It's going to be a busy seven days for the private space industry, with a pair of launches from the companies operating the new delivery trucks to the International Space Station. Both SpaceX and Orbital Sciences will be flying rockets in the coming week, and the launches are happening on opposite coasts.

First up is SpaceX, which has already made three flights to the ISS: one demo flight and two cargo flights. This weekend Elon Musk's company is expected to test-fly a new, stretched version of its Falcon 9 rocket. The new rocket will be launching from Vandenberg Air Force Base in California, the first time SpaceX has launched the Falcon 9 from anywhere other than Florida's Cape Canaveral.

The upcoming flight does have a payload on board — a Canadian spacecraft — but it is primarily a test flight, and SpaceX founder Elon Musk is understandably cautious.

"Upcoming Falcon 9 demo has a lot of new technology, so the probability of failure is significant," he said on Twitter.

Musk told Spacenews.com that the company is "being, as usual, extremely paranoid about the launch." With the higher risk of failure, the Canadian Space Agency did get a significant discount for carrying its payload, "maybe 20 percent of the normal price," Musk said.

In addition to the new hardware and launch site, SpaceX will also be attempting to relight the engine on the booster stage just before it hits the ocean. The effort is a small step towards SpaceX's goal of creating a reusable first-stage rocket that can return to a landing site after launch.

The company has performed several test flights of its Grasshopper test vehicle flying out of SpaceX's McGregor, Texas facility. The Grasshopper is a replica of a first stage, but also has landing gear (and a cowboy mannequin passenger). So far it's climbed to over 1,000 feet, hovered and returned to its launch pad during testing, in addition to the most recent flight last month where the Grasshopper made a hard turn just after liftoff, diverting laterally away from the pad. It then managed to hover, turn back and return to the pad. A new video released this weekend shows the cowboy on board could probably use the Grasshopper to heard cows.

In addition to the test flight in California this week, the Falcon 9 has its first commercial launch of a communications payload scheduled for later this year.

On the East Coast, Orbital Sciences is preparing for its first flight to the ISS. After its successful first demonstration flight in April, Orbital Sciences is slated to launch its Cygnus spacecraft for the first time on September 17. Cygnus will carry some non-essential cargo to the ISS, following a similar mission as SpaceX did with its Dragon spacecraft on its first visit.

Unlike Dragon, the Cygnus spacecraft is not reusable, and will burn up during reentry. The spacecraft will be launched using Orbital's Antares rocket from the Wallops Island Flight Facility on the Virginia coast. If all goes according to plan, Orbital could begin flying its first contracted cargo mission later this year.

Next week's flight will be the second this month for Orbital Sciences. The veteran space launch company flew its Minotaur V rocket on Saturday, delivering NASA's new Lunar Atmosphere and Dust Environment Explorer spacecraft into orbit where it will spend several more days before making its trip to the moon for some low-altitude surveying.

The Cygnus spacecraft is expected to dock with the ISS on September 22 and remain there for about a month. It will be filled with some trash before being released and ending its disposable flight during reentry.