Space News & Blog Articles

At their South Texas Launch Facility, just outside of the village of Boca Chica, SpaceX is gearing up to test the Super Heavy, the booster element of their Starship launch system. This massive reusable first stage rocket will be responsible for sending the Starship orbital vehicle to space, where it will deliver satellites to orbit, payloads and people to the Moon, and (if all goes as planned) the first human settlers to Mars.

According to a recent statement issued by SpaceX founder Musk Musk, the Starship could also be used to “chomp up debris” in Earth orbit. As usual, the statement was issued via Twitter, where Musk was once again addressing questions posted by followers and fans. The topic arose after Musk shared the latest updates about Starlink, one of a handful of satellite constellations that are bringing broadband internet services to every corner of the planet.

Specifically, Musk was sharing the latest artwork that will adorn the Starlink satellite covers, the visor-like appendages that make Starlink satellites less visible in orbit. Henceforth, these covers will feature a diagram of a transfer orbit from Earth to Mars, a clear reference to Musk’s long-term vision of colonizing the Red Planet. This is not unlike the terms of service for Starlink’s public beta test back in Nov. 2020, where participants had to acknowledge Mars as a “free planet.”

In any case, a user who goes by the Twitter handle Hide yo memes (@REQNews) asked if SpaceX had any other mitigation measures in mind to reduce the problem of space debris. Specifically, the user referenced the Kessler Syndrome (named for NASA space debris expert Don Kessler) which states that once orbital debris reaches a certain critical mass, it will create a chain reaction of collisions and more debris.

According to their initial FCC filing (issued in Nov. of 2016), SpaceX requested a license to operate a constellation of 4425 non-geostationary satellites (NGS) in orbits of between 1100 and 1300 km (680 and 800 mi). By Nov. of 2018, SpaceX announced that they were adjusting this plan and now wanted to send their first 1600 satellites to an altitude of 550 km (350 mi), where they would deorbit and burn up in the atmosphere sooner.

A team of astronomers has found that giant, organized magnetic fields can help drive some of the most powerful explosions in the universe. But when all is said and done, the shock wave from that blast scrambles any magnetic fields in a matter of minutes.

Some gamma-ray bursts (GRBs) occur when giant stars die. Their cores fold in on themselves, collapsing to form a black hole. Soon after it forms, material from the surrounding star falls inwards. There, the intense energies drive the creation of huge, powerful, structured magnetic fields. Those magnetic fields whip some of the in-falling material around the black hole and out along two long, thin jets. When viewed from Earth, its these jets that give this event its characteristic flash of high-energy gamma ray radiation.

But the story doesn’t end there. The remainder of the star continues exploding, sending out a shock wave. That shock wave quickly destroys the magnetic field, leaving only tangled wreckage in its wake.

At least, that’s the theory. But demonstrating the correctness of that theory has been a challenge, because astronomers have to measure the magnetic fields soon after the gamma ray burst event.

So a team of astronomers did just that, announcing their results in a recent paper.

Space may be pretty, but it’s dangerous. Astronauts face a much higher dose of ionizing radiation than us Earth-bound folks, and a new report says that NASA’s current guidelines and risk assessment methods are in serious need of an update.

On the surface of the Earth, protected by our extensive magnetic field and layers of thick atmosphere, we experience about 2-3 milliSieverts (mSv) of radiation exposure every year. Even that background level is enough to trigger the occasional cancer growth.

But astronauts, especially those hoping to go on upcoming long-term missions to the Moon and Mars, face a much greater risk due to the high-energy, ionizing radiation constantly soaking every cubic centimeter of space. To mitigate that risk, NASA currently implements a system based on “risk of exposure-induced death” (REID). The space agency estimates the exposure for each astronaut based on their sex, and if the REID exceeds 3%, their spacefaring careers are over.

However, a new report issued by the National Academies of Sciences, Engineering, and Medicine recommends that NASA update its guidelines. Instead, NASA should implement a single, uniform limit of 600 mSv, which would represent a 3% REID for a 35 year old female astronaut (considered the most suspectible group).

“NASA should continuously strive to base its standards on the best available science as it embarks on this new phase of space travel and exploration,” said Hedvig Hricak, chair of the department of radiology at Memorial Sloan Kettering Cancer Center, and chair of the committee that wrote the report. “As science on radiation-related cancer risks is constantly evolving, NASA has an important opportunity to revisit its space radiation health standard. We hope this report will guide NASA in protecting the health of astronauts throughout their careers.”

Planetary formation theory has been undergoing a lot of changes recently, with an ever expanding litany of events that can potentially impact it.  Everything from gravity to magnetic fields seems to impact this complex process.  Now scientists want to add another confounding factor – massive solar flares thousands of times more powerful than the most powerful we have ever observed from the Sun.

That most powerful flare, known as the Carrington Event, was still strong enough to damage the Earth’s atmosphere, and likely would have done significant damage to the world’s electrical grid, if it hadn’t happened in 1859.  But the kind of flares that Dr. Kostantin Getman of Penn State University and his colleagues found, while looking at young stars with the Chandra X-Ray Observatory, packed at least 100,000 times more energy than the Carrington Event.

The researchers found these powerful flares in 40 different star forming regions throughout the galaxy, observing a total of 24,000 stars.  Amazingly, all 40 regions had these events happening in them.  Incredibly powerful solar flares affect stars with different masses, and at different stages of evolution, such as when they are simply surrounded by dust or when they have planets formed already.  One important detail is that all of the stars in the study average to be about 5 million years old – relatively young compared to our sun at 4.5 billion years.  Another is the fact that the regular “super-flares” that had the power of 100,000 times a Carrington Event occurred multiple times per week on average in young stars, while more powerful megaflares, with at least 10 million times the energy of the Carrington Event, occurred around twice per year.

There were some similarities though.  Dr. Getman and his colleagues modeled some 55 of the flares in detail to see how they compared to the more familiar, tame version from our own sun.  They found loops of magnetic fields caused by the flares were anchored in the star itself, rather than connected between the star and its protoplanetary disk, similar to how coronal mass ejections work.

Despite their similarities, that much activity that consistently is sure to have an impact on its surroundings.  Many scientists had previously suggested that solar flare might help with the early stages of the planetary formation process – blowing away dust while causing rocks to meld together in pebbles, whose increased gravity then attracts other material.  While this is still plausible, it is likely only one component of a much more complex story of planetary formation, which scientists are still learning more about.