Will JUICE be doing science en-route?

Question

JUICE will fly by the Earth, the Moon and Venus on its way to Jupiter. Will it be doing any science during these fly-bys?

Answer 1

It appears that that answer is (as of May 2021) still unknown, but "expected".

Wikipedia's section on launch and trajectory links to Witasse et al. "JUICE (Jupiter Icy Moon Explorer): Plans for the cruise phase". From Section 2 (emphasis added):

The main limitations during the cruise phase are:

• Priority of operations in support of navigation and spacecraft safety, especially in the preparation of gravity assist manoeuvres, in particular the world premiere of Lunar-Earth gravity assist
• The thermal design of the spacecraft which imposes, for heliocentric distances lower than 1.34 AU, restricted pointing capabilities and limitations in the number of instruments that can operate simultaneously.
• Quiet Cruise baseline: Reduced number of ground contacts (one ground station pass per week except for planetary flybys).
• Operational constraint to minimize the use of the mass memory during Cruise to preserve unit lifetime, limiting the possibility to operate the instruments and store their data.
• Budgetary restrictions that result in small operation teams during this phase.

The baseline operations of the instruments are two one-week checkouts per year. It is expected that at least some of the observations will take place during the planetary flybys, with different possibilities still under study. The requests for operating the payload beyond this baseline will be carefully analyzed and agreed on a best-effort basis.

Section 3 details "potential scientific investigations to be performed during the cruise phase":

Instrument operations during the cruise phase are always useful: they allow calibrating instruments in known environments (e.g. solar wind, Earth’s magnetosphere), checking possible interferences between instruments, they provide scientific results (sometimes not expected and outstanding, resulting in high standard publications) and attract public attention. During the long cruise phase of the JUICE mission, a number of scientific opportunities have been identified, beyond the obvious case of the planetary flybys.

Full Reference:

Witasse, O., Altobelli, N., Andres, R., Atzei, A., Boutonnet, A., Budnik, F., Dietz, A., Erd, C., Evill, R., Lorente, R., Munoz, C., Pinzan, G., Scharmberg, C., Suarez, A., Tanco, I., Torelli, F., Torn, B., and Vallat, C. and the JUICE Science Working Team: JUICE (Jupiter Icy Moon Explorer): Plans for the cruise phase, European Planetary Science Congress 2021, online, 13–24 Sep 2021, EPSC2021-358, https://doi.org/10.5194/epsc2021-358, 2021.

Answer 2

No science objectives were planned for the cruise/interplanetary transfer phase of JUICE's journey. I did a cursory Google search to see if any have since been added, but I did not notice anything. A proposed objective is listed in Brendan's answer.

Sources:

• JUICE MISSION SCENARIO AND OPERATIONS - ESA
• JUICE Assessment Study Report - ESA [pdf] (also linked to from the first source)