The Senate has made its counteroffer on NASA's 2018 budget. The legislation, which was approved by the Senate Appropriations Committee last Thursday, would provide $19.53 billion for NASA, $124 million below the space agency's 2017 appropriation but significantly higher than the $19.1 billion requested by the Trump Administration. It's also $343 million less than the House's proposal, which would provide a much-healthier $19.87 billion for NASA in 2018.

The funding discrepancy between the Senate and House proposals is not unusual in recent years. And notably NASA has ended up on the higher end of the funding range by the time a compromise was worked out between the two chambers of Congress.

The majority of the proposed increases above the President's request are to the usual suspects: the Space Launch System rocket and Orion crew capsule. And in a complete repudiation of the Trump Administration, the Senate fully rejects cuts to NASA's Earth Science Division and the Education Directorate. The accompanying committee report specifies the continuation of every Earth Science mission proposed for cancellation by the Trump Administration proposal, and states that it "does not agree with the proposed cancellation of the activities" of the Education Directorate, though they will consider proposals to move the programs to other areas of NASA if the Administration can make a good case for doing so.

Planetary Science would receive significant cuts in the Senate proposal, dropping by $234 million from 2017 levels to $1.61 billion. This is also significantly below the Administration's proposal of $1.9 billion. While disappointing, this is also represents a consistent tactic taken by the Senate in recent years, which has responded to the much-higher budgets for plaentary proposed in the House of Representatives.

So, did the Senate endorse a new Mars orbiter to replace the aging telecom and high-resolution imaging assets at the Red Planet? It's hard to say, but it's promising. While there was no explicit directive either way, the committee provided an additional $75 million to the Mars Exploration Program, which is what The Planetary Society had recommended in order to support the start of a new orbiter by 2022 and begin investing in Mars Ascent Vehicle technology development to enable future sample return. This is the only logical need for the additional funding provided by the Senate, though the flexibility would be left to NASA within the Mars program for its application.

Also left unmentioned was how the rest of the cuts to the Planetary Science Division would be applied. There was no clarity on support for Europa mission, something I always find to be an oddity, since it is, so far, the only science mission currently in development that could utilize the Space Launch System—a priority program for the committee's chair, Sen. Richard Shelby.

Though we cannot and will not take anything for granted, the House's proposals tend to be represented in the final compromise bill. The Planetary Society will continue to strongly argue increased funding for science and the restoration of the Planetary Science Division budget in the coming months.