PALO ALTO, Calif. — Scientists attending the Next-Generation Suborbital Researchers Conference here could barely contain their excitement at the prospect of a new fleet of suborbital launch vehicles providing frequent access to microgravity.

“It will make all the difference in the world,” said Webster Cash, a professor of astrophysics and planetary sciences at the University of Colorado.

For decades, Cash has been developing instruments to map the sky in visible, infrared and X-ray light. It takes him three to four years to design an experiment and win approval to send it to high altitudes on a sounding rocket. The instrument then spends a few minutes in microgravity before crashing to the ground. After evaluating the results and piecing the hardware back together, Cash said he is lucky if he can fly the same experiment or a modified version in a year or two.

In contrast, scientists expect the new fleet of suborbital planes and rockets being developed by Virgin Galactic, Masten Space Systems, XCOR Aerospace, Armadillo Aerospace and Blue Origin to offer frequent, low-cost access to the edge of space.

“We could fly a new instrument and if the filter is wrong, we could fix it and fly again a few days later,” Cash said. That quick-turnaround will make an enormous difference in the amount of research conducted, he added.

Although representatives from the suborbital companies declined to offer specific timelines for commercial flights, one or more firms plan to begin service within two years. “We are hopeful that by mid-2013, there will be several vehicles flying test flights to space, and possibly nearing commercial operations,” said Alan Stern, chairman of the Commercial Spaceflight Federation’s Suborbital Applications Research Group and associate vice president for the Southwest Research Institute.

Virgin Galactic plans to conduct the first powered flight test of SpaceShipTwo, an air-launched suborbital spacecraft, later this year. Approximately 500 customers have paid $20,000 deposits on $200,000 tickets. William Pomerantz, Virgin Galactic vice president for special projects, announced Feb. 27 that NanoRacks LLC will build research payload racks for SpaceShipTwo. While prices have not been disclosed for those payloads, the cost is likely to be comparable to that for passengers, approximately $1,000 per pound, or 0.45 kilograms.

“Although for most people $200,000 for a ride into space is a lot of money, that cost is a bargain compared to other forms of space access, including suborbital sounding rockets,” Stern said. Some suborbital firms are expected to charge $100,000 per passenger or roughly $1,000 per kilogram.

“That’s a game changer,” Stern said. “A high school could fly a shoebox-size experiment funded by a school car wash. With 15,000 [U.S.] high schools, you don’t need a very high adoption rate to have healthy payload demand for education.”

Bretton Alexander, director of strategy and business development for Blue Origin of Kent, Wash., said it is impossible to imagine all the applications for suborbital and orbital transportation that will emerge once people have routine, affordable access to space.

“The platform of the past was the space shuttle, which cost $1 billion to launch,” Alexander said. “The platforms of the future are smaller suborbital vehicles and orbital vehicles. … We’ve talked about tourism, we’ve talked about research, we’ve talked about education, but what are the hundreds of thousands of real apps?”

Blue Origin is building New Shepard, a reusable vertical takeoff and landing vehicle featuring a propulsion module and separating crew capsule designed to carry three or more astronauts to an altitude of 100 kilometers. Company engineers are building the new spacecraft to replace one lost during a test flight in August. The company plans to conduct a pad escape test of the New Shepard crew capsule this summer as part of NASA’s Commercial Crew Development 2 program, Alexander said.

XCOR Aerospace plans to conduct flight tests this year of its Lynx horizontal takeoff and landing suborbital spacecraft. Until then, company engineers will be integrating the fuselage with vehicle components and continuing to test Lynx engines, said Andrew Nelson, XCOR chief operating officer.

In May, Armadillo Aerospace plans to fly its vertical takeoff and vertical landing tube-shaped rocket to an altitude of 120 kilometers offering three to four minutes in microgravity for research payloads. Armadillo plans to launch cargo as part of the firm’s incremental approach to developing suborbital and eventually orbital passenger vehicles, said Neil Milburn, vice president of program management.

Masten Space Systems, in contrast, is focusing exclusively on developing vertical takeoff and landing vehicles to provide low-cost space transportation for cargo. The company plans to fly its Xaero vehicle to an altitude of 20 to 30 kilometers later this year, said Joel Scotkin, chief executive of Masten Space Systems. Masten also is developing Xeus, a horizontal lunar lander that pairs a United Launch Alliance Centaur upper stage with four Masten propulsion modules.

Another contender to offer transportation in microgravity is Rocketplane Global. Since the company emerged from bankruptcy, Chuck Lauer, vice president of business development, has been traveling around the world seeking investors willing to provide “hundreds of millions of dollars” to pay for development of a spacecraft designed to offer 10 minutes in microgravity for payloads.

Researchers eager to send payloads into microgravity are urging NASA to expand funding for suborbital research. NASA’s 2013 budget request includes $17 million for the Flight Opportunities Program, including $15 million to send technology payloads on suborbital flights and $2 million for parabolic flights.

David Pierce, senior program executive for suborbital programs at NASA headquarters, said there is great support for suborbital programs within the agency but additional funding is not likely. “Until we launch the James Webb [Space Telescope] there’s probably not going to be a lot of money laying around for a lot of other things,” he said.

George Nield, the Federal Aviation Administration’s associate administrator for commercial space transportation, called for frequent suborbital and orbital launches. “We already know the basics of how to launch people and cargo into space,” Nield said. “What we haven’t been able to master is how to build launch vehicles and spacecraft that are capable of conducting … multiple flights per day with a very fast turnaround.”

To achieve that goal, Nield said, the United States should double the number of licensed or permitted launches conducted annually. In 2011, Sea Launch AG, Space Exploration Technologies and Blue Origin conducted a total of five launches. “My hypothesis is that by flying frequently, we are going to learn how to make better vehicles that will in turn enable us to fly more safely and more cost effectively,” Nield said.

Debra Werner is a correspondent for SpaceNews based in San Francisco. Debra earned a bachelor’s degree in communications from the University of California, Berkeley, and a master’s degree in Journalism from Northwestern University. She...