My thoughts are in blue, words to delete are in red, suggested rephrasing is in orange.

Can three headstrong brothers combine forces to save their city from a dusty disaster? Only if they don’t kill each other first! A rhetorical question isn't a great hook. I like the "dusty disaster" phrasing, but find a way to utilize the feel here without making it a question.

Ben McGuire’s seventh-grade priorities (ping pong and daydreaming, to name a few) are put on hold when deadly dust storms begin ravaging his hometown. Love the voice here, but because the rest of this reads very SF and off-planet, I think we need to know the where and when of home. When relief doesn’t come on the ground, quirky research company Indus Industries recruits Ben and his two brothers Why them? If ping pong and day dreaming are his big skills, why is he being chosen to save the world? into their Youth Space Fleet to solve the crisis from up above. Too easy! Except it’s not.

Near-asteroid collisions, moon sickness, and some serious sibling rivalry doom the mission at every turn. Despite the setbacks, the McGuires discover the key to purifying the Earth’s air lies within the moon’s lunar ice! But just as they’re celebrating, Ben learns that a traitorous insider is stealing millions from the company, and a profit-hungry competitor hacks the computer network to steal their work and destroy the base. And them? Are they in any personal danger? It will take the brothers’ craftiness, bravery, and determination to bring their discovery back home—or the whole Midwest could be destroyed. This feels like it shifts from an adventure to an economic tech thriller very quickly, which takes away some of the MG feel. Some re-wording suggested above. Also, what kind of threat is the hacker? It feels like a very non-present villain for them to contend with. If this person is sabotaging their ship in some way, or putting them in physical danger through their machinations, that needs to be included. Otherwise, it feels like a very remote antagonist.

MCGUIRES TO THE MOON is an upmarket middle grade novel with series potential. Fans of Gordon Korman’s UNPLUGGED will really enjoy this book. The manuscript is complete at 41,000 words.

I am a debut author with a B.F.A. from Texas Christian University and am a member of SCBWI. I have also been a technical writer for nearly 20 years. I would be thrilled if you would consider MCGUIRES TO THE MOON for representation. I look forward to hearing if you would like to read my entire manuscript.

Overall, this is quite good. You need to steer your hook away from question format, and interject a little more personality into the villain. I also question whether the other brothers need more room in the query. Your hook mentions all three, but it seems like Ben is the focal point. If that's the case, make him the focus of the hook. Otherwise you're starting with introducing three main characters, but never naming two of them.