Engineers have found two competitive solutions to reduce the access to space, by using reusable launch vehicles (RLVs), and using spaceplanes. Spaceplane is a winged vehicle that acts as an aircraft while in the atmosphere and as a spacecraft while in space. The companies like Space Exploration Technologies (SpaceX), Blue Origin and United Launch Alliance are demonstrating the other solution the reusable rocketry.
Blasting things into space has been expensive because rockets cost tens of millions of dollars and fly once before burning up in a free fall back through the atmosphere.But now they can make an upright landing and be refueled for another trip, setting the stage for a new era in spaceflight. If this can be done regularly and rockets can be refueled over and over, spaceflight could become a hundred times cheaper.The Lowering the cost of flight would open the door to many new endeavors in space.
SpaceX, led by billionaire Elon Musk, has demonstrated a number of landings, on both land and sea, of its Falcon 9 first stage. The other, Blue Origin, led by another billionaire in Jeff Bezos, has also made a handful of first stage landings of its own. Blue Origin intends to fly its New Glenn reusable rocket for the first time before the end of the decade.
SpaceX and Blue Origin bring their rockets down using onboard software to fire thrusters and manipulate flaps that slow or nudge the rockets at precise moments. SpaceX has the harder job because Blue Origin’s craft go half as fast and half as high and stay mostly vertical, whereas SpaceX’s rockets have to switch out of a horizontal position. While Blue Origin is focussing on space tourism, hopes to propel tourists in capsules on four-minute space rides, SpaceX already launches satellites and space station supply missions and will soon be a supplier of launch missions to the Defense Department. But both need reusable rockets to improve the economics of spaceflight.
“In an era of declining budgets and adversaries’ evolving capabilities, quick, affordable and routine access to space is increasingly critical for both national and economic security”, says DARPA. Current satellite launch systems, however, require scheduling years in advance for an extremely limited inventory of available slots. Moreover, launches often cost hundreds of millions of dollars each, due in large part to the massive amounts of dedicated infrastructure and large number of personnel required.
Outgoing Air Force Space Command (AFSPC) chief Gen. John Hyten, the new chief of U.S. Strategic Command (USSTRATCOM), believes reusable rockets can play a role in preventing a Space Pearl Harbor, or a disabling attack against the United States in space. Simberg, who worked on advanced concepts coming out of the Space Shuttle program at Shuttle-prime contractor Rockwell International, said the Air Force is stuck in a high-cost satellite paradigm where launch reliability is paramount. Nobody wants to go and testify before Congress on how they dropped a rocket on someone’s head because they tried something new,” commercial space advocate and industry consultant Rand Simberg said in a recent interview.
One problem is that the Air Force is simply not ready to track multiple launch vehicles in the sky at once. Outgoing Air Force Space and Missile Command (AFSMC) chief Lt. Gen. Samuel Greaves said, via a spokeswoman, that the fly-back aspect of reusable rockets drives new capabilities needed to protect the public from multiple vehicles in flight simultaneously. Rock, via another spokeswoman, said the Air Force is exploring the additional use of phased array technology and unmanned aerial vehicle (UAV) platforms to increase its multiple object tracking capabilities. However, Rock said, the key limiting factor is the capacity to send destruct commands to multiple vehicles to protect the public should any rockets become errant.
SpaceX’s Falcon 9
SpaceX’s Falcon 9 Full Thrust rocket’s first stage successfully landed on its drone ship April 8 during a successful mission to deliver SpaceX’s Dragon capsule to the international space station. The stage is now undergoing a fresh series of test firings as SpaceX prepares for regular reuse of rocket first stages .
The California-based company has successfully landed the first stage of its Falcon 9 rocket during orbital launches four times in the past seven months. SpaceX eventually wants to re-fly such boosters, as a way to reduce the cost of spaceflight and further open the heavens to exploration.
“On the reflight of the recovered booster, that’s going to be most likely in fall this year,” Hans Koenigsmann, vice president of flight reliability at SpaceX, said during a news conference Saturday (July 16) that previewed the Monday (July 18) launch of the company’s robotic Dragon cargo capsule toward the International Space Station (ISS).
“We are prepping the booster again,” Koenigsmann said. “Well, first of all, we have to wash them, right? They come back slightly blackened. And you have to go through a series of tests with the hardware on the booster itself, to make sure everything’s working.”
SpaceX President Gwynne Shotwell said the company could expect a 30 percent cost savings from reusing the first stage. If this translated into a 30 percent price reduction to customers, that would drop Falcon 9’s advertised price to $42.8 million from today’s $61.2 million. Musk has said the first-stage engine could be reused dozens of times. Jefferies assumes it is used 15 times.
Blue Origin is an American privately-funded aerospace manufacturer and spaceflight services company set up by Amazon.com founder Jeff Bezos with its headquarters in Kent, Washington. The company is developing technologies to enable private human access to space with the goal to dramatically lower costs and increase reliability. Blue Origin is employing an incremental approach from suborbital to orbital flight, with each developmental step building on its prior work.
Initially focused on sub-orbital spaceflight, the company has built and flown a testbed of its New Shepard spacecraft design at their Culberson County, Texas facility. The first developmental test flight of the New Shepard was 29 April 2015. The uncrewed vehicle flew to its planned test altitude of more than 93.5 km (307,000 ft) and achieved a top speed of Mach 3 (2,284 mph; 3,675 km/h). Another flight was performed on 23 November 2015. The vehicle went just beyond 100 km (330,000 ft) altitude, and both the space capsule and its rocket booster successfully achieved a soft landing.
On 22 January 2016 Blue Origin re-flew the same New Shepard booster that launched and landed vertically in November 2015, demonstrating reuse. This time, New Shepard reached an apogee of 333,582 feet (101.7 km) before both capsule and booster returned to Earth for recovery and reuse. On 2 April and 19 June 2016, the same New Shepard booster flew for its third and fourth flights, each time exceeding 330,000 feet in altitude, before returning for successful soft landings. The first manned test flights are planned to take place in 2017, with the start of commercial service in 2018.
The New Shepard system is a fully reusable vertical takeoff, vertical landing (VTVL) space vehicle. The system consists of a pressurized capsule atop a booster. The combined vehicles launch vertically, accelerating for approximately two and a half minutes, before the engine cuts off. The capsule then separates from the booster to coast quietly into space. After a few minutes of free fall, the booster performs an autonomously controlled rocket-powered vertical landing, while the capsule lands softly under parachutes, both ready to be used again.
“Reusability allows us to fly the system again and again. With each flight, we’ll continuously improve the affordability of space exploration and research, opening space for all,” says company.
ULA unveils its future with the Vulcan rocket family
Vulcan, the next-generation rocket family by United Launch Alliance comes with a bold reusability plan, multiple configurations for medium- to heavy-lift, all-American engines and serves as the eventual replacement for the historic Atlas and Delta rocket lines.
“Because the Next Generation Launch System will be the highest-performing, most cost-efficient rocket on the market, it will open up new opportunities for the nation’s use of space,” ULA boss Tory Bruno said. “Whether it is scientific missions, medical advancements, national security or new economic opportunities for businesses, ULA’s new Vulcan rocket is a game-changer in terms of creating endless possibilities in space.”
Vulcan, slated for its maiden launch in 2019, will be powered by either a pair of exotic Blue Origin BE-4 liquefied natural gas main engines for 1.1 million pounds of thrust or two conventional Aerojet Rocketdyne AR-1 kerosene powerplants for a million pounds of thrust.
Reusability will be part of the new launcher, just not at first. A mid-air recovery of the vehicle’s main engines and thrust section will be used to retrieve and reuse the powerplants, the most valuable pieces of equipment on the first stage. “It does not appear on the first flight, we add it later,” Bruno said. “For the next decade or so, what really is going to drive reusability is not frequency (of flights), but the pure economics of it. Can you do it less expensively with reusability than with an expendable approach?” Bruno asked.
“When you do that, the cost vs. reuse curve — it’s not a straight line, it’s not like ‘oh, I got to use it twice so now it’s half as much.’ It doesn’t work that way because the rocket itself, if it’s built for reuse, is more expensive than a rocket built for single use.
“You have to recover and refurbish, and all those things cost. So you save money in reusability as a function of how many times you can reuse it. You have to fly 7 times to break even and get out to 14-15-16 times to get a decent return. “You’re not going to go through all that energy and risk, 20-30 percent performance loss just to be equivalent to an expendable. You actually want to come out ahead.
“Conventual technologies on a booster, like you see other people doing, and being able to recover and reuse that booster 15 times with relatively minimal refurbishment costs, that’s pretty darn challenging and maybe not the right place, in our view, to work on that problem.” So ULA’s plan, using third-generation mid-air recovery technology, will see the bottom of the rocket disengage after doing its powered flight, decelerated with a hypersonic heatshield in the upper atmosphere and parachute down to be intercepted by a waiting helicopter for capture.
Other countries planning reusable rockets too
A Spanish space startup is designing a set of rockets that it hopes will be the first reusable launch vehicles from a European company. PLD Space’s approach to reusability involves a combination of passive and active braking to recover the rocket’s first stage for reuse. Torres said the company wants to use parachutes to slow the initial reentry, followed by a propulsive landing. This combination is necessary, he said, in order to effectively recover light-lift vehicles.
“We saw since the beginning that for very small rockets, the option of propulsive landing like SpaceX or Blue Origin maneuvers is not easy to do,” he said. “In this case, size matters.”The suborbital Arion 1 would be the first to test out these reusability technologies. Torres said the launcher’s first flight would likely only use parachutes; propulsive landing would make its debut on the third flight. Progress with proving reusability for Arion 1 will pave the way for Arion 2, if all goes according to plan.
In early November, PLD Space announced that ESA had selected the company to lead a project called LPSR, or Liquid Propulsion Stage Recovery, as part of the agency’s Future Launchers Preparatory Program (FLPP). The progress made within LPSR will feed directly into the development of Arion 1, a suborbital rocket for microgravity payloads weighing between 100 and 200 kilograms, and Arion 2, an orbital rocket with a baseline lift capacity of 150 kilograms to low Earth orbit.
The Roscosmos State Corporation for Space Activities, Russia’s space agency, has announced an interest in reusable rockets after their successful redeployment by SpaceX. “The innovations SpaceX is making are forcing us to work on lowering the cost price and raising the product quality,” Roscosmos chief Igor Komarov told Interfax.
“We are running pilot projects in the sphere of retrievable components,” he went on to say. “We have engines which can work a multiple number of times, for example Engine 191 and the engine for Angara [rocket]. We will also be using the potential of retrievable rocket components.” The Angara family is Russia’s latest rocket series, introduced in 2014. Meant to compete on a global stage, it won its first commercial bid last year with the South Korean government.
China developing system to recover, reuse space rockets
China is developing a system to recover parts of rockets used in space launches to bring down costs and make its space programme more commercially competitive, according to researchers involved in the project. The system would bring the rocket engine and booster safely back to the ground so they can be reused in future launches. Besides saving operational costs, the recovery would also reduce the threat of debris falling to the ground, the researchers said. The recovery system is under development at the China Academy of Launch Vehicle Technology in Beijing.
It involves using a set of multiple parachutes, which are stored in the first stage of the rocket, which is released from the rest of the craft before it burns its way through the Earth’s atmosphere. An airbag inflates under the discarded part of the rocket, which cushions impact when it finally hits the ground. The technology differs from the system used by the commercial company SpaceX on its Falcon 9 rockets.
As the first stage of Falcon 9 falls back to Earth, its engines reignite when it reaches a speed of 3km per second, slowing it down to reduce impact as it lands vertically on the ground. in an article on the academy’s website, Deng Xinyu, a researcher on the Chinese rocket recovery programme, said that vertical landing involved many challenges and was extremely difficult to achieve.
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