The HiRISE instrument on the Mars Reconnaissance Orbiter (MRO) is a powerful camera that is capable of imaging the Martian surface at a scale of up to 25 cm/px (10 inches/px) from its orbital height of 300 km. This allows us to see and interpret objects as small as a living room coffee table from space! Although in heavy use as a research tool, the camera's operators at the University of Arizona allow outside scientists and members of the general public to submit imaging requests through the HiWish program.. A small number of these requests are incorporated into HiRISE's regular imaging schedule and made available to the requester. This means that you too can act as an instrument targeting scientist for a day!
NASA's operations budget is very tight, and missions need to demonstrate that they are still returning exciting new scientific data to continue receiving funding. This means that HiRISE is heavily booked in its primary role as a scientific instrument. Only a handful of HiWish requests are selected during each planning cycle, and nearly all of these images are selected on their scientific merit. When submitting a HiWish request, you will need to fill out a 1000 character mini-essay describing why the target has scientific merit. Picking a target just because it is scenic will likely mean that your image sits in a queue forever. However, even successful requests may sit around for a while, a year or two between submission and selection is not uncommon.
Imaging rationales that are submitted to the HiWish program are not made public (probably for privacy reasons, which is plenty reason enough for me!). This unfortunately deprives us of models for writing good justifications, since it is impossible to see the rationales submitted for successful requests. On this page, I provide the rationales that I wrote for successful HiWish requests. Some of these requests were submitted to help my research, others were submitted for fun. I am not sure how my percentage of succesful requests compares to other people submitting requests. I have also been fortunate enough to be in contact with two members of the image scheduling team. So your mileage may vary when using my requests as a template.