Sounds like it might be fun:

Annual sci-fi convention Escape Velocity!

FAQS:
•      What is this convention? Escape Velocity is a 3-day event that's a mix of comic con and science festival, with science fiction as a common thread. We’ll have cutting edge tech on the exhibit floor, hands-on science and art activities for kids, and panel on literature, video gaming, pop culture, and hard science. We’ll also have a film festival and custom sci-fi escape rooms. In addition to Cas Anvar, we’ve already announced author Joe Haldeman and musician Thomas Dolby as special guests.
•      Dates? September 1-3, 2017, Labor Day weekend.
•      Where is the Museum of Science Fiction? Right now we are virtual, currently in the process of scoping out a location in the DC metro area where we can establish a permanent facility. In the meantime, we participate in a number of community events and host the Escape Velocity convention.
•      How big is this convention? Last year, we had over 2500 attendees, which we thought was great considering it was our first year and it was July 4th weekend! This year, we expect upwards of 4000.
•      Where is the convention? It will be held at the Marriott Wardman Park Hotel, on the Red line near Dupont Circle and the National Zoo.
•      What’s the cost? A regular 3 day pass is $50 for adults, without the promo code. There are discounted rates for youth 11-16 and kids 10 and under are free. We do have some specialty items, like a Cas Anvar Experience ticket and the sci-fi escape rooms, that do have additional costs.
•      Promo Code: You can give the promo code METRO20 to your followers as an added benefit of supporting your business. It's good for 20% off standard entry to the convention, but does not include specialty tickets. If you continue to share the Museum’s posts about Escape Velocity, keep sharing the promo code as well. We’ll do the same for you – if you’ve got something special you’d like us to boost, just reach out via facebook message – we have almost 16,000 followers.
•      Are you still accepting vendors? Yes! Please message or email for more information.
•      Do you have flyers or a poster I can put up in my shop? Yes, we do! We can mail some out or drop them by, please send us your address.
•      Websites: escapevelocity.events, and museumofsciencefiction.org
•      What if I have more questions? You can reach out to us on facebook or by email at tickets@museumofsciencefiction.org.
•      What if I want to become a member? You can join as Ground Crew for as little as $100, which is also tax deductible! You can also donate memorabilia. The more donations we can get, the faster we can get the museum built! Please check out our members page to join: http://www.museumofsciencefiction.org/join/