Space News thread

[harrybarracuda]

Well it's clearly worrying them.

It was on 23 August at 17:07 GMT that spacecraft operators at the European Space Agency’s (ESA) control centre in Darmstadt, Germany, noticed something was going wrong. Their flagship Earth observation satellite, Sentinel-1A, had suddenly jumped into a slightly different orbit and a slightly different orientation.


More seriously, the electrical power had dropped, and was not returning to normal. The spacecraft was only in its third year in orbit. Activating on-board cameras that had been used two years earlier to monitor the deployment of the solar panels, the operators found the problem.

It was enough to make an engineer’s blood run cold. There was a 40-centimetre-wide damaged area on one of the solar panels.


The spacecraft had been hit by a piece of space debris. Subsequent computer simulations of the damage indicated that the solar panel had been hit from behind and that the size of the impacting object was no more than just a few millimetres.


It packed such a punch because it was travelling at orbital velocities, which are measured in kilometres per second. It was lucky that the debris wasn’t any larger. If it had been, the entire solar panel could have been shattered and the mission ended. Worse, the fleck could have struck the main body of the satellite.



In that case, “the outcome might have been much more severe,” said Holger Krag this week at the opening of the 7th European Conference on Space Debris, which was held at ESA’s Space Operations Centre (ESOC) in Darmstadt, Germany.


Krag is Head of the ESA Space Debris Office. His team monitors the 10 satellites that ESA currently operate in low Earth orbit to protect them from the swarm of human-made debris that now surrounds our planet.

On average there is a high risk alert of a potential collision every week, and every ESA satellite has to be manoeuvred to avoid a collision once or twice a year. “It’s just normal life now,” says Krag.

Radar stations track 18,000 objects in orbit. Of these, only 7% are operational satellites. The rest is space debris. And radar only sees the big stuff.

Using observations and computer models, Krag estimates that there are around 5,000 objects larger than 1m, 20,000 objects larger than 10cm, 750,000 larger than 1cm (he calls these “flying bullets”), and a whopping 150 million larger than 1mm (or about the size of the piece that damaged Sentinel-1A).

Space debris comprises spent rocket parts and fragments from defunct spacecraft: old batteries can explode, leaks can occur in coolant systems that solidify into pellets, occasionally satellites actually collide. Worryingly each collision produces more fragments and exacerbates the problem.

And it’s not just satellites that are at risk. So too are human lives. The conference was addressed by ESA astronaut Thomas Pesquet, via a satellite link from the International Space Station (ISS).

Just like other satellites, the space station has been manoeuvred out of harm’s way in the past. Chillingly, however, if the collision alert comes with less than 24 hours warning, there is nothing that can be done.

Pesquet described how the astronauts must close all the hatches between the various modules and then wait in their Soyuz spacecraft, ready to perform an emergency evacuation to Earth if needed.

This procedure has been enacted four times in the 19-year history of the ISS. The latest was in July 2015, when the three man crew received just 90 minutes warning that a collision was possible. Thankfully, the space debris sailed cleanly by and to date no catastrophic debris strike has taken place.

But it’s set to get worse. So called mega-constellations of satellites are planned by companies such as One Web, Boeing, SpaceX and Samsung to bring Internet access to all sectors of the globe. These will loft more than ten thousand satellites into orbit.

By way of comparison, since the launch of the world’s first spacecraft, Sputnik One, in 1957, only 7000 spacecraft in total have been launched in the entire 60-year exploration of space.


The nightmare scenario that space debris experts contemplate is called the Kessler syndrome, after American astrophysicist Donald Kessler.

In 1978, while working for Nasa, he published an analysis that showed frequent collisions exponentially increased the amount of space debris, leading to many more collisions, leading to much more debris until we lose the use of certain orbits because anything we put there would certainly be hit.

Krag showed the conference a graph of the radar-tracked fragments and said that since 2002, “The growth has entered into the more feared exponential trend.”

There can be absolutely no doubt that the time to do something about space debris has arrived, and this is what the experts have spent the week discussing. At the conclusion of the conference today, Jan Wörner, ESA Director General, committed the Agency to leading European activities to combat space debris.

This includes detection, tracking, and development of automatic collision avoidance systems for satellites, and new binding guidelines on satellite design. He went further saying that there had to be a concerted effort to reduce and remove the space debris that is already there.

ESA knows this is challenging. Their own debris removal mission, called e.deorbit, failed to get the backing of enough European governments last year and so was not funded.

Addressing this point at the conference, Brigitte Zypries, German Federal Minister for Economic Affairs and Energy, said that the mission would be re-tabled at the next ministerial meeting in four years time.

Wörner also said that he would not tolerate any excuse for non-participation. Clearly there is palpable determination in the agency, and a growing interest around the world. For the first time in its history, the conference was oversubscribed, and had to turn researchers away.

But unless a global community comes together quickly to tackle this problem, it will inevitably end up being too little too late.

https://www.theguardian.com/science/...n-space-agency

[Takeovers]

and that the size of the impacting object was no more than just a few millimetres.

It is what I said. The problem are the very small pieces. Big ones can be avoided and routinely are avoided by small maneuvers ahead of potential impacts. Presently the US Airforce is doing the tracking and warning. So the big ones need be removed before they fracture and the operator should be responsible to do this. The operator should also make sure they do not fracture on their own.

[harrybarracuda]

It is what I said. The problem are the very small pieces. Big ones can be avoided and routinely are avoided by small maneuvers ahead of potential impacts. Presently the US Airforce is doing the tracking and warning. So the big ones need be removed before they fracture and the operator should be responsible to do this. The operator should also make sure they do not fracture on their own.

Well what they are saying is that the big bits, if they shatter, can wipe out entire orbits.

I don't know what you mean by "the operator should be responsible to do this". I would agree, but if no-one is doing it. someone needs to.

[Takeovers]

but if no-one is doing it. someone needs to.

Who would raise the money if not the operator who makes the money operating it? Nothing will be done, I am afraid.

[harrybarracuda]

Who would raise the money if not the operator who makes the money operating it? Nothing will be done, I am afraid.

ESA are paying for this trial I believe. They have a vested interest after all.

[Takeovers]

ESA are paying for this trial I believe. They have a vested interest after all.

They are doing research, which is ok. It raises awareness, though that is barely necessary in the business.

[Takeovers]

If anyone is interested in the history and chemistry of rocket propellants "Ignition" is the book to read.

http://library.sciencemadness.org/li...s/ignition.pdf

Here a link to a PDF for download.

This book is unique in many ways. Copyright 1971, but it is still a must read for any aspiring rocket engineer. At the same time it is very much readable and understandable for average people like us, just curiosity is required. Print copies of the book used to fetch a few thousand $. Not sure it is still true now that it is available in print again. A new edition came out in 2018

A window into the early days of rocket development. Plus it is hilariously funny.

[OhOh]

^Thanks.

[Luigi]

Congratulations to Hayabusa2 and the Japanese team behind it.


https://www.space.com/japanese-aster...nds-ryugu.html

Long story short.

They have successfully collected samples from the surface of asteroid Ryugu, will collect more in the coming weeks/months, then return them to Earth in Dec. 2020.

[harrybarracuda]

A brilliant photo that shows the shadow of the spacecraft as it approaches.

[harrybarracuda]

A nice shot of the SpaceX launch...

[BaitongBoy]

Hayabusa2 launched in December 2014 and arrived at Ryugu in June of last year.

********

How far away is that asteroid?...

[Luigi]

Hayabusa2 launched in December 2014 and arrived at Ryugu in June of last year.

********

How far away is that asteroid?...

Actually not that far. Though around 180 million miles when it arrived there, iirc.


It's between Earth and Mars.

It's due back to Earth with some nice goodies the end of next year.

[Luigi]

[BaitongBoy]

Cheers...

[Takeovers]

A nice shot of the SpaceX launch...

An interesting launch. The first time SpaceX launched a booster 3 times. At a mission that was the most challenging ever for landing the booster,.

A screenshot I made of the life transmisssion during reentry of the booster. I had never seen something like this and got slightly worried when life transmission from the booster terminated shortly after that. But they did land it successfully. Later Elon Musk tweeted that it is molten metal due to the highest reentry heating ever experienced. But he also tweeted that they will reuse this booster for a most critical mission for their commercial crew program. They plan to use it for the in flight abort test of their Crew Dragon. That would be reflight 4 with this booster.

SSL built the Nusantara Satu satellite for PT Pasifik Satelit Nusantara (PSN), a leading Asian provider ofsatellite-based telecommunication services. Nusantara Satu is Indonesia’s first high-throughput satellitethat will serve to improve internet connectivity in the region. Additionally, the satellite’s C-band and Kuband transponders will be used for voice and data communications and video distribution throughout theIndonesian archipelago. In order to bring a secondary payload to orbit, SSL designed Nusantara Satuusing its next-generation electric propulsion system. The launch demonstrates SSL’s ability to take smallrideshare satellites to geostationary orbit efficiently and economically.

The small rideshare satellite is for the US Airforce.

The Air Force Research Laboratory (AFRL) S5 experimental small spacecraft, developed and integratedby Blue Canyon Technologies, will carry out a one-year mission. The S5 mission leverages commercialadvances and services in a rapid demonstration of small satellite capabilities.

There was another very interesting secondary payload. The israeli moon lander that was initially developed for the Google Lunar X-price competition. But that competition was ended without any of the participants launching their lander. It is now flying as its own mission. As the lander is small it can ride along to Geostationary Transfer Orbit as common for communication satellites and does the remaining maneuvers on its own. GTO gives most of the speed needed for reaching the moon.

SpaceIL’s lunar spacecraft Beresheet (Hebrew for “in the beginning”), which competed in the GoogleLunar XPrize, will be the smallest spacecraft to ever land on the Moon, at only 1,322 lbs, or 600 kgs.Upon deployment, it will travel to the Moon using its own power, a voyage that will take nearly twomonths. Once it arrives, Beresheet will be Israel’s first spacecraft and the world’s first privately-fundedspacecraft to reach the Moon. Its mission is to transmit photos and video of its new home and conductscientific measurements.

Infos on the payloads are from the SpaceX press kit for this launch.

https://www.spacex.com/sites/spacex/..._press_kit.pdf

[Takeovers]

To add to the post above. Here a picture of the landed booster.



In another tweet Elon Musk mentioned that they now believe a booster can do 20-30 launches. Previously they were calculating with ~10 launches without major refurbishment and assumed they would need 30-50 boosters to do all the launches until Falcon is replaced by their new Starship.

He now gave ~20 boosters they will need, including Falcon Heavy flights. Results from checking the landed boosters must be very encouraging. The plan was to build up a stock of boosters, then shut down the production line.

[harrybarracuda]

Won this one, obviously not time sensitive.

Contract award: Space Exploration Technologies Corp., Hawthorne, California, has been awarded a $297,000,000 firm-fixed-price contract, for launch services to deliver the NROL-87, NROL-85, and AFSPC-44 missions to their intended orbits. This launch service contract will include launch vehicle production, mission integration, mission launch operations/spaceflight worthiness and mission unique activities for each mission. The locations of performance are Hawthorne, California; Cape Canaveral Air Force Space Station, Florida; and Vandenberg Air Force Base, California. NROL-85 and NROL-87 are expected to be completed by December 2021 and AFSPC-44 is expected to be completed by February 2021. This award is the result of a competitive acquisition and two offers were received. Fiscal 2018 and 2019 space procurement funds in the amount of $285,223,097 will be obligated at the time of award. The Contracting Division, Launch Systems Enterprise Directorate, Space and Missile Systems Center, Los Angeles Air Force Base, El Segundo, California, is the contracting activity (FA8811-19-C-0004).

[NamPikToot]

There are hundreds of thousands objects in space that can potentially be dangerous. No way to harpoon them all, even if there were will and money to clean up which isn't.

Wombles, we need space Wombles.

[Takeovers]

Won this one, obviously not time sensitive.

It is 3 launches, 2 Falcon 9, 1 Falcon Heavy.

[harrybarracuda]

It is 3 launches, 2 Falcon 9, 1 Falcon Heavy.

Yes, but it's A contract, not three contracts.

[Takeovers]

A big development for manned space flight.

Both Boeing and SpaceX are developing new crew transport vehicles to bring astronauts to the ISS. On friday NASA held the flight readiness review for the SpaceX Dragon 2 and concluded it is ready to fly on an unmanned flight doing the same mission profile as it will later with crew. This includes approach and docking to the ISS, then return to earth for a landing in the Atlantic near Florida. SpaceX is presently slightly ahead of Boeing. I also believe Boeing has more schedule uncertainty than SpaceX. It is the SpaceX DM-1 mission

Next steps would be:

In flight abort of Dragon, demonstrating that Dragon can get astronauts safely away from an exploding rocket. Though they will not explode the rocket, just shut it off, then escape. NASA schedule says this will happen in June, but Elon Musk expressed hope they will be able to do it in April. A very tight schedule as they will reuse the DM-1 Dragon. It needs to complete the DM-1 mission, be recovered from landing in the Atlantic and refurbished for the next flight. But it does not need all capabilities for the abort.

The DM-2 misison. A manned demo mission bringing astronauts to the ISS but only for a short time.

Then, if everything goes well, the first operational mission of Dragon bringing crew to the ISS for a 6 month stay. Dragon will stay on the ISS for that period to be available as a life boat if the ISS needs to be evacuated.

Launch is scheduled for March 2. The Falcon 9 rocket has already had a static fire to establish it is ready to fly.

Video of the announcement press conference

https://www.youtube.com/watch?time_co...&v=AkOHE-LCT_s

A spaceflight insider article on the decision.

https://www.spaceflightinsider.com/o...diness-review/

After years of development, SpaceX’s Crew Dragon is nearly ready to fly its first unpiloted test flight to the International Space Station.
On Feb. 22, 2019, NASA and SpaceX conducted a flight readiness review to judge whether SpaceX, the spacecraft, the space station and its crew and NASA are ready for the flight, which is currently scheduled to take place at 2:48 a.m. EST (07:48 GMT) March 2 from Kennedy Space Center’s Space Launch Complex 39A.
“It’s a test flight, but its more than a test flight,” said William Gerstenmaier, associate administrator for NASA’s Human Exploration and Operations. “It’s really a mission to the International Space Station. It’s part of the Commercial Crew Program that really gets us ready for the [Demo-2] crew flight that comes up later. This is a critical first step that we do as we move toward returning crew launch capability back here to the U.S.”

“Every human spaceflight program has risks that are out there,” said Kathy Lueders, NASA Commercial Crew Program manager. “The way you manage your risks is you identify them and you work them off.”
After everything is checked and verified safe, the first astronauts are slated to board a Crew Dragon for Demo-2, which is expected to fly the same mission profile as Demo-1. That flight is slated for July.
Crew Dragon is one of two human-rated spacecraft being developed by commercial companies under NASA’s Commercial Crew Program. The other company, Boeing, is building and testing its CST-100 Starliner and also plans to have its first test flight in the coming months.

[Takeovers]

Pulsar navigation. European ESA, the chinese space agency and recently with an experiment NASA are working on using the signals of pulsars for navigation of spacecraft in much the same way we use GPS here on earth.

https://en.wikipedia.org/wiki/X-ray_...sed_navigation

https://www.nasa.gov/sites/default/f...mitchell_0.pdf


This technology will be able to determine the position of a spacecraft with ~5km accuracy anywhere in our galaxy. For near term use it can be used in our own planetary system, which is part of our galaxy. The precision is absolutely good enough for maneuvering interplanetary spacecraft except when in the immediate vincinity of large bodies like planets or asteroids. We are able to get much better positioning, down to a meter, maybe, using the NASA DSN antenna network but that is expensive to use and always short of capacity.

[harrybarracuda]

Failed 1970s Venus Probe Could Crash to Earth This Year

Here's another warning about incoming space hardware — but this saga has an interplanetary connection.

First, we have to peel back space history to the early 1970s, just after the height of the Cold War space-race between the Soviet Union and the United States.

The Soviet Union launched the Cosmos 482 Venus probe on March 31, 1972. But the spacecraft messed up its rocket-powered escape to that cloud-veiled world and got trapped in Earth orbit.

A big chunk of that failed craft remains in orbit today as space junk — but it's due to come down soon, perhaps as early as this year, experts said.

Cosmos 482 was a sister probe to Venera 8,which in July 1972 became the second craft to land successfully on the surface of Venus, said Don Mitchell, who studies Soviet space history and has a keen interest in that country's Venus exploration missions.

Venera 8 relayed data from Venus' surface for 50 minutes and 11 seconds before succumbing to the harsh, lead-melting conditions.

But Cosmos 482 got stranded in an Earth parking orbit, Mitchell told Space.com. Some hardware from that failed flight — a heavy frame of tanks and equipment that was jettisoned — fell into Earth's atmosphere in rather short order. But some remained aloft.

Venera 8 comprised a spacecraft "bus" and a lander probe. The lander was a spherical pressure vessel of similar design to the Soviet Union's Venera 7 probe.

Venera 7 launched in August 1970 and made the first-ever successful Venuslanding on Dec. 15 of that year. It sent valuable data back to Earth from the surface, if only for a few brief minutes.

Still adrift around Earth, making one lap every 112 minutes, is the wayward Cosmos 482 Venus entry capsule, a contraption built to withstand the heat of diving into that cloud-veiled planet's thick atmosphere. The errant Venus lander mass is 1,091 lbs. (495 kilograms) and carries significant thermal protection.

And this piece of space junk will likely survive its inevitable descent back to its home planet, experts said.

"Yes, the descent craft will survive a re-entry with no problems," said satellite watcher Thomas Dorman of the northeastern Oklahoma community of Zeb. "It would be funny if it was spotted coming down and the parachute has deployed … but I am sure the batteries to fire the pyrotechnics to release the parachute have died long ago!"

Like Dorman, veteran astrophotographer Ralf Vandebergh of the Netherlands has been observing the wayward spacecraft for a while — the last eight years, in fact. He told Space.com he's done a new appraisal of Cosmos 482.

"My preliminary conclusion of Cosmos 482, observing using a 10-inch aperture telescope during varying passes, viewing angles, illumination angles and observing conditions, [is that it] seems [to be] an elongated object with strong brightness variations," Vandebergh reported. "There is an indication of smaller structures, but these are unconfirmed. Despite the successful results, the mystery around the true condition of Cosmos 482 and what elements of the spacecraft exactly are still in orbit still remains unsolved."

Meanwhile, Dorman recently captured Cosmos 482 on his skywatching equipment. His imagery showed the object flaring. A spherical object such as the Venus descent capsule seemingly wouldn't flare, he said, suggesting that more of the upper spacecraft bus was still intact.

"Our guess is maybe as much as 40 to 50 percent of the upper spacecraft bus may still be there," Dorman told Space.com. "It is interesting to note the apogee of the orbit is slowly starting to decay. My guess right now is that re-entry is late this year to mid next year. But predicting its decay is as much of an art [as] it is science. The other issue is, nobody can forecast solar activity for the next year, which could affect the decay time," he said.

Dorman said Cosmos 482 is in an orbit that swings it out from Earth over 1,700 miles (2,735 km) away, but the low point, the perigee of the orbit, is just 125 miles (200 km) above our planet.

"Trying to study Cosmos 482 and what remains of the spacecraft is like attempting to gain an understanding and insight of a shipwreck that is moving at hypervelocity speeds, under ever-changing lighting conditions from the surface of an ocean…this ocean being several hundred miles deep, with only a few seconds to see it at its closest and at best a few times a year!"

Another rough estimate suggests that what's left of the failed Venus probe might stay up for another 2.5 years, even with such a low perigee.

"This suggests the object is very dense, which could support that it might withstand re-entry," said T.S. Kelso of CelesTrak, an analytical group that keeps an eye on Earth-orbiting objects.

You can see Vandebergh's latest view of Cosmos 482 here.

https://www.space.com/failed-soviet-...arth-soon.html

[harrybarracuda]