Requests for ISDC 2027 visa invitation letters are now open. If you are traveling internationally to attend the International Space Development Conference in Los Angeles next May and your trip requires a U.S. visa, the National Space Society’s invitation letter is the first document to secure.
What Is an ISDC Invitation Letter?
The invitation letter is an official document confirming your participation in the International Space Development Conference (ISDC), issued by the National Space Society (NSS). According to NSS, the letter can be included in your visa application at your local U.S. embassy or consulate.
Who Needs an Invitation Letter?
NSS requires the letter from visitors who need a visa to enter the United States, so the first thing to establish is whether that applies to you.
Not every traveler does: the U.S. Department of State notes that most citizens of countries participating in the Visa Waiver Program may travel to the United States for short visits without a visa, provided they have ESTA approval, and that citizens of Canada generally do not need nonimmigrant visas for tourism. If your situation fits one of those paths, confirm your own requirements through official government sources before booking.
Which Request Form Should You Use?
NSS maintains two separate request forms for ISDC 2027, both linked from the conference’s invitation letters page.
The first form is for attendees participating in an NSS space contest, such as the Gerard K. O’Neill Space Settlement Contest or the Live in a Healthy Space Design Competition. The second form is a general request for all other ISDC attendees, whether you are coming as a professional, a researcher, an educator, or an enthusiast.
Choose the form that matches how you are attending.
What Happens After You Receive the Letter?
With the letter in hand, the application itself runs through the U.S. government’s standard process. The Department of State outlines the general shape of it: an online nonimmigrant visa application known as Form DS-160, a photo uploaded as part of that form, and an interview, which is generally required for visa applicants with limited exceptions. The order of the steps and how you complete them can vary by embassy or consulate, so the instructions from the office handling your application are the ones to follow.
The State Department’s own guidance lists participation in scientific, educational, professional, or business conferences among the activities a business visitor visa covers.
Why Requesting Early Is the Smart Move
ISDC 2027 takes place May 27 to 30, 2027, at the Sheraton Gateway Los Angeles Hotel near LAX.
NSS recommends applying for your visa as soon as possible because processing times can sometimes take longer than expected. Requesting your invitation letter now puts the longest possible runway between you and the conference dates, leaving room for embassy scheduling, document gathering, and travel booking to happen without pressure.
👉 Request your invitation letter
Frequently Asked Questions
Does an invitation letter guarantee a U.S. visa?
No. The State Department states that an invitation letter is not among the factors used to decide whether a visitor visa is issued or denied; applicants qualify based on their own circumstances, such as ties to their home country. NSS provides the letter so your purpose of travel is on record, and the same guidance advises against finalizing travel plans or buying tickets until a visa is issued.
What type of visa covers conference attendance?
The Department of State describes visitor visas as covering temporary travel for business under the B-1 category, tourism under the B-2 category, or a combination of both purposes as a B-1/B-2 visa.
Can I request a letter before registering for the conference?
Yes. The 2027 letter forms opened ahead of conference registration, which the conference website indicates begins in autumn 2026, so you can take care of both letter and visa well before registration starts.
Who can I contact with questions about invitation letters?
The conference maintains a contact page for questions about ISDC. Reaching out there connects you with the NSS team organizing the event.