What happened

Shares of space tourism company Virgin Galactic (SPCE -9.01%) are moving higher in Tuesday afternoon trading, up 4.7% as of 2 p.m. EST. It's not, however, immediately apparent why these shares are rising.

So far as I can tell, the company hasn't issued any press releases today (or tweets). On Wall Street, there's a dearth of upgrades (or price-target increases either).

Virgin Orbit Cosmic Girl Deploying LauncherOne.

Virgin Galactic is not the same as Virgin Orbit, pictured here. Image source: Virgin Orbit.

So what

That being said, while there's no news on Virgin Galactic today, there is a bit of news on its sister company, Virgin Orbit, which has not yet IPO'ed. Like Virgin Galactic, Virgin Orbit carries rockets attached to a mothership to a specified altitude, then deploys them to travel into space. The main difference between the two companies is that Virgin Orbit's rockets are designed to carry satellites that stay in orbit, while Virgin Galactic's rockets will carry passengers, who then descend and land back on Earth.

To wit, on Twitter this morning, Virgin Orbit announced that it has completed a "Launch Readiness Review" and is now ready to try again to launch a satellite into orbit.

Now what

As you may recall, Virgin Orbit's last launch attempt failed when the rocket's second stage failed to ignite. It could be that investors are confusing this attempt with Virgin Galactic's analogous attempt to repeat, successfully, a test flight that also failed to reach space in December. If investors are conflating the two companies, and the two launch attempts, anticipation of Virgin Orbit's Sunday launch could be the reason that Virgin Galactic's shares are rising today.