Third successful trial for SpaceX's giant spacecraft, new estimations as to the age of the universe, an attempt to save an old spacecraft, and the explosion of a Japanese rocket. This Week In Space

SpaceX has achieved a significant milestone with the successful launch of its massive spacecraft on its third attempt, following partial successes in the preceding trials. The spacecraft is launched atop the giant "Super Heavy" rocket, and the entire system is collectively known as "Starship," creating a bit of nomenclature confusion.

The launch proceeded smoothly, with all 33 engines of the launch rocket performing as expected. Shortly after, a "hot separation" was executed, where the spacecraft's engines were activated while some of the rocket's engines were still running. This maneuver also went smoothly, marking a significant improvement from the previous trials where issues arose. In the first trial, the spacecraft failed to separate from the rocket, while in the second trial, the rocket exploded shortly after separation. This time, the launch rocket successfully executed the planned return maneuver, presumably crashing into the sea near the launch site, although confirmation was pending due to broadcast cutoff. In future missions, SpaceX aims to land these rockets in a controlled vertical landing and prepare them for reuse.

Entering its intended orbit at an altitude of approximately 150 kilometers, the spacecraft shut down its engines as per plan, marking the first successful achievement of this milestone. This was the first time it managed to do so, having exploded before reaching the target altitude during the previous flight.

Apart from the flight itself, SpaceX aimed to evaluate three critical capabilities necessary for utilizing Starship as a spacecraft for manned lunar landings. One is the challenging task of transferring between tanks in zero-gravity conditions, which is essential for using Starship as a refueling spacecraft for other Starships, in Earth orbit or near the moon. The experiment was conducted, but detailed results are expected to be released later. The second is the successful opening of the cargo bay door, which had been welded shut in the previous two trials. Successful opening of the door was achieved during this trial, potentially enabling future satellite deployments and space operations. Lastly, the re-ignition of the spacecraft's engines in space, vital for precise maneuvering during atmospheric re-entry, moon landings, as well as missions to Mars, as envisioned by the company's founder, Elon Musk. SpaceX waived this part of the mission during the current trial and allowed the spacecraft to freely dive following its trajectory in this experiment, without performing an atmospheric re-entry maneuver, focusing on the first two objectives for this mission.

During the mission, continuous communication with the spacecraft was maintained, partly thanks to SpaceX's "Starlink" satellites, which also enabled the transmission of high-quality video images. As planned, the spacecraft initiated its re-entry into the atmosphere, and as anticipated, contact was lost due to the intense air heating and plasma formation, which disrupted communication. However, contrary to expectations, attempts to restore the connection were unsuccessful even after several minutes, with the last signal received from the spacecraft recorded at an altitude of 65 kilometers. The timing of the loss of contact with the spacecraft and its simultaneous disconnection from the satellites suggests the possibility that it disintegrated in the air. While this outcome clouds the success of the experiment,  it's important to note that the spacecraft was intended to crash into the sea regardless.  SpaceX can still acknowledge with satisfaction the accomplishment of numerous mission objectives and the marked progress made from the previous trial.

The impressive progress made with this third trial will surely provide some reassurance to NASA, eagerly awaiting the integration of Starship as the lunar landing vehicle in the Artemis program, which is set to mark humanity's first moon landing since the Apollo era. According to NASA's official plan, the Artemis 3 mission, marking the return of humans to the moon since the Apollo program, is scheduled for September 2026. This date was previously postponed by a year due to delays in the development of the Orion spacecraft, which will carry the astronauts to lunar orbit, and also due to delays in SpaceX's Starship development. Although the feasibility of this date may seem uncertain presently, there is optimism that SpaceX's substantial advancements from trial to trial are edging Starship closer to becoming an operational spacecraft, poised to revolutionize the space launch market.

The launch and the first minutes in space – the third trial of Starship:


The Expansion of the Universe Continues, as Does its Mystery.

The question "How fast is our universe expanding?" has been addressed with increasing precision in recent years, primarily due to observations made through the Hubble Space Telescope. One of the goals of launching the telescope in 1990 was to determine the age of the universe by the same method employed by Edwin Hubble, for whom the telescope is named, utilizing the technique developed by astronomer Henrietta Leavitt. This technique relies on the relationship between the pulsation rate of variable stars, known as "Cepheids," and their absolute brightness. By measuring the brightness of such stars and calculating their distance from Earth using additional methods, the Hubble Space Telescope enabled the derivation of the "Hubble constant," which led to the calculation of the currently accepted estimation for the age of the universe: 13.8 billion years.

However, contrasting observations, including measurements by the Planck Space Telescope, which measured cosmic background radiation, suggest that the universe's expansion rate was not uniform but significantly faster at its inception. The data from cosmic background radiation measurements contradict the data obtained through the Hubble Space Telescope. Researchers have now tried to resolve this discrepancy using measurements of Cepheid star distances done by the James Webb Space Telescope. The new measurements confirmed the accuracy of the measurements performed by the Hubble Space Telescope, suggesting that the universe's expansion rate aligns with previous estimates. However, these measurements still leave the enigma surrounding the contradiction between the calculated expansion rate and the rate variations suggested by cosmic background radiation data. This ongoing mystery complicates our ability to confidently ascertain the true age of the universe.

“With measurement errors negated, what remains is the real and exciting possibility that we have misunderstood the Universe,” said Adam Riess, one of the laureates of the 2011 Nobel Prize in Physics for the discovery of the universe's accelerated expansion. Riess, a physicist at Johns Hopkins University in the US and the lead researcher of the current study, added “We’ve now spanned the whole range of what Hubble observed, and we can rule out a measurement error as the cause of the Hubble Tension with very high confidence. We need to find out if we are missing something on how to connect the beginning of the Universe and the present day.”

The European Space Agency's Euclid Space Telescope, launched last year, and the American Roman Space Telescope, scheduled for launch in two years, hold promise in unraveling this mystery. Until these instruments yield fresh insights, uncertainties surrounding the age of the universe will persist.

While previous measurements are affirmed, the mystery remains unsolved.  James Webb Space Telescope | Illustration: ESA/ATG Medialab

Troubleshooting Beyond the Solar System: Technical Support for Voyager 1

For several months now, NASA and the JPL engineers have been grappling with a malfunction affecting the Voyager 1 spacecraft, which continues to drift away from us beyond the solar system, currently at a distance of about 24 billion kilometers from Earth. Despite ongoing communication, the spacecraft's radio signals have transmitted no meaningful data since November of the previous year. The fault is attributed to one of the spacecraft's three computers, the Flight Data System (FDS), suspected of experiencing a software issue.

Approximately a week and a half ago, the technical team discerned a subtly different pattern in the received signals. Upon analyzing the data, it was inferred that the computer had transmitted all of its memory contents, albeit in an unconventional encoding. This transmission followed a command issued to the computer by the engineers, indicating that some functionality remains intact. These data encompass not only the software stored in the computer's memory but also crucial operational data relied upon for accurate information transmission. This week, the team reported in the spacecraft's blog that engineering teams had commenced comparing this data with their software code in hopes of pinpointing the issue's source. Subsequently, they will endeavor to devise a solution or workaround for the software problem, potentially enabling the continued operation of the venerable spacecraft, which has been orbiting in space for over 46 years.

NASA has not yet given up on the possibility of restoring Voyager 1 to normal operations, the first spacecraft to venture beyond our solar system. Voyager 1 | Illustration: Caltech/NASA-JPL

No Place Like Home

Last week marked the safe Earth return of a crew of four astronauts from the International Space Station, completing 199-day stay in space. The seventh crew launched by SpaceX includes American astronaut Jasmin Moghbeli, Japanese astronaut Satoshi Furukawa, Russian cosmonaut Konstantin Borisov, and Danish astronaut Andreas Mogensen, who also worked with Israeli researcher Yoav Yair on capturing atmospheric phenomena from space. They made their way back to Earth aboard the SpaceX Dragon spacecraft "Endurance," after briefly overlapping with the eighth crew that SpaceX had launched to the station the previous week.

The spacecraft splashed down as planned in the sea not far from the northwest coast of Florida and was promptly recovered by the company's retrieval ship.Currently, SpaceX stands as the sole commercial entity ferrying humans to the space station, with Boeing's Starliner slated for its inaugural crewed mission in two months, following a series of postponements.

 Private transportation to and from the space station. The Dragon spacecraft is being towed to the recovery ship after this week's landing | Photo: NASA

Explosion During Inaugural Launch

The first step is always the hardest, especially in the space sector. Space One, a Japanese startup company, was reminded of this harsh reality last Wednesday, during the inaugural launch of its first rocket, Kairos. The rocket, designed to carry satellites weighing up to 250 kilograms into low Earth orbit, exploded roughly five seconds after liftoff from the Kii Peninsula in western Japan. The company's president, Masakazu Toyoda, attributed the explosion to difficulties in executing the launch, leading the rocket to activate its self-destruct system.However, further details were not provided, nor were future plans announced for another Kairos launch attempt. 

Standing at 18 meters tall, the Kairos rocket consists of three solid-fuel stages and an additional liquid-fuel stage. It carried a Japanese government satellite, with Space One having secured orders for two additional launches even before the initial launch attempt, including one for a foreign client. Established in 2018 as a joint venture between Canon Inc., engineering firm IHI Corporation, and several major banks, Space One has not disclosed the launch cost but announced that it intends to offer competitive prices. One of its main competitors in the small launcher market is the American company RocketLab, which launches its "Electron" rockets from New Zealand at a cost of approximately seven million dollars per launch. Despite the setback of its first launch, , the Japanese company intends to enter this market fully, with aspirations to conduct around 20 annual launches by the end of the decade


Self-destruction during live broadcast. The explosion of the Kairos rocket during its inaugural launch:



Translated with the assistance of ChatGTP. Revised, expanded and edited by the staff of the Davidson Institute of Science Education