You can find details on NASA's budget request for FY 2008 here. I have reproduced below, without comment, the subsection covering the Space Sciences.
The President's FY 2008 budget requests $4.019 billion to fund NASA's space science programs, including Heliophysics, which seeks to understand the Sun and how it affects the Earth and the solar system; Planetary Science, which seeks to answer questions about the origin and evolution of the solar system and the prospects for life beyond Earth; and Astrophysics, which seeks answers to questions about the origin, structure, evolution and future of the universe and to search for Earth-like planets. The proposed budget represents a $16.5 million increase (or about 0.4 %) over the President's proposed FY 07 budget.
Programmatic content changes in the FY 08 budget include the following:
- Geospace Missions of Opportunity Phase B studies not funded
- MMS Solar Terrestrial Probe descoped to stay within budget profile
- New Millenium ST-9 technology demonstrator mission award delayed at least two years
- Planetary Science program reserves reduced and re-phased; future Planetary Science projects and Juno and New Frontier missions "re-phased"
- New "Lunar Science" budget line created
- GLAST and Kepler astrophysics mission launch dates slipped
- Reserves for James Webb Space Telescope (JWST) increased
- Space Interferometry Mission (SIM) deferred and reduced to a technology development program with no identified launch date
- SOFIA project reinstated
The FY 08 budget request maintains the research and analysis (R&A) accounts at FY 07 budget levels and thus sustain the 15% R&A cuts included in the FY 06 and FY 07 NASA budgets. Astrobiology, an interdisciplinary field that NASA created to study the origin, evolution, and possible existence of life in the Universe, has been cut by some 50% since FY 06. The competitively-selected Explorer and small missions programs that National Academy decadal surveys have emphasized as vital, continue to lack the required funds to restore the 2-year cycle of issuing announcements of opportunity (AOs). The current AO rate has been diminished considerably compared to earlier periods. The last Explorer AO was issued in 2003; under the FY 08 budget request, the next AO is expected to be issued in late 2007 or 2008 leaving a gap of approximately 5 years in new selections.
Other Space Science issues include the following:
Mission Size and Programmatic Balance--The FY 08 budget request continues budgetary trends that are creating imbalances in science programs, especially in the research and analysis (R&A) accounts, which fund grants to analyze science mission data, and in the portfolio of sizes for science missions. Science programs that lack balance are not robust: they cannot be sustained or contribute adequately to high priority research questions laid out in National Academy decadal surveys. Moreover, in addition to their high scientific productivity, small and medium-sized missions are instrumental in training young scientists and engineers and in exciting the science and broader communities through the Principal Investigator team's promotion of the mission.
Cost-Growth in Missions--Several of the increases in the proposed FY 08 Science budget provide funds for projects that have run over budget or schedule, or that run the risk of doing so. The factors contributing to cost and schedule growth are not easy to pinpoint, but include underestimates in the technology developments required for mission readiness; increases in launch vehicle costs; inadequate models to estimate mission costs; internal decisions to delay missions or alter budget profiles; project management difficulties; and delays in contributions from international or interagency partners. Mission cost growth erodes opportunities to conduct other high priority science and can lead to delays, cancellations, or reduction in funds for other NASA science missions and activities.
Launch Services/ Access to Space--Officials from NASA's Science and Space Operations Mission Directorates have called attention to a potential crisis in launch vehicle access for science missions. The Space Science program has been a regular user of Delta II vehicles, which are reported to have a 98% success rate for science missions flown since 1961. Between 2007-2009, NASA's Science Mission Directorate plans to launch at least eight missions on the Delta II vehicle. NASA is uncertain about the availability of the Delta II beyond 2009 and is conducting a study to investigate options for alternatives to the Delta II. The potential loss of Delta II raises the question of reliable access to space for science missions. Shifting to alternative vehicles could affect mission costs and schedule.