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Glorified Desktop Support Wise, Aged Ars Veteran
NOV 22, 2021 12:56 PM
Cathbadhian wrote:
flerchin wrote:
Congrats Astra. Y'all beat Bezos to the club.BO's perpetual planning has really left them in a terrible place right now. Reputationally, the accumulation of lost contracts, scheduling delays, competitor successes, and rocket delivery complaints (unofficial, of course), don't add up to a company you want to throw cash at.
Well done, Astra.
Now, there could be a question of if BO (and ULA) can reach orbit before one of the small launch companies scale up like SpaceX did. It almost seems like there should be an equation where time to reach orbit is some function of funding, development time, and number of blown up rockets. Surprisingly, too much funding and not enough blown up rockets seems to greatly increase development time, perhaps exponentially.
Statistical Ars Legatus Legionis et Subscriptor
NOV 22, 2021 12:33 PM
DStaal wrote:
jbode wrote:
Damn, that thing was in a hurry to get off the pad.One thing I've learned from KSP that was mildly surprising, and I believe translates to real life: Higher TWR rockets are more efficient to launch. The less time you have to burn at full thrust the less fuel you need to carry, which means less fuel used, etc.
To a degree. Higher TWR also means mass used for additional engines which could just be used for more for more propellant. When you consider economics not just raw performance that is even more important. One ton of engines cost far more than one ton of propellant. Higher TWR also means higher drag losses. Higher TWR means you will hit max Q sooner in thicker atmosphere which may require more aggressive throttling (and thus losing some of the benefit of the mass you paid for).
All that means most orbital rockets tend to fall into a TWR range of 1.2 to 1.6 although there are notable exceptions at either end. Saturn V is sluggish off the pad at a initial TWR of 1.14. Electron has a TWR of 1.8. ///
[TWR: Thrust-Weight Ratio]
"I think that this flight really does prove out the approach we've taken." //
Astra never sought to build the best rocket, the biggest rocket, or the safest rocket. The California-based space company simply wanted to build a rocket that was just good enough, and to do it fast.
Early on Saturday morning, Astra proved the value of this philosophy by successfully launching a stripped-down rocket for the first time. The mission hefted a small test payload for the US Space Force into an orbit 500 km above the planet.
The launch came five years and one month after Astra was founded by Chris Kemp and Adam London in October 2016. With this weekend's success, Astra became the fastest company to reach orbit with a privately developed liquid-fueled rocket. With its Falcon 1 rocket, SpaceX required six years and four months. Firefly, Virgin Orbit, and Rocket Lab all needed seven or more years to successfully reach orbit.
To go fast, Astra decided to spend less time designing its rocket and more time testing it in real-world conditions. A first suborbital launch attempt was completed within two years of the company's founding, and Astra has been iterating on the vehicle's design since then. By using iterative design, Astra has had to stomach several failures along the way.
So how on Earth could Relativity Space compete with SpaceX?
Well, Relativity has something SpaceX doesn’t, a 3D printer that can make rockets! This might sound like a gimmick to some, but it is a truly revolutionary piece of technology in reality.
The printer is known as Stargate. It can print around 95% of a rocket, including fuel tanks, rocket engines and payload capsules in various metal alloys to an incredibly high level of accuracy.
This gives Relativity some crucial advantages over SpaceX. 3D printing is one of the fastest methods of production, Relativity claim they can build a functional rocket capable of commercial launches in just two months. This means they can do rapid prototyping and out develop their competitors. This is why their rocket engine, Aeon 1 has already had over 500 test fires, and is already a proven and refined engine, despite only being a few years old.
3D printing also means they can have some very unique architecture. This is most notable in the Aeon 1 engine, which only has a hundred parts, whereas other engines typically have well over a thousand parts. Things like cryogenic fuel lines are embedded into the combustion funnel walls rather than being welded onto them, as they are in other rocket engines. Not only does this mean assembly is quicker and easier, but it means the design can be optimised, far more than traditional engines, as there are fewer manufacturing limitations.
But, Relativity has also taken a note from SpaceX’s book. Their first launch vehicle, the Terran 1, has a reusable first stage that lands just like the Falcon 9. The first test launch is scheduled for early 2022, but we already know some details of what the commercial Terran 1 will be capable of, a cost per launch of $12 million for 1,250 kg to LEO.
Full-Scale Model of Apollo 11 12 13 14 Command Module Control Panel (CMCP)
All or nothing. This project will only be funded if it reaches its goal by Tue, September 21 2021 2:03 PM EDT.
Measuring a massive 82" wide, 33" tall, and 7" deep, all representing that same vision of teamwork, peaceful exploration, engineering accomplishment, and pioneering spirit.
"You can now take the controls of a historic NASA spacecraft — literally.
A team of Hollywood prop and visual artists are offering replicas of the Apollo command module control panel. The museum-quality reproduction features every switch, knob and indicator that was used on board the first three missions to land astronauts on the moon and to bring the Apollo 13 crew safely back to Earth.
"It is here where the impossible becomes possible," team leader Mark Lasoff, an Academy Award-winning artist whose credits include the 1995 feature film "Apollo 13," wrote about the control panel. "It is here where humans and machines interface. It is here where every vital operation, including navigation, propulsion, communication and life support is calculated, calibrated and controlled intricately."
"It is both an engineering feat and a work of art," Lasoff wrote of the flight deck." //
Measuring an expansive 82 inches wide, 33 inches tall, and 7 inches deep (208 by 84 by 18 cm), the replica control panel was designed using the original blueprints for the NASA spacecraft. Lasoff and his team also used 3D scans of the Apollo 11 command module produced by the Smithsonian's National Air and Space Museum to verify their details.
The Kickstarter campaign is offering the full-scale metal replica for $3,900.
On Friday, SpaceX founder Elon Musk sent a clear message to the FAA and other federal regulators. One evocative photo, in particular, drove home his message to anyone watching. It showed workers standing beneath Starship, as it was lowered onto the first-stage rocket. In releasing a black-and-white version, Musk knew exactly what he was doing in harkening back to the age of skyscrapers.
The 21st-century skyscrapers are being built right now, the photo screamed, by modern engineers and welders. Such rockets are not to be found in PowerPoints or wooden mockups any longer. They are living, breathing machines nearly ready to breathe fire.
It's taller than NASA's Saturn V moon rocket.
SpaceX's newest Starship prototype was briefly placed atop of its massive booster for the first time on Friday (Aug. 6), setting a new record for the world's tallest rocket ahead of a planned orbital test flight this year.
Engineers performed the stacking test at the SpaceX Starbase facility in South Texas, near the village of Boca Chica, in view of livestreams from NASA Spaceflight and Spadre.com. SpaceX has not commented on the stacking procedure yet on Twitter, although founder Elon Musk sent an update suggesting the company actually wanted to complete the stacking Thursday (Aug. 5), a few hours after Starship completed its rollout to the launch pad, but winds were too high. //
Super Heavy alone stands 230 feet (70 meters) tall and Starship SN4 added another 165 feet (50 m) of height. Together they stood a whopping 395 feet tall (120 m), taller than NASA's massive Saturn V moon rocket, which was 363 feet tall (110 m).
“Current plan is to increase base Raptor thrust to ~230 tons or ~500 million lbs & increase booster engine count to 32 or 33. All Raptors on booster, whether fixed or gimbaling, would be the same. 33*230 gets ~7600 tons of thrust & T/W of ~1.5.” //
“Center engines on ship will be same as booster engines. This is basically Raptor 2. Raptor Vacuum would be only variant. Tbd as to whether to commonize R-Vac with Raptor 2 (more thrust), keep same or tighten throat (more Isp). Adding 3 more R-Vac to ship with max Isp maybe …” //
SpaceX’s website shows the previous plan was for the Super Heavy to offer thrust of 16 million pounds. Musk’s comments suggest this figure could reach 17 million pounds.
By comparison, the most powerful rocket to ever fly was the Saturn V. It last flew in 1973, and generated just 7.6 million pounds of thrust. //
"Mass of initial SN ships will be a little high & Isp a little low, but, over time, it will be ~150t to LEO fully reusable.”
For Mars missions, the more important information could be that “T/W” of 1.5. The thrust-to-weight ratio shows how the thrust compares to the weight of the vehicle itself. Unlike an aircraft that takes off horizontally, a rocket that launches vertically needs its thrust to be higher than its weight. The higher thrust-to-weight, the greater acceleration. //
“T/W will be ~1.5, so it will accelerate unusually fast. High T/W is important for reusable vehicles to make more efficient use of propellant, the primary cost. For expendable rockets, throwing away stages is the primary cost, so optimization is low T/W.” //
November 2018 — BFR, first announced in September 2017, gets renamed to Starship.
December 2018 — Musk confirms the new ship has switched to stainless steel.
January 2019 — Shortened “Starhopper” prototype unveiled and Musk explains the switch to steel.
February 2019 — Raptor engine beats a long-standing rocket record.
April 2019 — Starhopper completes a tethered “hop.”
July 2019 — Starhopper launches 20 meters (67 feet).
August 2019 — Starhopper launches 150 meters (500 feet).
September 2019 — Starship Mk.1 full-size prototype unveiled.
May 2020 — Starship SN4 full-size prototype completes a static test fire.
August 2020 — SN5 launches 150 meters (500 feet).
October 2020 — SN8 completes the first triple-Raptor static fire.
December 2020 — SN8 launches 12.5 kilometers (41,000 feet) and crashes into the ground.
February 2021 — SN9 launches 10 kilometers (33,000 feet) and crashes into the ground.
March 2021 — SN10 launches 10 kilometers (33,000 feet), lands, and explodes eight minutes later. That same month, SN11 launches 10 kilometers (33,000 feet) and hits the ground in several pieces.
May 2021 — SN15 launches 10 kilometers (33,000 feet) and lands without a hitch, except for a small fire at the base.
"In every SpaceX animation, we saw a fade into black right when people walked out of the rocket on Mars," Ellis said. "So what was clear [is] that there needed to be some other company building humanity's industrial base on Mars. Replicating the infrastructure for a million people that live on Mars is a massive undertaking, and I think a lot of people need to work on it."
Relativity seeks to do this by pushing forward 3D-printing technology. Ellis intends to disrupt the long-standing aerospace practice of using fixed tooling to manufacture rockets, which are then finished using a hands-on process of adding thousands of parts. Ultimately, Relatively hopes to use what it learns about printing rockets on Earth to additively manufacture habitats and other materials on the surface of Mars.
Even as Relativity Space seeks to augment the efforts by Musk and SpaceX to make humans a multiplanetary species, the company is also directly competing with its much more established rival. If successfully developed, the Terran R would challenge SpaceX's Falcon 9 rocket for both government and commercial launch contracts. //
The Terran R vehicle will have a first stage that lands on a drone ship at sea, and the second stage will retain its payload fairing after satellite separation. Then, this combined stack, the second stage and payload fairing, will make a propulsive landing from orbit.
"To my knowledge, we're only the second fully reusable vehicle other than Starship that's even been planned," Ellis said. //
The rocket's first stage will be printed from a custom aluminum alloy, and the upper stage will be built from a more exotic, heat-resistant material to withstand re-entry temperatures. For the rocket's first missions, Relativity will seek to bring back the first stage, incorporating full-vehicle reuse over time, Ellis said.
If all of this sounds ambitious, that's because it is, especially for a company that has yet to launch a rocket or even perform an integrated-stage test firing. However, Relativity's steady growth, to about 400 employees now, and total fundraising of $1.34 billion lend some credence to the idea that it may indeed be successful.
Between 2007 and 2011 the European Space Agency worked with Russia to simulate the conditions of a trip to Mars, particularly as a psychological isolation experiment. Called Mars500, the longest part of this study ran between 2010 and 2011, and revealed a significant degradation of the simulacral explorers’ sleep patterns. While on wide-body airliners a business class cocoon seat can deliver comfort (and even luxury) during an overnight flight, such ergonomic palliatives won’t be as easy for a year-long journey. Space travel to Mars is supposed to be a bold and daring adventure. But what if it ends up feeling more like a super long red-eye flight? //
If the dream of space travel involves new horizons and feelings of unbound freedom—to explore, to discover, to spread humanity—a nightmare lurks just around the corner of consciousness. There will be no real “arrival” on this fantasy trip: It’s enclosures and pressurized chambers all the way down. When it comes to human space travel, the destination really is the journey. And the journey will be long, and claustrophobic. As far as “quarantine” goes, spacefaring may feel familiar to those who lived through the COVID pandemic—and certain survival tactics may crossover. //
The wish image of habitations on other planets is for simulated environments that feel as good as—if not better than—our home planet. The reality is bound to be precarious and highly contingent—no matter how awesome and intact space settlements might appear in artistic renderings. The motivation for spacefaring is, at least for Musk, premised on a desire to escape a planet in limbo; but the alternative is hardly a safe haven. This is the paradox of spacefaring: it’s a lose-lose proposition.
As anthropologist Lisa Messeri has found in her research on planetary scientists, ideas about inhabiting outer space can tend to revert back to making sense of our place on Earth. This isn’t necessarily a bad thing; in fact, one of the arguments for space exploration is to improve life back home.
For Sunday morning's launch, SpaceX used a first stage that had flown into space nine previous times. After this launch, the B1051 booster landed safely on a drone ship, completing its tenth flight to space. This is a notable milestone because in 2018, SpaceX founder Elon Musk said the goal for its Falcon 9 rocket would be to fly each first stage booster 10 times before requiring significant maintenance.
Recently, Musk said the company has found no showstoppers as it flies Falcon 9 first stages more and more times. The company plans to continue to use these older rockets for Starlink missions, thus risking its own payloads in flight rather than those of a paying customer. Musk said the company has set no predetermined limit on the lifetime of a Falcon 9 rocket and that SpaceX would fly some of its Falcon 9 rockets to failure in an effort to identify these limits.
This particular first stage went to orbit for the first time on March 2, 2019, for the first demonstration mission for NASA's commercial crew program. During this flight, a Crew Dragon spacecraft docked with the International Space Station for about five days, paving the way for the first crewed flight in May 2020. //
B1051 trails only NASA's Discovery, Atlantis, Columbia, and Endeavour space shuttle orbiters in terms of spaceflights. Three of those shuttles are now in museums. Columbia was lost in a fatal accident in 2003.
In flying 10 times since early March 2019, this single booster has now flown nearly as many missions as SpaceX's primary US launch competitor. Since the first flight of B1051, United Launch Alliance has flown a total of 11 missions with expendable rockets—two Delta IV launches, two Delta IV Heavy missions, and seven Atlas V rockets. //
Through Sunday's launch, SpaceX has launched 14 orbital missions in 2021, 11 of which have been Starlink flights. That is an average of one launch every nine days, and those missions have been spread across just six different Falcon 9 first stages.
The core stage of a Long March 5B rocket is expected to slam into Earth's atmosphere Saturday (May 8) or thereabouts, although nobody can pinpoint the date, time or location yet. Such predictions can generally only be made just hours before impact, because atmospheric drag changes significantly as solar activity shifts.
Odds are the 23-ton (21 metric tons) piece of space debris will break apart high in the atmosphere and largely burn up, experts say, with any remaining pieces hitting uninhabited areas, as 70% of Earth's surface is covered in ocean. But again: We don't know that for sure.
After months of attempts, including a successful landing and later rapid unscheduled disassembly (also known as an explosion), SpaceX has done the impossible by launching and landing their Starship prototype, at their “Starbase” located in Boca Chica, Texas, on the border with Mexico.
It was a great day for the flight as today was the 60 year anniversary of Alan Shepard’s history-making flight to become the first American in space.
McDowell said he hoped China would have enhanced the core stage to perform a controlled deorbit after separating from Tianhe. “I think by current standards it’s unacceptable to let it reenter uncontrolled,” McDowell said.
“Since 1990 nothing over 10 tons has been deliberately left in orbit to reenter uncontrolled.” The Long March 5B core stage, without its four side boosters, is thought to have a “dry mass”, or when it is empty of propellent, of about 21 metric tons in mass.
Holger Krag, head of the Space Safety Programme Office for the European Space Agency, says from their experience, there is an average amount of mass of about 100 tons re-entering in an uncontrolled way per year. “This relates to about 50-60 individual events per year.”
“It is always difficult to assess the amount of surviving mass and number of fragments without knowing the design of the object, but a reasonable “rule-of-thumb” is about 20-40% of the original dry mass.”
Components made of heat resistant materials, such as tanks and thrusters made stainless steel or titanium, can reach the ground. Surviving objects will fall vertically after deceleration and travel at terminal velocity.
SpaceX aims to resume launching satellites for its Starlink internet network with the liftoff of a Falcon 9 rocket Wednesday night at Cape Canaveral, and company founder Elon Musk says SpaceX will use the sizeable backlog of Starlink missions to keep pushing the envelope and find the Falcon booster’s reuse life limit.
“There doesn’t seem to be any obvious limit to the reusability of the vehicle,” Musk told Spaceflight Now in a press conference Friday after the launch of SpaceX’s third crewed flight to the International Space Station. //
SpaceX officials have previously said the most recent version of the Falcon 9 booster can make 10 flights with only inspections and minor refurbishment in between missions. With an overhaul, the Falcon 9 boosters could fly 100 missions, SpaceX said when the new Block 5 booster design debuted in 2018.
Musk said Friday that SpaceX plans to keep reusing Falcon 9 boosters until they break, likely exceeding the 10-flight milestone.
“We do intend to fly the Falcon 9 booster until we see some kind of a failure with the Starlink missions, obviously, just to have that be a life leader,” Musk said. //
Last year, a SpaceX manager said it costs less than $30 million to fly a Falcon 9 rocket with reused parts, such as the booster and payload fairing, the clamshell-like aero-structure that protects sensitive satellite payloads during the climb through the atmosphere.
Although SpaceX has proven it can safely reuse first stages, payload shrouds, and Dragon capsules, the Falcon 9 rocket’s upper stage remains a single-use component. None of SpaceX’s competitors in the commercial launch industry have successfully re-flown an orbital-class booster. Some companies, like Blue Origin and Rocket Lab, plan to eventually recover and reuse their rocket boosters. //
SpaceX says it can deliver payloads of more than 100 metric tons, or 220,000 pounds, or low Earth orbit.
“With Starship, we’ll hopefully reuse the whole thing,” Musk said. “This is a hard problem for rockets, that’s for sure. It’s taken us, we’re like 19 years in now. I think the Starship design can work. It’s just, it’s a hard thing to solve, and the support of NASA is very much appreciated in this regard. I think it’s going to work. I think it’s going to work.
“I’d say it’s only recently though that I feel that full and rapid reusability can be accomplished,” Musk said. “I wasn’t sure for a long time, but I am sure now.”
In three months, NASA will come upon the 10th anniversary of the final space shuttle flight, a period that was surely melancholy for the space agency.
When the big, white, winged vehicles touched down for the final time in July 2011, NASA surrendered its ability to get humans into space. It had to rely on Russia for access to the International Space Station. And the space agency had to fight the public perception that NASA was somehow a fading force, heading into the sunset.
Now we know that will not be the case, and the future appears bright for the space agency and its international partners. On Friday morning, NASA and SpaceX launched the third mission of Crew Dragon that has carried astronauts into space. After nearly a decade with no human orbital launches from the United States, there have been three in less than 11 months. Another successful mission further confirmed that the combination of Falcon 9 rocket and Crew Dragon spacecraft is a reliable means of getting crews to the International Space Station. //
The "team" is a collaboration between engineers at NASA and SpaceX that have worked to develop and certify the Crew Dragon system for human spaceflight for a fixed price of about $55 million per seat. Since 2017, NASA had been paying Russia more than $80 million for an astronaut to ride into orbit.
The partnership has also been very good for SpaceX, which has sought to develop rapid, low-cost access to space through reusable vehicles. Thanks to NASA's flexibility, SpaceX launched Monday's mission on a Falcon 9 rocket that flew in November and on a Crew Dragon vehicle, Endeavour, that first went into space last May. //
With the Falcon 9 and Crew Dragon, SpaceX has gotten mostly there. However, the Falcon 9 rocket's upper stage is expended after a launch, and the Dragon capsules undergo significant refurbishment between flights. Musk sees this launch system as an interim stage to full reuse, and SpaceX is still learning lessons. The company has already flown one of its Falcon 9 first stages nine times and will soon fly it a tenth time. The plan is to push the limits of the Falcon 9 with the company's own Starlink missions, Musk said.
"There doesn’t seem to be any obvious limits to the reusability of the vehicle," he said. "We intend to fly the Falcon 9 rocket until we see some kind of failure."
These lessons will be incorporated into SpaceX's next-generation Starship and Super Heavy launch system, which is designed to be fully reusable and able to launch again within days of landing. That's the aspirational goal, at least. NASA seems intrigued, as it recently selected Starship to land its astronauts on the Moon later this decade as part of the Artemis Program.
A few weeks back we brought word that Reddit users [derekcz] and [Xerbot] had managed to receive the 2232.5 MHz telemetry downlink from a Falcon 9 upper stage and pull out some interesting plain-text strings. With further software fiddling, the vehicle’s video streams were decoded, resulting in some absolutely breathtaking shots of the rocket and its payload from low Earth orbit.
Unfortunately, it looks like those heady days are now over, as [derekcz] reports the downlink from the latest Falcon 9 mission was nothing but intelligible noise. Since the hardware and software haven’t changed on his side, the only logical conclusion is that SpaceX wasn’t too happy about radio amateurs listening in on their rocket and decided to employ some form of encryption. //
At the end of the post [derekcz] echos a sentiment we’ve been hearing from other amateur radio operators recently, which is that pretty soon space may be off-limits for us civilians. As older weather satellites begin to fail and get replaced with newer and inevitably more complex models, the days of picking up satellite images with an RTL-SDR and a few lines of Python are likely numbered.
GRANT COUNTY, Wash. - A portion of the SpaceX rocket that re-entered Earth's atmosphere last week in a dazzling light show has been discovered in Eastern Washington, officials said. //
Kyle Foreman of the Grant County Sheriff's Office says the debris was a composite overwrapped pressure vessel that would have contained pressurized helium. //
A property owner in southwest Grant County located the debris earlier in the week. The property owner notified the Grant County Sheriff's Office and deputies responded to the scene.
Sheriff's officials then contacted SpaceX about the discovery.
Foreman says a team from SpaceX responded to the scene and reclaimed the portion of the SpaceX rocket.
The piece of debris left a 4-inch-deep indentation in the ground where it landed.
tokamaks are reactors which use thermal input and super-powered magnets to convert a cocktail of relatively abundant hydrogen isotopes into a self-sustaining plasma of unimaginable heat and radiance. Researchers are fine-tuning tokamaks at various labs around the globe, hunting for energy breakeven, the tipping point where the plasma in the tokamak generates at least as much energy from fusion as it requires in externally supplied thermal energy. Once breakeven has been achieved, mankind will be on the cusp of a limitless source of clean, self-sustaining energy, which for any number of reasons will be extremely bitchin’, at least until the science is bought by venture capitalists and sold back to the public at a price that effectively makes its owners gods. //
We have been assured by several researchers that whatever else is true about the development of tokamak science, the jillion-degree star juice in the core of the reactor can not be fired or ejected or otherwise expelled from the torus, due to physics or chemistry or whatever, and therefore cannot cause Chernobyl-like cataclysms. //
But now a PPPL researcher—one Fatima Ebrahimi, pictured above (right)—has designed a new “plasmoid rocket” concept which applies the ultra magnets and so forth of tokamaks in such a way that superheated plasma is used to generate thrust and propel a rocket through space, thus solving one of the most vexing challenges associated with manned travel into deep space: storing enough fuel to power a spacecraft all the way from Earth to Mars. Ebrahimi’s rocket concept harnesses both the juice of the Sun and the mechanics of solar flares to do magical magnet things and go vroom through space.
The new Princeton concept works by using the same mechanism that helps to blast solar flares away from the Sun. These flares consist of charged atoms and particles called plasma, which are trapped inside powerful magnetic fields where complex interactions take place.
For propulsion systems, Ebrahimi is particularly interested in one type of interaction called magnetic reconnection, which is where magnetic fields in highly charged plasmas restructure themselves to converge, separate, and re-converge. As they do so, they generate large amounts of kinetic energy, thermal energy, and particle acceleration. It’s a phenomenon not only seen on the Sun, but also in the Earth’s atmosphere and inside Tokamak fusion reactors, like PPPL’s National Spherical Torus Experiment (NSTX).
https://newatlas.com/space/magnetic-reconnection-rocket-thruster-concept-spaceflight-mars