NASA announced on 4th November 2015, that SLS budget for 2016 will be increased from $1.695 billion even to $1.9 billion.
Good news is always welcomed, but information about increasing research budget is splendid. One of most significant element of NASA strategy of development (especially if Mars missions are considered) was creating new rocket able to lift heavy cargo. Rocket multiple times powerful than Space Shuttle launch vehicle. SLS is going to be more powerful than launch vehicles offered on commercial market, with payload capability for LEO at seventy metric tons. If everything will go as NASA want we will see new quality in launch systems, confirming NASA science potential.
Space Launch System has its origins in Constellation program, developed in years 2005-2009. It was NASA program oriented for Moon landing in 2020 and, in far perspective, for manned mission to Mars. Unfortunately being recognized by President Obama administration as too expensive and non-innovative was cancelled in 2010. After Constellation, NASA stayed with two started projects: Orion spacecraft (developing by Lockheed with Boeing responsible for heat shield design) and boosters of future launch vehicle - Ares I (developed by Boeing, Alliant Techsystems and Rocketdyne). Core rocket, called Ares V, was not yet developed in 2009. Luckily Ares I and Ares V were transformed into SLS program in 2010. Main difference between SLS and launch vehicle from Constellation program is designation of rocket for both manned and cargo missions. In 2011 NASA announced that Ares V in combination with Orion will be designated launch system for future manned NASA missions. Generally positive development of both Orion and Ares, after cancellation of Constellation, was of course dependent from NASA budget. Cost of development only Ares and Orion will cost in years 2011 - 2017 (when first launch is scheduled) around $16 billion excluding cost of ground launch sites modifications. $10 million are intended for SLS program and $6 million for Orion. Plans were ambitious and it seemed that they are fully approved by government. Unfortunately in 2014 Government Accountability Office disclosed that NASA is not obtaining declared funds from budget and first launch in 2018 is threatened. In such circumstances it was positive that Congress raised SLS budget relatively to President's proposition in 2015 fiscal year. At the presence we can see, that SLS has still strong support and after the previous turmoil of project financing everything is heading into good direction.