The bidders said that the evaluation process was unfair and that NASA should award more than one contract when SpaceX won the human landing system contract worth $2.9 billion.
The human landing system contract is worth $2.9 billion and Bezos said "this offer is not a deferral, but is an outright permanent waiver."
The SLS rocket will send an empty Orion capsule to the moon and back in a test flight later this year or in 2022.
A key experiment shipped in the Cygnus cargo ship uses a light-activated protein to replace the function of damaged cells in the eye.
All four engines fired for barely a minute, rather than the intended eight minutes, on the test stand at NASA’s Stennis Space Center in Mississippi.
The upcoming Green Run hot fire test will be a key milestone event for NASA’s Artemis missions.
The first step in the plan marks the unmanned mission, called Artemis I, on the Moon in 2021.
The bricks are made from a combination of urea, lunar soil and guar resin extracted from guar beans.
The Artemis programme will explore as much of the moon's surface as possible and create sustainable missions to the Earth's satellite by 2028.
US President Donald Trump seeks to mine the moon, drafts international agreement called the Artemis Accords
The Accords are part of the Trump administration’s plan to forgo the treaty process at the UN and reach an agreement with “like-minded nations."
The satellite will be the first mission to look for water using lasers and use a safer fuel alternative.
The Artemis base camp will need infrastructure for power, waste disposal and communications, besides radiation shielding and a landing pad.
The space agency has put forward a plan showing what a US lunar presence may look like after the milestone.
There are two confirmed cases at NASA centres: Ames Research Center in California and Marshall Space Flight Center in Alabama.
They can go on any manned mission and will join the ranks of about 500 people who have been to space.
The lunar space station US intends to build will have a lifetime of at least 15 years, the NASA chief said.
NASA had asked 11 companies to carry out studies, produce prototypes of human landers for the Artemis program.
Two astronauts will walk on the moon during the 2024 Artemis mission and one will definitely be a woman.
A spacecraft and a mini space station will remain in lunar orbit and be used for a first crewed mission in 2024
Three NASA astronauts spent three days living inside each of the space habitat prototypes.