In my last post, I talked about the failed attempt of SpaceX to land a rocket booster on a barge. The booster actually came down on the barge but it experienced a crash instead of a soft landing. The hydraulic fluid that powered the steering fins ran out before the attempted landing. Today’s rockets deliver their package to orbit but then crash down in the ocean. They can be recovered in some cases and refurbished but it is an expensive and time consuming process. This is the reason that the SpaceX attempt, although a failure, is an important milestone in the exploration of space. Now that commercial firms are moving into space, there is pressure to reduce costs and turn-around time for launches.
       An important goal for launching payloads into space is what is called a “single stage to orbit” vehicle. An SSTO would utilize a “reusable launch vehicle” that could launch, deliver a payload to orbit and then come back to Earth for a soft landing at the launch site. It could be checked, refueled and launch again in a short time. There is a great deal of research going on to develop such a vehicle.
       Launching a single vehicle to orbit with all the fuel on board and a pure rocket engine is not currently possible. The weight of existing launch systems may be ninety percent fuel. The payload that is delivered to orbit may be only two to four percent of the starting weight of the launch vehicle. Currently, the only way to get a payload to orbit is to drop some of the weight in the form of external boosters as the fuel is consumed. This multi-stage design may place the boosters below the orbital craft as with the SpaceX Falcon 9 or strap them to the outside of the main vehicle such as was done with the U.S. Space Shuttle.
       SpaceX is a very innovative firm. They have made advancements “in restarting rocket engines, orientation control, guidance and navigation, thermal protection and deploying landing gear.” SpaceX has tried three times to test a soft landing. While they may very well achieve a soft landing in the near future, the real question that has to be answered is whether they can cut refurbishing costs and time down to the point where they can be competitive with other launch systems.     
       In the United Kingdom, they are developing the SABRE rocket engine to power the Skylon SSTO spacecraft. SABRE is a ramjet which captures and compresses atmosphere to supply oxygen to combine with the fuel. When SABRE exits the Earth’s atmosphere, it switches over to a pure rocket engine where all the fuel is carried aboard. When it re-enters the atmosphere, it will start up the ramjet mode again and land like an airplane.
      The real exploitation of space for commercial purposes will only be possible if we can substantially reduce the cost of delivering a pound of payload to orbit.
Artist’s concept of a SpaceX Falcon 9 Recoverable Launch Vehicle:

SpaceX Falcon 9R.jpg

          I have been a fan of science fiction since I was a kid. Books, magazines, movies, television shows, comics, etc. were a refuge from the daily grind. When rocket ships were part of the story, they were usually shown as tall and thin. When they took off and landed, they went straight up or straight down, landing on their tail. These fictional spaceships were single vehicles that were entirely self contained.
          When the space age actually arrived, the big rockets needed boosters that helped lift the vehicles out of the Earth’s atmosphere but then broke away from the orbital vehicles and fell back to Earth, usually over an ocean. This was usually safe but ultimately wasteful, raising the cost of transporting men and supplies to orbit. NASA developed a system that would allow them to bring boosters down with parachutes to land in the ocean. Then they would fish out the boosters, get them back to dry land and refurbish them. This was a time consuming and costly process. One of the big current goals for space flight is to find a way to recover launch vehicles by having them come down vertically on land, radically reducing the cost of recovery and making refurbishing cheaper.
          I have blogged about SpaceX, a commercial company that can launch supplies into orbit. They have passed a competition held by NASA to launch supplies to the International Space Station along with the Boeing company. The company has successfully launched supply packages to the ISS. Recently, SpaceX has begun working on a way to recover their first stage boosters by having them land back at the launch site.
         Last week, SpaceX launched a package of supplies in a Dragon cargo ship to the ISS with one of their Falcon 9 launch vehicles. Part of that mission was to test a soft vertical landing for the first stage booster. The plan was to haul a barge two hundred miles out into open ocean off Florida and land the booster gently on the barge. The booster was equipped with four landing legs and four fins to guide it to the landing place. The launch was successful and the Dragon cargo ship was delivered to orbit.
        The booster managed to make it to the vicinity of the barge but was descending too fast and crashed into the barge, breaking into pieces. The guidance fins functioned properly as the craft decelerated from hypersonic to subsonic velocity. However, the hydraulic fluid that powered the fins ran out right before the landing attempt on the barge.
        The next launch of a Falcon 9 will include fifty percent more hydraulic fluid to supply the steering fins. The first test landing may have failed but it almost succeeded. Hopefully the next test will actual succeed in landing a spent booster softly in a vertical descent. When the process has been thoroughly tested over open water, the next phase of testing will have the boosters landing on dry land at the launch site. The old fictional vision of spacecraft taking off vertically and landing vertically will finally be real.
Artist’s rendering of soft landing of SpaceX Falcon 9 first stage booster:

SpaceX booster barge.jpg

         The U.S. is developing a new spacecraft called the Orion Multi-Purpose Crew Vehicle. This spacecraft is intended to carry a crew of as many as four astronauts. It will be able to carry crews to low-earth orbit and beyond. The Orion will allow manned explorations of asteroids and of Mars. It can also ferry crews and supplies to and from the International Space Station, if necessary.
         In 2004, the United States announced plans for the Crew Exploration Vehicle. The new spacecraft was intended to replace the Space Shuttle program partly because of the crash of the Space Shuttle Columbia. Originally, a spacecraft called the Orbital Space Plane was going to replace  the Space Shuttles but it was cancelled and replaced by the CEV. Eventually, the project became the Constellation program and Orion was added to the name of the spacecraft.  NASA announced the Orion MPCV in May of 2011. The design of the Orion is based on the earlier CEV from Constellation project that was cancelled. The Orion consists of two main modules.
        The Orion command module resembles the Apollo command module and is being constructed at the Michoud Assembly Facility in New Orleans by the Lockheed Martin company. It will have a digital dashboard known as a “glass cockpit.” The command module contains an automatic docking system with a manual backup. The Orion service module is based on the Apollo service module The service module will handle life support and propulsion. It is being built by Airbus Defence and Space for the European Space Agency. Together, the two modules are about eleven feet high and about sixteen feet in diameter. The command module and the service module weigh about forty seven thousand pounds. The Orion can spend about twenty one days on a mission. Originally, the capsule was going to land on the ground with a system of airbags but the landing site was changed to an ocean splashdown.
         Orion features a Launch Abort System in case there is a problem with the launch or the ascent. A solid-rocket launch abort motor will fire and separate the command module from the service module if there is trouble.
        The Orion’s first test flight was referred to as Exploration Flight Test 1. The uncrewed spacecraft was carried aloft on a Delta IV Heavy rocket in December of 2014 for about four and a half hours and it landed in the Pacific Ocean. The Orion will not carry a live crew until 2021 or after.
        In 2010, President Obama laid out two major goals for space exploration including a manned exploration of a near-Earth asteroid in the mid-2020s and a manned expedition to Mars in the mid-2030s. The asteroid mission will include the capture of a small asteroid that will be brought into lunar orbit for the manned expedition. For the Mars mission, a Deep Space Habitat will have to be developed and attached to the Orion spacecraft. The NASA budget was revised to include these goals and the Orion spacecraft will be the main vehicle for such missions. The intermediate goal of a manned lunar base that had been part of the Constellation program was canceled.
Artist’s exploded view of the Orion spacecraft:

Orion_spacecraft_launch_configuration_.jpg

         I have posted a series of blogs about the history of India’s space program. There have been problems and delays partially due to the limited budget that India can devote to its space program. They have developed much of their own space technology from scratch. They are accomplishing amazing things on a fraction of the budget of other space programs. Their recent Mars probe cost about one tenth of the recent NASA Mars probe. Despite their success with launching small satellites, until now they have not been able to launch the heavier loads needed for manned spaceflight. Recently India has been in the news because of a new rocket that they launched that can double the weight of Indian payloads.
         The Indian Space Research Organization three-stage Geostationary Satellite Launch Vehicle Mk-III rocket weights six hundred and thirty tons. It can carry a payload of four tons into orbit. The rocket was developed to carry heavy communication and scientific satellites into orbit as well as manned space capsules. For the initial test, only the first two stages carried active engines that ignited. The first stage consisted of two solid-state engines. Each of these engines can generate up to two hundred tons of thrust. They are the third largest rocket boosters in the world. The third stage carried a cryogenic engine in passive mode.
         The first test launch carried an uncrewed manned space capsule to an altitude of about eighty miles. Twenty minutes after launch, the crew capsule separated and, using its own engines, re-entered the atmosphere at high velocity. The capsule successfully splashed down in the Bay of Bengal. Part of the test program had to do with testing the performance of the capsule’s heat shield against the seventy two hundred degrees Fahrenheit re-entry temperatures.
          When crewed, the capsule will carry up to three astronauts into orbit. ISRO has estimated that it may take up to seven years to ultimately launch a crewed capsule with the new rocket. The ISRO has requested about one billion nine hundred million dollars for the manned space program. If India can successfully developed a manned space program, it will be the forth country to put men into space. The U.S., Russia and China are the only other countries that currently have the ability to launch manned spaceflights.
         The next step is the development of a new cryogenic rocket engine in India to replace the European engine that was used to test the GSLV rocket. India wants to expand its market share of an estimated three hundred billion dollar international space marketplace. Major space powers such as the U.S., Russia, China and the European Union are currently engaged in a thriving business launching satellites for other countries. India hopes to be able to launch its own communication satellites and manned missions with the new rocket as well as launch satellites for other countries.
Geostationary Satellite Launch Vehicle:

India New Rocket.png

   One of the most interesting developments in space flight has been the entry of private companies into the game. There are several different companies which have developed their own space craft and are pursuing commercial applications of space flight. Two private companies were recently awarded a contract by NASA to help ferry astronauts and supplies to the International Space Station. Other companies are working toward orbital manufacture, orbiting solar power satellites and asteroid mining. One company, Virgin Galactic, is working on making low orbit flight available for tourists.
        Virgin Galactic is a British company that is a member of the Virgin group of companies headed by flamboyant entrepreneur Richard Branson. VG is working on the develop commercial spacecraft and provide suborbital spaceflights to space tourists, suborbital launches for space science missions, and orbital launches of small satellites, as well as an orbital launch vehicle.”
        SpaceShip Two is the VG experimental spacecraft being used for testing and development. SST is carried aloft by carrier aircraft known as White Knight Two. When WKT reaches maximum altitude, SST is released to continue into space. SST was completed at the end of 2009 when Branson claimed that suborbital flights for tourists would begin in 2011. In 2011, Branson announced that that he hoped that tourist flights could commence in 2013.
         By 2012, SST had completed fifteen test flights and sixteen glide tests. In mid-2013, SST finally took a rocket powered test flight with a sixteen second burn. The SST has been able to reach a speed of nine hundred miles per hour with an engine burn of twenty seconds. The maximium altitude achieved by SST has been thirteen miles. However, the SST will have to be able to achieve a speed of over two thousand miles per hour and reach an altitude of over sixty two miles to lift six passengers into space
        In 2014, the SST successfully made its third rocket powered flight and tested its Reaction Control System. An announcement was made by a company spokesman to the effect that VG would be able to begin commercial operations by the end of 2014. The rubber-based solid fuel that they had been testing had not worked out and they were switching to a plastic-based solid fuel. They continue work on SST with critics saying that they are trying to do too much too fast.
        In October of 2014, a SST test flight took place to test the new plastic-based fuel. The test flight ended in tragedy when SST broke apart in mid-air raining debris down on the Mojave desert shortly after it had separated from WKT. The test pilot died and the co-pilot was seriously injured. A number of different possible reasons for the accident were investigated and it was tentatively concluded that the air braking system deployed too early and functioned improperly. This resulted in vibrations that built up and tore the ship apart.
       The media has been full of pronouncements about how this is a serious setback for VG and the whole commercial space flight industry. VG denies that it is a serious setback and is firmly committed to continuing work despite the accident. Time will tell whether this has seriously injured commercial spaceflight but the accident is a valuable reminder that this is a new dangerous new frontier.
Artist’s concept of SpaceShip Two detaching from White Knight Two:

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        On October 23, 2014 China launched a lunar probe called Chang’e 5 T1 on a Long March-3C rocket. The main purpose of the probe was to test technologies and techniques for high speed reentry into Earth’s atmosphere. The findings of these tests will be incorporated into the  Chang’e 5 lunar mission to be launched in 2017.
        The Xiaofei probe entered the Earth atmosphere on October 31, 2014 after the eight day mission which flew around the Moon. The probe performed what is called a “skip” re-entry process. It hit the Earth’s atmosphere at twenty five thousand miles an hour. The probe bounced off the atmosphere to reduce speed and then re-entered the atmosphere to land at a location in China’s Inner Mongolia Autonomous Region. The skip process is analogous to skipping a stone on a lake. The purpose of the maneuver is to shorten the “braking distance” for a returning space probe.
        China’s Chang’e lunar space program started with the launch of Chang’e 1 in 2007 and Chang’e 2 in 2010 which both successfully orbited the moon. Then the Chang’e 3 landed on the Moon in late 2013 and dispatched the Yutu rover to explore. Following the successful mission of the Chang’e 5 T1 to test capabilities, the Chang’e 5 mission in 2017 will go to the moon, land, take samples from the lunar surface and return to Earth. The Chang’e 5 will perform the skip process for re-entry to return about four and one half pounds of rocks from the Moon.
         The Chang’e  5 mission will be launched on a Long March 5 rocket from a new launch facility that is still under construction. The Wenchang Satellite Launch Center in Hainan province. The WSLC is being constructed to handle the next-generation of Chinese rockets which will be used to launch large space station modules and deep-space missions. It will be host to the Long March 5 rocket which is still under development. The Long March 5 will make see its first launch in 2015.
         U.S. space scientists point out that with the completion of the Chang’e 5 mission in 2017, China will have experience in all phases necessary to launch astronauts to land on the Moon and return to Earth. China has published articles about future missions to the Moon. Recently, Chinese scientists working in the energy production field have discussed the possibility of mining helium-3 or tritium on the Moon. Tritium has been designated as a possible fuel for nuclear fusion reactors which are currently under development. Tritium is present in all the water on Earth but in minute amounts that  would be expensive to extract. However, billions of years of bombardment by the solar wind have resulted in substantial levels of tritium on the surface of the Moon. If nuclear fusion reactors that run on tritium can be developed, there is enough tritium on the Moon to supply Earth’s energy needs for thousands of years.
Artist’s concept of the Chang’e 5 T1 lunar probe:

Chinese Change 5 T1.jpg

        Since the U.S. cancelled the Space Shuttle program in 2011, it has had to rely on foreign governments and private companies to ferry supplies to the International Space Station. One of the company contracted for this job is Orbital Sciences. On October 28, 2014 they attempted to launch a Cygnus cargo spacecraft with five thousand pounds of cargo atop an Antares rocket from the NASA Wallops Island Flight Facility in Virginia. There were also some experiments designed by high school students included in the rocket’s load. Something blew out the side of the engine module on the rocket just as it was lifting off, then the rocket stopped climbing and settled back to the pad where it exploded in a huge ball of fire. The video of the explosion was quite dramatic. Fortunately, the rocket was unmanned but vital supplies for the Space Station were lost.
         It took several days for the authorities to determine what had caused the rocket to explode. They believe that the rocket’s turbopump blew up and the ground crew triggered the rocket’s self-destruct system as it fell back to the launch pad. The turbopump was part the AJ26 engine which was based on the design of an old NK-33 Soviet rocket engine that had been developed in the 1970s. The engine design had been modified to incorporate steerable nozzles. OS had successfully launched two cargo missions to the Space Station earlier this year using the same type of engine. OS says that it will fast track the replacement of the old Soviet engines with newer models.
       There have been concerns raised about NASA subcontracting spacecraft from private companies to supply the Space Station. One major problem is the tendency of corporations to cut costs where ever possible. Utilizing Soviet space technology from the 1970s would seem to qualify. However, as is often the case, cutting costs can result in the use of inferior components that may fail such as the turbopump in the Antares rocket. In spite of the setback for OS and the damage to the Wallops Island launch pad, OS has just been awarded a one hundred eighty six million dollar contract from NASA for their balloon program. NASA says that they have complete confidence in OS.
        The next launch by OS may be delayed for more than a year because of the accident. SpaceX, another private company just got a contract to deliver supplies to the Space Station with its Falcon 9 rocket equipped with Merlin engines. Both the rocket and its engines were designed by SpaceX.
        Members of Congress have been critical of the use of Soviet rocket engine designs and have demanded that the U.S. become more independent of the need for purchasing space technology from foreign sources. The U.S. House of Representative recently passes a National Defense Authorization Act which included two hundred and twenty million dollars to develop U.S. alternatives to Russian space technology, including engines.
The Antares rocket as it crashes back to the launch pad:

Antares Rocket Explodes.jpg

       The Rosetta probe was launched in 2004 by the European Space Agency to chase and ultimately rendezvous with the Churyumov-Gerasimenko Comet also known as Comet 67P. It completed its mission last week and is in orbit around Comet 67P this week. Upon arriving at Comet 67P, the Rosetta probe launched the Philae Lander for a soft landing on the comet. The approach and landing worked exactly as planned but then the problems began.
         The gravity of the comet is one ten thousandth the gravity of the Earth so the lander might possibly drift away from the surface if not tied down. In planning for the landing, the project team made some assumptions about the nature of the surface of the comet. It was believed that the comet’s surface would be solid. Each of the three legs of the lander is equipped with a drill. As the lander touched down, the drills would be deployed to drill into the rocky surface and hold it in place. There were also anchors that could be fired from the lander to provide additional attachment to the comet. It turned out that the surface of the comet was not the hard rock that was expected but more gravel and dust. The drills did not anchor the lander as expected and the anchors were useless.
        One of the experiments that was supposed to be carried out by the lander was the scooping up of surface material by a robotic arm on the lander. If the arm was deployed, its gentle contact with the comet’s surface might push the lander away from the comet. The project team had considered the possibility of problems with keeping the lander on the comet and they had added a thruster to the top of the lander so they could have it expel puffs of gas to push the lander down. Unfortunately it turned out that the pin that was supposed to push the plug of wax out of the nozzle of the thruster was unable to actually remove the wax so the thruster could not be used.
       The project team did deliberately cause the lander to push off from the comet after it first touched down. The lander drifted back to the comet but that did not improved the situation. After a second attempt to reposition the lander, it drifted back to the comet next to a cliff which cut off sunlight to the lander’s solar panels. The lander was able to conduct some experiments before it lost power.
       After all the hard work and ten years for flight, the Rosetta probe reached the target comet just as planned. Unfortunately, a combination of mistakes in planning and equipment malfunctions combined to shut down the lander after a few hours of operation.
 Philae Lander for the Rosetta mission:

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       The Rosetta probe was launched in 2004 by the European Space Agency to chase and ultimately rendezvous with the Churyumov-Gerasimenko Comet also known as Comet 67P. It is nearing the end of its journey and should reach Comet 67P this week.
         Comets are small icy bodies that travel in a variety of orbits that them from the outer reaches of the solar system to near the sun. As they approach the inner solar system, the heat of the sun causes them to spew out gas and steam. If they are large enough, they can been seen from Earth without a telescope. In some cases, the out gassing creates a long tail that is also visible from the Earth. The human race has been observing and record the passage of comets for thousands of years. Comets were believe to be harbingers of disaster. It is thought that much of the water on Earth may have been brought by comets which could also have brought organic molecules that made life possible.
        The Rosetta mission is named for the Rosetta Stone which was found on the island of Philae in the Nile River. It contained a royal decree that was written in three languages. The Stone made it possible to decipher Egyptian hieroglyphics. It is hoped that the Rosetta mission will enable the “deciphering” of the history of the solar system since its formation. The spacecraft is carrying thirteen thousand pages of text in twelve hundred languages etched in a nickel alloy disk.
        The spacecraft has two main components. The Rosetta space probe orbiter has twelve instruments aboard. The Philae robotic lander has an additional nine instruments. The obiter is intended to orbit the comet for seventeen months and it will conduct the “most detailed study of a comet that has ever been attempted.”  The spacecraft is powered by solar cell panels and has ten nozzles for directing propellant during manoeuvres. When Rosetta reached the comet, Philae will be launched to land on the comet.
        The Rosetta mission includes the following instruments:
 ALICE is an ultraviolet imaging spectroscope which will look at the noble gas content of the comet nucleus,
OSIRIS is an optical, spectroscopic, and infrared remote imaging system which will take pictures of the comet in different wavelengths.
VIRTIS is a visible and infrared thermal imaging spectrometer which will look for molecular spectra in the gas surrounding the comet.
MIRO is a microwave instrument which will look for microwave emissions from volatiles such as water, ammonia and carbon dioxide.
CONSERT is a device for comet nuclear sounding by radiowave transmission which will probe the deep interior of the comet with radar.
RSI is a device for radio science investigation which will use the communication system of the orbiter to probe the comet nucleus and the gas around the comet.
ROSIA is a spectrometer for ion and neutral analysis.
MIDAS is a micro-imaging dust analysis system which will analyze dust particles that are deposited on a silicon plate.
COSIMA cometary secondary ion mass analyzer will also analyze the dust particles.
GIADA is a grain impact analyzer and dust accumulator that will detect the cross-section, momentum, speed and mass of every grain of dust that enters the instrument.
Rosetta and Philae will search for complex organic compounds composed of carbon, hydrogen, oxygen and nitrogen. They will also search for organic molecules such as nucleic acids and amino acids.
The Rosetta probe:

Rosetta.jpg

          Yesterday, I talked about the threat to Earth of asteroid strikes and some possible ways of diverting approaching asteroids. Today I am going to continue listing some of the methods that have been suggested for deflecting asteroids that are on a collision course with Earth.
       A spacecraft could be sent to rendezvous with the asteroid. The spacecraft would direct an ion beam at the asteroid. If the asteroid was intercepted far enough from Earth, the slight impulse imparted by the ion beam could be sufficient to deflect it from crashing into the Earth.
       If a space station with huge lenses and magnifying glasses could be constructed and moved into position, it could direct solar radiation onto an incoming asteroid. Over time, the slight pressure from the solar radiation could change the trajectory of the asteroid.
       Given sufficient time and technology, a mass driver could be built on an incoming asteroid. The mass driver could use solar power to fling pieces of the asteroid into space. This would act as an “engine” to change the course of the asteroid. Alternatively, a mass driver on the moon could shoot rocks at an asteroid to deflect it.
       A conventional rocket engine could be constructed on an asteroid and used to drive it into a new orbit away from the Earth. One problem with this approach would be carrying enough fuel up to the asteroid to supply the rocket engine.
       An asteroid could be wrapped in a thin reflective foil covering that would serve as a solar sail to use solar radiation to change the trajectory of the asteroid.
       Several schemes have been proposed that would create a cloud of steam in the path of the asteroid. The resistance of the cloud to the passage of the asteroid would change its course.
      A tether with a mass at the other end could be attached to an asteroid. This would alter the center of mass of the asteroid which would affect its orbit and cause it to miss the Earth.
       A one square kilometer solar powered array of infrared lasers could be constructed and aimed at the asteroid to deflect it.
       If an asteroid contained a lot of iron, it might be possible to construct a huge coil of wire that the asteroid would pass through. This passage would generate an electromagnetic effect which would change the path of the asteroid.
       It has been pointed out that if we have the technology to successfully alter the course of an asteroid, it could be used to alter the course of an asteroid to impact with the Earth instead of preventing it from colliding with the Earth. This would make a formidable weapon. It would be more in the line of a doomsday device than a strategic weapon that could be precisely launched at a particular target. As with much technology, it can be use to save or take lives.
       So we have many different options that have different costs, technological requirements, space infrastructure, probabilities of success, etc. Even if we have a system that we think could work, it might fail to successfully deflect and incoming asteroid. If we are wrong, it is possible that a deflection scheme could cause the asteroid to break up, multiplying the impacts and not really improving the situation. With luck, it will be decades or centuries before we have to worry about deflecting an asteroid.
NASA artist’s concept of a solar sail:

Solar Sail.jpg