Daytime Aurora

Auroral oval captured by SMILE shows the northern lights dancing on both the night and day side of Earth. (Image credit: ESA & CAS/Smile/UVI, Background added in Canva Pro.)

From Space.com:

Captured by the Solar Wind Magnetosphere Ionosphere Link Explorer, or SMILE, the footage reveals the full ring of auroral activity encircling Earth's north pole in ultraviolet light, stretching across both the night and day sides of our planet. That means we can see auroras glowing on Earth's dayside — activity that would usually be lost in the glare of the sun.

Artist's impression of the SMILE spacecraft as of May 2020 (image credit: CAS/ESA)

The big yellow tanks on the right are fuel tanks for the rocket motor that will boost it its initial orbit to its working orbit.

From eoPortal:

SMILE is equipped for remote-sensing observations of the magnetosphere and its surroundings, imaging of Earth's auroras, and in situ measurements of the solar wind plasma and magnetic field – simultaneously.

This multi-faceted goal shapes the spacecraft's orbital parameters. SMILE must reach a high enough altitude to view the outside edge of Earth's magnetopause and at the same time obtain good spatial resolution of the auroral oval.

The chosen orbit is therefore highly elliptical and highly inclined (70 or 98 degrees depending on launcher), and takes SMILE a third of the way to the Moon at apogee (an altitude of 121 182 km, or 19 RE [Radius of Earth]). This type of orbit enables SMILE to spend much of its time (about 80%, equivalent to nine months of the year) at high altitude, allowing the spacecraft to collect continuous observations for longer periods of time. This orbit also limits the time spent in the high-radiation Van Allen belts, and in the two toroidal belts.

121,182 km is 75,000 miles with is about three times as high as geosynchronous satellites.

SMILE's operational orbit

P. S. Some Russian communications satellites used the Molniya Orbit, a very eccentric orbit.