The news is in the details of NASA’s $17.5 billion, stay-the-course budget request for fiscal 2015.

The request tries to maintain pace on all of the agency’s major priorities: the James Webb Space Telescope, Space Launch System and Orion crew capsule, along with the International Space Station (now extended until 2024) and commercial crew access to it.

But it relies on the White House’s proposed government-wide $56 billion wish list for another $886 million in nice-to-haves, including “more robust” competition in commercial crew vehicle development between at least two providers. It rewards congressional backers with some extra work for their constituents, while threatening to ground the Stratospheric Observatory for Infrared Astronomy (Sofia) unless its European partners ante up some extra operating funds.

“This budget keeps us on the same, steady path we have been following — a stepping-stone approach to send humans to Mars in the 2030s,” Administrator Charles Bolden said March 4. “It’s a path that has seen many recent successes, from the launch of the Global Precipitation Measurement mission last week — the first of an unprecedented five Earth Science launches this year — to returning space station resupply missions to U.S. soil with private American companies, to the power-up of Orion and the countdown toward its first flight test later this year, to the final mirrors for the James Webb Space Telescope being delivered.”

Officials say operating costs for Sofia — a large, infrared telescope mounted in a specially modified Boeing 747 — are second only to the Hubble Space Telescope. In a trade-off against other science programs deemed more productive, NASA plans to put the flying observatory in storage beginning in fiscal 2015 unless its partner — the German Aerospace Center DLR — or perhaps the European Space Agency can add some funding for continued operations.

Agency budgeters have punted other issues to Congress in the form of “wish-list” items under the Obama administration’s Opportunity, Growth and Security (OGS) initiative, an all-or-nothing proposal that would add specific funds to specific programs across the mission directorates. For example, NASA wants $848 million for its effort to seed development of commercial crew vehicles for transport to the ISS. Bids are in that include flight tests to the space station, but it remains an open question whether that funding would support the operational competition with at least two suppliers that NASA wants to hold down costs. If Congress approves the whole government-wide $56 billion wish list, it would add another $250 million to NASA’s commercial crew funding, which officials say would increase the odds for continued competition by making up some ground lost in past appropriations.

Congressional leaders like Rep. Frank Wolf (R-Va.), who oversees NASA appropriations in the House, have questioned whether the Treasury can afford the two-competitor approach, and NASA managers say they aren’t banking on the wish-list funding for any of the programs that would benefit.

The fiscal 2015 request seeks $2.8 billion total for the heavy-lift Space Launch System (SLS), Orion crew capsule and the necessary infrastructure at Kennedy Space Center to get the stack off the ground. That is a decrease of about $300 million from the fiscal 2014 level, but officials say the big rocket is on track for first flight — with an instrumented Orion prototype — by the end of 2017. The first flight with a crew is still slated for 2021-22, depending on whether problems arise in integrating the two vehicles, the whole stack and the ground support equipment, according to agency officials who spoke on background.

Still to be determined is whether the SLS, which gets $1.3 billion in the new budget request, will have an early mission in 2025 to take a crew to visit at least a piece of an asteroid repositioned in distant lunar retrograde orbit. The Asteroid Redirect Mission has received scant support on Capitol Hill, and its fiscal 2015 funding request of almost $160 million in fiscal 2015 covers a mixture of tasks – high-power solar electric propulsion, target detection and tracking and others – that can be applied to different goals, including non-asteroid operations in cislunar space and planetary protection from undetected near-Earth objects.

The SLS development is managed at Marshall Space Flight Center in Alabama. Sen. Richard Shelby of Alabama, ranking Republican on the Senate Appropriations Committee, and Sen. Barbara Mikulski (D-Md.), the panel chair, both will find their constituents on the NASA payroll well accommodated in the new budget request. While Shelby gets continued support for the SLS, Mikulski will see the Webb telescope that is managed at the Goddard Space Flight Center in her state remain on track for a launch in 2018.

NASA seeks $645 million for the Webb, as planned since the program was reset after cost and schedule overruns. It also has funding for preformulation work at Goddard on the Wide-Field Infrared Survey Telescope (Wfirst), including technology development for detectors and the coronagraph for the observatory. Wfirst, a top-priority astrophysics mission, will use a surplus 2.4-meter telescope donated to NASA by the National Reconnaissance Office to study the effects of dark energy on the observable Universe, and to scan the galactic core for evidence of extrasolar planetary systems.

Some of the Wfirst work will be done at the Jet Propulsion Laboratory in Pasadena, Calif., which would also receive some of the $15 million proposed for preformulation work on a Europa Clipper mission. The Clipper would fly through the recently discovered water geysers spewing into space from the Jovian moon’s frozen south pole, apparently from the underlying liquid ocean that may be another location for extraterrestrial life, as a relatively low-cost way to analyze the ocean’s contents.

Even so, the $1.3 billion for planetary science, including funds for a Curiosity-heritage Mars rover for launch in 2020, failed to satisfy the lawmaker whose district includes JPL.

“While I’m pleased to see the budget continues to provide funding for the Mars Exploration Program, in particular the Mars 2020 mission, and recognizes the importance of a future mission to Europa, a far greater investment will be necessary to ensure America’s pre-eminence in planetary science,” said Rep. Adam Schiff (D-Calif.).

The NASA budget request represents a decrease of $185 million from the overall NASA spending for fiscal 2014 enacted in January. But, given the cuts that followed the federal government’s sequestration spending reductions in fiscal 2013, it marks a $600 million increase over that fiscal year. With a 1% inflation allowance, NASA managers consider the budget an increase for their agency, even though it will require a reduction of funding in terms of 300 full-time employees. They hope to accommodate those cuts by reassigning civil servants, and don’t expect to face more workforce reductions in the outyears.

Subscribers to the Aviation Week Intelligence Network should keep visiting AWIN’s 2015 budget page for news, data and analysis of programs and priorities throughout the business day and as the proposal makes its way through Congress. The page can be found at http://www.aviationweek.com/awin/USBudget2015.aspx.