Over sixty years of space exploration have left their mark in Low Earth Orbit (LEO), where thousands of objects create the risk of collisions. These objects include the spent first stages of rockets, fragments of broken-up spacecraft, and satellites that are no longer operational. As Donald Kessler predicted, the growing presence of “space junk” could result in regular collisions, leading to a cascading effect (aka. Kessler Syndrome).
This evening – on Wednesday, Jan. 29th – such a collision might take place. These satellites are the Infrared Astronomical Satellite (IRAS), an old space telescope launched by NASA, the Netherlands, and the UK; and the GGSE-4 gravitational experiment launched by the US Air Force. These two satellites run the risk of colliding when their orbits cross paths at 06:40 p.m. EST (03:40 p.m. PST) about 900 km (560 mi) above Pittsburgh, Pennsylvania.
The task of tracking these satellites and keeping the public up to date on the likelihood of their collision is being carried out by LEOLabs, a that uses a worldwide network of orbital tracking arrays to provide mapping data and services. This data is made available to the public and private sector and allows for rapid orbit determination, early operational support, and assessment of collision risks.
Diagram showing the projected distance between the two satellites. Credit: LEOLabs
As they indicated on Monday, Jan. 27th, on Twitter, LeoLabs calculated that the two objects will come within 15 to 30 meters (50 to 100 ft) of one another. As they wrote:
“On Jan 29 at 23:39:35 UTC, these two objects will pass close by one another at a relative velocity of 14.7 km/s (900km directly above Pittsburgh, PA). Our latest metrics on the event show a predicted miss distance of between 15-30 meters… These numbers are especially alarming considering the size of IRAS at 3.6m x 3.24m x 2.05m. The combined size of both objects increases the computed probability of a collision, which remains near 1 in 100.”
However, since then, LeoLabs has updated those odds to factor in some previously unforeseen factors. This includes the 18 m (59 ft) boom that was deployed by the GGSE-4 and the fact that they “do not know which direction it is facing relative to IRAS.” This altered their computations about a possible collision and “yields an updated collision probability closer to 1 in 20.”
To make matters worse, there is nothing that can be done to reduce the likelihood of a collision. Whereas the International Space Station (ISS) and operative spacecraft are able to adjust their orbits to avoid collisions, both the IRAS and the GGSE-4 have been inoperable for decades and can’t perform any corrective maneuvers.
Artist’s impression of the Infrared Astronomical Satellite (IRAS). Credit: NASA/NIV/SERC
Of the two satellites, the IRAS is the larger, measuring 3.6 x 3.24 x 2.05 meters (11.8 x 10.6 x 6.7 feet) and weighing 1,083 kg (2,388 lb) when it was launched. This was NASA’s first infrared space telescope and was responsible for a number of discoveries, which included six new comets, the core of the Milky Way, and protoplanetary disks around Vega and Fomalhaut.
Since both satellites are orbiting Earth at a velocity of 14.7 km/s (9.1 mps), this makes a collision a major risk for generating orbital debris that will spread into other orbits. According to calculations performed by The Aerospace Corporation, which also monitors and tracks orbital debris, a collision would generate 90,000 chunks of debris that are at least 1 cm (0.4 inches) in diameter.
This would place them on the cusp between the 900,000 objects tracked by the European Space Agency’s that measure between 1 cm and 10 cm and the 128 million objects that measure between 1 mm and 1 cm. While small, objects of this size pose a severe risk to the ISS, spacecraft, operational satellites, and space telescopes.
4/ Events like this highlight the need for responsible, timely deorbiting of satellites for space sustainability moving forward. We will continue to monitor this event through the coming days and provide updates as available.
If there is a takeaway from this, it is just how important it is to track defunct satellites and assorted pieces of debris in orbit. As LeoLabs was sure to add:
“Events like this highlight the need for responsible, timely deorbiting of satellites for space sustainability moving forward. We will continue to monitor this event through the coming days and provide updates as available.”
As the orbital lanes become increasingly crowded due to the deployment of thousands of more telecom satellites, internet satellites, and CubeSats, mitigation strategies will also be needed. Many concepts are on the drawing board and several have already been validated in orbit. In the meantime, regular monitoring and vigilance are the best defense against collisions.
NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.
Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.
She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.
Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.
“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.
It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.
Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.
Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.
Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.
“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.
He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.
Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.
Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”
Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.
“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.
B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.
Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.
Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.
Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.
“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”
Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”
“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.
Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.
“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.
This report by The Canadian Press was first published Sept. 9, 2024.
