The budget request is also a fun read. Really! Any space advocate should be familiar with at least parts of it. The 700+ page document provides a fascinating insight into the scope and breadth of the U.S. space program.

I don't read the whole thing at once (I save that for cross-country flights). But on Tuesday, I will be looking at a few key areas to see what the Administration plans to do in its final year, how NASA will be set up for the next Administration, and what - if anything - they have learned from repeated clashes with Congress over funding priorities in the past few years.

1. NASA's Top-line Budget

The big question: will the Administration build on the budget increase provided by Congress last year?

Congress increased NASA's budget to $19.3 billion in 2016—$756 million above the President's request. That was an important increase, but the growth needs to be sustained. There's hope for this; last year's budget agreement between the White House and Congress would increase overall domestic spending in 2017, which would theoretically allow all federal agencies to benefit from additional resources. The rub? The budget agreement didn't pass until much of the work on the 2017 PBR had already finished. The White House may decide to apply that extra money to other priorities in government and cut NASA's budget below the Congressional level.

Good Outcome: Inflationary growth over 2016—$19.7 billion.

Most Likely Outcome: Something similar to the original request in 2016 with modest inflationary growth—let's say $18.8 billion.

Break Out the Champagne Outcome: 5% growth over last year's congressional level—$20.25 billion.

2. The Planetary Science Division Top-line Number

The past four years have been subject to the grinding cycle of White House-induced cuts to the Planetary Science Division's budget followed by Congress rejecting most said cuts in the final appropriation. Clearly, Congress wants to see Planetary Science funded at a higher level. Will the White House finally stop fighting this battle? I hope so but I'm not optimistic.

Glass Half Full Outcome: The White House cuts "only" $131 million—down to a manageable $1.5 billion. That's the minimum level we've been advocating for over the past few years.

Most Likely Outcome: The White House sticks with its previous plans and cuts the planetary program by around $230 million—$1.4 billion.

I Take the Rest of the Day Off Outcome: White House accepts the amount appropriated by Congress last year and allows it to grow with inflation—$1.66 billion.

3. Europa and Ocean Worlds

Every monolith's favorite Jovian moon had a great year in 2015, with a lot of action happening on the congressional side that may or may not be reflected in this upcoming PBR. In the 2016 appropriation bill, Congress mandated that a lander be added to the current Europa multiple flyby concept, that it launch by 2022, and that it use the Space Launch System rocket as the launch vehicle. By the way, these aren't suggestions. These are written into the law.

If that wasn't enough, Congress also mandated—again, in law—that NASA must include this beefed-up Europa mission concept in its five-year budget projections. Previously, these projections had shown relatively modest spending in line with NASA's stated "mid-to-late 2020s" goal for the mission.

Additionally—and this isn't in the actual law but in the accompanying committee report from the House of Representatives—NASA was directed to "create an Ocean World Exploration Program whose primary goal is to discover extant life on another world using a mix of Discovery, New Frontiers and flagship class missions".

In response, NASA has already added Titan and Enceladus as acceptable destinations in the next medium-class New Frontiers competition. We have yet to see if a Ocean Worlds Program will be created in a similar vein as the existing robotic Mars Exploration Program.

Good Outcome: NASA accelerates their schedule for the Europa flyby spacecraft and lander to 2024, Ocean Worlds becomes a full-fledged program by the next administration and the program outlined in the planetary science Decadal Survey is fully funded.

Arthur C. Clarke Outcome: The spacecraft and lander are moved up to 2022. NASA increases funding to support Europa in addition to the rest of the planetary science program as outlined in the Decadal Survey. An Ocean Worlds office is constituted and begins long-term planning for regular missions to the outer solar system.

Most Likely Outcome: NASA accepts the idea of a minimal lander but sticks with the current "mid-to-late 2020s" plan. Opens up Ocean Worlds destinations within the existing program structure while ignoring the balanced program proposed by the Decadal Survey.

OMB Just Flat Out Trolling Outcome: Europa spacecraft and lander moved to 2022 and are fully-funded within the five-year budget projections, but avoids increasing the budget to accommodate the new program, so they propose canceling the entire Mars Exploration Program in order to pay for it.

There's a lot else I will be looking for beyond these three items, but these are my top three, the ones I will flip to first. Other big things I'll be looking for are SLS/Orion funding levels, the shift of Commercial Crew from the Exploration Division to the Space Operations Division, if the Science Technology Mission Directorate contains the RESTORE-L satellite servicing program, the existence—or continued lack thereof—of an Asteroid Redirect Mission budget line-item, continued infrastructure investment in the Deep Space Network and Plutonium-238 production, etc.. There's a lot going on at NASA.

We'll find out on Tuesday, and expect more analysis and discussion then.