CORONAS programme

Lore & Background

CORONAS-I was launched in 1994 and carried 12 instruments, including the TEREK-C Solar XUV Telescope/Coronagraph and the RES-C Solar X-ray Spectral Polarimeter. CORONAS-F launched in 2001 and operated until 2005, carrying 16 instruments, adding new ones such as the SPR-N Solar X-ray Polarimeter and the RESIK X-ray Spectrometer.

CORONAS-Photon launched on 30 January 2009 from Plesetsk Cosmodrome aboard the final flight of the Tsyklon-3 rocket. It carried 11 instruments, including the TESIS telescope-spectrometer and the RT-2 Roentgen Telescope-2. On 1 December 2009 all scientific instruments were turned off due to power supply problems caused by a design flaw. On 18 April 2010 the creators announced the satellite was lost 'with a good deal of certainty.'

Reader's Guide

The CORONAS programme represents a significant Russian effort to observe the Sun from low Earth orbit, covering a range of wavelengths from radio to gamma rays. The three satellites provided continuous solar monitoring from 1994 through 2009, with CORONAS-F operating for four years. The programme's instruments were designed to study solar flares, coronal mass ejections, and solar cosmic rays. The loss of CORONAS-Photon due to a design flaw in its power supply, just months after launch, highlights the technical challenges of space-based solar observatories. Despite this, the data from CORONAS-I and CORONAS-F contributed to understanding solar activity and its effects on the near-Earth environment. The programme's legacy includes a diverse set of instruments, many of which were carried over between missions, allowing for comparative studies across solar cycles.

Did You Know?

• CORONAS-Photon was launched on the final flight of the Tsyklon-3 rocket.
• CORONAS-F carried 16 instruments, while CORONAS-I carried 12 and CORONAS-Photon carried 11.
• All scientific instruments on CORONAS-Photon were turned off on 1 December 2009 due to power supply problems caused by a design flaw.

Programme Identity and Mission Scope

The CORONAS programme — an acronym standing for Complex Orbital Observations Near-Earth of Activity of the Sun — represents Russia's dedicated effort to study solar activity from orbit. Conceived as a multi-mission initiative, the programme deployed three distinct satellites over roughly a fifteen-year span: CORONAS-I in 1994, CORONAS-F in 2001, and CORONAS-Photon in 2009. Each spacecraft was designed to carry a suite of scientific instruments aimed at probing different aspects of solar behaviour, from extreme ultraviolet emissions to high-energy particle events. The programme's naming convention reflects its core scientific ambition: to observe the Sun's dynamic processes from a vantage point close enough to Earth to capture rapid changes in solar output. By distributing its observational goals across three separate launches, the programme allowed for iterative refinement of its payload while maintaining a continuous thread of solar monitoring throughout the late twentieth and early twenty-first centuries.

A Broad Spectrum of Solar Instruments

Across the three CORONAS missions, the combined instrument suites covered an extraordinary range of the electromagnetic spectrum and particle physics. Core instruments such as the TEREK-C coronagraph, the RES-C X-ray polarimeter, the HELICON scintillation spectrometer, and the DIOGENESS flare diagnostic appeared on multiple spacecraft, ensuring continuity in key measurements. CORONAS-I carried twelve instruments in total, while CORONAS-F expanded the payload to sixteen by adding the SPR-N X-ray polarimeter, the RESIK X-ray spectrometer, the RPS-1 semiconductor spectrometer, and the IMAP-5 three-axis magnetometer. CORONAS-Photon took a different approach, fielding eleven instruments with a heavier emphasis on high-energy phenomena, including the Natalya-2M spectrometers for both radiation and particles, the Penguin-M hard X-ray polarimeter-spectrometer, the Konus-RF X-ray and gamma-ray spectrometer, and the TESIS telescope-spectrometer for X-ray solar imaging. Together, these payloads enabled observations from vacuum ultraviolet through radio waves and into the charged-particle domain.

CORONAS-Photon: Promise Cut Short

The final CORONAS mission carried particular symbolic weight. CORONAS-Photon lifted off from the Plesetsk Cosmodrome on 30 January 2009, riding atop the very last flight of the Tsyklon-3 launch vehicle — a fitting pairing of two programmes reaching their conclusion simultaneously. The satellite was equipped with eleven scientific instruments designed to study high-energy solar and astrophysical phenomena. However, the mission's operational life was tragically brief. By 1 December 2009, every scientific instrument aboard had been switched off after persistent power-supply problems traced back to a design flaw in the spacecraft's electrical architecture. The team responsible for building the satellite issued a formal statement on 18 April 2010, declaring the spacecraft lost "with a good deal of certainty." In the span of roughly three months, CORONAS-Photon went from a freshly deployed observatory to a confirmed casualty of an engineering oversight, ending the programme on a note of frustration rather than triumph.

Evolution and Instrumentation Strategy

The progression from CORONAS-I through CORONAS-F to CORONAS-Photon reveals a deliberate strategy of payload evolution. The 1994 CORONAS-I established a foundational set of twelve instruments spanning solar XUV, X-ray, UV, optical, radio, and cosmic-ray measurements. CORONAS-F, operational from 2001 to 2005, retained most of that core while expanding to sixteen instruments, introducing dedicated X-ray polarimetry via the SPR-N, semiconductor X-ray spectroscopy through the RPS-1, and three-axis magnetometry with the IMAP-5 to deepen the programme's ability to characterise flare physics and the surrounding magnetic environment. CORONAS-Photon, by contrast, shifted its focus toward harder X-ray and gamma-ray science, replacing much of the earlier suite with instruments like the RT-2 Roentgen telescope, the BRM fast X-ray monitor, the PHOKA ultraviolet monitor, and the STEP-F electron and proton telescope. This trajectory shows a programme that matured from broad-spectrum solar monitoring toward increasingly specialised high-energy diagnostics.