By Brett Line, National Geographic News

The tweets poured in after news broke Wednesday that a group called Inspiration Mars is planning to send a couple to fly by the red planet. The couple would spend 501 days in space before returning home. The mission, slated for 2018, is being funded by multimillionaire Dennis Tito, the world’s first space tourist.

Many tweets on Thursday expressed humor at the idea of a married couple going to space for 501 straight days (we examined the psychological challenges here):

A man and a woman. Going to Mars. A year and a half in a capsule. Coronal Mass Ejections are the least of their worries. #inspirationmars

— Ian Sample (@iansample) February 27, 2013

#InspirationMars seeking committed couples for a 501 day round trip to #Mars and back. No stopping for directions!

— Miles O’Brien (@milesobrien) February 27, 2013

Any volunteers? Married couple to go to Mars. My husband and I struggled with 10 days in a Eurocamp caravan! soc.li/wkWMKwf

— Mad Science(@MadScienceNW) February 27, 2013

Multimillionaire to fund weirdest date EVERhuff.to/13oahcB

— HuffPostBiz (@HuffPostBiz) February 27, 2013

Some on Twitter felt like the mission would be a tremendous bore.

Gosh, I hope that the astronauts on the 501-day long #InspirationMars mission can get Netflix.

— Jonathan Foley (@GlobalEcoGuy) February 27, 2013

Plenty of tweets expressed doubts about the worth and feasibility of the mission:

Problem with #InspirationMars mission is that it’s pointless. Put a field geologist on ground? Yes! Fly-by? @brianvastag

— Joel Achenbach (@JoelAchenbach) February 27, 2013

Experts say human #Mars fly-by in 2018 is feasible. “But do these guys have $1 billion?” They apparently do not. wapo.st/YzvpXU

— Brian Vastag (@brianvastag) February 27, 2013

But the mission captivated dreamers of all ages:

A 6-year-old boy sent a $10 donation, calling this mission “my Apollo.” #InspirationMars

— CNN Light Years (@CNNLightYears) February 27, 2013

And many others are hopeful:

Unlike space commerce co’s that have flashed on recently #inspirationmars has substantial $$ behind it at the onset bit.ly/YZGy4b

— SpaceRef (@SpaceRef) February 27, 2013

Some even thought of other “firsts” for the mission:

If the crew going to orbit Mars decided to crash land on the planet would they still count as the first people on Mars? #InspirationMars

— Oli Revel (@RevelAlliance) February 27, 2013

Does your family reflect this changing picture? If so, your family portrait could be made by world-famous photographer Martin Schoeller for the upcoming story in National Geographic Magazine. If your family is chosen, we will send Schoeller to your family or your family to him.

We are looking for a three-generation family (children, parents, and grandparents) with multiracial or ethnic members to photograph. More than three races or ethnicities should be represented.

To be considered, please send us a photo (or photos) of your family with faces clearly visible, along with a description of members’ ethnic/racial breakdown. We’ll also need your contact information (email and phone number) and where in the U.S. your family members are located.

Please send photographs and information in a single email to changingfaces@ngs.org by Thursday, February 28.