A House panel will mark up a NASA funding bill Wednesday that would grant the space agency roughly $1 billion below what President Barack Obama proposed and where current funding stands, and also will likely clash with a Senate plan.

Still, the fiscal year 2014 Commerce, Justice, Science (CJS) Appropriations bill released Tuesday by a House Appropriations Committee (HAC) subcommittee calls for keeping the schedules on track for the Orion Multi-Purpose Crew Vehicle and Space Launch System (SLS) heavy-lift rocket.  They are key components of  Obama’s manned-spaceflight program, which has a long-term goal of sending astronauts to Mars and invests in a nascent commercial spaceflight industry.

CapitolThe NASA funding bill the HAC Commerce, Justice, Science subcommittee (HAC-CJS) will craft Wednesday is not expected to jibe with a forthcoming Senate bill. The Democrat-led Senate Appropriations Committee (SAC) could propose more NASA funding when it crafts its version of the CJS appropriations bill. The SAC agreed to funding levels for the federal appropriations bill on June 20 and set overall CJS funding–which includes agencies in addition to NASA–at $52.3 billion. That’s compared to the $47.4 billion the HAC-CJS is proposing for CJS.

The House panel’s bill would grant NASA a $16.6 billion budget, which is $1.1 billion below the administration’s request and $926 million below current FY ’13 funding. It includes $3.61 billion for exploration, or $202 million below FY ’13 enacted levels. This amount would keep NASA “on schedule” for upcoming Orion and SLS program milestones, the GOP-led HAC says in a statement.

The HAC-CJS legislation includes $1.05 billion for Orion and $1.78 billion for the SLS, with $1.48 billion of that going to launch-vehicle development and $300 million pegged for exploration ground systems. The House measure says the SLS “shall have a lift capability not less than 130 metric tons and…shall have an upper stage and other core elements developed simultaneously.”

Meanwhile on Capitol Hill, a separate NASA authorization bill being crafted by the House Science, Space, and Technology Committee includes similar, though not identical, NASA funding. Draft legislation presented at a June 19 hearing of the House authorizing panel calls for giving NASA a $16.8 billion budget. That includes $1.2 billion for Orion and $1.77 billion going to SLS, with $1.45 billion going to the rocket development and $318 million going to exploration ground systems.