NASA is processing immense sets of images and data from Mars and the moon into a special Microsoft format for viewing in the Redmond company's WorldWide Telescope online program. But the U.S. space agency also plans to publicly release, as open-source software, the tools it's developing to make the conversion.

That technological balancing act is among the details revealed in a federal Space Act Agreement establishing the terms of a collaboration announced by NASA and Microsoft earlier this year. The text of the agreement wasn't disclosed at the time, but NASA has now released the documents in response to a request made by TechFlash under the federal Freedom of Information Act.

The text will get a close look, at least, from people worried about governments tethering themselves too tightly to Microsoft's technologies. The agreement is non-exclusive, leaving the door open for NASA to make similar conversions to formats used by alternative space-viewing programs. But data formats have historically been a source of conflict between Microsoft and open-source advocates concerned about government agencies leaning too heavily on proprietary approaches, making them de facto standards.

Google CEO Eric Schmidt -- whose company uses NASA images in Google Earth, Google Sky and other programs -- last year called on the agency to focus on open, collaborative technologies.

NASA seems to be seeking a middle ground in its Microsoft agreement, based on the newly disclosed contract language. The details are laid out in an "umbrella" agreement (PDF, 24 pages); and a related contract, known as an "annex" (PDF, 6 pages).

The documents focus on WorldWide Telescope, an online program launched publicly by Microsoft last year. The program pulls together images from across space, letting people zoom around the universe on their computer screens. The Microsoft-NASA collaboration, announced in March, promises to add 100 terabytes of data to the program -- equal to 20,000 DVDs, the company said at the time.

WorldWide Telescope was initially available only as a Windows program, but the company has since released a preview of a WorldWide Telescope Web client for Intel-based Macs, using Microsoft's Silverlight technology. 

Microsoft Research offers WorldWide Telescope as a free educational and scientific resource, but Microsoft's business groups compete commercially with Google and other companies to provide images, maps and digital models of the natural environment.

The technology at the center of Microsoft's NASA agreement is called TOAST, which is short for Tessellated Octahedral Adaptive Subdivision Transform -- a technique and format developed by Microsoft to display flat images (such as those from telescopes) on representations of spherical objects (such as planets and moons) on a computer screen. It's one of the key technological underpinnings of the WorldWide Telescope's well-regarded on-screen interface.

Here are excerpts from NASA's Microsoft agreements:

"NASA has experience in working with planetary data and is uniquely qualified to adjust and format the data while maintaining its accuracy and integrity. Microsoft has requested that NASA make such planetary data available in a format such that it can be used in WWT. NASA (Ames Research Center) has begun to develop the hardware and software infrastructure (and partnerships) with relevant teams of scientists that enable a focused data reprocessing and curation effort aimed at making NASA planetary data widely accessible and useful. NASA plans to design. develop, and test the technology and infrastructure necessary to make certain NASA planetary data sets available to web-based applications entities engaged in web-based astronomy education, such as Microsoft. ...

"During this pilot project phase, the Parties will focus on the two planetary data sets that are of the greatest current interest to both the general public and the scientific community: HiRISE, High Resolution Imaging Science Experiment, Mars imagery (available today. and being collected on an ongoing basis) and LROC. Lunar Reconnaissance Orbital Camera, Moon imagery (available in the second quarter of 2009). NASA will develop and deploy a simple, flexible architecture and infrastructure for geospatial data reprocessing, initially supporting the TOAST output format native to WorldWide Telescope and the two input data sets described above, with an architectural eye towards supporting other viewing technologies such as Microsoft Virtual Earth and other data sets in a scalable manner in the future."

It later adds, "NASA plans to release software tools developed under this Annex as open source software."

One Microsoft page describes TOAST as a "proprietary" technology, but Microsoft blogger Jon Udell has said it isn't. We've asked Microsoft for clarification, and we'll update this post depending on the response.

The answer could help determine how much leeway other software developers will have to implement and use the TOAST techniques and format in their own programs. Our initial search of U.S. patent applications didn't turn up any filings from the Redmond company that appear related to TOAST.

Update: A Microsoft spokesman says the company "makes the TOAST technology freely available for anyone to use." I've asked for further details on how that technology is made available for use, and any licensing terms Microsoft might apply.

Update II: Microsoft says the TOAST tool is available via the WorldWide Telescope Academic Development Kit. Information and download link is here.

Some portions of the Microsoft-NASA documents were redacted under Freedom of Information Act provisions that protect companies from the disclosure of confidential business or financial information. Specific monetary terms weren't disclosed, but one clause says NASA will not transfer any U.S. government funds to Microsoft as part of the arrangement.