NASA says it is considering putting commercial satellites in orbit around Mars to increase communication capacity with its landers and rovers on the Red Planet.

A commercially owned and operated satellite network could take over for the space agency's two orbiting communications spacecraft, which are beginning to show their age.

The Mars Odyssey spacecraft in orbit around Mars launched in 2001, and the Mars Reconnaissance Orbiter took off for the Red Planet in 2005.

"There is a potential communications gap in the 2020s," NASA wrote in a posting on a federal procurement website. "With that in mind, NASA is interested in exploring alternative models to sustain and evolve the Mars relay infrastructure."

Future missions placing ever-larger payloads on the surface of Mars will require more data links capable of transmitting massive amounts of scientific data from there back to Earth, agency officials say.

"Looking ahead, we need to seriously explore the possibility of the commercialization of Mars communications services," says Lisa May, NASA's lead program executive for Mars exploration.

There are plans for the Mars Odyssey and Mars Reconnaissance Orbiter to be joined by two new spacecraft.

NASA's Mars Atmosphere and Volatile Evolution (Maven) satellite is set for a September 2014 arrival at Mars and the European ExoMars Trace Gas Orbiter craft has a planned 2016 rendezvous.

However, beyond that there are no plans -- and no funding -- for additional missions.

NASA, in posting a Request for Information on the federal website, says it is only looking for ideas and proposals at this point and has no formal plans or a budget to seek commercial communications capabilities for Mars to Earth data links.

Its request seeks ideas from universities and commercial companies, and the proposal process is open to international organizations as well, NASA said.

"We are looking to broaden participation in the exploration of Mars to include new models for government and commercial partnerships," said John Grunsfeld, associate administrator of NASA's Science Mission Directorate.

Future technology, such as laser communication, could increase data transfer speeds between Mars and Earth.

In a test of a laser system as part of the Lunar Atmosphere and Dust Environment Explorer mission in 2013, rates from the Moon to Earth of 622Mbps were achieved.

Current rates of the Mars Odyssey and Mars Reconnaissance Orbiter, beaming data from the Curiosity rover back to Earth, are around 2Mbps.

Proposals in response to NASA's request are due by August 25.