RBE 595: Space and Planetary Robotics Lecture 5

1. RBE 595: Space and Planetary RoboticsLecture 5 Professor Marko B Popovic A term 2019

2. Space & Planetary Robotics: A few historical highlights The first satellite was launched by the Soviet Union in 1957. The Sputnik 1 satellite completed a total of 1,440 orbits around the Earth before it entered into the atmosphere in 1958. Vanguard 1, US satellite launched in 1958, is 4th satellite to be successfully launched (following Sputnik 1, Sputnik 2, and Explorer 1); the first satellite to have solar electric power. Communication with the satellite was lost in 1964. It is the oldest man-made object still in orbit, together with the upper stage of its launch vehicle. Of the Moon landings, Luna 2 of the Soviet Union was the first spacecraft to reach its surface successfully, intentionally impacting the Moon on 13 September 1959. The first space probe to successfully perform an interplanetary mission was the US Mariner 2 which passed within 35,000 km of the planet Venus in 1962. Developed by Bell Telephone Laboratories for AT&T, Telstar was the world's first active communications satellite and the world's first commercial payload in space. Telstar was launched by NASA on July 10, 1962, from Cape Canaveral, Fla., and was the first privately sponsored space-faring mission. Two days later, it relayed the world's first transatlantic television signal between US Maine and France.

3. In 1966, Luna 9 became the first spacecraft to achieve a controlled soft landing, while Luna 10 became the first mission to enter orbit. • The first robot lunar rover to land on the Moon was the Soviet vessel Lunokhod 1 on November 17, 1970, as part of the Lunokhod program. • Venera 7 (Russian: Венера-7, meaning Venus 7) was a Soviet spacecraft, part of the Venera series of probes to Venus. When it landed on the Venusian surface on 15 December 1970, it became the first spacecraft to land on another planet and first to transmit data from there back to Earth. • The first monolithic space station was Salyut 1, which was launched by the Soviet Union on April 19, 1971. Monolithic stations consist of a single vehicle and are launched by one rocket. • The first robotic arm to be launched into space was the Shuttle Remote Manipulator System (SRMS), also known as the Canadarm, mounted on the Space Shuttle. The arm was launched in November 1981 and has been in operation since then. • The Soviet space station Mir was the first space station that had a modular design; a core unit was launched, and additional modules, generally with a specific role, were later added to that. It operated in low Earth orbit from 1986 to 2001

4. Mars Pathfinder was a U.S. spacecraft that landed a base station with a roving probe on Mars on July 4, 1997. It consisted of a lander and a small 10.6 kilograms (23 lb) rover named Sojourner, the first rover to operate on the surface of Mars. • In 1997 the National Space Development Agency of Japan (NASDA) launched the Engineering Test Satellite No. 7 (ETS-VII), the first ever satellite to be equipped with a robotic arm. • Deep Space 1 was the first NASA spacecraft to use ion propulsion rather than the traditional chemical-powered rockets. Launched on 24 October 1998, the Deep Space 1 spacecraft carried out a flyby of asteroid 9969 Braille, which was its primary science target. The mission was extended twice to include an encounter with comet 19P/Borrelly and further engineering testing. • The first ISS component was launched in 1998, with the first long-term residents arriving on 2 November 2000. This is the longest continuous human presence in low Earth orbit, having surpassed the previous record of 9 years and 357 days held by Mir. The latest major pressurized module was fitted in 2011, with an experimental inflatable space habitat added in 2016. The ISS is the largest human-made body in low Earth orbit and can often be seen with the naked eye from Earth • On 12 February 2001, after a five-year, 3.2 billion km journey, the NASA NEAR (Near Earth Asteroid Rendezvous) Shoemaker spacecraft has touched down on the surface of the asteroid Eros 433, the first time such a feat has ever been tried or accomplished.

5. NASA’s Dawn spacecraft, launched in 2007 investigated the giant protoplanetVesta (2011-12) and later the dwarf planet Ceres. It is the first mission to orbit an object in the asteroid belt between Mars and Jupiter, and the only spacecraft ever to orbit two destinations beyond Earth. • The latest Robonaut version, R2, the first US-built robot on the ISS, delivered by STS-133 in Feb 2011, is a robotic torso designed to assist with crew EVA's and can hold tools used by the crew. • After streaking through space for nearly 35 years, NASA's robotic Voyager 1 probe finally left the solar system in August 2012, the first space probe to leave the solar system. • The European Space Agency Rosetta's Philae lander successfully made the first soft landing on a comet nucleus when it touched down on comet Churyumov–Gerasimenko on 12 November 2014. • China's robotic Chang'e 4 mission touched down on the floor of the 115-mile-wide (186 kilometers) Von Kármán Crater on January 2, 2019, pulling off the first-ever soft landing on the lunar far side. • On June 20, 2019, the robot, called “Bumble”, one of a series of 1-foot cubed NASA Astrobeerobots was the first ever to fly on its own in space inside ISS. The robots can dock at a companion station to charge, and each has a little perching arm that lets it grab on to stuff to anchor itself or hold things.

6. Canadarm The Shuttle Remote Manipulator System (SRMS), also known as Canadarm (Canadarm 1), is a series of robotic arms that were used on the Space Shuttle orbiters to deploy, maneuver and capture payloads. After the Space Shuttle Columbia disaster, the Canadarm was always paired with the Orbiter Boom Sensor System (OBSS), which was used to inspect the exterior of the Shuttle for damage to the thermal protection system. In 1969, Canada was invited by the National Aeronautics and Space Administration (NASA) to participate in the Space Shuttle program. At the time what that participation would entail had not yet been decided but a manipulator system was identified as an important component. Canadian company, DSMA Atcon, had developed a robot to load fuel into CANDU nuclear reactors; this robot attracted NASA's attention. In 1975, NASA and the Canadian National Research Council (NRC) signed a memorandum of understanding that Canada would develop and construct the Shuttle Remote Manipulator System. F. Story Musgrave, anchored on the end of the Canadarm, prepares to be elevated to the top of the Hubble Space Telescope during STS-61.

7. NRC awarded the manipulator contract to Spar Aerospace. Three systems were constructed within this design, development, test and evaluation contract: an engineering model to assist in the design and testing of the Canadarm, a qualification model that was subjected to environmental testing to qualify the design for use in space, and a flight unit. Frank Mee is credited as the inventor of the Canadarm End Effector. Its design was inspired by the opening and closing of a camera's iris. His design won over the claw-like mechanisms that were being considered. The main controls algorithms were developed by SPAR and by subcontractor Dynacon Inc. of Toronto. CAE Electronics Ltd. in Montreal provided the display and control panel and the hand controllers located in the Shuttle aft flight deck. Other electronic interfaces, servo-amplifiers and power conditioners located on the Canadarm were designed and built by SPAR at its Montreal factory. The graphite composite booms that provides the structural connections between joints were produced by General Dynamics in the US. Dilworth, Secord, Meagher and Associates, Ltd. in Toronto was contracted to produce the engineering model end effector then SPAR evolved the design and produced the qualification and flight units. The shuttle flight software that monitors and controls the Canadarm was developed in Houston, Texas, by the Federal Systems Division of IBM. Rockwell International's Space Transportation Systems Division designed, developed, tested and built the systems used to attach the Canadarm to the payload bay of the orbiter.

9. An acceptance ceremony for NASA was held at Spar's RMS Division in Toronto on the 11th of February 1981. Here Larkin Kerwin, then the head of the NRC, gave the SRMS the informal name, Canadarm. The first remote manipulator system was delivered to NASA in April 1981. The Canadarm is 15.2 m (50 ft) long and 38 cm (15 in) diameter with six degrees of freedom. It weighs 410 kg (900 lb) by itself, and 450 kg (990 lb) as part of the total system. The Canadarm has six joints that correspond roughly to the joints of the human arm, with shoulder yaw and pitch joints, an elbow pitch joint, and wrist pitch, yaw, and roll joints. The end effector is the unit at the end of the wrist that grapples the payload's grapple fixture. The two lightweight boom segments are called the upper and lower arms. The upper boom connects the shoulder and elbow joints, and the lower boom connects the elbow and wrist joints. The Canadarm2 moves toward a P5 truss section, being held by Discovery's Canadarm, in preparation for a hand-off during STS-116

11. The basic Canadarm configuration consists of a manipulator arm, a Canadarm display and control panel, including rotational and translational hand controllers at the orbiter aft flight deck flight crew station, and a manipulator controller interface unit that interfaces with the orbiter computer. Most of the time, the arm operators see what they are doing by looking at the Advanced Space Vision System screen next to the controllers. One crew member operates the Canadarm from the aft flight deck control station, and a second crew member usually assists with television camera operations. This allows the Canadarm operator to view Canadarm operations through the aft flight deck payload and overhead windows and through the closed-circuit television monitors at the aft flight deck station. The Canadarm is outfitted with an explosive-based mechanism to allow the arm to be jettisoned. This safety system allows the Orbiter's payload bay doors to be closed in the event that the arm fails in an extended position and is not able to be retracted. The original Canadarm was capable of deploying and retrieving payloads weighing up to 332.5 kg (733 lb) in space. In the mid-1990s the arm control system was redesigned to increase the payload capability to 3,293 kg (7,260 lb) in order to support space station assembly operations. While able to maneuver payloads with the mass of a loaded bus in space, the arm motors cannot lift the arm's own weight when on the ground.[

12. Canadarm 2 The Mobile Servicing System (MSS), also known as Canadarm2, is a robotic system on board the International Space Station (ISS). Launched to the ISS in 2001, it plays a key role in station assembly and maintenance; it moves equipment and supplies around the station, supports astronauts working in space, and services instruments and other payloads attached to the ISS and is used for external maintenance. Astronauts receive specialized training to enable them to perform these functions with the various systems of the MSS. The MSS is composed of three components - the Space Station Remote Manipulator System (SSRMS), known as Canadarm2, the Mobile Remote Servicer Base System (MBS) and the Special Purpose Dexterous Manipulator (SPDM, also known as "Dextre" or "Canada hand"). The system can move along rails on the Integrated Truss Structure on top of the US provided Mobile Transporter cart which hosts the MRS Base System. The MSS was designed and manufactured by MDA Space Missions (previously called MD Robotics; previously called SPAR Aerospace) for the Canadian Space Agency's contribution to the International Space Station. Astronaut Stephen K. Robinson anchored to the end of Canadarm2 during STS-114, 2005 Canadarm2 moves Rassvet to berth with the station on STS-132, 2010

13. Mir Space Station and Lyappa arms Mir (Russian: Мир, IPA: [ˈmʲir]; lit. peace or world) was a space station that operated in low Earth orbit from 1986 to 2001, operated by the Soviet Union and later by Russia. Mir was the first modular space station and was assembled in orbit from 1986 to 1996. It had a greater mass than any previous spacecraft. At the time it was the largest artificial satellite in orbit, succeeded by the International Space Station (ISS) after Mir's orbit decayed. During the 1960s and 70s, when the United States was largely focused on Apollo and the Space Shuttle program, Russia began to focus on developing expertise in long-duration spaceflight, and felt that a larger space station would allow for more research in that area. Authorized in February 1976 by a government decree, the station was originally intended to be an improved model of the Salyut space stations. Mir seen from Space Shuttle Endeavour during STS-89 (9 February 1998) On February 19th, 1986, the assembly process began with the launching of Mir’s core module on a Proton-K rocket into orbit. Between 1987 and 1996, four of the six modules were launched and added to the station – Kvant-2 in 1989, Kristall in 1990, Spektr in 1995 and Priroda in 1996. In these cases, the modules were sent into orbit aboard a Proton-K, chased the station automatically, and then used their robot Lyappa arms to mate with the core.

14. Lyappa arm The Lyappa (or Ljappa) arm was a robotic arm used during the assembly of the Soviet/Russian space station Mir. Each of the Kvant-2, Kristall, Spektr and Priroda modules was equipped with one of these arms, which, after the module had docked to the core module's forward port, grapples one of two fixtures positioned on the core module's hub module. The module's main docking probe was then retracted, and the arm raised the module so that it could be pivoted 90° for docking to one of the four radial docking ports. It was a mechanically driven arm which was used to move modules from the forward (or axial) docking ports which had rendevouz equipment fitted to the permanent radial docking ports. The arm mated with a socket located on Mir’s multiple docking assembly node adjacent to the -XB end of the Base Block. Once connected, the modules main docking probe retracted and the arm raised the module so that it pivoted 90° for docking to a radial port.

15. Soviet/Russian space station Mir, after completion in 1996. The date shown for each module is its year of launch. Credit: Encyclopedia Britannica

16. The arm would then lift the module away from the forward docking port and rotate it on to the radial port where it was to mate, before lowering it to dock. The node was equipped with only two Konus drogues, which were required for dockings. This meant that, prior to the arrival of each new module, the node would have to be depressurized to allow spacewalking cosmonauts to manually relocate the drogue to the next port to be occupied.

17. Homework 2 arm Space station XX Consider space station XX with two link manipulator arm depicted below. Assume that trajectories during first 10 seconds are known. dock x, y a) Find joint torques required to accomplish this task during first ten seconds. b) Find manipulator end effector trajectory during first ten seconds.

18. A few hints One may solve this problem using different approaches. One approach is to realize that center of mass location is unchanged and that overall linear momentum is zero. Still further angular momentum is also zero. For each moment in time based on motion of links one could then take these into consideration and correct instantaneous . Another possible approach is to use Lagrangian. This system has 5 degrees of freedom, , i.e 3 rotational dof and 2 translational dof. If we completely ignore the gravity then the lagrangian of this system can be expressed only in terms of kinetic energy. Furthermore, if we simplify the problem even more and assume that mass inertial properties of the links can be represented as mass inertial properties of point like masses located at the centers of appropriate links the equations become much simpler.

19. The kinetic energy of main body of space station is The docking module center of mass location is And similarly kinetic energy of docking module is The proximal arm segment center of mass location is And kinetic energy of proximal arm is

20. Finally, the distal arm segment center of mass location is And kinetic energy of distal arm is

21. Therefore, the lagrangian for V=0 is Now we could use Euler Lagrange equations to obtain equations of motion, but wait! To give interpretation of joint torques it is easier to work with Hence and

23. Let’s assume that trajectory is known. This also implies knowledge of first and second derivatives. Therefore if state,, is known for particular time t and if are also known then three Euler Lagrange equation for , i.e. can be utilized to obtain as this is system of three equations with three unknowns. Clearly the acceleration gives velocity and position at the following moment in time.

24. Finally, the obtained may be substituted to Euler Lagrange equation for to obtain required torque that joint mechanism/motors need to generate (this is then directly related low level command sent to joints) in order to accomplish desired trajectory. When all trajectories are solved for one could also obtain the end-effector trajectory as Hence one could generate end effector trajectory based on input trajectory.