Congratulations are in order to Orbital Sciences Corp. for the successful inaugural flight April 21 of its Antares medium-lift rocket, which will be used to launch commercial logistics missions to the international space station.

Antares continues a string of successful rocket debuts that follows a demoralizing rash of inaugural-flight failures in the 1990s. More than 50 years into the Space Age, rocket science finally appears to be maturing to the point that one can envision spaceflight becoming truly routine in the not-to-distant future.

It’s not that Orbital didn’t have to overcome challenges, including the cost growth and persistent delays that are typical of large space hardware development programs. Orbital, which has had its rocket-related struggles in recent years, also got more than it bargained for in deciding to base Antares at the Mid-Atlantic Regional Spaceport at NASA’s Wallops Flight Facility in Virginia. This required building a brand new launch pad at Wallops, which is used mostly for sounding rocket launches — Antares was by far the biggest rocket to launch from that venerable facility. The construction project was marred by errors and delays and became the pacing item in the march toward the Antares demonstration, which placed an instrumented dummy payload into orbit.

Orbital can certainly be proud of its achievement, but it has no time to rest on its laurels. The company remains well behind the schedule laid out in its Commercial Orbital Transportation Services agreement with NASA, which requires the company to conduct a demonstration delivery mission to the space station before it can begin making regular cargo runs to the orbital outpost. That demonstration, which will debut the company’s Cygnus cargo capsule, is now scheduled for this summer.

There also are longer-term challenges, among them the limited number of Russian-built main engines for the Antares rocket. Although there is a sufficient supply of the Aerojet-refurbished AJ-26 engines for Orbital to fulfill its $1.9 billion Commercial Resupply Services (CRS) contract with NASA, the company has broader ambitions for Antares, which could help fill a void in the medium-lift capability class that will be left once the Delta 2 rocket is retired in the coming years.

What’s most important, however, is that Orbital has taken a big step toward fulfilling NASA’s plan to commercialize cargo delivery to the space station. Space Exploration Technologies is already executing on its CRS contract with NASA; together the companies are making the case for outsourcing astronaut-related operations in low Earth orbit.

At the same time, the Antares program promises a boon to the space-based economy in and around the long-underutilized Wallops facility, at least for the next several years. If the vehicle can someday meet the price and availability points necessary to enable a new class of medium-sized space missions, government, commercial or both, that will be a bonus.

The measurable progress marked by the Antares debut, coupled with the less-tangible yet real possibilities the vehicle could open, made April 21 a good day not just for Orbital but for the wider space community.