CASSIOPE

CASSIOPE is a 500 kg (1,100 lb) small satellite that is 180 cm (5.9 ft) long and 125 cm (4.10 ft) high. It combines the function of two distinct missions in order to be more cost-effective and reduce risk.[11]

The spacecraft carries a primary payload of two instrument suites: the Cascade commercial communications system and a scientific payload named e-POP.

After a successful launch on September 29, 2013, CASSIOPE entered into a commissioning phase that lasted to January 1, 2014, with no faults detected on the spacecraft bus or payloads. Three ground stations were utilized, including Kiruna (Sweden), Inuvik (Canada), and the German Antarctic Receiving Station at the General Bernardo O'Higgins Base in Antarctica. Routine operations were scheduled to run to March, 2015. The mission was extended via funding from the Technology Partnerships Canada program through the Industrial Technologies Office that was part of the Canadian government at the time. In February 2018, the European Space Agency, through the Third Party Mission Program, integrated the mission into the Swarm constellation of satellites, dubbing CASSIOPE "Swarm-Echo", recognizing the synergy between the two missions in collecting space weather data in low Earth orbit. The partnership allowed for four ground station contacts per day, rather than one, greatly increasing the amount of data that could be downloaded from the e-POP suite of instruments.

On August 11, 2016, one of the four reaction wheels used for spacecraft attitude control failed. This did not affect spacecraft operations in a significant way since only three wheels are required for 3-axis stabilized pointing. A second reaction wheel failed on February 27, 2021, forcing the spacecraft into a slowly spinning, safe-hold attitude configuration. Three-axis stabilized control was restored in September 2021 by implementing a bias momentum configuration on the two remaining wheels (spinning the wheels in opposite directions), and using the magnetic torque rods for attitude control. Three months later, on December 17, 2021, a third reaction wheel failed, leaving the spacecraft with no viable methods for fixed attitude pointing. Although most of the e-POP instruments were fully operational, without stabilized pointing much of the science objectives could not be met, resulting in a conclusion of the operational portion of the mission on December 31, 2021.[13]

The satellite that became CASSIOPE began with a 1996 concept for a small (70 kg/150 lb), inexpensive microsatellite called Polar Outflow Probe, or POP. The Canadian Space Agency funded a 1997 feasibility study that led to a modified mission concept that was designed during 2000-2005.[9] The revised concept was to combine an enhanced version of POP, called e-POP, with an MDA Corporation commercial satellite called Cascade, into a single satellite, and to design and build a generic, low-cost small satellite bus that would be useful for other Canadian satellite missions in the future.

The eight e-POP scientific instruments were built, calibrated, and tested in 2005-2007, with integration onto the satellite bus for spacecraft-level testing in 2008-2009.[9]

The satellite was launched on September 29, 2013, aboard a SpaceX Falcon 9 v1.1 rocket.[14]

At the time the launch was contracted in 2005, a SpaceX Falcon 1 was the planned launch vehicle. The launch was originally scheduled for 2008 from Omelek Island. The launch date slipped several times, and after SpaceX discontinued the Falcon 1, the launch was shifted to the much larger Falcon 9 in June 2010.[8][15]

MDA contracted with SpaceX to put the CASSIOPE payload on the first flight of an essentially new launch vehicle—a non-operational demonstration launch.[16] The Falcon 9 v1.1, upgraded from the original Falcon 9, is a 60 percent heavier rocket with 60% more thrust.[16] The flight was contracted with a payload mass that is very small relative to the rocket's capability, at a discounted rate because it was a technology demonstration mission for SpaceX, approximately 20% of the normal published price for SpaceX Falcon 9 LEO missions.[17]

Since this was the first flight of a new launch vehicle, the US Air Force had estimated the overall probability of failure on the mission was nearly fifty percent.[18] In the event, the mission was successful, as was each of the next 13 Falcon 9 v1.1 missions before a launch vehicle failure and loss of mission occurred on Falcon 9 Flight 19 in June 2015.

The Falcon 9 upper stage used to launch CASSIOPE was left derelict in a decaying elliptical low Earth orbit that, as of January 20, 2016, had a perigee of 317 km (197 mi) and an apogee of 1,283 km (797 mi).[19]

• List of Falcon 9 and Falcon Heavy launches

• Yau, Andrew W.; James, H. Gordon (June 2009). "CASSIOPE Enhanced Polar Outflow Probe (e-POP) Small Satellite Mission: Space Plasma Observations and International Collaborations". AIP Conference Proceedings. 1144: 192–195. Bibcode:2009AIPC.1144..192Y. doi:10.1063/1.3169287.
• Fujikawa, Nobuko; Hayakawa, Hajime; Tsuruda, Koichiro; et al. (2005). Neutral mass and velocity spectrometer (NMS) on e-POP/CASSIOPE spacecraft (PDF). International Sessions of Japan Earth and Planetary Science Joint Meeting 2005.
• Yau, Andrew W.; James, H. Gordon (2011). "Scientific Objectives of the Canadian CASSIOPE Enhanced Polar Outflow Probe (e-POP) Small Satellite Mission". The Sun, the Solar Wind, and the Heliosphere. IAGA Special Sopron Book Series, Volume 4. Springer Netherlands. pp. 355–364. Bibcode:2011sswh.book..355Y. doi:10.1007/978-90-481-9787-3_26. ISBN 978-90-481-9786-6.
• Yau, A. W.; James, H. G.; Bernhardt, P. A.; et al. (April 2009). "The Canadian Enhanced Polar Outflow Probe (e-POP) Mission: Current Status and Planned Observations and Data Distribution". Data Science Journal. 8: S38–S44. doi:10.2481/dsj.8.S38.

• CASSIOPE at the Canadian Space Agency
• CASSIOPE at MacDonald, Dettwiler and Associates