Blue Origin, the space company owned by Jeff Bezos, is suing the US government over its decision to award a massive Moon exploration contract to its competitor SpaceX, it said in a statement Monday.

The company has filed a suit with the US Court of Federal Claims "in an attempt to remedy the flaws" in how the contract was awarded, according to the statement.

The human landing system (HLS) contract, worth $2.9 billion, was given to SpaceX, owned by Bezos's billionaire rival Elon Musk, in April.

It was protested by the other bidders, who argued NASA was required to make multiple awards and that the evaluation process was unfair.

"We firmly believe that the issues identified in this procurement and its outcomes must be addressed to restore fairness, create competition, and ensure a safe return to the Moon for America," Blue Origin said.

Since losing the contract, Blue Origin has strongly lobbied to have the decision reversed.

A European Vega rocket lifted off Monday night from French Guiana carrying an Earth observation satellite and four miniature "cubesats".

It was the second launch this year of the Vega, a crucial component of European ambitions to compete with rivals such as Elon Musk's SpaceX in the booming commercial aerospace market.

The rocket blasted off from the Guiana Space Centre in Kourou at 10:47 pm (0147 GMT), successfully delivering the satellites in just under two hours.

Its main cargo was a high-resolution satellite, the second of four for a new Earth observation constellation operated by Airbus. The first was put in orbit in April by a Vega rocket.

The Pleiades Neo constellation will offer high-resolution imaging of Earth for military or civilian uses such as disaster response, according to Airbus.

Vega's operator Arianespace is a subsidiary of the ArianeGroup, of which Airbus owns half.

A novel experiment aimed at studying the mechanics of amyloid fibrils—a type of protein aggregation associated with diseases like diabetes, Alzheimer's, and Parkinson's—started today aboard the International Space Station (ISS), led by a team at Rensselaer Polytechnic Institute.

The project was designed by Amir Hirsa, a professor of mechanical, aerospace, and nuclear engineering at Rensselaer and member of the Center for Biotechnology and Interdisciplinary Studies (CBIS). He was looking for a way to study fluid dynamics without interference from the solid walls of a container, which would typically be necessary to hold a fluid being studied on Earth.

The concept, which Hirsa calls a ring-sheared drop, requires a microgravity environment, like the one found in orbit, where surface tension alone can hold a drop of liquid together. This will allow researchers to observe the effects of stress on protein—in this case: insulin.

"We're trying to understand this particular form of protein aggregation," Hirsa said. "And we're trying to remove the complication of wall nucleation."

The ring-sheared drop hardware—built by NASA and its contractors, and inspired by Hirsa's concept—includes a syringe that dispenses a large drop of liquid made up of water and dissolved insulin.

A pair of researchers at the Japan Aerospace Exploration Agency (JAXA) has published a perspective piece in the journal Science outlining the efforts being conducted this decade to find out if Mars once hosted life. In their article, Ryuki Hyodo and Tomohiro Usui outline the three main efforts that are involved in looking for evidence of life on Mars over the next ten years, and explain why they and others at JAXA believe the best chance of finding evidence of life on Mars lies on one or both of its moons.

As Hyodo and Usui note, NASA is currently conducting a study of the Jezero Crater on the surface of Mars with its Perseverance rover.