abbr=on}}{{cite web|url=https://space.skyrocket.de/doc_sdat/sedsat.htm|title=SEDSat 1 (SO 33, SEDSat-OSCAR 33)|work=Gunter's Space Page|author=Gunter Dirk Krebs|accessdate=10 February 2020}}

| launch_mass = {{Convert|35|kg|lb|abbr=on}}

| power =

| launch_date = 24 October 1998, 12:08 UTC

| launch_rocket = Delta-7326 D-261

| launch_site = Cape Canaveral SLC-17A

| launch_contractor =

| last_contact =

| decay_date =

| orbit_epoch = 24 October 1998{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/displayTrajectory.action?id=1998-061B|title=Telemetry Details|work=NSSDCA Master Catalog|author=NASA GSFC|accessdate=10 February 2020}}

| orbit_reference = Geocentric

| orbit_regime = Low Earth

| orbit_periapsis = {{convert|547|km|mi}}

| orbit_apoapsis = {{convert|1,079|km|mi}}

| orbit_eccentricity = 0.03699

| orbit_inclination = 31.4°

| orbit_period = 101 minutes

| apsis = gee

| programme = OSCAR

| previous_mission = OSCAR 32

| next_mission = OSCAR 34

}}

SEDSAT-1 (also known as SEDSAT-OSCAR 33) is a U.S. amateur radio satellite built by students and developed at the University of Alabama in Huntsville (UAH).

The microsatellite bears the name of one of its sponsoring organizations, the Students for the Exploration and Development of Space (SEDS). It was launched into a low Earth orbit on October 24, 1998 as a Secondary payload with the Deep Space 1 spacecraft using a Delta II rocket at Cape Canaveral Air Force Station, Florida, USA.

History

The satellite was to be built by the partnership between NASA's Marshall Space Flight Center and UAH with the primary objective of testing a newly developed small expendable deployer system developed for NASA's Space Shuttle, while allowing the students to add instrumentation to complete secondary missions after the primary data regarding the deployer's tether system had been captured.{{Cite book|last=COSPAR Colloquium on Microsatellites as Research Tools (Tʻai-nan shih, Taiwan) (1997). Auteur.|title=Microsatellites as research tools proceedings of COSPAR Colloquium on Microsatellites as Research Tools held in Tainan, Taiwan, 14-17 December 1997|date=2014|publisher=Pergamon|isbn=978-0-444-50196-7|oclc=881679774}} After the Tethered Satellite System (TSS-1R) experienced a failure resulting in the ignition of a strong electrical discharge shortly after being deployed from the Space Shuttle Columbia in 1996, the small expendable deployer system was subject to a Space Shuttle safety review that resulted in extensive design and requirements changes.{{Cite journal|last1=Stone|first1=N. H.|last2=Bonifazi|first2=C.|date=1998|title=The TSS-1R Mission: Overview and scientific context|journal=Geophysical Research Letters|language=en|volume=25|issue=4|pages=409–412|doi=10.1029/97GL02980|bibcode=1998GeoRL..25..409S |s2cid=129860770 |issn=1944-8007|doi-access=free}} As a result, SEDSAT-1 became a free-flying secondary payload on the Delta II, after securing sponsorship from other governmental and commercial partners.{{Cite web|url=http://archive.seds.org/sedsat/info/sponsors.html|title=Project Information Details|website=archive.seds.org|access-date=2020-02-14}}

Mission

The satellite was intended to have a novel link to the internet that would allow amateur radio operators from around the globe to request and receive imagery from the satellite anytime it flew overhead.{{Cite web|url=https://www.spacedaily.com/news/sedsat-98a.html|title=SEDSAT Puts Students Over The Earth|website=www.spacedaily.com|access-date=2020-02-18}} To this end, the satellite carries two cameras as part of the SEASIS (SEDS, earth, atmosphere, and space imaging system) instrument.{{Cite journal|last=Bankston|first=Cheryl Dawn|editor-first1=Firooz A. |editor-first2=Michael |editor-first3=Concetto R. |editor-first4=W. Pete |editor-first5=James F. |editor-last1=Allahdadi |editor-last2=Chrisp |editor-last3=Giuliano |editor-last4=Latham |editor-last5=Shanley |date=1994-06-08|title=SEDS, earth, atmosphere, and space imaging system (SEASIS)|journal=Space Instrumentation and Dual-Use Technologies|publisher=International Society for Optics and Photonics|volume=2214|pages=257–268|doi=10.1117/12.177665|bibcode=1994SPIE.2214..257B |s2cid=140552198 }} SEDSAT-1 also includes instruments which monitor battery performance management and control. After launch, telemetry data was received at the satellite's university led mission control center at the University of Arizona in Tucson, AZ. However, an uplink could never be established and no photographic data could be received from the SEASIS instrument. The telemetry data received from the satellite did allow for some of the battery control experiments to be received, and as of 2013 the satellite is still active.{{Cite web|url=https://space.skyrocket.de/doc_sdat/sedsat.htm|title=SEDSat 1 (SO 33, SEDSat-OSCAR 33)|website=space.skyrocket.de|access-date=2020-02-18}}

Frequency

  • Downlink: 437.91 MHz
  • Mode: 9600 bps FSK{{cite web|url=https://www.n2yo.com/satellite/?s=25509|title=SEDSAT 1|author=N2yo.com|accessdate=10 February 2020}}

See also

{{Portal|Spaceflight}}

Bibliography

  • Mark W. Maier, Shi-Tsan Wu: SEDSAT-1 lessons learned. In: F.-B. Hsiao (Hrsg.): Microsatellites as research tools. Elsevier, Amsterdam 1999, pg. 365–375.
  • Students for the Exploration and Development of Space Satellite. In: NASA Historical Data Book, Volume VII. Government Printing Office, Washington, D.C. 2009, pg. 669–671

References

{{Reflist}}

{{Orbital launches in 1998}}

{{OSCAR satellites}}

{{US-spacecraft-stub}}

Category:Satellites orbiting Earth

Category:Amateur radio satellites

Category:Spacecraft launched in 1998