Idea Bank (Free to use, but please reference widgetblender.com)
L4AP
This concept is based on recent news of the second Earth Trojan being found. Some has speculated that there are thousands of objects in similar orbits here. The key is to find those that are in a very similar plane to Earth and closer to the center of L4 or L5 the better. More specifics:
https://en.wikipedia.org/wiki/2020_XL5
Related: The Case for a Deep Search for Earth’s Trojan Asteroids: https://arxiv.org/pdf/1903.01922.pdf
https://space.nss.org/l5-news-harvesting-the-asteroids/
It just seems like L4 is begging to have high res and optical sensors give it a flyby to see it there are a bunch of good object there. I chose L4 over L5 since you can drift "under" L4 and get great lighting from the sun (from Earth we see it pretty much from the side).
Orbital Arc
A notion for a standard orbits with close spacing to enable travel between orbital space stations in the future.
SLuCE
Although I can find something in the 1 km/s range using Green Monopropellant (see Vacco) I don't see 2 km/s as a non-custom job for a single thruster. While the high ISP ion thrusters are there with 1000s+ ISPs to get you from LEO, LTI, GTO ... they apply a little thrust over very long time periods (days, weeks). But to hit the breaks about a landing target on the moon that won't work. So, the other option is to put 4 of these on a face and create a 4x2 or 4x3 cubesat, you have a lot of engine mass vs payload mass, but that is the cost of breaking hard from speeds many times that of a bullet. So this probably needs to be a pricy 12U cubesat. Bonus is that you have room for a lot of solar and sensors.
Note that the Japanese tried using a solid rocket for the stop DV above the skylight, but it failed.
Create a tiny Aldrin cycler cubesat just to prototype the orbit
Perhaps some 10 GB type data retrieval since bandwidth is very limited to Mars.
The Lunar surface is covered in a dust of fine volcanic glass
We submitted a proposal for a active surface that could electronically remove dust called Lunar Smart Surface (LSS). We also included a proposal for testing device (LASSIE) that could be attached to a CLPS lander to validate LSS concepts.
Vestal Lunar proposes modifying a Crew Starship to enable LEO -> Lunar Surface -> LEO round trips
By using the Starship tanks and engines as an OTV to NRHO and just taking the lander down to the Lunar surface and back to NRHO, you can do round trips from LEO to the Lunar surface on one fill-up in LEO. They system is highly reusable. The presentation is based on a HeroX.com challenge we sponsored.