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"Boeing became furious and tried to get me fired." //
In the early and mid-2010s, Sowers was leading the advanced programs group at United Launch Alliance (ULA), the rocket company co-owned by Boeing and Lockheed Martin. Propellant depots were among the technologies he was working on. Sowers is now a professor at the Colorado School of Mines. //
One of ULA's chief assets was its Centaur upper stage, and the company wanted to build an innovative version that could be refueled in space, and reused, called the Advanced Cryogenic Evolved Stage, or ACES. As part of this development, in 2011, ULA proposed an in-space test of depots to NASA that would cost less than $100 million.
"We had released a series of papers showing how a depot/refueling architecture would enable a human exploration program using existing (at the time) commercial rockets," Sowers tweeted on Wednesday. "Boeing became furious and tried to get me fired. Kudos to my CEO for protecting me. But we were banned from even saying the 'd' word out loud. Sad part is that ULA did a lot of pathfinding work in that area and could have owned the refueling/depot market, enriching Boeing (and Lockheed) in the process. But it was shut down because it threatened SLS." //
SpaceX privately developed the Falcon Heavy rocket for about $500 million, and it flew its first flight in February 2018. It has now flown three successful missions. NASA has spent about $14 billion on the SLS rocket and related development costs since 2011. That rocket is not expected to fly before at least mid or late 2021.
On July 28th, SpaceX wrapped up modifications to a rented robotic lift vehicle and carefully moved Starhopper back to its launch facilities three days after its inaugural flight. Another two days after that, SpaceX filed road closure requests confirming the date for the Starship prototype’s next launch. According to those road closures, SpaceX is preparing […] //.
Mach diamonds
SpaceX CEO Elon Musk has posted a unique, uninterrupted view of Falcon 9’s latest landing, completed by booster B1056 on July 25th after successfully launching Cargo Dragon on its 18th mission (CRS-18) to the International Space Station (ISS). Combining four separate views, the video also happens to feature an extremely rare instance of audio clearly […] //
Thanks to that successful second launch and landing, itself a milestone for NASA’s acceptance of Falcon 9 Block 5 reusability, B1056 now has a strong shot at becoming the first Falcon 9 booster to launch three NASA missions. Pending a good post-launch inspection and NASA’s go-ahead, B1056’s next flight will likely be a third Cargo Dragon launch (CRS-19) set to occur no earlier than December 2019,
The investigation shows a fixable problem, but don't count out on SpaceX flying astronauts in 2019. //
According to Koenigsmann, engineers prepared the Dragon’s escape engines for ignition by raising the pressure in the propellant system. About a cup of liquid oxidizer had leaked into the wrong plumbing, and when the pressure was turned on, that slug of liquid oxidizer impacted a titanium valve. Upon contact, the oxidizer and titanium reacted explosively.
Koenigsmann said that going forward, SpaceX engineers would isolate the oxidizer from the pressurization system and replace the four titanium valves with a simpler component called a “burst disc.” He said the impact on the schedule might be “relatively minor,” but said about 20% of the accident investigation remained to be done and that other documented issues needed to be solved as well.
“This will be a unique rocket,” says SLS systems engineer, Dawn Stanley. “It’s going to get us back to the Moon and beyond the Moon to asteroids and Mars, further than we’ve ever gone before.”
Stanley is based at Marshall Spaceflight Center in Huntsville, Alabama, behind the high security fences of the Redstone Arsenal – for more than 60 years the home of America’s missile and rocket programme. The 154 sq kilometre (60 sq mile) site is dotted with firing ranges, test stands and discarded space hardware.
Conscious of all this history around her, Stanley says the new spacecraft is designed to be more versatile than anything that has gone before.
“If they want us to go to an asteroid to do a retrieval mission, this rocket can get you there or if you want to go to Mars, this rocket can get there,” she says. “The SLS can meet those many missions that our government has.”
The first four SLS launchers will use spare engines left over from the Space Shuttle programme, the solid rocket boosters are longer versions of the ones used on Shuttle; and the upper stage engine is based on a 1960s Saturn 5 design. Stanley makes no apologies for this rocketry recycling.
“To get off the Earth, we still need a rocket so we’re using Shuttle technology and technology from Apollo but we’re also infusing new technology,” she says. “Our core stage is a new design and we’re using new manufacturing techniques to get an efficient and affordable rocket built.”
The SLS itself is taking shape some six hours drive south of Huntsville in Nasa’s vast Michoud assembly facility near New Orleans. Almost a kilometre long, this factory was used to build the Saturn V rocket and, until, recently the Shuttle’s external fuel tank.
Because of its size most of the workers get around the rocket factory on bicycles or, if they are really lucky, white Austin Powers-style electric buggies – complete with Nasa emblems on the side.
We drive past the first barrels, rings and domes of the new rocket, arranged across the factory floor like some sort of modernistic Stonehenge. Each one is made from sheets of aluminium, only a few millimetres thick in places but given structural integrity by an internal lattice of thicker metal. These gleaming structures will soon be welded together to form the central core of the rocket. This will be filled with fuel tanks, engines and control systems.
“Welding typically uses lots of heat, fire and smoke,” explains SLS engineer Brent Gaddes. “Friction stir welding is totally different because you never completely melt the metal – you actually stir it together. The metal never gets above the melting point.”
It’s a remarkable process to watch – two panels are clamped together and a computer-controlled rotating spindle moves along the join. It takes only a few minutes for even the longest welds, which are stronger and more reliable than anything produced using conventional welding techniques.
When Nasa’s giant SLS rocket carries out its first mission, it will be brought to the launchpad by one of the largest vehicles ever built. And driving it requires massive concentration.
Within the next two years, Nasa plans to blast the first of its Space Launch System (SLS) rockets on a 384,400 km (238,855 mile) uncrewed voyage around the Moon. With plans for lunar space stations, Moon bases and Mars missions, the future of America’s state-funded astronaut programme depends on its success.
Although the SLS is brand new, the multi-billion-dollar 98m-tall (322 ft) launcher will begin its journey at the Kennedy Space Center in Florida on a vehicle that is more than 50 years old. And, for the team charged with conveying the rocket the seven kilometres (4.3 miles) to the launchpad, the pressure is on.
The four-tracked crawlers were built in 1965 to carry the Saturn 5 rocket that took astronauts to the Moon. They were adapted in the 70s for the Space Shuttle. Now, one of these has been refurbished and strengthened to convey the SLS. Despite some modernisation, the fundamental design of the 40-metre-long (131 feet), 35 metre-wide (114 feet), 2,700 tonne (six million pound) giant tracked vehicle remains the same.
“We brag sometimes that the crawlers were made with a slide rule and not a computer,” says Myers, who has been driving the crawler-transporters for more than 35 years. “They were built better – overbuilt – than many vehicles today and as a result they’re very reliable.”
That a machine so vast can move at less than a mile an hour (1.6km/h) is one of the greatest achievements of the original engineers. “It’s not about how fast it can go – it’s about how slow it can go,” says Myers. “It has the capability for positioning and docking its platform on the launch pad to within half an inch and on command it can move an eighth of an inch.”
With 50 years and some 3,000 km (2,000 miles) on the clock, Nasa expects the crawlers to be in operation for at least another three decades. With the latest refurbishment complete, testing is well underway for the first SLS mission. And, just to be certain they’ve got their calculations right, before the strengthened crawler is used to carry the new rocket, it will be tried out with an equivalent weight in concrete beams.
111: Height of Saturn V rocket in metresAt 36 storeys high, the Saturn V ranks as one of the greatest technical and engineering achievements of the 20th Century. Its development was led by Wernher von Braun who, even while building V2 rockets for Hitler, dreamed of building a rocket to carry men to the Moon. “Not only was he technically competent,” says Jay Honeycutt, a rocket engineer and later senior manager at Nasa, “but he had great leadership skills and a great ability to communicate with government officials who funded the projects.”
2: Maximum speed of the crawler transporters, in miles per hour
The Saturn Vs were put together in the Vehicle Assembly Building (VAB), a structure so large it even has its own weather system. Engineers then had the challenge of getting the rockets to the launch pad, some five or so kilometres away. After an initial suggestion to float the spacecraft on barges, it was decided to build giant tracked vehicles called crawler-transporters.
With eight giant tracks – driven by 16 electric motors, powered by two generators – the crawler-transporters are more like ships than vehicles. And, like ships, the drivers are part of a team of operators and engineers that keep the vehicles moving slowly to the launch pad. Very slowly.
“The crawler has the power to go two miles an hour,” says driver Sam Dove. “However, you really don’t want to get it up to two, especially with a load on it – the most we ever go is one.”During Apollo, it could take up to 16 hours to deliver the spacecraft the few kilometres from the VAB to the launchpad. The time from pad to orbit was just eight minutes.
5: Saturn V upper stages on the Moon
Just nine minutes after launch, the Saturn V had already shed its first and second stages, sending them tumbling away towards the Atlantic Ocean. The third stage (rather confusingly known as the S4B), with its single engine, gave the spacecraft enough speed to reach orbit before shutting down.
Then, after one and a half revolutions of the Earth, the crew relit the S4B’s engine. In a manoeuvre known as Trans Lunar Injection, the rocket thrust the spacecraft out of orbit on a trajectory towards the Moon.
After the astronauts shut the engine down for a second time, and with the lunar lander extracted from the casing at the top, the rocket was abandoned. But – because it was travelling at the same speed and in the same direction as the spacecraft – unless the crew changed trajectory, the spent rocket would follow them to the Moon.
For the first few Apollo missions, Nasa’s solution was to send the S4B into orbit around the Sun. And, today, the S4B stages for Apollos 8, 9, 10 and 11 are still orbiting the Sun. Apollo 12’s upper stage, however, has been recaptured by the Earth’s gravity.
For the remaining missions, Nasa came up with a more imaginative plan.
The Apollo Lunar Surface Experiment Package (Alsep), left by the moonwalkers of Apollo 12 onwards, included a seismometer which relayed data to Earth. By smashing the S4B stages into the Moon, geologists could trace the resulting tremors through the lunar rock to help determine its geological composition.
As the missions progressed, and the more stages they crashed, the more data they got back. The Alseps continued to return data until 1977, when Nasa shut the programme down.
The Apollo programme pushed space and computing technology to its limit. Cutting edge at the time, some of the tech used seems alarmingly simple today.
74: Memory (ROM) of Apollo guidance computer, in kilobytes
Computer technology was one of the greatest – and long lasting – achievements of Apollo. From the solid-state microcomputer fitted to the lunar lander, to mighty IBM mainframes, with their flashing lights and banks of magnetic tape.
Although the 74 KB ROM and 4 KB RAM memory of the AGC sounds puny today – the equivalent of a 1980s home computer such as the Sinclair ZX Spectrum or Commodore 64 – it was an impressive machine. Designed for the rigours of spaceflight, its software was hard-wired into coils and, crucially, it was set up so it couldn’t crash.
22: Diameter of Saturn V computer, in feet
If the Apollo Guidance Computer was impressive for its miniaturisation, then the computer controlling the Saturn V Moon rocket must rank as the largest ever launched.
Fitted within a ring above the top of the upper (third) stage of the rocket, the Saturn V instrument unit was massive. As well as digital and analogue computers, the unit contained all the electronics to control and monitor the rocket that would get men to the Moon.
Designed by Wernher von Braun’s rocketry team in Huntsville, Alabama, the computer was built by IBM. It was practically the equivalent of flying a mainframe computer into space and then abandoning it.
When Apollo 12 was struck by lightning during launch, knocking out power in the command module, mission controllers believe the circular design of the rocket’s computer saved it from the power surge.
View from the fairing during the STP-2 mission; when the fairing returns to Earth, friction heats up particles in the atmosphere, which appear bright blue in the video
SpaceX CEO Elon Musk says that the first full-scale Starship engine to be tested has already been pushed to the point of damage less than three weeks after the campaign began, setting the stage for the second full-scale Raptor to take over in the near future. //
Raptor’s main combustion chamber (the bit directly above the nozzle) has been designed to nominally operate at and reliably withstand extraordinary pressures of 250+ bar (3600+ psi), performance that demands even higher pressures in the components that feed hot methane and oxygen gas into Raptor’s combustion chamber. One prime example hinted at by Musk in a 2018 tweet is its oxygen preburner, used to convert liquid propellant into a high-velocity gas that can then feed a dedicated oxygen turbopump. Aside from the absurdly corrosive environment created by extremely hot gaseous oxygen, the preburner must also survive pressures that could peak as high as 800+ bar, or 12,000 psi.
Current location of Elon Musk's cherry red Tesla Roadster and Starman launched by SpaceX on the Falcon Heavy maiden flight
Where is Starman? Track Elon Musk's Tesla Roadster in Space!
On February 6, 2018, at 2045 UTC, the first Falcon Heavy was launched into space. It contained a very special payload- a Tesla Roadster with Starman.
But where is this vehicle? The current location is 32,757,279 miles (52,717,747 km, 0.352 AU, 2.93 light minutes) from Earth, moving toward Earth at a speed of 6,998 mi/h (11,263 km/h, 3.13 km/s).
The car is 83,879,929 miles (134,991,702 km, 0.902 AU, 7.50 light minutes) from Mars, moving away from the planet at a speed of 43,648 mi/h (70,244 km/h, 19.51 km/s). //
It has been 2 years, 11 months, 27 days, 23 hours, 49 minutes and 54 seconds since launch.