Space Sunday: space stations, Vulcans, rockets

ISS Updates

In a further sign that the International Space Station is in its final decade of operations, NASA is seeking to extend the current contracts for re-supply missions to the station from the period January 2027 through December 2030, in what is referred to as a “final” contract period.

In March 2022, NASA awarded additional contracts for ISS re-supply missions through until the end of 2026 to SpaceX (Cargo Dragon) Northrop Grumman (Cygnus) and Sierra Space (Dream Chaser Cargo). Under the extension, all three companies will be allowed to bid on remaining re-supply mission slots through until December 2030, but contract opportunities will not be issued to additional companies beyond these three.

Under the current contract, SpaceX are required to fly a total of 15 resupply missions through until the end of 2026, at an average of US $157 million per flight; Northrop Grumman 14 Cygnus flights at an average of US $150 million; and Sierra Space three Dream Chaser Cargo flights at US $367 apiece. It is not clear if any additional flights granted between January 2027 and December 2030 will be at the current rates or whether the three companies will seek to raise their fees – with the 2018 contract extension, SpaceX hiked their fees by 50%.

No further re-supply missions to ISS to be scheduled beyond 2030, that is the year the station is to be decommissioned and the majority of it de-orbited to burn up in the atmosphere, with any surviving elements crashing into the Pacific Ocean at Point Nemo – the area of that ocean furthest of land in any direction. However, modules due to be delivered to the ISS by Axiom Space starting in 2025 will be detached to form the nucleus of a new private-sector space station.

Currently, it is not clear whether Russia plans to remain with the ISS programme through until 2030 or withdraw some time before. In 2022, the country announced plans to withdraw “after 2024” (which many pundits took to mean “from 2025”) in order to focus on a national space station – the Russian Orbital Service Station. The power module for this new station had originally been slated for 2024, with the core module targeting 2025. However, the power module will now not launch before 2027, and the core module “no earlier” than 2028, so it would seem likely Russia will remain engaged in ISS operations through until at least then.

In the interim, there was a degree of excitement aboard the ISS in the past week. At 12:42 UTC on Monday, March 6th, 2023, the ISS has to use the thrusters on the Progress M-22 re-supply vehicle currently docked at the station’s Zvezda module to avoid a potential collision with an orbiting satellite.

The satellite in question – believed to be Nusat-17, part of an Argentinean earth observation constellation, the majority of which were launched in the 2020s, and all ten satellites in the network are in orbits deteriorating towards that of the ISS. The potential for collision was known in advance, allowing the orbital boost – called a pre-determined avoidance manoeuvre (PDAM) – to be completed with the minimum of fuss, the Progress firing its thrusters for 6 minutes and without disruption to overall ISS operations.

The manoeuvre marked the 33rd such change to the station’s orbital track resulting from the risk of collision since 1999, and there is mounting concern that the greater use of low-altitude constellations of satellites such as those operated by SpaceX Starlink and the UK’s OneWeb could see the ISS facing greater exposure to potential collisions over the next 7-8 years.

The distraction of the manoeuvre was not enough to delay preparations for the return of NASA’s Crew 5 mission from the ISS aboard SpaceX Crew Dragon Endurance, with the vehicle departing the ISS on Saturday, March 11th, 2023 at 0720 UTC. Aboard were NASA astronauts Josh Cassada and Nicole Mann, together the Japanese astronaut Koichi Wakata and cosmonaut Anna Kikina of Russia, returning home after 157 days on-orbit aboard the ISS, and having completed a hand-over to the personnel of Crew 6, who arrived at the ISS on March 3rd.

After undocking, Endurance performed a series of orbital manoeuvres throughout the day, prior to completing re-entry to splashdown off the Florida coast at 02:02 UTC on Sunday, March 12th, bringing to an end a mission marked by firsts: Mann being the first Native American to reach orbit; Kikina the first Russian national to fly on a private US space vehicle, and Wakata setting the record for the longest cumulative time a Japanese astronaut has spent in space thus far – 505 days in total. He is also the only Japanese astronaut to fly into space in three different space craft: the US space shuttle (4 times), Soyuz (once) and Crew Dragon (once).

The Russian space agency Roscosmos is turning its eyes to the that the recent coolant leaks which left the crew of Soyuz MS-22 without a ride back to Earth and also affected Progress MS-21 towards a manufacturing fault.

Russian mission managers initially blamed a micrometeoroid strike on the leak which crippled Soyuz MS-22 on December 14th, 2022. However, when the Progress vehicle (referred to as Progress 82 by NASA) suffered a similar, but lesser rupture in its coolant loop, questions started to be asked as to whether something else was to blame – the Soyuz and Progress vehicles are essentially the same vehicles using the same systems, with the exception that Progress had none of the crew facilities or life support systems, instead being equipped for carrying cargo; they are also without any heat shield, so the entire vehicle burns-up on re-entering the atmosphere.

With Progress MS-21, Roscosmos stated the leak, which occurred in February, was the result of a launch incident five months before the vehicle docked with the ISS. However, Roscosmos has now joined with Soyuz / Progress manufacturer Energia to investigate a possible manufacturing issue affecting both vehicles – particularly given the failures occurred after both craft had been in space for roughly the same amount of time, suggesting some form of related failure.

As I noted in my previous Space Sunday update, Soyuz MS-22 has been replaced at the International Space Station (ISS) by MS-23, which is intended to provide the crew of Frank Rubio (NASA) and cosmonauts Sergey Prokopyev and Dmitry Petelin with a ride home in September 2023. However, NASA in particular is monitoring it and Progress MS-22 (launched in February 2023) for any signs of problems as the vehicles remain at the station.

Well Poops; “Vulcan” Isn’t a Planet After All

Vulcan, the planet of Spock’s birth in Star Trek, has long ben held to be within the 40 Eridani star system, 16.39 light years from our own Sun.

Then in 2018, and in what appeared to be a bizarre case of fact mirroring fiction, astronomers reported they had discovered a “super Earth”, potentially capable of supporting life, to be orbiting 40 Eridani A, one of the three stars making up the 40 Eridani trinary system. What’s more, and like Star Trek’s Vulcan, the world was believed to be a hot world, one which whipped around its parent star once every 42 terrestrial days (see: Space Sunday: Moon trips, Mr Spock’s “home” and roving an asteroid).

Unfortunately, it now appears the discovery is less of a planet and more of an “oopsie”. Whilst poring over their data as part of a NASA project to draw up a list of nearby exoplanets worthy of follow-up study – 40 Eridani is just 16.3 light years from our Sun), the researchers responsible for reporting the discovery of “Vulcan” – or 40 Eri b – realised they had in fact made an error.

The potential for this has been raised in 2021 on the basis that the planet’s orbital period appeared to be in lockstep with 40 Eridani’s rotational period. While not impossible, such a lockstep would be incredibly unusual. However, in revisiting their data, the team responsible for “discovering” 40 Eri b realised that the evidence they’d thought they found for the planet – what appeared to be a gravitational tug repeatedly “pulling” at the star to give it a “wobble” in its spin (a classic sign of planets orbiting a star), doesn’t exist. Instead they found the data was the result of surface activity on the star causing alterations in its light spectrum, and they misinterpreted misinterpreted these fluctuation as variations in the star’s as radial velocity, making it seem as if it was wobbling under the influence of a planet.

So, no Vulcan, sadly. But if it is of any consolation to Star Trek fans, a reassessment of the data for “40 Eri b” revealed that it would likely be well inside its star’s habitable zone and exposed to levels of stellar radiation greater than that experienced by the sunward side of Mercury – and so probably way to hot even for Vulcans, were the planet to exist.

Launch Updates

Vulcan Readies for Launch

And speaking of Vulcans: the maiden flight for Vulcan Centaur, the new and powerful launch vehicle built by United Launch Alliance (ULA), has been scheduled for May 4th, 2023.

The vehicle, which has suffered numerous setbacks during its development, is designed to cover a broad range of launch options, from low-Earth orbit (LEO) – including flights to the ISS (Vulcan Centaur is the launch vehicle for Sierra Space’s Dream Chaser) – through to lobbing payloads to the Moon. It is intended to have a maximum LEO capability of 27.2 tonnes, and will replace both the Delta IV and Atlas V launchers currently operated by ULA, and comprises a core stage powered by Blue Origin BE-4 engines, supported by up to six solid rocket boosters; future versions of the core stage will be  re-usable to help lower launch costs.

For its maiden flight, Vulcan Centaur will be carrying several payloads, including the Peregrine lunar lander and the first batch of yet another planned constellation of Internet satellites – this one Amazon’s Project Kuiper.

Also on the vehicle will be a special payload from Celestis. This will carry the DNA remains of four US Presidents – Washington, Eisenhower, Kennedy and Reagan – as well as a number of past cast and crew of Star Trek, including Nichelle Nichols (Uhura), DeForest Kelly (McCoy) and James Doohan (Scotty) and the show’s creator Gene Roddenberry and his wife Mabel Barrett Roddenberry.

Ahead of the launch, the booster’s core  with its upper stage stacked in place, was rolled-out to Space Launch Complex-41 at Florida’s Cape Canaveral Space Force Station for a set of final “pathfinder tests” to assure the booster is ready for flight.

These will build on similar tests carried out in 2021 with a test article stage, and will additionally include propellant loading tests and a simulated launch countdown. Following the tests, the vehicle will be returned to the Vertical Integration Facility (VIF) close to the launch pad, where it will be mated with its boosters, payload and fairings.

Japan Suffers H3 Loss on Maiden Flight

Japan’s hopes of competing with SpaceX within the commercial launch market suffered a setback on March 6th, 2023, when the maiden flight of it new H3 launch vehicle – 10 years in development – had to be aborted 5 minutes and 27 seconds after lift-off.

Like the Vulcan Centaur, H3 is intended to fly in several variants to carry payloads to a range of orbits – including payload to cislunar space. It has been developed by the Japan Aerospace Exploration Agency (JAXA) and Mitsubishi Heavy Industries (MIH), with the intention of meeting government and commercial launch requirements in both national and international markets, with MIH planning to offer launch services for the expendable rocket at around the same cost to customers as charged by SpaceX – US $67 million for up to 5.5 tonnes to geostationary transfer orbit (GTO).

The maiden flight appeared to go well until staging – the separation of the upper stage from the core. While this appeared to proceed as planned, launch controller noted that the upper stage was losing velocity, and ignition of the rocket’s upper stage could not be confirmed. As a result, a destruct command was issued, and both vehicle and payload – the Advanced Land Observing Satellite-3 (ALOS-3) were destroyed. At the time of writing, the cause of the upper stage failure has yet to be determined, and it is not clear if the issue might be connected to an electrical fault in the engine ignition circuitry, similar to the one which resulted in the first launch attempt on February 17th, 2023, being aborted.

 3D Printed Rocket Aborts at Launch

The world’s first 3D printer rocket – Terran 1  – made several launch attempts on Saturday, March 11th, 2023, but ultimately failed to lift-off on its maiden flight.

Billed as the world’s largest 3D printed object, the 33.5 metre tall, 2 m diameter rocket has been designed by space launch start-up Relativity Space, based in California. It has a maximum payload capacity of 1.25 tonnes, and is designed to service both the small satellite launch market and form the test bed for a larger, fully reusable vehicle the company is developing.

The initial launch of Terran 1, from Launch Complex 16, Cape Canaveral Space Force Station was not intended to lift a payload to orbit, had been postponed from March 8th to technical issues. While the countdown proceeded smooth to the point of engine ignition, software in the rocket shut everything down before the engines reached lift-off thrust. Following checks, a further attempt was made, only to be stopped as a private boat strayed into the launch safety zone. Then, when the countdown resumed, sensors were reported a propellant temperature / pressure issue – the same problem with the March 8th launch attempt – and the launch was scrubbed. A further attempt will be made on March 16th.

Some 85% of Terran 1 – including its engines – is printed using 3D technologies, with nine of the company’s Aeon 1 engines powering the first stage using a liquid oxygen / liquid methane mix, and a single vacuum rated version of the same engine used in the upper stage. A core selling point of the printed approach to the vehicle is that it uses far fewer parts than a conventional rocket, reducing costs, and a new rocket can be constructed in just 60 days.

This rapid build time means that the company can in theory be more responsive to client needs: if a launch vehicle isn’t available, they can fabricate one for the customer(s) fair quicker than other companies. The larger, reusable Terran R is designed to lift up to 20 tonnes to LEO, and is being squarely aimed at exceeding SpaceX Falcon 9 capabilities at much lower price-per-kilogramme launch costs.

Eight payload carrying flights of Terran 1 are planned for 2023, with customers ranging from NASA and the US DoD to commercial clients. Terran R is due to enter service in 2024, and will include the ability to send small payloads to the Moon and Mars.