ISIS (satellite)#ISIS II
{{Short description|Satellites studying Earth's inosphere}}
{{About|Canadian satellites launched to study Earth's ionosphere|international studies of infarct survival|International Studies of Infarct Survival}}
{{Infobox spaceflight
| name = ISIS 1 /ISIS-A
| image =
| image_caption =
| mission_type =
| COSPAR_ID = 1969-009A
| SATCAT = 03669
| mission_duration =
| spacecraft_type =
| manufacturer = RCA Victor
| dry_mass =
| launch_mass = {{convert|241.0|kg}}
| power =
| launch_date = {{start-date|30 January 1969, 06:43:00|timezone=yes}} UTC
| launch_rocket = Delta E1 485/D65
| launch_site = Vandenberg SLC-2E
| launch_contractor =
| landing_date =
| orbit_epoch =
| orbit_reference = Geocentric
| orbit_regime = LEO
| orbit_eccentricity = 0.017475
| orbit_periapsis = {{convert|578|km|mi}}
| orbit_apoapsis = {{convert|3526|km|mi}}
| orbit_inclination = 82.42º
| orbit_period = 128.42 minutes
| apsis = gee
}}
{{Infobox spaceflight
| name = ISIS 2 (ISIS-B)
| image =
| image_caption =
| mission_type =
| COSPAR_ID = 1971-024A
| SATCAT = 05104
| mission_duration =
| spacecraft_type =
| manufacturer = RCA Victor
| dry_mass =
| launch_mass = {{convert|264.0|kg}}
| power =
| launch_date = {{start-date|01 April 1971, 02:53:00|timezone=yes}} UTC
| launch_rocket = Delta E1
| launch_site = Vandenberg SLC-2E
| launch_contractor =
| landing_date =
| landing_site =
| orbit_epoch =
| orbit_reference = Geocentric
| orbit_regime = LEO
| orbit_eccentricity = 0.0045
| orbit_periapsis = {{convert|1358|km|mi}}
| orbit_apoapsis = {{convert|1458|km|mi}}
| orbit_inclination = 88.1º
| orbit_period = 113.6 minutes
| apsis = gee
}}
ISIS 1 and 2 ("International Satellites for Ionospheric Studies") were the third and fourth in a series of Canadian satellites launched to study the ionosphere over one complete solar cycle. After the success of Canada's Alouette 1, Canada and the United States jointly sent up three more satellites in the ISIS program. The first was named Alouette 2 (after originally being named ISIS-X). As was the case for the Alouette satellites, RCA Ltd. of Montreal was the prime contractor for both ISIS 1 and 2.{{Cite web|last=Agency|first=Canadian Space|date=2000-06-16|title=Building on the Success of Alouette with ISIS I and II|url=https://www.asc-csa.gc.ca/eng/satellites/isis.asp|access-date=2021-04-09|website=www.asc-csa.gc.ca}}
A third satellite, ISIS 3, was scheduled for construction, but when the government's focus shifted toward communications satellites, it was cancelled in 1969. The funds were instead used to produce the Communications Technology Satellite (also known as Hermes), which was launched in 1976.{{Cite web|date=2012-09-06|title=Alouette 1 – Celebrating 50 Years of Canada in Space|url=https://spaceq.ca/alouette_1_celebrating_50_years_of_canada_in_space/|access-date=2021-04-09|website=SpaceQ|language=en-US}}
ISIS 1
ISIS 1 (1969-009A) was launched at 6h43 UTC{{cite web|title=ISIS 1 Launch Information|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/displayTrajectory.action?id=1969-009A|publisher=NASA NSSDCA|access-date=December 18, 2022}} on January 30, 1969, by a Delta rocket at the Western test range at Vandenberg AFB in California.{{Cite web|title=NASA NSSDCA - Spacecraft Details -ISIS 1|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1969-009A|access-date=2021-04-09|website=NASA Space Science Data Coordinated Archive}}
Unlike the Alouette satellites, ISIS had complex navigational equipment and a tape recorder to record some experiments when they were out of communications range and play back the results when the satellites came over Canada again. Some other experiments were not recorded but data was sent in over several stations around the globe. In total it conducted 10 experiments.
ISIS 2
ISIS 2 (1971-024A) was launched at 2h53 UTC{{cite web|title=ISIS 2 Launch Information|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/displayTrajectory.action?id=1971-024A|publisher=NASA NSSDCA|access-date=December 18, 2022}} on April 1, 1971, on a Delta rocket also from the Western test range at Vandenberg AFB in California.{{Cite web|title=NASA NSSDCA - Spacecraft Details - ISIS 2|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1971-024A|access-date=2021-04-09|website=NASA Space Science Data Coordinated Archive}} Due to budget constraints, the design of ISIS 2 was largely similar to that of ISIS I. The main difference was the addition of two experiments designed to study atmospheric optical emissions, including a photometer. This allowed images to be taken for the first time of an Aurora Borealis as seen from above.{{Cite web|date=2021-03-29|title=ISIS-II space mission launched University of Calgary's international reputation for auroral research|url=https://science.ucalgary.ca/news/isis-ii-space-mission-launched-university-calgarys-international-reputation-auroral-research|access-date=2021-04-09|website=University of Calgary|language=en}} James Gosling wrote some of the software to analyze data from ISIS 2, as a high school student working for the University of Calgary physics department.{{cite web |url=https://archive.computerhistory.org/resources/access/text/2019/10/102781080-05-01-acc.pdf |title=Oral History of James Gosling, part 1 of 2 |publisher=Computer History Museum |date=March 15, 2019 |author1=James Gosling |author2=Hansen Hsu |author3=Marc Weber |id=Catalog number 102781080 |pages=23–24}}
On March 13, 1984, both ISIS 1 and ISIS 2 were loaned to Japan's Communications Research Laboratory, which continued to operate the satellites until 1990, when they were shut down due to deterioration of battery capacity.{{Cite web|title=Alouette/ISIS: How it all Began|url=https://www.ieee.ca/millennium/alouette/alouette_franklin.html|access-date=2021-04-09|website=www.ieee.ca}}
See also
{{Portal|Spaceflight}}
External links
- [http://www.asc-csa.gc.ca/eng/satellites/isis.asp ISIS program from the Canadian Space Agency]
- [http://friendsofcrc.ca/Projects/ISIS/isis.html ISIS Satellite program]
- [https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1969-009A ISIS-I] at NSSDC (1969-009A)
- [https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1971-024A ISIS-II] at NSSDC (1971-024A)
References
{{Reflist}}{{Canadian Space Agency}}{{Orbital launches in 1969}}
{{Orbital launches in 1971}}