Spaceflight

There's another leak on the International Space Station, and NASA has already delayed one crew launch to the orbiting laboratory as a result.

Beyond that, the space agency is not offering much information about the unfolding situation in orbit. However, multiple sources have confirmed to Ars that the leak is a serious concern for the space agency as it deals with hardware that is approaching three decades in orbit.

Roscosmos recently confirmed that it completed its most recent repairs on the PrK module earlier this month, saying it had been "completely sealed." NASA has also said that repairs were recently wrapped up. After this, both Roscosmos and NASA said the leak rate inside the PrK module had halted.

This seems like good news. However, the overall air pressure in the space station at large continued to drop, according to two sources. So if the PrK module was not leaking, as it had been doing for half a decade, why was the space station still losing air pressure?

No one is certain. The best guess is that the seals on the hatch leading to the PrK module are, in some way, leaking. In this scenario, pressure from the station is feeding the leak inside the PrK module through these seals, leading to a stable pressure inside—making it appear as though the PrK module leaks are fully repaired.

At this point, NASA is monitoring the ongoing leak and preparing for any possibility. A senior industry source told Ars that the NASA leadership of the space station program is "worried" about the leak and its implications.

This is one reason the space agency delayed the launch of a commercial mission carrying four astronauts to the space station, Axiom-4, on Thursday.

One of his first steps would have been to attempt to accelerate the timeline for the Artemis II mission, which is scheduled to fly four astronauts around the Moon in April 2026. He planned to bring in "strike" teams of engineers to help move Artemis and other programs forward. Isaacman wanted to see the Artemis II vehicle on the pad later this summer, with the goal of launching in December of this year, echoing the historic launch of Apollo 8 in December 1968.

Isaacman also sought to reverse the space agency's decision to cut utilization of the International Space Station due to budget issues.

"Instead of the current thinking, three crew members every eight months to manage the budget, I wanted to go seven crew members every four months," he said. "I was even going to pay for one of the missions, if need be, to just get more people up there, more cracks at science, and try and figure out the orbital economy, or else life will be very hard on the commercial LEO destinations."

"I wanted to bring back the Payload Specialist program and open it up to the NASA workforce," he said. "Because things are pretty difficult right now, and I wanted to get people excited and reward the best."

Isaacman's signature issue was going to be a full-bore push into nuclear electric propulsion, which he views as essential for the sustainable exploration of the Solar System by humans. Nuclear electric propulsion converts heat from a fission reactor to electrical power, like a power plant on Earth, and then uses this energy to produce thrust by accelerating an ionized propellant, such as xenon. Nuclear propulsion requires significantly less fuel than chemical propulsion, and it opens up more launch windows to Mars and other destinations.

"We would have gone right to a 100-kilowatt test vehicle that we would send somewhere inspiring with some great cameras," he said. "Then we are going right to megawatt class, inside of four years, something you could dock a human-rated spaceship to, or drag a telescope to a Lagrange point and then return, big stuff like that. The goal was to get America underway in space on nuclear power."

"I'm sure a lot of supporters in the space community would love to hear me say that I’m done with politics, but I'm not sure that’s the case," he said. "I want to serve our country, give back, and make a difference. I don’t know what, but I will find something."

Toulouse-based startup Alpha Impulsion has completed a short test firing of an autophage rocket engine. The company plans to use the novel propulsion system to power its 25-metre Grenat rocket.

The Alpha Impulsion autophage engine features a solid fuel tube with a liquid oxidiser sealed in its core. Two pistons push the tube into the combustion chamber where a catalyst converts the oxidiser into hot gas. This gas then reacts with the solid fuel, generating thrust. Put simply, the engine consumes its own structure as it burns.

In late May, Alpha Impulsion conducted a six-day test campaign at Agen Airport in the south of France. On 27 May, the company carried out a 17-second static fire test of what it described as the “largest autophage rocket engine in the world.”

According to a press release published by the company following the test, all of its technical goals were achieved. These included stable ignition and controlled combustion, as well as confirmation that the structure remained intact under operational pressure. The test also validated the tightness of the engine’s dynamic seals and confirmed the correct functioning of the oxidiser filling procedure.

Quebec’s government announced an award of $10 million Canadian dollars ($7.3 million) to Canadian rocket startup Reaction Dynamics and software developer Maya HTT.

The funding will enable Reaction Dynamic to continue working with Canadian software and engineering services firm Maya HTT to qualify the hybrid propulsion system and establish a testing facility.

Reaction Dynamics, founded in 2017, is developing the Aurora rocket to send satellites with a mass of 200 kilograms or less to low-Earth orbit. The first suborbital launch is expected in late 2025, followed by orbital flights in 2027 or 2028.

Quebec made this investment with commercial, civil and defense applications in mind. Legault alluded to the geopolitical instability that is prompting nations to seek sovereign space systems.

Canada can into space?

The company announced June 9 that its DARK propulsion system, incorporated into a D-Orbit ION vehicle launched in March, has carried out a series of test firings in orbit. Arkadia said the system, featuring a thruster producing five newtons of thrust, performed both hundreds of very short pulses firing for tens of milliseconds at a time as well as longer “steady state” burns of up to five seconds.

Francho Garcia, chief executive and co-founder of Arkadia Space, said in a recent interview that the goal of that test campaign was to compare the performance of the thruster in space to previous ground tests. “What we have found is that it is exactly the same as the ground data,” he said of the thruster’s in-space performance. “It was much better than what we were expecting, honestly.”

The test is a milestone both for Arkadia and for the development of so-called “green” propulsion systems that use non-toxic propellants as an alternative to hydrazine. He said that the company showed the benefits of green propulsion, including easier and less expensive fueling during pre-launch processing, when preparing the ION vehicle for launch on SpaceX’s Transporter-13 mission from Vandenberg Space Force Base.

Before 2025 began, Limp had set expectations alongside Blue Origin founder Jeff Bezos: New Glenn would launch eight times this year.

However, since the rocket's mostly successful debut in January, five months have passed. At one point the company targeted "late spring" for the second launch of the rocket. However, on Monday, Limp acknowledged on social media that the rocket's next flight will now no longer take place until at least August 15. Although he did not say so, this may well be the only other New Glenn launch this year.

The mission, with an undesignated payload, will be named "Never Tell Me the Odds," due to the attempt to land the booster.

"One of our key mission objectives will be to land and recover the booster," Limp wrote. "This will take a little bit of luck and a lot of excellent execution. We’re on track to produce eight GS2s this year, and the one we’ll fly on this second mission was hot-fired in April."

A year after the launch of a flawed crewed test flight of Boeing’s CST-100 Starliner, NASA has yet to determine the next mission for the spacecraft with mixed signals about the vehicle’s future.

In a statement June 6, NASA said it was still studying options for the next flight of Starliner, expected no earlier than early 2026. That includes whether that next flight will be crewed or uncrewed.

“NASA is assessing the earliest potential for a Starliner flight to the International Space Station in early 2026, pending system certification and resolution of Starliner’s technical issues,” the agency stated. “The agency is still evaluating whether Starliner’s next flight will be in a crew or cargo configuration.”

Ryo Ujiie, ispace's chief technology officer, said the final data received from the Resilience lander—assuming it was correct—showed it at an altitude of approximately 630 feet (192 meters) and descending too fast for a safe landing. "The deceleration was not enough. That was a fact," Ujiie told reporters in a press conference. "We failed to land, and we have to analyze the reasons."

The company said in a press release that a laser rangefinder used to measure the lander's altitude "experienced delays in obtaining valid measurement values." The downward-facing laser fires light pulses toward the Moon during descent, and clocks the time it takes to receive a reflection. This time delay at light speed tells the lander's guidance system how far it is above the lunar surface. But something went wrong in the altitude measurement system on Thursday.

"As a result, the lander was unable to decelerate sufficiently to reach the required speed for the planned lunar landing," ispace said. "Based on these circumstances, it is currently assumed that the lander likely performed a hard landing on the lunar surface."

If NASA were to terminate its contracts with SpaceX, it would effectively mean the end of the International Space Station. The problem with this is that SpaceX also holds the contract to safely de-orbit the space station, which is currently due to occur in 2030. With a mass of more than 400 metric tons, the space station will be the largest human-made object ever to return to Earth and could cause substantial damage in populated areas if not safely de-orbited into a remote part of the Pacific Ocean.

SpaceX also is on the critical path of NASA's program to return humans to the Moon, Artemis. NASA has contracted with SpaceX to use its developmental Starship vehicle as a lunar lander, taking crew down to the surface and bringing them back up to lunar orbit. Although it is true that NASA has also awarded Blue Origin a contract for the same service, it is unlikely that Blue Origin's human lander will be complete for seven to 10 years. This means that if NASA wants to have any chance of beating China back to the Moon, it needs SpaceX to deliver.

For the US military, SpaceX is one of two main contractors that delivers national security payloads into orbit. However, the other provider, United Launch Alliance, has had difficulty getting its new rocket, Vulcan, through the certification process. This has led the US Space Force to begin moving missions from Vulcan to SpaceX's Falcon 9 and Falcon Heavy rockets. Given SpaceX's reliability and responsiveness, the military has decided to award a majority of future launch contracts to the company.

The reason that Biden did not terminate these contracts, as Trump asserts he might well have, is because SpaceX has generally provided space services to the US government at a lower cost and on a faster timeline than its competitors. Were the Trump administration to sever its relationship with SpaceX, it would effectively set the US space enterprise back a decade or more and give China's ascendant space program clear supremacy on the world stage.

The Tokyo-based company slightly revised the landing time for its Resilience lunar lander in a statement late June 3. The landing, in the Mare Frigoris region of the northern hemisphere of the near side of the moon, is now scheduled for 3:17 p.m. Eastern June 5, seven minutes earlier than previously announced.

The tweak in the landing time, ispace said, came after engineers reviewed maneuvers performed May 28 to lower the spacecraft’s orbit to 100 kilometers. “Their review of the orbit, the performance of the spacecraft, and the landing sequence have resulted in an updated landing time,” the company stated.