More from Terry’s SLS article:
But [SLS] development has been hit by delays and cost overruns -- its first flight was set to take place in November 2018, and its price tag has risen from $6.2 billion to $8 billion, or 29 percent, according to a June audit report.
...
It's not just the cost of the rocket that has spiralled: NASA will have spent roughly $34 billion on the SLS, Orion, and Exploration Ground Systems Program programs through 2019, a sum projected to increase to over $50 billion by 2024.
The future of the mission rests on continued political support, both from the White House and Congress, which is ultimately responsible for budget allocations.
https://news.yahoo.com/nasa-says-core-stage-next-moon-rocket-now-160541505.htmlLet’s review.
SLS may be (potentially) the world’s most powerful rocket — for a little while, until SpaceX Starship takes over that crown — but:
Can SLS land on the moon? No. (Will Starship? Yes.) On Artemis 1, the SLS upper stage with an uncrewed Orion will simply do a flyby of the moon with a free return to earth — a low-energy orbit not used since the crippled Apollo 13 made it necessary.
Is SLS reusable? No. Well, its engines are from the space shuttle. Not that
design, the
actual engines that were used on the space shuttle. But they’ll burn up in the atmosphere upon reentry this time. (Edit: the SLS also uses two five-segment Solid Rocket Boosters and an Interim Cryogenic Propulsion Stage.)
Is SLS affordable? No. $1.6 Billion per SLS launch, possibly less if rockets are ordered in bulk — but Congress has not agreed to spend the billions to get SLS past the first Artemis mission, let alone for bulk SLS purchases.
(Compare Falcon Heavy at about $90 million per launch, with only slightly less lift capacity than SLS.)Will SLS get the Lunar Gateway and a lander to the moon? No.
NASA is contracting commercial space companies to build an orbiting power and propulsion module and a small habitat/docking node with an attached commercial lander system that will orbit the moon. Other vehicles will dock to it and deliver cargo and/or crew to the moon’s surface, stay for a few days, then ascend back to the orbiting module. Not until Artemis 3, if it happens, will Orion rendezvous with that platform.
In March 2018 it was decided to launch the first Lunar Gateway module on a commercial launch vehicle because of delays in building the mobile launch platform needed to hold the more powerful Exploration Upper Stage for SLS. As of 2018, the Artemis 2 mission plan is to send four astronauts in the first crewed Orion capsule into a lunar flyby for a maximum of 21 days. The mission profile is a multi-translunar injection (MTLI), or multiple departure burns, and includes a free return trajectory from the Moon. Basically, the spacecraft will orbit Earth twice while periodically firing its engines to build up enough velocity to push it toward the Moon before looping back to Earth.
In 1968, the Apollo 8 mission, crewed by three astronauts, was designed to test-fly command and service module beyond low Earth orbit. Although similar to Artemis 2 in that it was crewed and did not land on the Moon, it differed by entering lunar orbit for an extended stay. Apollo 13 (1970) was the only Apollo mission that flew past the Moon by a free-return trajectory.
https://en.m.wikipedia.org/wiki/Artemis_2Timeline: Artemis 1 (SLS first launch) is still not on the KSC launch schedule, not even as “TBD” for late in the year.